ENDOCRINOLOGY ENDOCRINOLOGY --OVERVIEWOVERVIEW--

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--OVERVIEWOVERVIEW--

Dr. HESHAM ANWARDr. HESHAM ANWAR

TYPES OF GLANDSTYPES OF GLANDS11-- EndocrineEndocrine-- ductlessductless, , secretesecrete directlydirectlyinto the into the bloodblood, e.g. , e.g. Thyroid, adrenalThyroid, adrenal, etc..., etc...22-- ExocrineExocrine-- duct,duct, secretesecrete their products their products through a ductthrough a duct onto the onto the epithelial surfaceepithelial surface, ,

e.g. e.g. sweat glands, salivary glands, sweat glands, salivary glands,

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e.g. e.g. sweat glands, salivary glands, sweat glands, salivary glands, mammary glands, stomach, livermammary glands, stomach, liver, etc..., etc...33-- MixedMixed-- contain both contain both endocrineendocrine and and exocrineexocrine functions in functions in one glandone gland, e.g. , e.g. PancreasPancreas ((trypsintrypsin--exocrineexocrine, , insulininsulin--

endocrineendocrine))

DEFINITION OF HORMONEDEFINITION OF HORMONE11-- HormonesHormones are are organic chemical messengersorganic chemical messengersproduced and secreted by produced and secreted by endocrineendocrine cellscells into into the the bloodstreambloodstream to a to a specific sitespecific site of action of action

((target organtarget organ))22-- HormonesHormones regulateregulate and and controlcontrol a wide range a wide range

of of physiologic functionsphysiologic functions

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of of physiologic functionsphysiologic functions33-- They present in They present in tracestraces (microgram or less)(microgram or less)44-- They are They are not used as a source of energynot used as a source of energy but but acts to acts to regulate reactionsregulate reactions to produce an to produce an appropriate response of the organism appropriate response of the organism

((responses are usually positiveresponses are usually positive, if , if negativenegative the the hormone can be referred to as a hormone can be referred to as a ChaloneChalone))

TARGET CELLSTARGET CELLS## They are They are cellscells that contain that contain specific receptorsspecific receptors

((binding sitesbinding sites) for a ) for a particular hormoneparticular hormone## Once a Once a hormone bindshormone binds to to receptorsreceptors on a on a targettarget cellcell, a series of , a series of cellular eventscellular events starts starts concerning concerning gene expressiongene expression & & protein protein

synthesissynthesis

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synthesissynthesis

HORMONE RECEPTORSHORMONE RECEPTORS## They are the They are the binding sitesbinding sites on the on the target celltarget cell(either on the (either on the surfacesurface or in the or in the cytoplasmcytoplasm or or nucleusnucleus of the of the target celltarget cell) that are ) that are activatedactivatedonly when only when specific hormonesspecific hormones bind to thembind to them

CLASSES OF HORMONESCLASSES OF HORMONES11-- STEROID HORMONESSTEROID HORMONES22-- PEPTIDE HORMONESPEPTIDE HORMONES33-- LOCAL HORMONESLOCAL HORMONES

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11-- STEROID HORMONESSTEROID HORMONES

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11-- STEROID HORMONESSTEROID HORMONES## Steroid hormonesSteroid hormones are produced by the are produced by the

adrenal cortexadrenal cortex and and gonadsgonads## Steroid hormonesSteroid hormones are made from are made from

cholesterolcholesterol in the in the smooth smooth endoplasmicendoplasmicreticulumreticulum & & mitochondriamitochondria of of endocrine cellsendocrine cells

## Steroid hormonesSteroid hormones cannotcannot be stored in be stored in vesiclesvesicles in the endocrine cells that produce in the endocrine cells that produce

themthem## As soon as As soon as steroid hormonessteroid hormones are are

produced, they produced, they diffusediffuse out of the out of the endocrineendocrinecellcell and enter the and enter the bloodstreambloodstream

## Steroid hormonesSteroid hormones are are lipid solublelipid soluble and and their their receptorsreceptors are are located insidelocated inside their their

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their their receptorsreceptors are are located insidelocated inside their their target celltarget cell

## Example of Example of steroid hormonessteroid hormones: : AA-- AdrenoAdreno--cortical hormonescortical hormones and and

