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Bill
bull Explain how a nerve impulse passes through a neuron
bull Resting potential creates electrical chemical gradient between external and internal environments of neuron creating membrane potential
bull Depolarization occurs where Na and K ions diffuse in and out of membrane channels creating nerve impulse
bull Self-propagating action travels down the axonbull Repolarization occurs where charges return to resting statebull Refractory period- when neuron cannot carry another nerve
impulse until fully returned to resting potential
Topic 65Endocrine System
IB Biology II Van Roekel
657 ndash 6512 Statementsbull 657 State that the endocrine system consists of glands that release hormonesbull that are transported in the blood
bull 658 State that homeostasis involves maintaining the internal environmentbull between limits including blood pH carbon dioxide concentration bloodbull glucose concentration body temperature and water balance
bull 659 Explain that homeostasis involves monitoring levels of variables andbull correcting changes in levels by negative feedback mechanisms
bull 6510 Explain the control of body temperature including the transfer of heat inbull blood and the roles of the hypothalamus sweat glands skin arterioles andbull shivering
bull 6511 Explain the control of blood glucose concentration including the roles ofbull glucagon insulin and 1048576 and 1048576 cells in the pancreatic islets
bull 6512 Distinguish between type I and type II diabetes
Endocrine System
bull Nervous System (autonomic nervous system) and endocrine system work closely together in order to maintain homeostasis
bull Endocrine System consists of all an animalrsquos hormone secreting cells and glands
bull Endocrine Glands called ductless glands because they secrete chemical messengers directly into body fluids
bull Hormones chemical signals formed in specialized cells that travel through body fluids and coordinate various parts of the organism by interacting with target cells
Hormones
bull Two types of signalingbull Hormones penetrate
cell membrane and bind to receptor protein inside cell
bull Acts as transcription factor and changes gene expression
Lipid-solublehormone(testosterone) 1
Targetcell
Nucleus
Receptorprotein
2
DNA
Hormone-receptorcomplex
3
mRNA
Transcription
Newprotein
Cellular responseactivation of a gene andsynthesis of new protein
4
Plasmamembrane
Receptorprotein
Water-solublehormone(epinephrine)
2
Signaltransductionpathway
Relaymolecules
1
Targetcell
Hormone
bull Hormones bind to external protein receptor triggering a signal-transduction pathway
bull Can result in either change in gene expression or cytoplasmic activity
Bill
bull What are the two types of signaling pathways we see used with hormones
bull Internal- hormones diffuse through cell membrane and bind to intracellular protein receptor Change gene expressionprotein production
bull External signaling- hormones bind to external protein receptor and trigger signal transduction pathway Can alter cytoplasmic activity or gene expression
Homeostasis
bull Human Body has adapted several mechanisms to deal with homeostasis (maintaining balance)
bull Uses negative feedback mechanisms (physiological changes that bring a value back closer to a set point) to maintain homeostasisndash so if levels vary too far a series of steps occurs to return it to normal
bull Body must controlndash blood pHndash carbon dioxide concentrationndash blood glucose concentrationndash body temperaturendash water balance within tissues
Homeostasis and Negative Feedback
Hypothalamus and Pituitary Gland
bull Hypothalamus region of lower brain that receives info from nerves throughout body and initiates endocrine signals appropriate to environmental conditions (monitors levels of variables)
bull Pituitary Gland small organ regulated by hypothalamus that stores andor regulated multiple endocrine secretions (initiates negative feedback mechanisms)
Posterior pituitaryComposed of nervous tissuestores and secretes hormonesmade by hypothalamus
Brain HypothalamusMaster controlcenter of theendocrine system
Anterior pituitaryComposed ofendocrine tissuecontrolled byhypothalamusproduces andsecretes itsown hormones
Homeostatic Control of Body Temperature
bull Body has thermoreceptors that detect heat and send message to hypothalamus
bull Hypothalamus (in conjunction with pituitary gland) senses an increase or decrease in body temp
bull Employs mechanisms to return to maintain body temperature
Homeostatic control of body temp
Cooling Mechanismsbull Increase activity of sweat
glandsndash Causes heat loss by
evaporation of waterbull Vasodilation of blood
vesselsndash Fills capillaries with
blood heat leaves by convectionradiation
Heating Mechanismsbull Constricting skin arterioles
so blood is diverted to deeper organs and tissues less heat loss by convection
bull Stimulates skeletal muscle contractions aka shivering
Control of Blood Glucosebull Blood glucose level is the
concentration of glucose in the blood plasma
bull Cells never cease respiration therefore you must have a constant (steady) supply of blood glucose available
bull Negative feedback mechanisms by the body ensure the proper uptakerelease of glucose in the blood
bull Most blood is acted on by Hepatocytes liver cells directed by insulin and glucagon to regulated blood glucose concentration
Control of Blood Glucose
High Blood Glucose Levelsbull Beta Cells in Pancreas produce
and secrete insulin into bloodbull Insulin signals to cells to open
protein channels to allow diffusion of glucose into the cells for cell respiration
bull Stimulates Hepatocytes to convert glucose into glycogen and store it as granules in cytoplasm (same in muscle cells)
bull Lowers Glucose level in blood
Low Blood Glucose Levelsbull Alpha Cells in Pancreas
produce and secrete glucagon
bull Stimulates hydrolysis of glycogen in hepatocytes and muscle cells into glucose
bull Glucose enters bloodstreambull Increases Glucose
concentration in blood
Insulin
4Beta cellsof pancreas stimulatedto release insulin intothe blood
Glucoselevel
Homeostasis Normal blood glucose level(about 90 mg100 mL)
Glucoselevel
Glucagon
Low bloodglucose level
High bloodglucose level
Bodycellstake up moreglucose
Blood glucose leveldeclines to a set pointstimulus for insulinrelease diminishes
Liver takesup glucoseand stores it asglycogen
Alphacells ofpancreas stimulatedto release glucagoninto the blood
StimulusDeclining bloodglucose level(eg afterskipping a meal)
StimulusRising blood glucoselevel (eg after eatinga carbohydrate-richmeal)
Blood glucose levelrises to set pointstimulus for glucagonrelease diminishes
Liverbreaks downglycogen andreleases glucoseto the blood
7
6
1
2
5
8
3
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Topic 65Endocrine System
IB Biology II Van Roekel
657 ndash 6512 Statementsbull 657 State that the endocrine system consists of glands that release hormonesbull that are transported in the blood
bull 658 State that homeostasis involves maintaining the internal environmentbull between limits including blood pH carbon dioxide concentration bloodbull glucose concentration body temperature and water balance
bull 659 Explain that homeostasis involves monitoring levels of variables andbull correcting changes in levels by negative feedback mechanisms
bull 6510 Explain the control of body temperature including the transfer of heat inbull blood and the roles of the hypothalamus sweat glands skin arterioles andbull shivering
