Adrenal Glands Flashcards
What are the 3 main stresses an organsim responds to? [3]
Hypotension
Infection
Starvation
Adrenal Cortex:
Zona [] - adreno androgens. Eg. [].
Zona [] - glucocorticoid hormones eg. []
Zona [] - minerocorticoid hormones eg. []
Adrenal Cortex
Zona reticulars - adreno androgens. Eg. testosterone
Zona fasciculata - glucocorticoid hormones eg. cortisol
Zona glomerulosa - minerocorticoid hormones eg. aldosterone
How is direct communication possible between the adrenal cortex and medulla? [1]
No barrier between the medulla and the zona reticulata - so direct communicaton is possible
The medulla contains [] cells.
chromaffin cells
Cortex – derived from the embryonic [].
Medulla – derived from the [] neural crest cells.
Cortex – derived from the embryonic mesoderm.
Medulla – derived from the ectodermal neural crest cells.
What are the 3 arteries that supply the adrenal glands? [3]
Which arteries do they come from? [3]
Superior adrenal artery – arises from the inferior phrenic artery
Middle adrenal artery – arises from the abdominal aorta.
Inferior adrenal artery – arises from the renal arteries.
Label A-D
A: superior adrenal artery
B: inferior phrenic artery
C: middle adrenal artery
D: inferior adrenal artery
Hyperplasia of the ZF would cause which disease? [1] Because of an overproduction of what? [1]
Cushings disease: high levels of cortisol
Why might you see expansion of ZG in body?
If the Na is low in blood: expansion of the ZG to produce more aldosterone.
All pathways in the steroidogenic enzyme pathway start with which molecule? [1]
Cholesterol: The different enzymes of the different zones allow cholesterol to be turned into di#erent hormones.
Different enzymes expressed in the cortex zones:
ZG: For aldosterone synthesis? [1]
ZF: For cortisol synthesis? [1]
ZR: for testosterone synthesis? [1]
ZG: For aldosterone synthesis: Aldosterone synthase: P450c 11AS
ZF: For cortisol synthesis: p450c 11B-hydroxylase
ZR: for testosterone synthesis: 17a-hydroxylase
What is release of aldosterone stimulated by? [2]
rising K+ [1]
fall in blood volume/BP [1]
ZG cells are distinguished by expression of the type I [] receptor , [] synthase, low levels of [], and no expression of [].
ZG cells are distinguished by expression of the type angiotensin II receptor (AT1), aldosterone synthase, low levels of p450c17 (which produces testosterone) and no expression of p450c11β (which produces cortisol)
Explain hyperaldosteromism affects the RAAS system
Renin converts angiotensin -> ANG1
ANG1 converted to ANGII by ACE (from lungs) ANG II:
Causes direct vasoconstricton + binding to ANG II receptors in ZG
ZG cells produce aldosterone: causes vasoconstriction + remodelling - (ininflammation in heart + vasculature).
Second effect of aldosterone: ‘sodium savour’: Na reabsorption + water reabsorption : Have to exchange K+ at the ENAC channels on the distal tubule.
Aldosterone release triggered by RAAS and high serum K+ levels.
RAAS system is triggered by? [4]
Na loss
haemorrhage
upright posture
decreasing renal blood