Upload
randy-marmer
View
220
Download
0
Embed Size (px)
Citation preview
8/10/2019 Hormones Endocrine System
1/35
Mader: Biology 8thEd.
Hormones and Endocrine System
Chapter 42
8/10/2019 Hormones Endocrine System
2/35
Mader: Biology 8thEd.
Chemical Signals
Chemical signals that act between
individuals are termed pheromones.
Work at a distance between individuals,
organs, or locally between adjacent cells.!Studies have shown that a womans
axillary extract can alter another
womans menstrual cycle by a fewdays.
8/10/2019 Hormones Endocrine System
3/35
Mader: Biology 8thEd.
Chemical Signals
8/10/2019 Hormones Endocrine System
4/35
Mader: Biology 8thEd.
Action of Hormones
Hormones are chemical signals producedby one or more cells that regulate metabolic
function of other cells in the body.
Steroid Hormones
!Can cross cell membranes.
Peptide Hormones
!Most bind to receptor in plasmamembrane. (First Messenger)
"Produces cAMP
# Second Messenger
8/10/2019 Hormones Endocrine System
5/35
Mader: Biology 8thEd.
Figure 45.3 Mechanisms of chemical signaling: a review
8/10/2019 Hormones Endocrine System
6/35
Mader: Biology 8thEd.
Action of Steroid Hormone
8/10/2019 Hormones Endocrine System
7/35Mader: Biology 8thEd.
Action of Peptide Hormone
8/10/2019 Hormones Endocrine System
8/35Mader: Biology 8thEd.
Human Endocrine System
Endocrine glandsare ductless glands thatsecrete hormones directly into the
bloodstream.
Most are peptidehormones.
!Only gonads and adrenal cortexproduce steroid hormones.
Hormone effects controlled two ways:
!Negative feedbackopposes release.
!Antagonistic hormonesoppose eachothers actions.
8/10/2019 Hormones Endocrine System
9/35Mader: Biology 8thEd.
Figure 45.8 Feedback control loops regulating the secretion of thyroid hormones T3 and T4
8/10/2019 Hormones Endocrine System
10/35Mader: Biology 8thEd.
Figure 45.1 An example of how feedback regulation maintains homeostasis
8/10/2019 Hormones Endocrine System
11/35Mader: Biology 8thEd.
Figure 45.5 Human endocrine glands surveyed in this chapter
8/10/2019 Hormones Endocrine System
12/35Mader: Biology 8thEd.
Table 45.1 Major Vertebrate Endocrine Glands and Some of Their Hormones (HypothalamusParathyroid glands)
1 G S f ( )
8/10/2019 Hormones Endocrine System
13/35Mader: Biology 8thEd.
Table 45.1 Major Vertebrate Endocrine Glands and Some of Their Hormones (PancreasThymus)
8/10/2019 Hormones Endocrine System
14/35Mader: Biology 8thEd.
Hypothalamus and Pituitary Gland
Hypothalamus regulates internal
environment through autonomic system.
Also controls glandular secretions of
pituitary gland.!Posterior Pituitary
"Antidiuretic Hormone (ADH)
# Controlled by negative feedback.
"Oxytocin
# Controlled by positive feedback.
8/10/2019 Hormones Endocrine System
15/35Mader: Biology 8thEd.
Hypothalamus and Pituitary Gland
Anterior Pituitary
Hypothalamus controls anterior pituitary
by producing hypothalamic-releasing
hormones and hypothalamic-inhibitinghormones.
8/10/2019 Hormones Endocrine System
16/35Mader: Biology 8thEd.
Anterior Pituitary Hormones
Affect Other Glands
Thyroid-Stimulating Hormone (TSH)
Adrenocorticotropic Hormone (ACTH)
Gonadotropic Hormones
Do Not Affect Other Glands
Prolactin (PRL)
Melanocyte-Stimulating Hormone (MSH)
Growth Hormone (GH)
Figure 45 6a Hormones of the hypothalamus and pituitary glands
8/10/2019 Hormones Endocrine System
17/35
Mader: Biology 8thEd.
Figure 45.6a Hormones of the hypothalamus and pituitary glands
Figure 45 6b Hormones of the hypothalamus and pituitary glands
8/10/2019 Hormones Endocrine System
18/35
Mader: Biology 8thEd.
Figure 45.6b Hormones of the hypothalamus and pituitary glands
8/10/2019 Hormones Endocrine System
19/35
Mader: Biology 8thEd.
