Adrenals Flashcards
What does the adrenal cortex make?
Steroidds
What does the adrenal medulla secrete?
Catecholamines (NE/E)
Which embryonic tissue are the cortical cells derived from?
Mesodermal mesenchyma
Which embryonic tissue are the medullary cells derived from?
Neural crest
Where do the following suprarenal branches come from?
Superior suprarenal a.
Middle suprarenal a.
Inferior suprarenal a.
Superior suprarenal a. - inferior phrenic a.
Middle suprarenal a. - aorta
Inferior suprarenal a. - renal a.
Once the blood vessels enter the capsule, what does the capsular capillaries, fenestrated cortical sinusoidal capillaries, and medullary arterioles supply?
Capsular capillaries- supply capsule
Fenestrated cortical sinusoidal capillaries- supply cortex
Medullary arterioles- traverse the cortex and bring arteriol blood to the medullary capillary sinusoids
What are the 3 layers of the adrenal cortex from superficial –> Deep?
Zona glomerulosa (ZG) Zona Fasciculata (ZF) Zona reticulata (ZR)
“Go Find Rex, Make Good Sex”
Where does the R suprarenal v drain?
IVC
Where does the L suprarenal v drain?
L renal v
What is the hormone released from the ZG?
Minerocorticoids
“Go Find Rex, Make Good Sex”
What is the main mineralcorticoid released from the ZG?
Aldosterone
What are the H’s released from the ZF?
Glucocorticoids (coricosterone and cortisol)
“Go Find Rex, Make Good Sex”
What are the H’s released from the ZR?
Gonadocorticoids (DHEA)
“Go Find Rex, Make Good Sex”
What are the H’s released from the adrenal medulla?
Catecholamines (NE/E)
Which cells in the adrenal medulla make the catecholamines?
Chromaffin cells
What makes the catecholamines different (as far as structure) than the cortical adrenal H’s?
They’re peptides rather than steroids.
Which type of SANS fibers inntervate the chromaffin cells (pre- or post-ganglionic)?
Preganglionic SANS fibers
Which NT does the preganglionic SANS fibers release to stimulate the chromaffin cells to release the catecholamines?
Ach
Which drug depletes catecholamines from the vesicles and inhibits transport?
Reserpine
Which H’s from the adrenal cortex induce the conversion of NE –> E in chromaffin cells via enzyme methylation?
Glucocorticoids
Which “zona” is the largest in the adrenal cortex?
80% is made of the ZF
What triggers the release of cortisol from the ZF?
Stress
What are the actions of the glucocorticoids on glucose metabolism?
↑ gluconeogenesis, ↑ glycogenolysis
(stressed from seeing a bear –> cortisol released –> glucose put into blood for energy to run away –> can’t run away because those big Mac’s are catching up to you –> trip over a fallen branch –> accept your fate –> turn around –> bear staring at you –> looks you deep in the eyes –> you tightly shut your eyes waiting for the life-ending claw swipe –> hear “are you scared?” –> open 1 eye –> bear pulls its head off and ashton kutcher is inside –> “you’re on punk’d.”)
Why is hydrocortisone used to treat allergies and inflammation? What does hydrocortisone (cortisol) inhibit normally?
immune and inflammatory responses
Which hormone stimualtes the release of aldosterone from the ZG?
Angiotensin II
“Go Find Rex, Make Good Sex”
Which hormones stimulates the release of cortisol and DHEA from the ZF and ZR?
ACTH
“Go Find Rex, Make Good Sex”
Which molecule are all steroid H’s derived from?
Cholesterol
Which enzyme converts cholesterol –> pregnenolone?
P450scc
Pregnenolone –> ________ –> DHEA
17-hydroxypregnenolone
Pregnenolone is also coverted to which molcule to eventually make Aldosterone and Cortisol?
Progesterone
using 3-B-hydroxysteroid dehydrogenase
This is the group of diseases caused by genetically determined deficiency in a variety of enzymes required for cortisol synthesis.
Congenital adrenal hyperplasia (CAH)
Which enzyme is needed to covert progestrone to 11-deoxycorticosterone and 11-a-hydroxyprogestrone to 11-deoxycortisol?
21-a-hydroxylase
So a deficiency in 21-a-hydroxylase will decrease the synthesis of which H’s?
Aldosterone
Cortisol
What happens to DHEA levels in 21-a-hydroxylase?
it increases cuz the other’s decrease –> ↑ androgens –> prenatal masculinization in females and postnatal virilization in males
“in 21-a-OH deficiency you look 21 y/o real quick”
Which H accumulates in 11-B-hydroxylase deficiency?