BB-- Sex hormonesSex hormones

22-- PEPTIDE HORMONESPEPTIDE HORMONES## They consist of They consist of chains on Am Acschains on Am Acs

## Like most Like most proteinsproteins, , peptide hormonespeptide hormones are are synthesizedsynthesized on on ribosomesribosomes of the of the rough ERrough ER

of of endocrine cellsendocrine cells## They can be They can be storedstored in in vesiclesvesicles in in

endocrine cellsendocrine cells until they are needed at until they are needed at some some later pointlater point

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some some later pointlater point## Peptide hormonesPeptide hormones do not readilydo not readily pass pass

through cell membranesthrough cell membranes ((lipid bilayerslipid bilayers) ) and and they are referred as they are referred as water solublewater soluble

## ReceptorsReceptors for for peptide hormonespeptide hormones are are found found on the cell surfaceon the cell surface of their of their target cellstarget cells

Example of Polypeptides and protein Example of Polypeptides and protein hormoneshormones

AA-- Hypothalamic hormonesHypothalamic hormones (or factors)(or factors)BB-- Anterior pituitary hormonesAnterior pituitary hormonesCC-- Posterior pituitary hormonesPosterior pituitary hormones

DD-- Pancreatic hormonesPancreatic hormonesEE-- Gastrointestinal hormonesGastrointestinal hormones e.g. e.g. secretinsecretin

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EE-- Gastrointestinal hormonesGastrointestinal hormones e.g. e.g. secretinsecretinand and cholecystokinincholecystokinin

Example of AminoExample of Amino--acid derivativesacid derivativesAA-- Thyroid hormonesThyroid hormones BB-- CatecholaminesCatecholaminesCC-- --aminobutyric acidaminobutyric acid DD-- MelatoninMelatonin

33-- LOCAL HORMONESLOCAL HORMONES## These are These are physiologically activephysiologically active

substancessubstances that are that are releasedreleased from from generalgeneralor or specificspecific sites in tissues and they sites in tissues and they actact

at or near their pointat or near their point of origin & normally of origin & normally destroyeddestroyed before they have a chance to before they have a chance to

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destroyeddestroyed before they have a chance to before they have a chance to disperse further disperse further

E.g.:E.g.: Acetyl cholineAcetyl choline, , HistamineHistamine, , SerotoninSerotonin, , ProstaglandinsProstaglandins andand ThromboxanesThromboxanes

IIII-- Pituitary glandPituitary gland II-- Pineal glandPineal gland

IVIV-- ThymusThymus

IIIIII-- Thyroid glandThyroid gland

The major endocrine glands include:The major endocrine glands include:

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VV-- Adrenal glandAdrenal glandVIVI-- PancreasPancreas

VIIaVIIa-- OvaryOvary

VIIbVIIb-- TestisTestis

II-- THE PINEAL GLANDTHE PINEAL GLAND# # It is a It is a small endocrine glandsmall endocrine gland in the in the

vertebrate vertebrate brainbrain. . It produces the It produces the serotoninserotoninderivative melatoninderivative melatonin, , a hormone that a hormone that affects the affects the modulation of wake/sleepmodulation of wake/sleeppatternspatterns and and seasonal functionsseasonal functions

## MelatoninMelatonin exerts a powerful exerts a powerful antioxidantantioxidant

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## MelatoninMelatonin exerts a powerful exerts a powerful antioxidantantioxidantactivityactivity

## MelatoninMelatonin enhances the enhances the immune systemimmune system## Individuals with Individuals with autism spectrum autism spectrum disordersdisorders ((ASDASD) ) may have may have lowerlower than than

normal levels of normal levels of melatoninmelatonin

IIII-- PITUITARY GLANDPITUITARY GLAND# # The human pituitary gland is a The human pituitary gland is a reddish reddish gray oval glandgray oval gland and is and is locatedlocated at the base at the base

of the of the brainbrain# # It is composed of It is composed of 33 parts which are:parts which are:

AA-- Glandular partGlandular part, , the adenohypophysis or the adenohypophysis or

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AA-- Glandular partGlandular part, , the adenohypophysis or the adenohypophysis or anterior lobeanterior lobe

BB-- Neural partNeural part, , the neurohypophysis or the neurohypophysis or posterior lobeposterior lobe