bull 6511 Explain the control of blood glucose concentration including the roles ofbull glucagon insulin and 1048576 and 1048576 cells in the pancreatic islets
bull 6512 Distinguish between type I and type II diabetes
Endocrine System
bull Nervous System (autonomic nervous system) and endocrine system work closely together in order to maintain homeostasis
bull Endocrine System consists of all an animalrsquos hormone secreting cells and glands
bull Endocrine Glands called ductless glands because they secrete chemical messengers directly into body fluids
bull Hormones chemical signals formed in specialized cells that travel through body fluids and coordinate various parts of the organism by interacting with target cells
Hormones
bull Two types of signalingbull Hormones penetrate
cell membrane and bind to receptor protein inside cell
bull Acts as transcription factor and changes gene expression
Lipid-solublehormone(testosterone) 1
Targetcell
Nucleus
Receptorprotein
2
DNA
Hormone-receptorcomplex
3
mRNA
Transcription
Newprotein
Cellular responseactivation of a gene andsynthesis of new protein
4
Plasmamembrane
Receptorprotein
Water-solublehormone(epinephrine)
2
Signaltransductionpathway
Relaymolecules
1
Targetcell
Hormone
bull Hormones bind to external protein receptor triggering a signal-transduction pathway
bull Can result in either change in gene expression or cytoplasmic activity
Bill
bull What are the two types of signaling pathways we see used with hormones
bull Internal- hormones diffuse through cell membrane and bind to intracellular protein receptor Change gene expressionprotein production
bull External signaling- hormones bind to external protein receptor and trigger signal transduction pathway Can alter cytoplasmic activity or gene expression
Homeostasis
bull Human Body has adapted several mechanisms to deal with homeostasis (maintaining balance)
bull Uses negative feedback mechanisms (physiological changes that bring a value back closer to a set point) to maintain homeostasisndash so if levels vary too far a series of steps occurs to return it to normal
bull Body must controlndash blood pHndash carbon dioxide concentrationndash blood glucose concentrationndash body temperaturendash water balance within tissues
Homeostasis and Negative Feedback
Hypothalamus and Pituitary Gland
bull Hypothalamus region of lower brain that receives info from nerves throughout body and initiates endocrine signals appropriate to environmental conditions (monitors levels of variables)
bull Pituitary Gland small organ regulated by hypothalamus that stores andor regulated multiple endocrine secretions (initiates negative feedback mechanisms)
Posterior pituitaryComposed of nervous tissuestores and secretes hormonesmade by hypothalamus
Brain HypothalamusMaster controlcenter of theendocrine system
Anterior pituitaryComposed ofendocrine tissuecontrolled byhypothalamusproduces andsecretes itsown hormones
Homeostatic Control of Body Temperature
bull Body has thermoreceptors that detect heat and send message to hypothalamus
bull Hypothalamus (in conjunction with pituitary gland) senses an increase or decrease in body temp
bull Employs mechanisms to return to maintain body temperature
Homeostatic control of body temp
Cooling Mechanismsbull Increase activity of sweat
glandsndash Causes heat loss by
evaporation of waterbull Vasodilation of blood
vesselsndash Fills capillaries with
blood heat leaves by convectionradiation
Heating Mechanismsbull Constricting skin arterioles
so blood is diverted to deeper organs and tissues less heat loss by convection
bull Stimulates skeletal muscle contractions aka shivering
Control of Blood Glucosebull Blood glucose level is the
concentration of glucose in the blood plasma
bull Cells never cease respiration therefore you must have a constant (steady) supply of blood glucose available
bull Negative feedback mechanisms by the body ensure the proper uptakerelease of glucose in the blood
bull Most blood is acted on by Hepatocytes liver cells directed by insulin and glucagon to regulated blood glucose concentration
Control of Blood Glucose
High Blood Glucose Levelsbull Beta Cells in Pancreas produce
and secrete insulin into bloodbull Insulin signals to cells to open
protein channels to allow diffusion of glucose into the cells for cell respiration
bull Stimulates Hepatocytes to convert glucose into glycogen and store it as granules in cytoplasm (same in muscle cells)
bull Lowers Glucose level in blood
Low Blood Glucose Levelsbull Alpha Cells in Pancreas
produce and secrete glucagon
bull Stimulates hydrolysis of glycogen in hepatocytes and muscle cells into glucose
bull Glucose enters bloodstreambull Increases Glucose
concentration in blood
Insulin
4Beta cellsof pancreas stimulatedto release insulin intothe blood
Glucoselevel
Homeostasis Normal blood glucose level(about 90 mg100 mL)
Glucoselevel
Glucagon
Low bloodglucose level
High bloodglucose level
Bodycellstake up moreglucose
Blood glucose leveldeclines to a set pointstimulus for insulinrelease diminishes
Liver takesup glucoseand stores it asglycogen
Alphacells ofpancreas stimulatedto release glucagoninto the blood
StimulusDeclining bloodglucose level(eg afterskipping a meal)
StimulusRising blood glucoselevel (eg after eatinga carbohydrate-richmeal)
Blood glucose levelrises to set pointstimulus for glucagonrelease diminishes
Liverbreaks downglycogen andreleases glucoseto the blood
7
6
1
2
5
8
3
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
657 ndash 6512 Statementsbull 657 State that the endocrine system consists of glands that release hormonesbull that are transported in the blood
bull 658 State that homeostasis involves maintaining the internal environmentbull between limits including blood pH carbon dioxide concentration bloodbull glucose concentration body temperature and water balance
bull 659 Explain that homeostasis involves monitoring levels of variables andbull correcting changes in levels by negative feedback mechanisms
bull 6510 Explain the control of body temperature including the transfer of heat inbull blood and the roles of the hypothalamus sweat glands skin arterioles andbull shivering
bull 6511 Explain the control of blood glucose concentration including the roles ofbull glucagon insulin and 1048576 and 1048576 cells in the pancreatic islets
bull 6512 Distinguish between type I and type II diabetes
Endocrine System
bull Nervous System (autonomic nervous system) and endocrine system work closely together in order to maintain homeostasis
bull Endocrine System consists of all an animalrsquos hormone secreting cells and glands
bull Endocrine Glands called ductless glands because they secrete chemical messengers directly into body fluids
bull Hormones chemical signals formed in specialized cells that travel through body fluids and coordinate various parts of the organism by interacting with target cells
Hormones
bull Two types of signalingbull Hormones penetrate
cell membrane and bind to receptor protein inside cell
bull Acts as transcription factor and changes gene expression
Lipid-solublehormone(testosterone) 1
Targetcell
Nucleus
Receptorprotein
2
DNA
Hormone-receptorcomplex
3
mRNA
Transcription
Newprotein
Cellular responseactivation of a gene andsynthesis of new protein
4
Plasmamembrane
Receptorprotein
Water-solublehormone(epinephrine)
2
Signaltransductionpathway
Relaymolecules
1
Targetcell
Hormone
bull Hormones bind to external protein receptor triggering a signal-transduction pathway
bull Can result in either change in gene expression or cytoplasmic activity
Bill
bull What are the two types of signaling pathways we see used with hormones
