Online modules- adrenal Flashcards
(51 cards)
Name the layers in the adrenal gland
Cortex
Medulla
Name the subdivisions of the cortex
Zona reticularis
Zona fasciculate
Zona glomerulosa
Connective tissue
What is secreted from the zona reticularis and what does it control?
Responsible for the Renin-angiotension-aldosterone control. Secretes aldosterone.
Also controlled by ACTH and secretes sex hormones.
What is secreted from the zona fasciculate and what does it control?
It is controlled by ACTH release from the anterior pituitary gland.
It controls release of glucocorticoids such as cortisol, cortisone and corticosterone.
Put the subdivisions of the adrenal gland into order starting with the deepest going to the most superficial
Medulla Zona reticularis Zona fasciculate Zona glomerulosa Connective tissue
What are mineralocorticoid hormones?
They are hormones responsible for control of water and salt balance.
Characteristics of steroid hormones
All derived from cholesterol.
Only synthesised when the cells producing them respond to stimuli
Not stored within the cell
Bound to proteins during transport giving them a slow response.
What hormones are secreted from the medulla
Adrenaline and nor-adrenaline.
Describe the precursors to forming adrenaline
Tyrosine is converted to dopamine. Dopamine is converted to either adrenaline or noradrenaline.
Where is adrenaline made?
Chromaffin cells.
Why does adrenaline have a short half life?
It is unbound when transported giving it a very short half life.
What stimulates aldosterone release?
Angiotensin II
How does angiotensin II stimulate aldosterone release?
Works by stimulating cell growth of the cells within the zona glomerulosa.
What does secretion of aldosterone do to the body?
It causes NaCl retention. This means that due to an osmotic gradient water is reabsorbed in the kidney. Pottasium is however lost due to the Na+K+ATPase.
What can cause renin release?
A decrease in blood pressure
A decrease in sodium chloride concentration
A decrease in extracellular volume.
What would happen if a patient has too much aldosterone?
Water retention therefore increased bp
Hypokalaemia due to pottasium being excreted a lot
Levels of sodium would be high
What is Conn’s syndrome?
A tumour in the zona glomerulosa causing aldosterone to be secreted.
Biochemical test results for Conns syndrome
Increased Na+
Increased water
Decreased K+
Symptoms of Conns syndrome
Hypertension
Hypokalaemia
Conns syndrome is the only disease causing more aldosterone to be released. T or F
F- another cause of excess aldosterone release is adrenal hyperplasia. Usually it occurs bilaterally.
Diagnostic tests for primary aldosteronism
Aldosterone to renin ratio (you would expect them to be proportional to one another considering renin ultimately causes aldosterone release.
If the ratio is greater than 750 then carry out a saline supression test. Give the patient 2L of saline solution over the period of 4 hours. You would expect their aldosterone to stop being released because the patient has plenty of salt and water, however in these conditions this wont occur. If the aldosterone levels fail to fall by 50% then it is primary aldosteronism.
Treatment of primary aldosteronism
If unilateral e.g. in Conns syndrome- surgery may be an option. The adenoma is removed laparoscopically.
If bilateral you cant remove both adrenal glands therefore should treat with aldosterone receptor antagonists e.g. spiranolactone that reduce the absorption of NaCl.
Name a treatment alternative to spiranolactone in bilateral hypersecretion of aldosterone
Eplerenone.
Where are glucocorticoids made and secreted from?
The zona fasciculate.