CC-- The middle lobeThe middle lobe

Higher centers in the brainHigher centers in the brain

The hypothalamusThe hypothalamus

Posterior pituitaryPosterior pituitaryAnterior pituitaryAnterior pituitary

Nerve impulsesNerve impulses

Nerve impulsesNerve impulsesRFRF

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Posterior pituitaryPosterior pituitaryAnterior pituitaryAnterior pituitary

Target endocrine glandsTarget endocrine glands

Trophic hormonesTrophic hormones

hormoneshormones

Action

Action

HypothalamusHypothalamus

Anterior lobe of pituitary glandAnterior lobe of pituitary gland

Trophic hormones to Trophic hormones to other endocrine glandsother endocrine glands

RHRH

Inhibitory Inhibitory effecteffect

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other endocrine glandsother endocrine glands

Target endocrine glandsTarget endocrine glands

Hormones secreted into bloodHormones secreted into blood

The major pituitary gland hormonesThe major pituitary gland hormones

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AA-- Anterior pituitary (Adenohypophysis)Anterior pituitary (Adenohypophysis)Anterior pituitary hormones are released under Anterior pituitary hormones are released under

the influence of the hypothalamus the influence of the hypothalamus 11-- Adrenocorticotropic hormoneAdrenocorticotropic hormone ((ACTHACTH), release ), release under influence of under influence of hypothalamic Corticotropin hypothalamic Corticotropin

Releasing HormoneReleasing Hormone ((CRHCRH))22-- ThyroidThyroid--stimulating hormonestimulating hormone ((TSHTSH), release ), release

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22-- ThyroidThyroid--stimulating hormonestimulating hormone ((TSHTSH), release ), release under influence of under influence of hypothalamic Thyrotropin hypothalamic Thyrotropin

Releasing HormoneReleasing Hormone ((TRHTRH) ) 33-- Growth hormoneGrowth hormone ((GHGH), release under ), release under

influence of influence of hypothalamichypothalamic Growth Hormone Growth Hormone Releasing HormoneReleasing Hormone ((GHRHGHRH); inhibited by ); inhibited by

hypothalamic Somatostatinhypothalamic Somatostatin

44-- ProlactinProlactin ((PRLPRL), also known as ), also known as 'Luteotropic'Luteotropic' ' hormone (hormone (LTHLTH), release under influence of ), release under influence of multiple hypothalamic Prolactin Releasing multiple hypothalamic Prolactin Releasing

FactorsFactors ((PRHPRH))

55-- The two major 'Gonadotropins :The two major 'Gonadotropins :AA-- Lutenizing hormoneLutenizing hormone (('Lutropin'Lutropin' or ' or 'LH'LH))BB-- Follicle stimulating hormoneFollicle stimulating hormone ((FSHFSH), ),

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BB-- Follicle stimulating hormoneFollicle stimulating hormone ((FSHFSH), ), ## Both LH & FSH released under influence of Both LH & FSH released under influence of Gonadotropin Releasing Hormone, Gonadotropin Releasing Hormone, ((GnRHGnRH))

As well as: As well as: CC-- EndorphinEndorphin called called 'beta'beta endorphinendorphin''DD-- MelanocyteMelanocytestimulating hormonesstimulating hormones ((MSHMSH) or ) or

""intermedinsintermedins""

BB-- Posterior pituitary (Neurohypophysis)Posterior pituitary (Neurohypophysis)11-- OxytocinOxytocin, , is best known for roles in is best known for roles in female female reproductionreproduction as it is released in large amounts as it is released in large amounts after after expansionexpansion of the of the cervixcervix and and uterusuterus during during labor, labor, facilitating birthfacilitating birth and later in and later in breastfeedingbreastfeeding22-- Antidiuretic hormoneAntidiuretic hormone ((ADHADH) ) also known as also known as

vasopressinvasopressinCC-- Intermediate lobeIntermediate lobe

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CC-- Intermediate lobeIntermediate lobe## It produces It produces melanocytemelanocyte--stimulating hormonestimulating hormone((MSHMSH), which stimulate the production & release ), which stimulate the production & release

of of melaninmelanin in in skinskin and and hairhair## MSHMSH signalssignals to the to the brainbrain have effects on have effects on

