Week 2 Flashcards
(43 cards)
For the adrenal glands, the cortex is ____ in origin and develops from the celomic epithelium of the ____ abdominal wall
The medulla is ____ in origin and develops from the ___
Mesodermal, posterior
Ectodermal, neural crest cells
During the development of the adrenal glands, by the 8th week the cortical elements consist of an outer definitive cortex and a thicker inner ___ cortex, which makes steroids during gestation and goes away after birth and are replaced by adrenal zones after the first year of life
Adrenocortical ___s (some ectopic adrenal tissue) can occur as the medulla is moving in towards the cortex.
^** These can be in contact with the capsule at one pole, etc.
The adrenal ___ and sympathetic nervous system develop in concert
Fetal
Rests
Medulla
During the early stages of gestation the fetal adrenal cortex makes ___, which is a precursor for the synthesis of estrogen by the placenta
If the enzyme ___ is deficient, progesterone, glucocorticoids, mineralocorticoids, and androstenedione will be prevented from being synthesized
DHEA (dehydroepiandrosterone)
3-beta-HSD (3-beta-hydroxysteroid dehydrogenase)
Glucocorticoids are essential for 3 main reasons
1) Production of ___ by type II alveolar cells
2) Development of a functional ___ axis
3) Induction of ___ involution (shrinking)
1) Surfactant
2) Hypothalamopituitary
3) Thymic
The adrenal cortex produces ___ hormones and the adrenal medulla produces ___
Steroid, catecholamines (norepinephrine and epinephrine)
For the adrenal cortex, the outermost layer is the zona ____, the middle is the zona ___, and the innermost is the zona ___
Glomerulosa, fasciculata, reticularis
The zona glomerulosa makes ____, primarily aldosterone which is produced in response to Angiotensin II or ACTH
This zone lacks the enzyme ____, and therefore can NOT produce sex steroids or cortisol (but remember, they can make aldosterone)
Remember, aldosterone stimulates the retention of Na, water, and secretion of K and H
Mineralcortiocids
17-alpha-hydroxylase
The zona Fasiculata, which has cells specifically called ____, secretes ____
^** There are cuboid cells, with the structural features of steroid-producing cells arranged in longitudinal cords separated by cortical fenestrated capillaries
Spongiocytes, glucocorticoids and androgens
The zona fasciculata and and reticularis contain the enzyme ____, and therefore can produce glucocorticoids, and the enzyme ___ for sex hormones (this doesn’t allow them to produce aldosterone though since the 3-b-hydroxysteroid dehydrogenase is needed for that)
Both of these layers are stimualted by ___
17-alpha-hydroxylase, 17,20-hydroxylase
ACTH
Cortisol has _____ effects and also metabolic effects when glycogen stores are depleted and it causes stimulation of _____ to increase concentrations of glucose in the blood
Anti-inflammatory
Gluconeogenesis
The primary site of adrenal sex hormone production (androgens) is the zona ____, which synthesizes DHEA and androstenedione which can be converted into testosterone and estrogen in the tissues
** Remember though the zona reticularis produces not only androgens, but also glucocorticoids
Reticularis
The cells of the adrenal medulla are called ____, which can produce ___ and ____ even though they lose their axons and dendrites during embryonic development
___ is what stimulates ACTH to act on the adrenal medulla (a sympathetic response)
Chromaffin cells
Epineohrine or nor-epinephrine
Stress
Remember, there are three adrenal arteries that enter the adrenal gland capsule and form an arterial plexus
That includes the superior adrenal a. Which branches from the ___, the middle which branches from the ___, and inferior which branches from the ___
Inferior phrenic a
Aorta
Renal artery
From the three adrenal arteries, there are three branches that emerge from the plexus
There is a ____ that supplies the capsule
There is a ____ that go to the glomerulosa and then down through fenestrated capillaries/sinusoids to the zona fasciculata and then as it gets into the zonna reticularis is forms more of a capillary bed, and then it enters the medulla
There is a ____ that is a direct blood supply to the medulla
Subcapsular plexus
Short cortical artery
Long cortical artery
Remember, to much aldosterone is called ____ syndrome, which results in primary hyperaldosteronism from a tumor in the zona ___
Secondary hyperaldosteronism can occur from an increase in ____ secretion
Conn’s syndrome, glomerulosa
