Hormones III

Frage	Antworten
What is each adrenal gland equiv. to	2 endocrine organs
What's on outer/inner	Outer adrenal cortex under hormonal control Inner adrenal medulla which functions independently
Structure of adrenal medulla	Modded part of SNS Specialised sympathetic ganglion
Hormones of adrenal medulla are	Catecholamine epinephrine/norepinephrine amino acid-derived tyrosine hormones
What is the medulla chiefly composed of	Chromaffin cells which produce adrenaline/noradrenaline
What are chromaffin cells?	Specialised postganglionic neurons
What is the adrenal medulla stimulated by?	Preganglionic thoracic sphlanchnic nerve fibres
What is the neurotransmitter?	Acetylcholine
What is the purpose of these hormones?	Prepare body for acute stress
Major effects of adrenaline on the CV system (5)	1. Increased HR + stroke volume. 2. Increased systolic BP. 3. Vasodilation of coronary + skeletal muscle BVs. 4. Vasoconstriction of BV to nonessential tissues. 5. Bronchodilation.
Metabolic effects	1. Liver converts glycogen to glucose 2. Increased met. rate 3. BF altered, decreased digestive system activity and urine output.
Adrenaline receptors	Alpha 1,2 Beta 1,2,3 (Reacts w/ Beta most)
Adrenal Cortex	Zona Glomerulosa - Mineralocorticoids -aldosterone Zona Fasciculata - Glucocorticoids - Cortisol Zona Reticularis - Gonadocorticoids - Androgens
What type of hormone are all of these?	Steroid hormones
Where are steroid hormone receptors found?	In nucleus, as they effect gene transcription
Cholesterol -> Steroid hormones	Cholesterol (C27) Pregnenolone (21) Progestagens (C21) Glucocorticoids Minc. Androgen (C19) -> Estrogen (C18)
What does Z. Glomerulosa lack?	17alpha-hydroxylase
What does Z. Fasciculata + Z. Reticularis lack	18-hydroxylase
21-hydroxylase deficiency	All cholesterol converted to androgen in utero
Zona Reticularis weak androgens (ASD DHEAS)	Androstenedione Dehydroepiandrosterone Converted into testosterone in perinephric tissues
Production of sex hormones in males	Mainly in gonads Andrenal male sex hormone production minor in comparison
Production of sex hormones in females	Adrenal gland secretes 1/2 androgenic requirement
What hormone regulates the release of these hormones?	ACTH from the A.P.
How is aldosterone secretion regulated?	By plasma Na+/K+ levels via Renin-Angiotensin-Aldosterone system
What are the effects?	Controls ECF. Vol. Increase BP + Vol. Stim. reabsorption of Na+ in DCT in exchange for K+
What zona is involved in stress/ mental+emotional trauma?	Zona Fasciculata - Glucocorticoids
What are the catabolic effects of cortisol on skeletal muscle?	Increase protein breakdown AA-> Glucose via gluconeogenesis
What are the catabolic effects of cortisol on adipose tissue?	Increased lipolysis -> Free FA + TAG
What are the effects on plasma	^ [Glucose] + [Free FA]
What are the effects of cortisol on the immune system?	Anti-inflammatory Suppress AB production and lymphocyte circulation Useful in transplant patients
What controls cortisol release?	CRH - Corticotrophin releasing hormone
Draw hormone feedback cycle for cortisol	a
What are the other roles of ACTH?	Maintains adrenal cortex structural integrity Regulates secretion of Glucocorticoid steroid hormones in response to stress.
Symptoms of hyperfunction (6)	Cushing's syndrome Body fat redistribution Muscle wastage Thin skin Hyperglycaemia Hypertension
What receptors does cortisol in excess bind	Aldosterone - hypertension
What are the causes and symptoms of excessive ADRENAL androgen production?	Overproduction of ACTH Acne, hirsutism, baldness
Causes of hypofunction?	Damage to adrenal glands
Symptoms	Deficit in glucocorticoids and mineralcorticoids
What does excess ACTH do and why?	Act as melanocytes to produce melanin as AA sequence of ACTH is similar to MSH
Why is there excessive ACTH?	As adrenal gland isn't producing enough andrenal hormones the AP creates more stims. to try and stim cortisol release.

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