appetiteappetite and and sexual stimulationsexual stimulation

HORMONE OF HORMONE OF THE ANTERIOR PITUITARY THE ANTERIOR PITUITARY

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THE ANTERIOR PITUITARY THE ANTERIOR PITUITARY

11-- Adrenocorticotropic Hormone Adrenocorticotropic Hormone ## It is a It is a polypeptidepolypeptide formed of formed of 39 39 amino acidsamino acids

with a with a molecular weightmolecular weight of of 4545,,000000## ACTHACTH synthesize & secretes synthesize & secretes GlucocorticoidsGlucocorticoids, , mineralocorticoidsmineralocorticoids and and androgenic steroidsandrogenic steroids

((from the adrenal glandfrom the adrenal gland))## ACTHACTH stimulates lipoproteinstimulates lipoprotein uptake into uptake into

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## ACTHACTH stimulates lipoproteinstimulates lipoprotein uptake into uptake into cortical cellscortical cells. This . This increasesincreases the the biobio--availabilityavailabilityof of cholesterolcholesterol in the cells of the in the cells of the adrenal cortexadrenal cortex## ACTHACTH increasesincreases the the transport of cholesteroltransport of cholesterolinto the into the mitochondriamitochondria & activates its & activates its hydrolysishydrolysis

22-- Thyrotropic Hormone Thyrotropic Hormone

## It is a It is a glycoproteinglycoprotein with a molecular with a molecular weight of about weight of about 3030,,000000

## It acts on the It acts on the thyroid glandthyroid gland to to increase increase the synthesisthe synthesis and and releaserelease of of thyroid thyroid

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the synthesisthe synthesis and and releaserelease of of thyroid thyroid hormone (Thormone (T3 3 and Tand T44))

33-- Growth hormoneGrowth hormone## It is a It is a singlesingle polypeptidepolypeptide formed of formed of 191 191 amino acids, It has the following actions:amino acids, It has the following actions:11.. Protein metabolism:Protein metabolism: it has an it has an anabolicanaboliceffect,effect, increasing increasing amino acid uptakeamino acid uptake by by cells, increases cells, increases protein synthesisprotein synthesis and and

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cells, increases cells, increases protein synthesisprotein synthesis and and produces a produces a positive nitrogen balancepositive nitrogen balance and and

gain of weightgain of weight22.. Fat metabolism:Fat metabolism: It produces It produces lipolysislipolysis

and and ketogenesisketogenesis

33.. Carbohydrate metabolism:Carbohydrate metabolism: It It possesses an possesses an insulin antagonistic effectinsulin antagonistic effectwith a tendency to with a tendency to increase blood increase blood glucoseglucose level (diabetogenic effect)level (diabetogenic effect)

44.. Mineral metabolism:Mineral metabolism: It It increases increases intestinal absorptionintestinal absorption of of calciumcalcium and and

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intestinal absorptionintestinal absorption of of calciumcalcium and and produces produces retentionretention of of NaNa++, K, K++, Mg, Mg22++ as as well as of well as of chlorideschlorides and and phosphatephosphate

44-- Lactogenic hormoneLactogenic hormone## It is a It is a polypeptidepolypeptide hormone with a hormone with a molecular weight of about molecular weight of about 2323,,000000

## It causes It causes milk secretionmilk secretion from the from the breastbreast in in lactating femaleslactating females

## Abnormally Abnormally high prolactinhigh prolactin can can delay delay pubertypuberty, , interfereinterfere with with ovulationovulation in in womenwomen, ,

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pubertypuberty, , interfereinterfere with with ovulationovulation in in womenwomen, , decrease libidodecrease libido in in menmen & & decrease fertilitydecrease fertility## In In animalsanimals and and not in humannot in human it has a it has a lutetropic effectlutetropic effect i.e. i.e. activatesactivates the the corpus corpus luteumluteum & & stimulates progesterone stimulates progesterone

productionproduction by the developed by the developed corpus luteumcorpus luteum

55-- Luteinizing hormoneLuteinizing hormone## It is a It is a glycoproteinglycoprotein