Renin
Destruction of the adrenal cortex by an autoimmune process or tuberculosis can cause a cortisol deficiency. To counteract this, ____ secretion increases and can cause skin pigmentation (because remember, MSH is derived from the same precursors as ACTH) and is called ____ disease
**There is also a lack of mineralcorticoids that can lead to hypotension and shock
Addison’s disease
ACTH, Addison’s disease
Chromaffin cells of the adrenal medulla can have benign tumors, which is called ____ and this causes excessive secretion of ___ which turns up the sympathetic NS all the way
Pherochromocytomas, epi and norepinephrine
A transport protein that regulates cholesterol transfer into the mitochondria in order to produce steroid hormones is called ___
** So without this cholesterol will not be taken up into the mitochondria will it can turn to pregnenolone via desmolase
StAR (steroidogenic acute regulatory protein)
Cortisol acts on various tissues including liver to increase ____, muscle to increase _____ and adipose tissue to increase ___. It also acts on the immune system for immune supression
Cortisol secretion is highest in the ___ and lowest in the __
Gluconeogensis, protein catabolism, lipolysis
Morning, evening
Hypercortisolism, such as in cushings syndrome which remember is from an ___ tumor, is when there is to much cortisol that leads to increased negative feedback to the system and therefore ___ ACTH levels and ___ CRH levels
**^This is primary disease
Hypercortisolism can also be caused by cushings disease, which is from a ___ tumor, and therefore levels of ACTH are ___, cortisol is of course increased, and negative feedback of cortisol leads to ___ levels of CRH **But the negative feedback does not decrease levels of ACTH because of the tumor
**^ This is a secondary disease
adrenal, Decreased, decreased
Pituitary, pituitary, increased, decreased
Hypocortisolism aka to little cortisol can occur such as in Addison’s disease, which is an autoimmune disease that destroys the adrenal gland. Since the adrenal gland is defective, there is a ___ cortisol level and this causes a positive response to ___ CRH levels and ____ ACTH levels
**^Primary adrenal insufficiency
Secondary adrenal insufficiency such as if a drug blocks the hypothalamus or pituitary lead to ___ levels of either ACTH and CRH and therefore decreased levels of cortisol
Decreased, increased, increased
Decreased
A cosyntropin (synthetic ACTH) stimulation test (CST) can be used to detect adrenal gland insufficiency
If cortisol levels are more than 15 ug/dL, no adrenal gland insufficiency
If levels are less than 3 ug/dL, then it is 100% an adrenal gland insufficiency because no cortisol is being produced… However we now need to determine if it is a primary (aka the adrenal cortex itself is destroyed) of it it’s secondary or tertiary (aka the pituitary or hypothalamus is defective)
^We do this by measuring ACTH, if the adrenal gland itself is destroyed (aka primary) then cortisol is low, and this causes ACTH to be increased in order to compensate…
If it’s a secondary or tertiary problem, then cortisol is still low but when ACTH is suppose to increase in order to compensate it CANT because it’s a secondary or tertiary problem so the pituitary or hypothalamus is defective and therefore no ACTH can be made no matter what…
So to conclude, elevated ACTH = ___ adrenal insufficiency
Low/normal ACTH levels = ___ adrenal insufficiency
Now if your cortisol levels were between 3 and 15 ug/dL, you must administer cosyntropin which acts as a synthetic ACTH. After you give them this drug, when you remeasure, if your cortisol levels are above 18 then you had a normal response and an adrenal gland insufficiency is ruled out
If it’s below 18 then that means there was some problem making cortisol, so you must measure ACTH in order to determine what the problem was
Primary
Secondary/Tertiary
___ increases the availability of cholesterol for steroid hormone biosynthesis
ACTH
Aldosterone can be stimulated for secretion via three major mechanisms
1) ___ can stimulate the hypothalamus to release CRH -> AP release ACTH -> Adrenal cortex release aldosterone
2) ____ Na+ or ___ K+ in the blood can cause direct stimulation to the adrenal cortex to release aldosterone
3) Decreased blood volume or pressure leads to the ___ to become activation
All of these stimulate the zona ___ of the adrenal cortex to release aldosterone
1) Stress
2) Decreased, Increased
3) RAAS
Glomerulosa