bull Internal- hormones diffuse through cell membrane and bind to intracellular protein receptor Change gene expressionprotein production
bull External signaling- hormones bind to external protein receptor and trigger signal transduction pathway Can alter cytoplasmic activity or gene expression
Homeostasis
bull Human Body has adapted several mechanisms to deal with homeostasis (maintaining balance)
bull Uses negative feedback mechanisms (physiological changes that bring a value back closer to a set point) to maintain homeostasisndash so if levels vary too far a series of steps occurs to return it to normal
bull Body must controlndash blood pHndash carbon dioxide concentrationndash blood glucose concentrationndash body temperaturendash water balance within tissues
Homeostasis and Negative Feedback
Hypothalamus and Pituitary Gland
bull Hypothalamus region of lower brain that receives info from nerves throughout body and initiates endocrine signals appropriate to environmental conditions (monitors levels of variables)
bull Pituitary Gland small organ regulated by hypothalamus that stores andor regulated multiple endocrine secretions (initiates negative feedback mechanisms)
Posterior pituitaryComposed of nervous tissuestores and secretes hormonesmade by hypothalamus
Brain HypothalamusMaster controlcenter of theendocrine system
Anterior pituitaryComposed ofendocrine tissuecontrolled byhypothalamusproduces andsecretes itsown hormones
Homeostatic Control of Body Temperature
bull Body has thermoreceptors that detect heat and send message to hypothalamus
bull Hypothalamus (in conjunction with pituitary gland) senses an increase or decrease in body temp
bull Employs mechanisms to return to maintain body temperature
Homeostatic control of body temp
Cooling Mechanismsbull Increase activity of sweat
glandsndash Causes heat loss by
evaporation of waterbull Vasodilation of blood
vesselsndash Fills capillaries with
blood heat leaves by convectionradiation
Heating Mechanismsbull Constricting skin arterioles
so blood is diverted to deeper organs and tissues less heat loss by convection
bull Stimulates skeletal muscle contractions aka shivering
Control of Blood Glucosebull Blood glucose level is the
concentration of glucose in the blood plasma
bull Cells never cease respiration therefore you must have a constant (steady) supply of blood glucose available
bull Negative feedback mechanisms by the body ensure the proper uptakerelease of glucose in the blood
bull Most blood is acted on by Hepatocytes liver cells directed by insulin and glucagon to regulated blood glucose concentration
Control of Blood Glucose
High Blood Glucose Levelsbull Beta Cells in Pancreas produce
and secrete insulin into bloodbull Insulin signals to cells to open
protein channels to allow diffusion of glucose into the cells for cell respiration
bull Stimulates Hepatocytes to convert glucose into glycogen and store it as granules in cytoplasm (same in muscle cells)
bull Lowers Glucose level in blood
Low Blood Glucose Levelsbull Alpha Cells in Pancreas
produce and secrete glucagon
bull Stimulates hydrolysis of glycogen in hepatocytes and muscle cells into glucose
bull Glucose enters bloodstreambull Increases Glucose
concentration in blood
Insulin
4Beta cellsof pancreas stimulatedto release insulin intothe blood
Glucoselevel
Homeostasis Normal blood glucose level(about 90 mg100 mL)
Glucoselevel
Glucagon
Low bloodglucose level
High bloodglucose level
Bodycellstake up moreglucose
Blood glucose leveldeclines to a set pointstimulus for insulinrelease diminishes
Liver takesup glucoseand stores it asglycogen
Alphacells ofpancreas stimulatedto release glucagoninto the blood
StimulusDeclining bloodglucose level(eg afterskipping a meal)
StimulusRising blood glucoselevel (eg after eatinga carbohydrate-richmeal)
Blood glucose levelrises to set pointstimulus for glucagonrelease diminishes
Liverbreaks downglycogen andreleases glucoseto the blood
7
6
1
2
5
8
3
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Endocrine System
bull Nervous System (autonomic nervous system) and endocrine system work closely together in order to maintain homeostasis
bull Endocrine System consists of all an animalrsquos hormone secreting cells and glands
bull Endocrine Glands called ductless glands because they secrete chemical messengers directly into body fluids
bull Hormones chemical signals formed in specialized cells that travel through body fluids and coordinate various parts of the organism by interacting with target cells
Hormones
bull Two types of signalingbull Hormones penetrate
cell membrane and bind to receptor protein inside cell
bull Acts as transcription factor and changes gene expression
Lipid-solublehormone(testosterone) 1
Targetcell
Nucleus
Receptorprotein
2
DNA
Hormone-receptorcomplex
3
mRNA
Transcription
Newprotein
Cellular responseactivation of a gene andsynthesis of new protein
4
Plasmamembrane
Receptorprotein
Water-solublehormone(epinephrine)
2
Signaltransductionpathway
Relaymolecules
1
Targetcell
Hormone
bull Hormones bind to external protein receptor triggering a signal-transduction pathway
bull Can result in either change in gene expression or cytoplasmic activity
Bill
bull What are the two types of signaling pathways we see used with hormones
bull Internal- hormones diffuse through cell membrane and bind to intracellular protein receptor Change gene expressionprotein production
bull External signaling- hormones bind to external protein receptor and trigger signal transduction pathway Can alter cytoplasmic activity or gene expression
Homeostasis
bull Human Body has adapted several mechanisms to deal with homeostasis (maintaining balance)
bull Uses negative feedback mechanisms (physiological changes that bring a value back closer to a set point) to maintain homeostasisndash so if levels vary too far a series of steps occurs to return it to normal
bull Body must controlndash blood pHndash carbon dioxide concentrationndash blood glucose concentrationndash body temperaturendash water balance within tissues
Homeostasis and Negative Feedback
Hypothalamus and Pituitary Gland
bull Hypothalamus region of lower brain that receives info from nerves throughout body and initiates endocrine signals appropriate to environmental conditions (monitors levels of variables)
bull Pituitary Gland small organ regulated by hypothalamus that stores andor regulated multiple endocrine secretions (initiates negative feedback mechanisms)
Posterior pituitaryComposed of nervous tissuestores and secretes hormonesmade by hypothalamus
Brain HypothalamusMaster controlcenter of theendocrine system
Anterior pituitaryComposed ofendocrine tissuecontrolled byhypothalamusproduces andsecretes itsown hormones
Homeostatic Control of Body Temperature
bull Body has thermoreceptors that detect heat and send message to hypothalamus
bull Hypothalamus (in conjunction with pituitary gland) senses an increase or decrease in body temp
bull Employs mechanisms to return to maintain body temperature
Homeostatic control of body temp
Cooling Mechanismsbull Increase activity of sweat
glandsndash Causes heat loss by
evaporation of waterbull Vasodilation of blood
vesselsndash Fills capillaries with
blood heat leaves by convectionradiation
Heating Mechanismsbull Constricting skin arterioles
so blood is diverted to deeper organs and tissues less heat loss by convection
bull Stimulates skeletal muscle contractions aka shivering
Control of Blood Glucosebull Blood glucose level is the
concentration of glucose in the blood plasma
bull Cells never cease respiration therefore you must have a constant (steady) supply of blood glucose available