## In In femalesfemales it is responsible for it is responsible for ovulationovulation and development of and development of corpus corpus luteumluteum with with stimulationstimulation of of estrogenestrogen and and

progesteroneprogesterone secretionsecretion

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progesteroneprogesterone secretionsecretion## In In malesmales it it stimulates testosteronestimulates testosteroneproduction by the production by the testistestis which in turn which in turn

maintain maintain spermatogenesisspermatogenesis## Its Its actionaction involves an increase in involves an increase in cAMPcAMP

66-- Follicle Stimulating hormone Follicle Stimulating hormone

## It is a It is a glycoproteinglycoprotein## In In femalesfemales it is responsible for it is responsible for

maturationmaturation of of ovarian follicleovarian follicle and and releasereleaseof of estrogenestrogen

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## In In malesmales it plays important role in the it plays important role in the early stages of early stages of spermatogenesisspermatogenesis

## Its Its actionaction is mediated through is mediated through cyclic cyclic AMPAMP

HormoneHormone Sit of Action Sit of Action EffectsEffects

11-- ACTHACTH ## Adrenal Adrenal cortexcortex

## Release of Glucocorticoids, Release of Glucocorticoids, mineralocorticoids and mineralocorticoids and androgenic steroids androgenic steroids

22-- TSHTSH ## Thyroid Thyroid folliclesfollicles

## Stimulation of synthesis and Stimulation of synthesis and release of thyroid hormonesrelease of thyroid hormones

Summary for anterior pituitary hormones Summary for anterior pituitary hormones

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folliclesfollicles release of thyroid hormonesrelease of thyroid hormones

33-- GHGH ## Bone, muscle Bone, muscle & soft tissue & soft tissue

## Growth promotion:Growth promotion:Directly & through Directly & through somatomedins somatomedins

44-- Prolactin Prolactin ## Lactating Lactating mammary mammary ggland land

## Milk synthesis Milk synthesis

HormoneHormone Sit of Action Sit of Action EffectsEffects

55-- LHLH ## Mature follicle Mature follicle in female in female

## Leydig cells in Leydig cells in male male

## Ovulation, corpus luteum Ovulation, corpus luteum formation and release of formation and release of estrogen and progesteroneestrogen and progesterone## Testosterone release which Testosterone release which complete spermatogenesis complete spermatogenesis

66-- FSHFSH ## Ovarian Ovarian ## Maturation of folliclesMaturation of follicles

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66-- FSHFSH ## Ovarian Ovarian follicles in follicles in femalesfemales

##Testes in maleTestes in male

## Maturation of folliclesMaturation of follicles## Estrogen release. (Stimulation Estrogen release. (Stimulation of seminal & testicular growth)of seminal & testicular growth)## Initiation of spermatogenesis Initiation of spermatogenesis

HORMONE OF HORMONE OF

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HORMONE OF HORMONE OF THE POSTERIOR PITUITARY THE POSTERIOR PITUITARY

## The posterior pituitary secretes two The posterior pituitary secretes two hormones:hormones:11-- OxytocinOxytocin

22-- Antidiuretic hormoneAntidiuretic hormone == (Vasopressin)(Vasopressin)## These two hormones are These two hormones are synthesized in synthesized in

the cell bodies of the cell bodies of neuronesneurones in the in the

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the cell bodies of the cell bodies of neuronesneurones in the in the hypothalamushypothalamus & & transportedtransported to the to the

posterior pituitaryposterior pituitary where they are where they are storedstored## Each of them is Each of them is cyclic polypeptidecyclic polypeptide

containing containing 9 9 amino acids (amino acids (nonapeptidenonapeptide))

11-- OxytocinOxytocin11.. ContractionContraction of the of the myomyo--epithelialepithelial cells cells that line the that line the ducts of the breastducts of the breast. This . This results in results in squeezing the milksqueezing the milk out of the out of the breast = (breast = (milk ejectionmilk ejection) in ) in lactating breastlactating breast22.. ContractionContraction of the of the smooth musclessmooth muscles of of

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22.. ContractionContraction of the of the smooth musclessmooth muscles of of uterus at labouruterus at labour

33.. In a In a nonnon--pregnantpregnant uterusuterus it facilitates it facilitates sperm transportsperm transport up the up the female genitalfemale genitaltracttract to the to the uterine tubesuterine tubes where where fertilizationfertilization normally takes place normally takes place

