Kidney regulation: hormones• Antidiuretic hormone (ADH) ~ secretion

increases permeability of distal tubules and collecting ducts to water (H2O back to body); inhibited by alcohol and coffee

• Juxtaglomerular apparatus (JGA) ~ reduced salt intake--->enzyme renin initiates conversion of angiotension (plasma protein) to angiotension II (peptide); increase blood pressure and blood volume by constricting capillaries

• Angiotension II also stimulates adrenal glands to secrete aldosterone; acts on distal tubules to reabsorb more sodium, thereby increasing blood pressure (renin-angiotension-aldosterone system; RAAS)

• Atrial natriuretic factor (ANF) ~ walls of atria; inhibits release of renin, salt reabsorption, and aldosterone release

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Chemical Signals in AnimalsChemical Signals in Animals

Without hormones, what would we be like?

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Hormones Are SpecificHormones Are Specific HormoneHormone~ chemical signal ~ chemical signal

secreted into body fluids (blood) secreted into body fluids (blood) communicating regulatory communicating regulatory messagesmessages

Target cellsTarget cells~ body cells that ~ body cells that respond to hormonesrespond to hormones

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Glands and Glands and CellsCells

Endocrine Endocrine system/glandssystem/glands hormone hormone secreting secreting system/glands system/glands (ductless) (ductless) exocrine glandsexocrine glands

secrete chemicals secrete chemicals (sweat, mucus, (sweat, mucus, enzymes) through enzymes) through ductsducts

Neurosecretory Neurosecretory cellscells~ actual cells ~ actual cells that secrete that secrete hormoneshormones

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Regulatory Regulatory SystemsSystems

Feedback regulation is Feedback regulation is a feature of both the a feature of both the endocrine and nervous endocrine and nervous systems.systems.

Negative feedback Negative feedback regulates many regulates many endocrine and nervous endocrine and nervous mechanisms.mechanisms.

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Local regulators: cells adjacent to or near point of Local regulators: cells adjacent to or near point of secretionsecretion

Growth factorsGrowth factors ~ ~ proteins for cell proliferationproteins for cell proliferation

Nitric oxide (NO)Nitric oxide (NO) ~ ~ neurotransmitter; cell destruction; vessel neurotransmitter; cell destruction; vessel dilationdilation

ProstaglandinsProstaglandins ~ ~ modified fatty acids secreted by placenta and modified fatty acids secreted by placenta and immune system; also found in semenimmune system; also found in semen

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Explain the difference between Explain the difference between these two modes of signaling:these two modes of signaling:

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Mode of Action: Chemical Mode of Action: Chemical SignalingSignaling

1- Plasma membrane reception 1- Plasma membrane reception • signal-transduction pathways (neurotransmitters, growth • signal-transduction pathways (neurotransmitters, growth factors, most hormones) factors, most hormones)

2- Cell nucleus reception 2- Cell nucleus reception • steroid hormones, thyroid hormones, some local regulators • steroid hormones, thyroid hormones, some local regulators

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QuickTime™ and aCinepak decompressor

are needed to see this picture.

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QuickTime™ and aCinepak decompressor

are needed to see this picture.

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Vertebrate Endocrine SystemVertebrate Endocrine System Tropic hormones ~ Tropic hormones ~

a hormone that has another a hormone that has another endocrine gland as a targetendocrine gland as a target

Hypothalamus~pituitaryHypothalamus~pituitary Pituitary glandPituitary gland Pineal glandPineal gland Thyroid glandThyroid gland Parathyroid glandsParathyroid glands ThymusThymus Adrenal glandsAdrenal glands PancreasPancreas Gonads (ovary, testis)Gonads (ovary, testis)

PRACTICE!!

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The The hypothalamus hypothalamus

& pituitary & pituitary

Hypothalamus- Releasing and Hypothalamus- Releasing and inhibiting hormonesinhibiting hormones

Anterior pituitary:Anterior pituitary:

Growth (GH)~bonesGrowth (GH)~bones gigantism/dwarfismgigantism/dwarfism acromegalyacromegaly

Prolactin (PRL)~mammary glands; Prolactin (PRL)~mammary glands; milk productionmilk production

Follicle-stimulating (FSH) &Follicle-stimulating (FSH) &

Luteinizing (LH)~ovaries/testesLuteinizing (LH)~ovaries/testes

Thyroid-stimulating (TSH)~ thyroid Thyroid-stimulating (TSH)~ thyroid Adrenocorticotropic (ACTH)~ Adrenocorticotropic (ACTH)~

adrenal cortexadrenal cortex

Melanocyte-stimulating (MSH)Melanocyte-stimulating (MSH)

Endorphins~natural ‘opiates’; brain Endorphins~natural ‘opiates’; brain pain receptorspain receptors

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The pituitary, IIThe pituitary, II

The posterior The posterior pituitary:pituitary:

OxytocinOxytocin~~uterine and mammary gland uterine and mammary gland cell contractioncell contraction