bull Negative feedback mechanisms by the body ensure the proper uptakerelease of glucose in the blood
bull Most blood is acted on by Hepatocytes liver cells directed by insulin and glucagon to regulated blood glucose concentration
Control of Blood Glucose
High Blood Glucose Levelsbull Beta Cells in Pancreas produce
and secrete insulin into bloodbull Insulin signals to cells to open
protein channels to allow diffusion of glucose into the cells for cell respiration
bull Stimulates Hepatocytes to convert glucose into glycogen and store it as granules in cytoplasm (same in muscle cells)
bull Lowers Glucose level in blood
Low Blood Glucose Levelsbull Alpha Cells in Pancreas
produce and secrete glucagon
bull Stimulates hydrolysis of glycogen in hepatocytes and muscle cells into glucose
bull Glucose enters bloodstreambull Increases Glucose
concentration in blood
Insulin
4Beta cellsof pancreas stimulatedto release insulin intothe blood
Glucoselevel
Homeostasis Normal blood glucose level(about 90 mg100 mL)
Glucoselevel
Glucagon
Low bloodglucose level
High bloodglucose level
Bodycellstake up moreglucose
Blood glucose leveldeclines to a set pointstimulus for insulinrelease diminishes
Liver takesup glucoseand stores it asglycogen
Alphacells ofpancreas stimulatedto release glucagoninto the blood
StimulusDeclining bloodglucose level(eg afterskipping a meal)
StimulusRising blood glucoselevel (eg after eatinga carbohydrate-richmeal)
Blood glucose levelrises to set pointstimulus for glucagonrelease diminishes
Liverbreaks downglycogen andreleases glucoseto the blood
7
6
1
2
5
8
3
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Hormones
bull Two types of signalingbull Hormones penetrate
cell membrane and bind to receptor protein inside cell
bull Acts as transcription factor and changes gene expression
Lipid-solublehormone(testosterone) 1
Targetcell
Nucleus
Receptorprotein
2
DNA
Hormone-receptorcomplex
3
mRNA
Transcription
Newprotein
Cellular responseactivation of a gene andsynthesis of new protein
4
Plasmamembrane
Receptorprotein
Water-solublehormone(epinephrine)
2
Signaltransductionpathway
Relaymolecules
1
Targetcell
Hormone
bull Hormones bind to external protein receptor triggering a signal-transduction pathway
bull Can result in either change in gene expression or cytoplasmic activity
Bill
bull What are the two types of signaling pathways we see used with hormones
bull Internal- hormones diffuse through cell membrane and bind to intracellular protein receptor Change gene expressionprotein production
bull External signaling- hormones bind to external protein receptor and trigger signal transduction pathway Can alter cytoplasmic activity or gene expression
Homeostasis
bull Human Body has adapted several mechanisms to deal with homeostasis (maintaining balance)
bull Uses negative feedback mechanisms (physiological changes that bring a value back closer to a set point) to maintain homeostasisndash so if levels vary too far a series of steps occurs to return it to normal
bull Body must controlndash blood pHndash carbon dioxide concentrationndash blood glucose concentrationndash body temperaturendash water balance within tissues
Homeostasis and Negative Feedback
Hypothalamus and Pituitary Gland
bull Hypothalamus region of lower brain that receives info from nerves throughout body and initiates endocrine signals appropriate to environmental conditions (monitors levels of variables)
bull Pituitary Gland small organ regulated by hypothalamus that stores andor regulated multiple endocrine secretions (initiates negative feedback mechanisms)
Posterior pituitaryComposed of nervous tissuestores and secretes hormonesmade by hypothalamus
Brain HypothalamusMaster controlcenter of theendocrine system
Anterior pituitaryComposed ofendocrine tissuecontrolled byhypothalamusproduces andsecretes itsown hormones
Homeostatic Control of Body Temperature
bull Body has thermoreceptors that detect heat and send message to hypothalamus
bull Hypothalamus (in conjunction with pituitary gland) senses an increase or decrease in body temp
bull Employs mechanisms to return to maintain body temperature
Homeostatic control of body temp
Cooling Mechanismsbull Increase activity of sweat
glandsndash Causes heat loss by
evaporation of waterbull Vasodilation of blood
vesselsndash Fills capillaries with
blood heat leaves by convectionradiation
Heating Mechanismsbull Constricting skin arterioles
so blood is diverted to deeper organs and tissues less heat loss by convection
bull Stimulates skeletal muscle contractions aka shivering
Control of Blood Glucosebull Blood glucose level is the
concentration of glucose in the blood plasma
bull Cells never cease respiration therefore you must have a constant (steady) supply of blood glucose available
bull Negative feedback mechanisms by the body ensure the proper uptakerelease of glucose in the blood
bull Most blood is acted on by Hepatocytes liver cells directed by insulin and glucagon to regulated blood glucose concentration
Control of Blood Glucose
High Blood Glucose Levelsbull Beta Cells in Pancreas produce
and secrete insulin into bloodbull Insulin signals to cells to open
protein channels to allow diffusion of glucose into the cells for cell respiration
bull Stimulates Hepatocytes to convert glucose into glycogen and store it as granules in cytoplasm (same in muscle cells)
bull Lowers Glucose level in blood
Low Blood Glucose Levelsbull Alpha Cells in Pancreas
produce and secrete glucagon
bull Stimulates hydrolysis of glycogen in hepatocytes and muscle cells into glucose
bull Glucose enters bloodstreambull Increases Glucose
concentration in blood
Insulin
4Beta cellsof pancreas stimulatedto release insulin intothe blood
Glucoselevel
Homeostasis Normal blood glucose level(about 90 mg100 mL)
Glucoselevel
Glucagon
Low bloodglucose level
High bloodglucose level
Bodycellstake up moreglucose
Blood glucose leveldeclines to a set pointstimulus for insulinrelease diminishes
Liver takesup glucoseand stores it asglycogen
Alphacells ofpancreas stimulatedto release glucagoninto the blood
StimulusDeclining bloodglucose level(eg afterskipping a meal)
StimulusRising blood glucoselevel (eg after eatinga carbohydrate-richmeal)
Blood glucose levelrises to set pointstimulus for glucagonrelease diminishes
Liverbreaks downglycogen andreleases glucoseto the blood
7
6
1
2
5
8
3
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Plasmamembrane
Receptorprotein
Water-solublehormone(epinephrine)
2
Signaltransductionpathway
Relaymolecules
1
Targetcell
Hormone
bull Hormones bind to external protein receptor triggering a signal-transduction pathway
bull Can result in either change in gene expression or cytoplasmic activity
Bill
bull What are the two types of signaling pathways we see used with hormones
bull Internal- hormones diffuse through cell membrane and bind to intracellular protein receptor Change gene expressionprotein production
bull External signaling- hormones bind to external protein receptor and trigger signal transduction pathway Can alter cytoplasmic activity or gene expression
Homeostasis
bull Human Body has adapted several mechanisms to deal with homeostasis (maintaining balance)
bull Uses negative feedback mechanisms (physiological changes that bring a value back closer to a set point) to maintain homeostasisndash so if levels vary too far a series of steps occurs to return it to normal
bull Body must controlndash blood pHndash carbon dioxide concentrationndash blood glucose concentrationndash body temperaturendash water balance within tissues
Homeostasis and Negative Feedback