22-- ANTIDIURETIC HORMONE (ADH)ANTIDIURETIC HORMONE (ADH)## It is essential for It is essential for water rewater re--absorptionabsorption in the in the

distal tubulesdistal tubules of kidneyof kidney

## It It increasesincreases the the permeabilitypermeability of the of the renal renal tubulestubules with a resultant with a resultant water reabsorptionwater reabsorption

into the into the renal pyramidsrenal pyramids leading to leading to concentration of urineconcentration of urine

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concentration of urineconcentration of urine

## It It increases peripheral vascular resistanceincreases peripheral vascular resistance, , which in turn increases which in turn increases arterial blood pressurearterial blood pressure

## It plays a key role in It plays a key role in homeostasishomeostasis, and the , and the regulationregulation of of glucoseglucose and and saltssalts in the in the bloodblood

HormoneHormone Sit of Action Sit of Action EffectsEffects

11-- OxytocinOxytocin ## UterusUterus## Lactating Lactating

mammary glandmammary gland

## Stimulates uterus at labourStimulates uterus at labour## Milk ejection by stimulation of Milk ejection by stimulation of myoepithelial cells of mammary myoepithelial cells of mammary

ductsducts## Facilitates transport of sperms Facilitates transport of sperms

up to the fallopian tubesup to the fallopian tubes

Summary for posteriorSummary for posterior pituitary hormones pituitary hormones

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up to the fallopian tubesup to the fallopian tubes

22-- ADHADH ## Distal & Distal & collecting collecting tubulestubules

## AntiAnti--diuretic effectdiuretic effect## Increases arterial blood Increases arterial blood

pressurepressure

IIIIII-- THYROID GLANDTHYROID GLAND## The The thyroid glandthyroid gland is found in the is found in the neckneck, ,

inferiorinferior to the to the thyroid cartilagethyroid cartilage(also known as the (also known as the Adam's AppleAdam's Apple) )

## The The thyroid glandthyroid gland produce produce thyroid hormonesthyroid hormones, , the principal ones being the principal ones being triiodothyroninetriiodothyronine ((TT33) )

and and thyroxinethyroxine ((TT44) )

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and and thyroxinethyroxine ((TT44) ) ## These hormones regulate the rate of These hormones regulate the rate of

metabolismmetabolism and affect the and affect the growthgrowth and and rate of rate of functionfunction of many other body systems of many other body systems ## The thyroid gland also produces the The thyroid gland also produces the hypercalcemiahypercalcemia hormone, hormone, calcitonincalcitonin

IVIV-- THYMUS GLANDTHYMUS GLAND## The The functionsfunctions of the of the thymusthymus are the are the

""schoolingschooling" of " of TT--lymphocyteslymphocytes ((T cellsT cells), of the ), of the immune systemimmune system, and the production and , and the production and secretion of secretion of thymosins hormonesthymosins hormones which which control control TT--lymphocytelymphocyte activities and various activities and various other aspects of the other aspects of the immune systemimmune system

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other aspects of the other aspects of the immune systemimmune system## The The thymusthymus is composed of is composed of two identical two identical lobeslobes and is located in and is located in frontfront of the of the heartheart and and

behind the sternumbehind the sternum## The The thymusthymus is is largestlargest and most active and most active

during the during the neonatalneonatal & & prepre--adolescentadolescent periods periods

VV-- ADRENAL GLANDADRENAL GLAND## Adrenal glandsAdrenal glands ((suprarenal glandssuprarenal glands) are ) are triangulartriangular--shaped endocrineshaped endocrine glands that glands that

sit on sit on toptop of the of the kidneyskidneys

## They are chiefly They are chiefly responsibleresponsible for for releasingreleasing and and synthesissynthesis of the of the hormones hormones

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releasingreleasing and and synthesissynthesis of the of the hormones hormones corticosteroidscorticosteroids, , mineralocorticoidsmineralocorticoids,,androgensandrogens and and catecholaminescatecholamines

## Adrenal glandsAdrenal glands play play no directno direct role in the role in the functioningfunctioning of,of, or or healthhealth of the of the kidneyskidneys

## Each Each adrenal glandadrenal gland is separated into is separated into two two distinct structuresdistinct structures, the , the adrenal cortexadrenal cortex and and medullamedulla, , both of which both of which produce hormonesproduce hormones## The The cortexcortex mainly produces mainly produces cortisolcortisol, , aldosteronealdosterone, and , and androgensandrogens, , while the while the

medullamedulla chiefly produces chiefly produces epinephrineepinephrine and and norepinephrinenorepinephrine