Effect of Growth Hormone
8/10/2019 Hormones Endocrine System
20/35
Mader: Biology 8thEd.
Thyroid Glands
Thyroid gland composed of large number of
follicles filled with triiodothyronine (T3) and
thyroxine (T4).
Effect of Thyroid Hormones Increase metabolic rate.
!Simple goiter- Poor hormone production.
!Cretinism- Poor thyroid development.
!Myxedema- Hypothyroidism.
!Exophthalmic goiter- Hyperthyroidism.
8/10/2019 Hormones Endocrine System
21/35
Mader: Biology 8thEd.
Thyroid Malfunction
8/10/2019 Hormones Endocrine System
22/35
Mader: Biology 8thEd.
Calcitonin
Blood calcium level is regulated in part by
calcitonin.
Secreted by thyroid gland when blood
calcium level rises.!Brings about deposit of calcium in the
bones.
Low blood calcium level stimulates therelease of parathyroid hormone (PTH).
8/10/2019 Hormones Endocrine System
23/35
Mader: Biology 8thEd.
Parathyroid Glands
Parathyroid hormone causes the blood
phosphate level to decrease and the blood
calcium level to increase.
Insufficient parathyroid hormoneproduction leads to tetany.
Figure 45.9 Hormonal control of calcium homeostasis in mammals
8/10/2019 Hormones Endocrine System
24/35
Mader: Biology 8thEd.
Figure 45.9 Hormonal control of calcium homeostasis in mammals
8/10/2019 Hormones Endocrine System
25/35
Mader: Biology 8thEd.
Adrenal Glands
Sit atop kidneys.
Each consists of inner portion, adrenal
medulla, and outer portion, adrenal cortex.
!Adrenal medulla produces epinephrineand norepinephrine.
"Short-term response to stress.
!Adrenal cortex producesmineralocorticoids and glucocorticoids.
"Long-term response to stress.
8/10/2019 Hormones Endocrine System
26/35
Mader: Biology 8thEd.
Adrenal Glands
8/10/2019 Hormones Endocrine System
27/35
Mader: Biology 8thEd.
Glucocorticoids
Cortisol
Raises blood glucose level.
!Promotes breakdown of muscle
proteins to amino acids.!Promotes metabolism of fatty acids.
Counteracts inflammatory response.
8/10/2019 Hormones Endocrine System
28/35
Mader: Biology 8thEd.
Mineralocorticoids
Aldosterone Promotes renal absorption of sodium and
renal excretion of potassium.
Renin-angiotensin-aldosterone systemraises blood pressure.
!Angiotensin II constricts arterioles.
!Aldosterone causes kidneys to
reabsorb sodium.Atrial natriuretic hormone (ANH) is
antagonistic to aldosterone.
8/10/2019 Hormones Endocrine System
29/35
Mader: Biology 8thEd.
Malfunction of Adrenal Cortex
Hyposecretion - Addison disease
Bronzing of skin.
8/10/2019 Hormones Endocrine System
30/35
Mader: Biology 8thEd.
Malfunction of Adrenal Cortex
Hypersecretion - Cushing syndrome
8/10/2019 Hormones Endocrine System
31/35
Mader: Biology 8thEd.
Pancreas
Pancreas made up up exocrine and
endocrine tissue. Endocrine tissue, pancreatic islets, produce
and secrete insulin and glucagon.
!Insulinsecreted during high bloodglucose level.
"Stimulates uptake of glucose by cells.
!
Glucagonsecreted during low bloodglucose level.
"Stimulates liver to break downglycogen.
Figure 45.10 Glucose homeostasis maintained by insulin and glucagon
8/10/2019 Hormones Endocrine System
32/35
Mader: Biology 8thEd.
8/10/2019 Hormones Endocrine System
33/35
Mader: Biology 8thEd.
Other Endocrine Glands
Gonads
Testes
!Produce testosterone
"Secondary sex characteristics.
Ovaries
!Produce estrogen and progesterone.
"Reproduction
"Secondary sex characteristics.
8/10/2019 Hormones Endocrine System
34/35
Mader: Biology 8thEd.
Other Endocrine Glands
Pineal Gland Produces melatonin.
!Involved in Circadian rhythms.
Thymus Gland Secrete thymosins.
!Aid in differentiation of lymphocytes.
Prostaglandins Produced within cells.
! Not distributed in blood.
8/10/2019 Hormones Endocrine System
35/35