Hypothalamus and Pituitary Gland
bull Hypothalamus region of lower brain that receives info from nerves throughout body and initiates endocrine signals appropriate to environmental conditions (monitors levels of variables)
bull Pituitary Gland small organ regulated by hypothalamus that stores andor regulated multiple endocrine secretions (initiates negative feedback mechanisms)
Posterior pituitaryComposed of nervous tissuestores and secretes hormonesmade by hypothalamus
Brain HypothalamusMaster controlcenter of theendocrine system
Anterior pituitaryComposed ofendocrine tissuecontrolled byhypothalamusproduces andsecretes itsown hormones
Homeostatic Control of Body Temperature
bull Body has thermoreceptors that detect heat and send message to hypothalamus
bull Hypothalamus (in conjunction with pituitary gland) senses an increase or decrease in body temp
bull Employs mechanisms to return to maintain body temperature
Homeostatic control of body temp
Cooling Mechanismsbull Increase activity of sweat
glandsndash Causes heat loss by
evaporation of waterbull Vasodilation of blood
vesselsndash Fills capillaries with
blood heat leaves by convectionradiation
Heating Mechanismsbull Constricting skin arterioles
so blood is diverted to deeper organs and tissues less heat loss by convection
bull Stimulates skeletal muscle contractions aka shivering
Control of Blood Glucosebull Blood glucose level is the
concentration of glucose in the blood plasma
bull Cells never cease respiration therefore you must have a constant (steady) supply of blood glucose available
bull Negative feedback mechanisms by the body ensure the proper uptakerelease of glucose in the blood
bull Most blood is acted on by Hepatocytes liver cells directed by insulin and glucagon to regulated blood glucose concentration
Control of Blood Glucose
High Blood Glucose Levelsbull Beta Cells in Pancreas produce
and secrete insulin into bloodbull Insulin signals to cells to open
protein channels to allow diffusion of glucose into the cells for cell respiration
bull Stimulates Hepatocytes to convert glucose into glycogen and store it as granules in cytoplasm (same in muscle cells)
bull Lowers Glucose level in blood
Low Blood Glucose Levelsbull Alpha Cells in Pancreas
produce and secrete glucagon
bull Stimulates hydrolysis of glycogen in hepatocytes and muscle cells into glucose
bull Glucose enters bloodstreambull Increases Glucose
concentration in blood
Insulin
4Beta cellsof pancreas stimulatedto release insulin intothe blood
Glucoselevel
Homeostasis Normal blood glucose level(about 90 mg100 mL)
Glucoselevel
Glucagon
Low bloodglucose level
High bloodglucose level
Bodycellstake up moreglucose
Blood glucose leveldeclines to a set pointstimulus for insulinrelease diminishes
Liver takesup glucoseand stores it asglycogen
Alphacells ofpancreas stimulatedto release glucagoninto the blood
StimulusDeclining bloodglucose level(eg afterskipping a meal)
StimulusRising blood glucoselevel (eg after eatinga carbohydrate-richmeal)
Blood glucose levelrises to set pointstimulus for glucagonrelease diminishes
Liverbreaks downglycogen andreleases glucoseto the blood
7
6
1
2
5
8
3
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Bill
bull What are the two types of signaling pathways we see used with hormones
bull Internal- hormones diffuse through cell membrane and bind to intracellular protein receptor Change gene expressionprotein production
bull External signaling- hormones bind to external protein receptor and trigger signal transduction pathway Can alter cytoplasmic activity or gene expression
Homeostasis
bull Human Body has adapted several mechanisms to deal with homeostasis (maintaining balance)
bull Uses negative feedback mechanisms (physiological changes that bring a value back closer to a set point) to maintain homeostasisndash so if levels vary too far a series of steps occurs to return it to normal
bull Body must controlndash blood pHndash carbon dioxide concentrationndash blood glucose concentrationndash body temperaturendash water balance within tissues
Homeostasis and Negative Feedback
Hypothalamus and Pituitary Gland
bull Hypothalamus region of lower brain that receives info from nerves throughout body and initiates endocrine signals appropriate to environmental conditions (monitors levels of variables)
bull Pituitary Gland small organ regulated by hypothalamus that stores andor regulated multiple endocrine secretions (initiates negative feedback mechanisms)
Posterior pituitaryComposed of nervous tissuestores and secretes hormonesmade by hypothalamus
Brain HypothalamusMaster controlcenter of theendocrine system
Anterior pituitaryComposed ofendocrine tissuecontrolled byhypothalamusproduces andsecretes itsown hormones
Homeostatic Control of Body Temperature
bull Body has thermoreceptors that detect heat and send message to hypothalamus
bull Hypothalamus (in conjunction with pituitary gland) senses an increase or decrease in body temp
bull Employs mechanisms to return to maintain body temperature
Homeostatic control of body temp
Cooling Mechanismsbull Increase activity of sweat
glandsndash Causes heat loss by
evaporation of waterbull Vasodilation of blood
vesselsndash Fills capillaries with
blood heat leaves by convectionradiation
Heating Mechanismsbull Constricting skin arterioles
so blood is diverted to deeper organs and tissues less heat loss by convection
bull Stimulates skeletal muscle contractions aka shivering
Control of Blood Glucosebull Blood glucose level is the
concentration of glucose in the blood plasma
bull Cells never cease respiration therefore you must have a constant (steady) supply of blood glucose available
bull Negative feedback mechanisms by the body ensure the proper uptakerelease of glucose in the blood
bull Most blood is acted on by Hepatocytes liver cells directed by insulin and glucagon to regulated blood glucose concentration
Control of Blood Glucose
High Blood Glucose Levelsbull Beta Cells in Pancreas produce
and secrete insulin into bloodbull Insulin signals to cells to open
protein channels to allow diffusion of glucose into the cells for cell respiration
bull Stimulates Hepatocytes to convert glucose into glycogen and store it as granules in cytoplasm (same in muscle cells)
bull Lowers Glucose level in blood
Low Blood Glucose Levelsbull Alpha Cells in Pancreas
produce and secrete glucagon
bull Stimulates hydrolysis of glycogen in hepatocytes and muscle cells into glucose
bull Glucose enters bloodstreambull Increases Glucose
concentration in blood
Insulin
4Beta cellsof pancreas stimulatedto release insulin intothe blood
Glucoselevel
Homeostasis Normal blood glucose level(about 90 mg100 mL)
Glucoselevel
Glucagon
Low bloodglucose level
High bloodglucose level
Bodycellstake up moreglucose
Blood glucose leveldeclines to a set pointstimulus for insulinrelease diminishes
Liver takesup glucoseand stores it asglycogen
Alphacells ofpancreas stimulatedto release glucagoninto the blood
StimulusDeclining bloodglucose level(eg afterskipping a meal)
StimulusRising blood glucoselevel (eg after eatinga carbohydrate-richmeal)
Blood glucose levelrises to set pointstimulus for glucagonrelease diminishes
Liverbreaks downglycogen andreleases glucoseto the blood
7
6
1
2
5
8
3
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Homeostasis
bull Human Body has adapted several mechanisms to deal with homeostasis (maintaining balance)
bull Uses negative feedback mechanisms (physiological changes that bring a value back closer to a set point) to maintain homeostasisndash so if levels vary too far a series of steps occurs to return it to normal