11-deoxycorticosterone (mineralcorticoid) and 11-deoxycotisol
So what is the main complaint in 11-B-hydroxylase deficiency?
moderate HTN and high virulization
“11 year old MEN with HTN.”
Which H’s accumulate in 17-a-hydroxylase deficiency?
aldosterone
So what is the main complaint in 17-a-OH deficiency?
Super HTN
“on a scale of 1-10, my BP is at a 17.”
Which AA are catecholamines derived from?
Tyr
Which molecule is required fro Phe –> dopa?
BH4 (tetrahydrobiopterin)
What is formed when dopa is decarboxylated?
Dopamine
Which ion is required fro the hydroxylation of dopamine to form NE?
Cu++
What is added to NE to form E using SAM?
Methyl group
What are the 2 products when MAO degrades NE?
NH4 + an aldehyde
Which enzyme converts NE (using SAM) to an aldehyde by methylating the 3-OH group?
COMT
Which 2 factors are required to make SAM?
B12 and folate
The products of MAO and COMT eventually parallel to form which final product?
VMA
What does an increased VMA in the CSF indicate?
Dopamine degradation
like in Parkinsons
What happens to the VMA levels in a pheochromocytoma?
they ↑
Where can u measure the levels of VMA?
urine
What is the cholesterol mirochondiral transport protein regulated by ACTH?
StAR
ACTH also regulates the transport of cholesterol into adrenal cortex cells by regulating what 2 molcules?
HDL and LDL
What is the hormone that generated pregnenolone in the mitochondria, that is regulated by ACTH?
cholesterol desmolase (CPY11A1)
So pregnenolone is made in the mitochrondria, and where doe sit travel next to continue its reactions?
SER
In the ZG, what product returns to the mitochrondria from the SER to make Corticosterone?
DOC
In the ZF, what product returns to the mitochrondria from the SER to make Cortisol?
11-deoxycortisol
In the ZR, what product returns to the mitochrondria from the final H?
trick Q
it never returns to the mitochondria
Which cells does aldosterone work on?
Principal cells of the CD
What does aldosterone do to Na and K?
reabsorb Na
secrete K
An increase in aldosterone does what do plasma pH?
Alkalosis because it ↑ tubular H secretion
What does aldosterone instert into the apical membrane of the principal cells?
Na/K ATPases
An increase in which of the following factors stimulates aldosterone secretion?
K in ECF, ATII, Na+ in ECF, ACTH
K, ATII and ACTH
What is the syndrome from ↑ aldosterone from a tumor in the ZG?
Conn’s syndrome
primary aldosteronism
What happens to the BP, serum K, serum Na, serum pH, and serum renin in Conn’s?
HTN HypoKalemia HyperNatremia Metbolic alkalosis ↓ serum Renin (b/c of ↑ BP)
Which IL do glucocorticoids inhibit as part of its anti-inflammatory effects?
IL-2
↓ T-cells
Glucocorticoids induce the synthesis of which factor, which inhibits PLA2 normally, contributing to the anti-inflammatory effects?
Lipocortin
What does glucocorticoids do to mast cells which contributing to the anti-inflammatory effects?
inhibit release of serotonin and histamine
The inhibition of the production of IL-2 from glucocorticoids helps with what treatment?
Prevention of transplant rejection
Which NE receptor do glucocorticoids stimulate to ↑ the vasoconstrictor effect of NE?
a1
What is the primary active glucocorticoid in the body?
Cortisol
What does cortisol do to proteins?
↓ protein synthesis
↑ catabolism of proteins
↑ transport of AA’s to liver (for gluconeogensis)
What does cortisol do to fat?
metabolize FA’s –> ↑ FA’s in plasma
What are the 5 things that cortisol does to block the early stages of inflammation?
- Stabilizes lysosomal membranes
- Decreases permeability of the capillaries
- Decreases both migration of WBC’s into the inflamed area and phagocytosis of the damaged cells
- Suppresses the immune system, causing lymphocyte reproduction to decrease
- Reduces fever bc it reduces the release of IL-1 from the WBC’s
So generally what does cortisol do a persons immune system?
suppress it
What does cortisol bind to once inside the target cell?
Glucocorticoid response elements (GRE)
What do GRE’s do, like any othere steroid H-R complex?
increase or decrease txn of genes
What is the cortisol pathway from hypothal –> tissues?
hypothal releases CRH –> AHP releases ACTH –> ZF releases cortisol –> liver, fat, muscle, lymphocytes, etc.