adrenocortical function and dysfunction Flashcards
the adrenal medulla is a modified sympathetic ganglion, that [….]
secretes catecholamines (neurohormones)
adrenal cortex is a true endocrine gland that secretes steroids […].
classical hormones
T/F the adrenal medulla and adrenal cortex were 2 distinct endocrine glands of different embryological origins and eventually fused together
TRUE
each region of the adrenal gland secretes different hormones. From innermost to the capsule:
- the adrenal medulla secretes [….],
- the zona reticularis of cortex primarily secretes [….],
- the zone fasciculata of cortex primarily secretes […..]
- the zone glomerulosa of cortex secretes [….]
catecholamines
sex hormones
glucocorticoids
aldosterone
overlap of adrenal cortex regional hormone production occurs in the [….] and […].
fasciculata and reticularis region.
Sex hormones (androgens, estrogens, dihydroepiandosterone (DHEA)) are mainly made in the reticularis, but also the fasciculata.
reticularis region
fasciculata.
glucocorticoids, such as [….], are made mainly in the fasciculata but also the reticularis. These zones are stimulated by the [….] axis.
[…] from the anterior pituitary is tropic to both the ZF and ZR.
cortisol
HPA
ACTH
The mineralcorticoid, […], is made in the zona glomerulosa of the adrenal cortex. The production is stimulated by RAAS and [….]
aldosterone
plasma K+
most hormones are derived from cholesterol, however they differentiate due to the presence of different […] in cells of different regions of the gland. Ex. Cortisol is derived from progesterone (after cholesterol) by the activity of [….]. Estradiol is derived from progesterone through the activity of [….].
enzymes
21-hydroxylase enzyme
aromatase enzyme.
cortisol has different functions on different organs/tissues. On the immune system, it causes […]. On the liver it stimulates […]. In skeletal muscle, it causes […]. On adipose tissue, it causes [….]. On long bones it causes [….]
immune suppression
gluconeogeneisis
skeletal muscle protein catabolism (substrate for gluconeogenesis)
lipolysis (liberating fatty acids for energy)
negative calcium balance by decreasing absorption, increasing excretion, causing bone breakdown.
CRH (from the PVN of hypothalamus) is released on the the anterior pituitary gland via a vascular system, […]. This promotes production of [….] from the [….] region of the adrenal cortex.
hypothalamic hypophyseal portal system.
cortisol.
zona fasciculata
CRH production from the hypothalamus can be influenced by […..] and [….]
circadian rhythm and stress
CRH has several other functions besides anterior pituitary stimulation, including effects on inflammation and immune response, […] of appetite via the brain neuropeptide [….], signals the onset of [….]
inhibiition of appetite via urocortin.
onset of labour.
ACTH is part of the [….] family of MSH hormones.
ACTH and beta-endorphin (blocks pain production) are produced from the giant protein, [….], by proteolysis.
Outside the pituitary, [POMC] is proteolysed into alpha-MSH, which acts to decrease food intake and increase [….].
melanocortin.
POMC (pro-opiomelanocortin)
POMC (pro-opiomelanocortin)
skin melanin
cortisol is essential for life, helps the body cope with long-term [….], and follows a [….] rhythm.
stress
diurnal
long term use of cortisol (and cortisol analogs, corticosteroids) can result in [….] of acth secretion and [….] of cortisol and secreting cells.
inhibition
atrophy
hypersecretion of adrenal cortex may result in hyperaldosteronism, causing [….], […], and [….].
primary hyperaldosteronism is known as {…..]
hypokalaemia, hypernatremia, and hypertension
(secondary hyperaldosteronism–>RAS)
Conn’s Disease.
hypersecretion of adrenal cortex may result in excess cortisol (cushing’s syndrome) due to primary adrenal cortex dysfunction, secondary […..] tumor (cushing’s disease), or due to iatrogenic causes (corticosteroids)…
May result in [….] excess, protein [….], and abnormal […..] distribution.
pituitary
glucose excess
protein shortage
abnormal fat distribution
hypersecretion of adrenal cortex may result in excess androgen and estrogen, known as […..] syndrome.
This is due to deficient […] in the cortisol steroidogenic pathway.
This may result in [….] in all cases except adult males.
This can be Tx with [….] to repair the deficit and inhibit [….].
adrenogenital.
enzyme.
inappropriate masculinisation
glucorticoids
ACTH (reducing further steroid secretion)
In cushing’s syndrome, excess [….] causes hyperglycaemia (diabetes-like symptoms).
glucorticoids
In cushing’s syndrome, […..] breakdown and lipolysis causes wasting coupled with paradoxical fat deposits in trunk and face due to increased appetite—>patient present with thin arms & legs, trunk obesity and [….] face.
muscle protein
Moon face.
In cushing’s syndrome, The mineralcorticoid action of excess gluocorticoids causing increased [..&..] retention, further exacerbating the […] face appearance of the pt. This also leads to weakness and […]tension.
salt and water.
moon.
hypertension.
In cushing’s syndrome, excess cortisol can lead to increased calcium […] and decreased calcium [….] from […].
As well as […] disorders, difficulty learning, and memory.
excretion
resorption
long bones.
mood.