bull Body must controlndash blood pHndash carbon dioxide concentrationndash blood glucose concentrationndash body temperaturendash water balance within tissues
Homeostasis and Negative Feedback
Hypothalamus and Pituitary Gland
bull Hypothalamus region of lower brain that receives info from nerves throughout body and initiates endocrine signals appropriate to environmental conditions (monitors levels of variables)
bull Pituitary Gland small organ regulated by hypothalamus that stores andor regulated multiple endocrine secretions (initiates negative feedback mechanisms)
Posterior pituitaryComposed of nervous tissuestores and secretes hormonesmade by hypothalamus
Brain HypothalamusMaster controlcenter of theendocrine system
Anterior pituitaryComposed ofendocrine tissuecontrolled byhypothalamusproduces andsecretes itsown hormones
Homeostatic Control of Body Temperature
bull Body has thermoreceptors that detect heat and send message to hypothalamus
bull Hypothalamus (in conjunction with pituitary gland) senses an increase or decrease in body temp
bull Employs mechanisms to return to maintain body temperature
Homeostatic control of body temp
Cooling Mechanismsbull Increase activity of sweat
glandsndash Causes heat loss by
evaporation of waterbull Vasodilation of blood
vesselsndash Fills capillaries with
blood heat leaves by convectionradiation
Heating Mechanismsbull Constricting skin arterioles
so blood is diverted to deeper organs and tissues less heat loss by convection
bull Stimulates skeletal muscle contractions aka shivering
Control of Blood Glucosebull Blood glucose level is the
concentration of glucose in the blood plasma
bull Cells never cease respiration therefore you must have a constant (steady) supply of blood glucose available
bull Negative feedback mechanisms by the body ensure the proper uptakerelease of glucose in the blood
bull Most blood is acted on by Hepatocytes liver cells directed by insulin and glucagon to regulated blood glucose concentration
Control of Blood Glucose
High Blood Glucose Levelsbull Beta Cells in Pancreas produce
and secrete insulin into bloodbull Insulin signals to cells to open
protein channels to allow diffusion of glucose into the cells for cell respiration
bull Stimulates Hepatocytes to convert glucose into glycogen and store it as granules in cytoplasm (same in muscle cells)
bull Lowers Glucose level in blood
Low Blood Glucose Levelsbull Alpha Cells in Pancreas
produce and secrete glucagon
bull Stimulates hydrolysis of glycogen in hepatocytes and muscle cells into glucose
bull Glucose enters bloodstreambull Increases Glucose
concentration in blood
Insulin
4Beta cellsof pancreas stimulatedto release insulin intothe blood
Glucoselevel
Homeostasis Normal blood glucose level(about 90 mg100 mL)
Glucoselevel
Glucagon
Low bloodglucose level
High bloodglucose level
Bodycellstake up moreglucose
Blood glucose leveldeclines to a set pointstimulus for insulinrelease diminishes
Liver takesup glucoseand stores it asglycogen
Alphacells ofpancreas stimulatedto release glucagoninto the blood
StimulusDeclining bloodglucose level(eg afterskipping a meal)
StimulusRising blood glucoselevel (eg after eatinga carbohydrate-richmeal)
Blood glucose levelrises to set pointstimulus for glucagonrelease diminishes
Liverbreaks downglycogen andreleases glucoseto the blood
7
6
1
2
5
8
3
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Homeostasis and Negative Feedback
Hypothalamus and Pituitary Gland
bull Hypothalamus region of lower brain that receives info from nerves throughout body and initiates endocrine signals appropriate to environmental conditions (monitors levels of variables)
bull Pituitary Gland small organ regulated by hypothalamus that stores andor regulated multiple endocrine secretions (initiates negative feedback mechanisms)
Posterior pituitaryComposed of nervous tissuestores and secretes hormonesmade by hypothalamus
Brain HypothalamusMaster controlcenter of theendocrine system
Anterior pituitaryComposed ofendocrine tissuecontrolled byhypothalamusproduces andsecretes itsown hormones
Homeostatic Control of Body Temperature
bull Body has thermoreceptors that detect heat and send message to hypothalamus
bull Hypothalamus (in conjunction with pituitary gland) senses an increase or decrease in body temp
bull Employs mechanisms to return to maintain body temperature
Homeostatic control of body temp
Cooling Mechanismsbull Increase activity of sweat
glandsndash Causes heat loss by
evaporation of waterbull Vasodilation of blood
vesselsndash Fills capillaries with
blood heat leaves by convectionradiation
Heating Mechanismsbull Constricting skin arterioles
so blood is diverted to deeper organs and tissues less heat loss by convection
bull Stimulates skeletal muscle contractions aka shivering
Control of Blood Glucosebull Blood glucose level is the
concentration of glucose in the blood plasma
bull Cells never cease respiration therefore you must have a constant (steady) supply of blood glucose available
bull Negative feedback mechanisms by the body ensure the proper uptakerelease of glucose in the blood
bull Most blood is acted on by Hepatocytes liver cells directed by insulin and glucagon to regulated blood glucose concentration
Control of Blood Glucose
High Blood Glucose Levelsbull Beta Cells in Pancreas produce
and secrete insulin into bloodbull Insulin signals to cells to open
protein channels to allow diffusion of glucose into the cells for cell respiration
bull Stimulates Hepatocytes to convert glucose into glycogen and store it as granules in cytoplasm (same in muscle cells)
bull Lowers Glucose level in blood
Low Blood Glucose Levelsbull Alpha Cells in Pancreas
produce and secrete glucagon
bull Stimulates hydrolysis of glycogen in hepatocytes and muscle cells into glucose
bull Glucose enters bloodstreambull Increases Glucose
concentration in blood
Insulin
4Beta cellsof pancreas stimulatedto release insulin intothe blood
Glucoselevel
Homeostasis Normal blood glucose level(about 90 mg100 mL)
Glucoselevel
Glucagon
Low bloodglucose level
High bloodglucose level
Bodycellstake up moreglucose
Blood glucose leveldeclines to a set pointstimulus for insulinrelease diminishes
Liver takesup glucoseand stores it asglycogen
Alphacells ofpancreas stimulatedto release glucagoninto the blood
StimulusDeclining bloodglucose level(eg afterskipping a meal)
StimulusRising blood glucoselevel (eg after eatinga carbohydrate-richmeal)
Blood glucose levelrises to set pointstimulus for glucagonrelease diminishes
Liverbreaks downglycogen andreleases glucoseto the blood
7
6
1
2
5
8
3
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Hypothalamus and Pituitary Gland
bull Hypothalamus region of lower brain that receives info from nerves throughout body and initiates endocrine signals appropriate to environmental conditions (monitors levels of variables)
bull Pituitary Gland small organ regulated by hypothalamus that stores andor regulated multiple endocrine secretions (initiates negative feedback mechanisms)
Posterior pituitaryComposed of nervous tissuestores and secretes hormonesmade by hypothalamus
Brain HypothalamusMaster controlcenter of theendocrine system
Anterior pituitaryComposed ofendocrine tissuecontrolled byhypothalamusproduces andsecretes itsown hormones
Homeostatic Control of Body Temperature
bull Body has thermoreceptors that detect heat and send message to hypothalamus
bull Hypothalamus (in conjunction with pituitary gland) senses an increase or decrease in body temp
bull Employs mechanisms to return to maintain body temperature
Homeostatic control of body temp