Antidiuretic (ADHAntidiuretic (ADH)~ )~ retention of water by retention of water by kidneyskidneys

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The pineal, thyroid, & parathyroidThe pineal, thyroid, & parathyroid

MelatoninMelatonin~ pineal gland; ~ pineal gland; biological rhythmsbiological rhythms

Thyroid Thyroid hormoneshormones: : Calcitonin - lowers blood Calcitonin - lowers blood calcium calcium Thyroxine - metabolic Thyroxine - metabolic processesprocesses

Parathyroid Parathyroid (PTH)~(PTH)~ raises blood raises blood

calciumcalcium

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The pancreasThe pancreasIslets of LangerhansIslets of Langerhans

Alpha cells: Alpha cells: •glucagon~ raises blood glucose levels•glucagon~ raises blood glucose levels

Beta cells: Beta cells: •insulin~ lowers blood glucose levels•insulin~ lowers blood glucose levels

Type I diabetes mellitus Type I diabetes mellitus (insulin-dependent; autoimmune (insulin-dependent; autoimmune disorder)disorder)

Type II diabetes mellitus Type II diabetes mellitus (non-insulin-dependent; reduced (non-insulin-dependent; reduced responsiveness in insulin targets)responsiveness in insulin targets)

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AdrenalsAdrenals

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The adrenal glandsThe adrenal glandsAdrenal medullaAdrenal medulla (catecholamines): (catecholamines):

••epinephrine & norepinephrine~epinephrine & norepinephrine~ increase basal metabolic rate (blood glucose increase basal metabolic rate (blood glucose and pressure)and pressure)

Adrenal cortexAdrenal cortex (corticosteroids): (corticosteroids):

••glucocorticoidsglucocorticoids (cortisol)~(cortisol)~ raise blood glucoseraise blood glucose

••mineralocorticoids (aldosterone)~mineralocorticoids (aldosterone)~ reabsorption of Na+ and K+reabsorption of Na+ and K+

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AdrenalsAdrenals Top of kidneyTop of kidney Cortex- from mesodermCortex- from mesoderm

mineralcorticoids control water and mineralcorticoids control water and electrolyte balance (Na+ and K+).electrolyte balance (Na+ and K+).

glucocorticoids (ACTH) control cortisol, glucocorticoids (ACTH) control cortisol, corticosterone, and cortisone which corticosterone, and cortisone which promotes normal metabolismpromotes normal metabolism

Cannot live without the CortexCannot live without the Cortex

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Adrenals cont….Adrenals cont….

Medulla from ectodermMedulla from ectoderm Epinephrine=adrenalineEpinephrine=adrenaline

• Isolated by Japanese chemist Jokichi TakamineIsolated by Japanese chemist Jokichi Takamine

• Prepared synthetically, formerly from adrenal glandsPrepared synthetically, formerly from adrenal glands

• Stimulates heart, constricts small blood vessels, raises Stimulates heart, constricts small blood vessels, raises blood pressure, converts glycogen to glucose in liverblood pressure, converts glycogen to glucose in liver

Norepinephrine=noradrenalin, same as Norepinephrine=noradrenalin, same as neurotransmitter from autonomic nervesneurotransmitter from autonomic nerves

Mimics sympathetic nervesMimics sympathetic nerves Can live without medullaCan live without medulla Can be removedCan be removed

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The gonadsThe gonadsSteroid hormonesSteroid hormones: : precursor is cholesterolprecursor is cholesterol

androgens androgens (testosterone)~ (testosterone)~ sperm formation; male secondary sperm formation; male secondary

sex characteristics; gonadotropinsex characteristics; gonadotropin

estrogensestrogens (estradiol)~uterine lining growth; (estradiol)~uterine lining growth; female secondary sex female secondary sex characteristics; gonadotropincharacteristics; gonadotropin

progestins progestins (progesterone)~uterine lining (progesterone)~uterine lining growthgrowth

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Graves Disease: HyperthyroidismGraves Disease: Hyperthyroidism

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Hypothyroidism: GoiterHypothyroidism: Goiter

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Hypothyroidism (in Babies)Hypothyroidism (in Babies)CretinismCretinism

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Hypothyroidism (Myxedema)Hypothyroidism (Myxedema)

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DwarfismDwarfism

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AgromegalyAgromegaly

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Growth HormoneGrowth Hormone=HGH=HGH

restores muscle mass restores muscle mass decreases body fat decreases body fat increases sexual function increases sexual function thickens the skin reducing thickens the skin reducing

wrinkles wrinkles restores lost hairrestores lost hair restores hair color restores hair color Increases energyIncreases energy improves cholesterol improves cholesterol

profile profile Improves vision Improves vision improves memory improves memory elevates mood and elevates mood and

improves sleepimproves sleep normalizes blood pressure normalizes blood pressure increases cardiac output increases cardiac output

and staminaand stamina