Essential hormones for life

Under supervision of:

prof:Nermeen Mady

Students (287__294):

1-rowan ayman

2-rowan samir

3-rowan Adel

4-rawda el kady

5-rawnaa el deeb

6-reem el genedy

7-reem ashour

8-reem el amrousy

Essential hormones for life

1. Growth Hormone (GH)

2. ParaThormone Hormone (PTH)

3. Minralocorticoids (aldosterone)

4. Glucocorticoids (cortisol)

1-Growth hormone

-It Is a Polypeptide hormone containing 191 amino acids Unlike the other anterior Pituitary hormones, it exerts its effects directly on almost all tissues of the body to promote tissue growth

Direct effect of GH Indirect effect

• Stimulate the release of somatomedines from the liver

• Somatomedines have insulin-like effect

Surface membrane receptor

GHRECEPTOR WITH TYROSIN KINASE ACTIVITY

2-parathormone

*This hormone is secreted from the chief (chromophobe cells)of the parathyroid glands.

*Parathyroid glands are small four endocrine glands. they are embedded in the posterior surface of the thyroid gland.

*The parathyroid glands are essential for life.

PTH is a polypeptide hormoneIt contains 84 amino acids

Cellular mechanism of action

Surface membrane receptor

PTH

Hypoparathyrodism:results from surgical removal of parathyroid glands during thyroidectomy

it cause hypoglycemia and consequently tetany

Control of parathormone secretion:parathormone is not under the pituitary control.

the following factors control PTH secretion:

the blood Ca level:1-by the negative feedback mechanism.

2-the blood Po4 level:

the PTH secretion is direct proportional to Po4 level--the effect of Po4 is excreted via the Ca to maintain the constant solubility

product).)

3-the blood Mg level:inversly proportional

4-sympathetic stimulation &catechoalmines--stimulate the parathormone secretion via the B-adrenergic receptors.

b)increase the blood glucose level•

aldosterone

aldosterone exerts about 90%

of aldosterone is bound to albumin.60%

40%of aldosterone is present in free form

cellular mechanism of action

induced proteins have the following effects

1-increase the activity of sodium channels (rapid effect

2-increase the synthesis of sodium channels(slow effect)

3-increase the activity of membrane NA+ k+ ATPase enzyme.

-functions of aldosterone:

1-it increase NA+ &decrease K+ concentration in (ECF)

bya)it increases the NA+ reabsorption &stimulates K+ excretion

by distal convoluted tubules & collecting ducts of kidneys.

b) it increases the NA+ reabsorption from the sweat glands , salivary glands and GIT especially the colon.

2- increases the tubular secretion of H+

3-it has an antidiuretic action

4-it increases the blood volume & the ABP due to Na+ and water retention.

Pineal gland

Adrenoglomerulation & serotonin are secreted from the pineal gland lead to stimulation of the adrenal cortex

afferent impulses

A)from the cardiovascular system:e.g.- Impulses from the volume receptors of the right side & pressure receptors of the left side are inhibitory to aldosterone secretionImpulses from the chemoreceptors of the left side are stimulatory to aldosterone secretion.B) Pain produced from physical trauma or anxiety are stimulatory to aldosterone secretion.

hyperaldosteronism

Types

1-primary(conn’s syndrome)because of a tumor of zona glomerulosa

2-secondary hyperaldosteronism a-heart failure or renal failure :stimulation of renin

angiotensin system

b-hepatic failure :decrease degradation of aldosterone in liver

Manifestations of hyperaldosteronism

1-cardiovascular

hypertension due to Na retention

2-Blooda-increase plasma Na thus increase blood volume

b-decrease plasma K “hypokalemia”

c-alkalosis due to excess H secretion

Glucocorticoids

•cortisol is the principle glucocorticoid

•Its amounts for about 95% of all glucocorticoids activity

Function of glucocorticoids:

•

1-Mineralocorticoids action:It have weak mineralocorticoid activity2-Water balance:a) promote water excretion in the urine as a result of inhibition secretion of ADH lead to diuresis.b)Antidiuretic action by their mineralocorticoids effects

3-Metabolic effect:a)On carbohydrate metabolism:

diabetogenic effect, due to:i)stimulation of gluconeogrnrsis in the liver.ii)Decrease glucose utilization by tissues.

b)on protein metabolism:

i) Cortisol decrease protein synthesis & increase protein catabolism in all tissues except the liver ,so it increase blood amino acidsii) in the liver it increase the uptake of amino acid & their conversion into carbohydrate (i.e. gluconeogenesis )c) On fat metabolism:

i)cortisol increase mobilization of fat from adipose tissue & decrease hepatic lipogenesis increase plasma level of free fatty acid.

ii)it affects the distribution of fat in the body.

4-Blood cells & immunity:

i)increase the number of RBCs, platelets & neutrophils.

ii)It decrease number of eosinophils & lymphocytes in the blood.

5-Anti-inflammatory effect:

It suppresses the inflammatory reaction.

6-Anti-allergic effect:

It suppresses all manifestation of allergy (prevent release of histamine from the mast cells)

Thank you