Cooling Mechanismsbull Increase activity of sweat
glandsndash Causes heat loss by
evaporation of waterbull Vasodilation of blood
vesselsndash Fills capillaries with
blood heat leaves by convectionradiation
Heating Mechanismsbull Constricting skin arterioles
so blood is diverted to deeper organs and tissues less heat loss by convection
bull Stimulates skeletal muscle contractions aka shivering
Control of Blood Glucosebull Blood glucose level is the
concentration of glucose in the blood plasma
bull Cells never cease respiration therefore you must have a constant (steady) supply of blood glucose available
bull Negative feedback mechanisms by the body ensure the proper uptakerelease of glucose in the blood
bull Most blood is acted on by Hepatocytes liver cells directed by insulin and glucagon to regulated blood glucose concentration
Control of Blood Glucose
High Blood Glucose Levelsbull Beta Cells in Pancreas produce
and secrete insulin into bloodbull Insulin signals to cells to open
protein channels to allow diffusion of glucose into the cells for cell respiration
bull Stimulates Hepatocytes to convert glucose into glycogen and store it as granules in cytoplasm (same in muscle cells)
bull Lowers Glucose level in blood
Low Blood Glucose Levelsbull Alpha Cells in Pancreas
produce and secrete glucagon
bull Stimulates hydrolysis of glycogen in hepatocytes and muscle cells into glucose
bull Glucose enters bloodstreambull Increases Glucose
concentration in blood
Insulin
4Beta cellsof pancreas stimulatedto release insulin intothe blood
Glucoselevel
Homeostasis Normal blood glucose level(about 90 mg100 mL)
Glucoselevel
Glucagon
Low bloodglucose level
High bloodglucose level
Bodycellstake up moreglucose
Blood glucose leveldeclines to a set pointstimulus for insulinrelease diminishes
Liver takesup glucoseand stores it asglycogen
Alphacells ofpancreas stimulatedto release glucagoninto the blood
StimulusDeclining bloodglucose level(eg afterskipping a meal)
StimulusRising blood glucoselevel (eg after eatinga carbohydrate-richmeal)
Blood glucose levelrises to set pointstimulus for glucagonrelease diminishes
Liverbreaks downglycogen andreleases glucoseto the blood
7
6
1
2
5
8
3
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Posterior pituitaryComposed of nervous tissuestores and secretes hormonesmade by hypothalamus
Brain HypothalamusMaster controlcenter of theendocrine system
Anterior pituitaryComposed ofendocrine tissuecontrolled byhypothalamusproduces andsecretes itsown hormones
Homeostatic Control of Body Temperature
bull Body has thermoreceptors that detect heat and send message to hypothalamus
bull Hypothalamus (in conjunction with pituitary gland) senses an increase or decrease in body temp
bull Employs mechanisms to return to maintain body temperature
Homeostatic control of body temp
Cooling Mechanismsbull Increase activity of sweat
glandsndash Causes heat loss by
evaporation of waterbull Vasodilation of blood
vesselsndash Fills capillaries with
blood heat leaves by convectionradiation
Heating Mechanismsbull Constricting skin arterioles
so blood is diverted to deeper organs and tissues less heat loss by convection
bull Stimulates skeletal muscle contractions aka shivering
Control of Blood Glucosebull Blood glucose level is the
concentration of glucose in the blood plasma
bull Cells never cease respiration therefore you must have a constant (steady) supply of blood glucose available
bull Negative feedback mechanisms by the body ensure the proper uptakerelease of glucose in the blood
bull Most blood is acted on by Hepatocytes liver cells directed by insulin and glucagon to regulated blood glucose concentration
Control of Blood Glucose
High Blood Glucose Levelsbull Beta Cells in Pancreas produce
and secrete insulin into bloodbull Insulin signals to cells to open
protein channels to allow diffusion of glucose into the cells for cell respiration
bull Stimulates Hepatocytes to convert glucose into glycogen and store it as granules in cytoplasm (same in muscle cells)
bull Lowers Glucose level in blood
Low Blood Glucose Levelsbull Alpha Cells in Pancreas
produce and secrete glucagon
bull Stimulates hydrolysis of glycogen in hepatocytes and muscle cells into glucose
bull Glucose enters bloodstreambull Increases Glucose
concentration in blood
Insulin
4Beta cellsof pancreas stimulatedto release insulin intothe blood
Glucoselevel
Homeostasis Normal blood glucose level(about 90 mg100 mL)
Glucoselevel
Glucagon
Low bloodglucose level
High bloodglucose level
Bodycellstake up moreglucose
Blood glucose leveldeclines to a set pointstimulus for insulinrelease diminishes
Liver takesup glucoseand stores it asglycogen
Alphacells ofpancreas stimulatedto release glucagoninto the blood
StimulusDeclining bloodglucose level(eg afterskipping a meal)
StimulusRising blood glucoselevel (eg after eatinga carbohydrate-richmeal)
Blood glucose levelrises to set pointstimulus for glucagonrelease diminishes
Liverbreaks downglycogen andreleases glucoseto the blood
7
6
1
2
5
8
3
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Homeostatic Control of Body Temperature
bull Body has thermoreceptors that detect heat and send message to hypothalamus
bull Hypothalamus (in conjunction with pituitary gland) senses an increase or decrease in body temp
bull Employs mechanisms to return to maintain body temperature
Homeostatic control of body temp
Cooling Mechanismsbull Increase activity of sweat
glandsndash Causes heat loss by
evaporation of waterbull Vasodilation of blood
vesselsndash Fills capillaries with
blood heat leaves by convectionradiation
Heating Mechanismsbull Constricting skin arterioles
so blood is diverted to deeper organs and tissues less heat loss by convection
bull Stimulates skeletal muscle contractions aka shivering
Control of Blood Glucosebull Blood glucose level is the
concentration of glucose in the blood plasma
bull Cells never cease respiration therefore you must have a constant (steady) supply of blood glucose available
bull Negative feedback mechanisms by the body ensure the proper uptakerelease of glucose in the blood
bull Most blood is acted on by Hepatocytes liver cells directed by insulin and glucagon to regulated blood glucose concentration
Control of Blood Glucose
High Blood Glucose Levelsbull Beta Cells in Pancreas produce
and secrete insulin into bloodbull Insulin signals to cells to open
protein channels to allow diffusion of glucose into the cells for cell respiration
bull Stimulates Hepatocytes to convert glucose into glycogen and store it as granules in cytoplasm (same in muscle cells)
bull Lowers Glucose level in blood
Low Blood Glucose Levelsbull Alpha Cells in Pancreas
produce and secrete glucagon
bull Stimulates hydrolysis of glycogen in hepatocytes and muscle cells into glucose
bull Glucose enters bloodstreambull Increases Glucose
concentration in blood
Insulin
4Beta cellsof pancreas stimulatedto release insulin intothe blood
Glucoselevel
Homeostasis Normal blood glucose level(about 90 mg100 mL)
Glucoselevel
Glucagon
Low bloodglucose level
High bloodglucose level
Bodycellstake up moreglucose
Blood glucose leveldeclines to a set pointstimulus for insulinrelease diminishes
Liver takesup glucoseand stores it asglycogen
Alphacells ofpancreas stimulatedto release glucagoninto the blood
StimulusDeclining bloodglucose level(eg afterskipping a meal)
StimulusRising blood glucoselevel (eg after eatinga carbohydrate-richmeal)
Blood glucose levelrises to set pointstimulus for glucagonrelease diminishes
Liverbreaks downglycogen andreleases glucoseto the blood
7
6
1
2
5
8
3