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## GlucocorticoidsGlucocorticoids ((cortisolcortisol) ) increasing increasing blood sugarblood sugar through through gluconeogenesisgluconeogenesis, ,

suppressing the immune systemsuppressing the immune system, , aiding in aiding in fatfat, , proteinprotein & & carbohydratescarbohydrates metabolismmetabolism

## MineralocorticoidsMineralocorticoids ((aldosteronealdosterone) ) influence influence on on saltsalt and and water balanceswater balances

## AldosteroneAldosterone acts on the acts on the kidneyskidneys to provide to provide active reabsorptionactive reabsorption of of sodiumsodium, , passive passive

reabsorptionreabsorption of of waterwater & & active secretionactive secretion of of potassiumpotassium

## This in turn results in an This in turn results in an increase of blood increase of blood pressurepressure and and bloodblood volumevolume

## EpinephrineEpinephrine increases heart rateincreases heart rate, , contracts contracts blood vesselsblood vessels, , dilates air passagesdilates air passages and and

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blood vesselsblood vessels, , dilates air passagesdilates air passages and and participates in the participates in the fight responsefight response of the of the CNSCNS## EpinephrineEpinephrine inhibits insulin secretioninhibits insulin secretionstimulates glycogenolysisstimulates glycogenolysis, , stimulates stimulates glycolysisglycolysis in muscle, in muscle, triggers glucagon triggers glucagon secretionsecretion & & increases lipolysisincreases lipolysis by by adipose adipose

tissuetissue

## These effects lead to These effects lead to increased blood increased blood glucoseglucose & & fatty acidsfatty acids, providing , providing substratessubstratesfor for energyenergy production within all body cellsproduction within all body cells## NorepinephrineNorepinephrine is a is a stress hormonestress hormone, , affects parts of the affects parts of the brainbrain where where attentionattentionand and responding actionsresponding actions are controlledare controlled## Along with Along with epinephrineepinephrine, , norepinephrinenorepinephrine

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## Along with Along with epinephrineepinephrine, , norepinephrinenorepinephrinealso underlies the also underlies the fight responsefight response, directly , directly increasing heart rateincreasing heart rate, , triggeringtriggering the the releaserelease

of of glucoseglucose from from energy storesenergy stores, and , and increasing blood flowincreasing blood flow to to skeletal muscleskeletal muscle## It It increasesincreases the the brain's oxygenbrain's oxygen supplysupply

VIVI-- PANCREASPANCREAS## The pancreas is a The pancreas is a gland organgland organ in the in the digestivedigestive and and endocrineendocrine system of system of

vertebratesvertebrates## It is both an It is both an endocrine glandendocrine gland producing producing several important several important hormoneshormones, including , including

insulininsulin, , glucagonglucagon, and , and somatostatinsomatostatin, as well , as well

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insulininsulin, , glucagonglucagon, and , and somatostatinsomatostatin, as well , as well as an as an exocrine glandexocrine gland, secreting , secreting pancreatic pancreatic juicejuice containing containing digestive enzymesdigestive enzymes that that

pass to the pass to the small intestinesmall intestine## These These enzymesenzymes help to further help to further break downbreak down

the the carbohydratescarbohydrates, , proteinsproteins and and fatsfats

## The part of the The part of the pancreaspancreas with with endocrine endocrine functionfunction is made up of approximately a is made up of approximately a million million cell clusterscell clusters called islets of called islets of LangerhansLangerhans## Four main cell typesFour main cell types exist in the isletsexist in the islets

11-- cellscells secrete secrete glucagonglucagon ((increase glucose in increase glucose in bloodblood) ) 22-- cellscells secrete secrete insulininsulin ((decrease decrease glucose in bloodglucose in blood) ) 33-- cellscells secretesecrete

somatostatinsomatostatin ((regulates/stops regulates/stops andand cellscells) )

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somatostatinsomatostatin ((regulates/stops regulates/stops andand cellscells) ) 44-- PP cellsPP cells secrete secrete pancreatic polypeptidepancreatic polypeptide

