additional hormone

7/28/2019 Additional Hormone

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Small endocrine gland attached tothe roof of the third ventricle of the

brain in the midline

Part of the epithalamus (small region

posterior to the thalamus, consists of thepineal gland and habenuclear nuclei)



Positioned between the two superior colliculi, covered by a capsule (pia

mater)

Consists of masses neuroglia and

secretory cells (pinealocyte)

0.1-0.2 g



Contribute to the setting of the body’sbiological clock (controled by

suprachiasmatic nucleus of thehypothalamus)

Amine hormone, derived from serotonin,water soluble

More melatonin liberated duringdarkness than in light – promotesleepiness



Visualinput from

retina

N.Suprachias

matic

Superior cervicalganglion

Pinealgland



Small doses of melatonin given orallycan induce sleep and reset daily rhytms

Potent antioxidant, provide someprotection against damaging freesradicals – (used as suplement ??)

Higher in children and decline with ageinto adulthood – correlate with puberty(?)

Causes atrophy of the gonads (??)



Located behind the sternum betweenthe lungs

Play important role in immunity The hormone produced by thymus

promote the maturation of T-cells, may

retard the aging process



Partially embedded in the posterior surface of the lateral lobes of the thyroid

gland Small, round masses, 40 mg

Contain 2 kinds of epithelial cells (chief

cells – numeous and oxyphil cell Chief (principal) cells produce

parathyroid hormone (PTH



Major regulator of the levels of Ca2+

Control of secretion: The blood calcium

level (low blood Ca2+ level stimulatesecretion, high blood Ca2+ level inhibitsecretion

Principal actions: Increase blood Ca

2+

level



Increase bone resorption by osteoclast› High level of Ca2+ stimulates thyroid gland to

release calcitonin. Calcitonin inhibits

osteoclast.

Increase Ca2+ reabsorption by renaltubule (kidney)

Promotes formation of calcitriol (activeform of vitamine D) in juxta glomerularis,which increases rate of dietary Ca2+

absorption



Calsium dari makanan (diet) dapatdiserap di usus apabila terdapat vitamin

D aktif (calcitriol). Di usus, calcitriol akan:

› Meningkatkan alkali fosfatase yangmenggiatkan penyerapan Ca2+

› Meningkatkan ATP-ase

› Meningkatkan Ca-binding protein



Inner region of the adrenal gland

Modified sympathetic ganglion of

autonomic nervous system Develops from the same embryonic

tissue as all other sympatetic ganglia,lack axon

Not releasing neurotransmitter, releasinghormones



Hormone-producing cells : chromaffincells

Inervated by sympathetic preganglionicneurons of ANS – hormone release canoccur very quickly

Two major hormones synthesized byadrenal medulla: epinephrin (80%) andnorepinephrine (20%)



Hormon E dan NE disekresi pada situasi“fight” (stres, olah raga)

Reseptor sensoris

Amygdala HipotalamusNeuron

preganglionsimpatis

Selchromaffin

NE & EFight or

flight



Pada sekresi E & NE, jantung danpembuluh darah akan terpacu,

sehingga terjadi:› peningkakan denyut jantung,

› peningkatan kontraktilitas jantung,

› peningkatan curah jantung,

› peningkatan tekanan darah

› Peningkatan aliran darah ke organ vital



Pada sekresi E & NE, saluran nafas akanberdilatasi sehingga lebih banyak udara

bersirkulasi dalam paru Dengan adanya E & NE, cadangan

glikogen pada otot skelet akandibongkar sehingga terjadi peningkatan

glukosa darah



Ghrelin is produced in the stomach and upper intestine in the absence of food in the digestivesystem and stimulates appetite.

Peptide YY is produced in the GI tract in responseto a meal in the system and inhibits appetite.

Leptin is secreted by adipocytes, in response to

increased in high fat mass conditions, implicatedas an anorexigenic factor that reduces appetite

All of these hormones work on the brain to helpregulate the intake of food for energy



Hormone Principal Action

Human chorionicgonadotropih (hCG)

Stimulates the corpus luteum in the ovary tocontinue the production of estrogens &

progesterone to maintain pregnancy

Esterogen & Progesterone Maintain pregnancy, help preparemammary glands to secrete milk

Human choroinicsomatomammotropin(hCS)

Stimulates the development of themammary glands for lactation



Hormone Principal action

Renin Part of a sequence of reactions

that raises blood pressure bybringing about vasoconstrictionand secretion of aldosteron

Erythropoietin (EPO) Increase rate or red blood cellproduction

Calcitriol Aids in the absorption of dietarycalcium and phosphorus



Atrial natriuretic peptide – decreaseblood pressure

Increase in

blood volume

Stretching of

the atria

Stimulatessecretion of

ANP by cells inthe atria



Secretion of ANP:

› Inhibit reabsorption of Na+ and water in theproximal convoluted tubule & collectingduct

› Supresses the secretion of aldosteron andADH

› Increase the excretion of Na+ in urine,increase urine output (diuresis)

› Decrease blood volume and blood pressure



Prostaglandins, leukotrienes,thromboxane

Act as local hormones (paracrines or autocrines) in response to chemical or mechanical stimuli

Present only briefly due to rapid

inactivation Bind to receptors on target cell plasma

membranes, stimulate or inhibit thesynthesis of 2nd mesengers (cAMP)



Leukotrien: stimulasi kemotaksis sel darahputih, mediator inflamasi

Tromboxan: konstriksi pembuluh darah,aktivasi trombosit

Prostaglandin: mempengaruhi kontraksisel otot polos, sekresi kelenjar, alirandarah, proses reproduksi, metabolismelipid, respons imun, mediator inflamasidan demam



Disintesis dari asam arakhidonat

Disekresi oleh semua sel kecuali sel

darah merah Water soluble

Reseptor berada di membran

Bekerja dengan mengaktifkan 2nd messengers



Insulinlike growth factor, thymosin, insulin,thyroid hormone, human growth

hormone, prolactin Stimulate cell growth and division –

mitogenic substance. Play importantroles in tissue development, growth, and

repair.

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