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Homeostatic control of body temp
Cooling Mechanismsbull Increase activity of sweat
glandsndash Causes heat loss by
evaporation of waterbull Vasodilation of blood
vesselsndash Fills capillaries with
blood heat leaves by convectionradiation
Heating Mechanismsbull Constricting skin arterioles
so blood is diverted to deeper organs and tissues less heat loss by convection
bull Stimulates skeletal muscle contractions aka shivering
Control of Blood Glucosebull Blood glucose level is the
concentration of glucose in the blood plasma
bull Cells never cease respiration therefore you must have a constant (steady) supply of blood glucose available
bull Negative feedback mechanisms by the body ensure the proper uptakerelease of glucose in the blood
bull Most blood is acted on by Hepatocytes liver cells directed by insulin and glucagon to regulated blood glucose concentration
Control of Blood Glucose
High Blood Glucose Levelsbull Beta Cells in Pancreas produce
and secrete insulin into bloodbull Insulin signals to cells to open
protein channels to allow diffusion of glucose into the cells for cell respiration
bull Stimulates Hepatocytes to convert glucose into glycogen and store it as granules in cytoplasm (same in muscle cells)
bull Lowers Glucose level in blood
Low Blood Glucose Levelsbull Alpha Cells in Pancreas
produce and secrete glucagon
bull Stimulates hydrolysis of glycogen in hepatocytes and muscle cells into glucose
bull Glucose enters bloodstreambull Increases Glucose
concentration in blood
Insulin
4Beta cellsof pancreas stimulatedto release insulin intothe blood
Glucoselevel
Homeostasis Normal blood glucose level(about 90 mg100 mL)
Glucoselevel
Glucagon
Low bloodglucose level
High bloodglucose level
Bodycellstake up moreglucose
Blood glucose leveldeclines to a set pointstimulus for insulinrelease diminishes
Liver takesup glucoseand stores it asglycogen
Alphacells ofpancreas stimulatedto release glucagoninto the blood
StimulusDeclining bloodglucose level(eg afterskipping a meal)
StimulusRising blood glucoselevel (eg after eatinga carbohydrate-richmeal)
Blood glucose levelrises to set pointstimulus for glucagonrelease diminishes
Liverbreaks downglycogen andreleases glucoseto the blood
7
6
1
2
5
8
3
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Control of Blood Glucosebull Blood glucose level is the
concentration of glucose in the blood plasma
bull Cells never cease respiration therefore you must have a constant (steady) supply of blood glucose available
bull Negative feedback mechanisms by the body ensure the proper uptakerelease of glucose in the blood
bull Most blood is acted on by Hepatocytes liver cells directed by insulin and glucagon to regulated blood glucose concentration
Control of Blood Glucose
High Blood Glucose Levelsbull Beta Cells in Pancreas produce
and secrete insulin into bloodbull Insulin signals to cells to open
protein channels to allow diffusion of glucose into the cells for cell respiration
bull Stimulates Hepatocytes to convert glucose into glycogen and store it as granules in cytoplasm (same in muscle cells)
bull Lowers Glucose level in blood
Low Blood Glucose Levelsbull Alpha Cells in Pancreas
produce and secrete glucagon
bull Stimulates hydrolysis of glycogen in hepatocytes and muscle cells into glucose
bull Glucose enters bloodstreambull Increases Glucose
concentration in blood
Insulin
4Beta cellsof pancreas stimulatedto release insulin intothe blood
Glucoselevel
Homeostasis Normal blood glucose level(about 90 mg100 mL)
Glucoselevel
Glucagon
Low bloodglucose level
High bloodglucose level
Bodycellstake up moreglucose
Blood glucose leveldeclines to a set pointstimulus for insulinrelease diminishes
Liver takesup glucoseand stores it asglycogen
Alphacells ofpancreas stimulatedto release glucagoninto the blood
StimulusDeclining bloodglucose level(eg afterskipping a meal)
StimulusRising blood glucoselevel (eg after eatinga carbohydrate-richmeal)
Blood glucose levelrises to set pointstimulus for glucagonrelease diminishes
Liverbreaks downglycogen andreleases glucoseto the blood
7
6
1
2
5
8
3
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Control of Blood Glucose
High Blood Glucose Levelsbull Beta Cells in Pancreas produce
and secrete insulin into bloodbull Insulin signals to cells to open
protein channels to allow diffusion of glucose into the cells for cell respiration
bull Stimulates Hepatocytes to convert glucose into glycogen and store it as granules in cytoplasm (same in muscle cells)
bull Lowers Glucose level in blood
Low Blood Glucose Levelsbull Alpha Cells in Pancreas
produce and secrete glucagon
bull Stimulates hydrolysis of glycogen in hepatocytes and muscle cells into glucose
bull Glucose enters bloodstreambull Increases Glucose
concentration in blood
Insulin
4Beta cellsof pancreas stimulatedto release insulin intothe blood
Glucoselevel
Homeostasis Normal blood glucose level(about 90 mg100 mL)
Glucoselevel
Glucagon
Low bloodglucose level
High bloodglucose level
Bodycellstake up moreglucose
Blood glucose leveldeclines to a set pointstimulus for insulinrelease diminishes
Liver takesup glucoseand stores it asglycogen
Alphacells ofpancreas stimulatedto release glucagoninto the blood
StimulusDeclining bloodglucose level(eg afterskipping a meal)
StimulusRising blood glucoselevel (eg after eatinga carbohydrate-richmeal)
Blood glucose levelrises to set pointstimulus for glucagonrelease diminishes
Liverbreaks downglycogen andreleases glucoseto the blood
7
6
1
2
5
8
3
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Insulin
4Beta cellsof pancreas stimulatedto release insulin intothe blood
Glucoselevel
Homeostasis Normal blood glucose level(about 90 mg100 mL)
Glucoselevel
Glucagon
Low bloodglucose level
High bloodglucose level
Bodycellstake up moreglucose
Blood glucose leveldeclines to a set pointstimulus for insulinrelease diminishes
Liver takesup glucoseand stores it asglycogen
Alphacells ofpancreas stimulatedto release glucagoninto the blood
StimulusDeclining bloodglucose level(eg afterskipping a meal)
StimulusRising blood glucoselevel (eg after eatinga carbohydrate-richmeal)
Blood glucose levelrises to set pointstimulus for glucagonrelease diminishes
Liverbreaks downglycogen andreleases glucoseto the blood
7
6
1
2
5
8
3
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Diabetes
bull Disease characterized by hyperglycemia (high blood sugar)
bull People have plenty of glucose in their blood but not in their body cells ndash Type I caused when Beta cells do not produce
enough insulin treated with injection of insulinndash Type II caused by body cell receptors that do not
respond properly to insulin controlled by diet
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Diabetes Mellitus
bull Type Indash Autoimmune disorderndash Body attacks and destroys
beta cells therefore no insulin is produced
ndash Blood sugar remains abnormally high as a result
ndash Less than 10 of diabetics have Type I
ndash Most often develops in children and young adults
bull Type II ndash Body cells no longer
respond to insulin (insulin resistance)
ndash Body stops creating insulin because it has developed resistance typically caused by constant elevated blood glucose levels
ndash Most common (90)ndash Associated with obesity
lack of exercise advanced age and genetics
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)
Uncontrolled Diabetes
bull If left untreatedndash Damage to retina leading to blindnessndash Kidney Failurendash Nerve damagendash Increased risk of Cardiovascular diseasendash Poor wound healing (possibly gangrene
amputation)