((self regulate the pancreas secretionself regulate the pancreas secretion activities, activities, endocrineendocrine and and exocrineexocrine & also has effects on & also has effects on hepatic glycogenhepatic glycogen levels and levels and gastrointestinal gastrointestinal

secretionssecretions))

VIIa VIIa -- OVARIESOVARIES## The The ovaryovary is an is an ovumovum--producingproducing

reproductive organreproductive organ found in found in pairspairs as part of as part of the vertebrate the vertebrate female reproductive systemfemale reproductive system## OvariesOvaries in in femalesfemales are are homologoushomologous to to

testestestes in in malesmales, in that they are both , in that they are both gonadsgonadsand and endocrine glandsendocrine glands

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and and endocrine glandsendocrine glands## In the human the In the human the paired ovariespaired ovaries lie within lie within the the pelvic cavitypelvic cavity, on , on either sideeither side of the of the uterusuterus, to which they are , to which they are attachedattached via a via a fibrous cordfibrous cord called the called the ovarian ligamentovarian ligament## OvariesOvaries secrete secrete estrogenestrogen & & progesteroneprogesterone

## EstrogenEstrogen is responsible for the is responsible for the appearance of appearance of secondary sex secondary sex

characteristicscharacteristics of of femalesfemales at at pubertypuberty and and for the for the maturationmaturation & & maintenancemaintenance of the of the reproductive organsreproductive organs in their mature in their mature

functional statefunctional state## ProgesteroneProgesterone functions with functions with estrogenestrogen

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## ProgesteroneProgesterone functions with functions with estrogenestrogenby by promoting cyclic changespromoting cyclic changes in the in the endometriumendometrium (it prepares the (it prepares the

endometriumendometrium for for pregnancypregnancy), as well as ), as well as by helping by helping maintainmaintain the the endometriumendometrium in a in a

healthy state healthy state during pregnancyduring pregnancy

VIIb VIIb TESTICLESTESTICLES## In mammals, the In mammals, the testestestes are often are often contained within an contained within an extensionextension of the of the

abdomenabdomen called the called the scrotumscrotum## TestesTestes are components of both the are components of both the

reproductive systemreproductive system ((being gonadsbeing gonads) and the ) and the endocrineendocrine systemsystem ((being endocrine glandsbeing endocrine glands) )

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endocrineendocrine systemsystem ((being endocrine glandsbeing endocrine glands) ) in malein male

## The The functionsfunctions of the of the testestestes are:are:11-- Producing spermProducing sperm ((spermatozoaspermatozoa) )

22-- Producing male sex hormonesProducing male sex hormones of which of which testosteronetestosterone

## Both Both functions of the testiclefunctions of the testicle, , spermsperm--formingforming and and endocrineendocrine, are under control of , are under control of

gonadotropic hormones gonadotropic hormones LHLH & & FSHFSH

## TestosteroneTestosterone is a is a steroid hormonesteroid hormone from from the the androgensandrogens and it is primarily and it is primarily secretedsecretedin the in the testestestes of of malesmales and the and the ovariesovaries of of femalesfemales ((precursor of precursor of estrogensestrogens), although ), although

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femalesfemales ((precursor of precursor of estrogensestrogens), although ), although smallsmall androgenandrogen amounts are also amounts are also secreted by the secreted by the adrenal glandsadrenal glands

## It is the It is the principal male sex hormoneprincipal male sex hormone and and an an anabolic steroidanabolic steroid

## In In menmen, , testosteronetestosterone plays a key role in the plays a key role in the developmentdevelopment of of male reproductive tissuesmale reproductive tissues such such as the as the testistestis and and prostateprostate as well as promoting as well as promoting secondary sexual characteristicssecondary sexual characteristics such as such as

increased muscleincreased muscle, , bone massbone mass and and hair growthhair growth## In addition, In addition, testosteronetestosterone is essential for is essential for

healthhealth and and wellwell--beingbeing as well as the as well as the preventionpreventionof of osteoporosisosteoporosis

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of of osteoporosisosteoporosis## The The primaryprimary and most welland most well--known known androgenandrogen

is is testosteronetestosterone as well as as well as DehydroepiandrosteroneDehydroepiandrosterone (DHEA), (DHEA), DihydrotestosteroneDihydrotestosterone & & AndrosteroneAndrosterone

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