C9: Adrenal Glands Flashcards
the adrenals are composed of what 2 parts?
these 2 parts develop from which cells?
- Cortex
- develop from mesoderm - Medulla
- from neural crest cells/neuro-ectoderm
which part of the adrenal develops first
cortex
during cortical development, what occurs at 6 wks gestation
- proliferation of the mesoderm from the post abdo wall
- the proliferated mesoderm penetrates the retroperitoneum and becomes the primitive adrenal cortex
during cortical development, what occurs at 8 wks gestation
-structure separates from the post peritoneal surface and is surrounded by retroperitoneal c-tissue which forms the adrenal capsule
whats happening in terms of cortical development shortly after birth
-primitive adrenal cortex disappears by age 1
whats happening in terms of cortical development at age 3
permanent adrenal cortex differentiates into 3 zones/layers
- glomerulosa
- fasciculata
- reticularis
during medullary development, what occurs at 7 wks gestation
-neural crest cells migrate and invade the medial side of the cortex and then differentiate into chromaffin cells of the medulla
where do the neural crest cells develop?
outside the cortex, then migrate in
another name for adrenals
suprarenals
whats the relationship of the adrenals to the kidneys
anterior, medial and superior
what fascia and fat surround the adrenals
- gerotas fascia
- perinephric fat
do the adrenals have there own fascicle supports?
do they move with the kidney
yes… they move independent of the kidney
what the norm size of the adrenals in adults
L: 4-6 cm
W: 2-3 cm
AP: 0.3-0.6 cm
1/13 of the kidney size
what the norm size of the adrenals in kids
L: 0.9-3.6 cm
W: 0.2-0.5 cm
1/3 of kidney size
which adrenal is usually largest
L
whats the relationship of the R adrenal to the liver and curs of the diaphragm
- post to L lobe liver and medial to R lobe of liver
- lateral (for R and L adrenal)
can the inferior border of the L adrenal extend to the renal hilum
yes
whats the relationship of the L adrenal to the stomach and lesser sac
posterior
whats the relationship of the inferior part of the L adrenal to the pan tail and splenic vessels
posterior
if there was a mass on the L adrenal, how would that effect the pan tail
would push it anterior
name the 3 arteries the supple each adrenal gland and where do they branch from
- superior suprarenal artery (from inferior phrenic arteries)
- middle suprarenal artery (from AO)
- inferior suprarenal artery (from renal artery)
how is blood drained from the adrenals and where does it drain into
suprarenal veins
R (short): drains into IVC
L (long) : drains into LRV
what kind of gland is the adrenal often described as?
whats its general function and how does it accomplish it
double endocrine gland
-maintains homeostasis through hormone secretion
what %. of the gland does the cortex make up?
is the adrenal cortex (AC) essential to life
90%
yes
in general, what type of hormones does the cortex release? what type of system regulates the release of these hormones?
list the specific hormones it releases
steroid hormones
+ regulated by - feedback system b/w the hypothalamus, anterior pituitary and adrenal gland
- mineral corticoids
- glucocorticoids
- gonadal hormones
describe how the - feedback system work to control the release of AC hormones
-blood level of adrenal cortex hormones are detected which causes the hypothalamus to secrete ACTHRF… ACTHRF stimulates the anterior pituitary to release ACTH which causes the cortex to produce hormones
describe the the zona glomerulosa of the cortex.
what does it secrete
- makes up 15 % of the cortex
- outer layer
+ secretes mineralocorticoids… specifically aldosterone which acts on the renal tubule to increase sodium retention and increase BP
describe the the zona fasciculate of the cortex.
what does it secrete
- makes up 75 % of the cortex
- middle layer
+ secretes glucocorticoids…. specifically cortisone and hydrocortisone which are for metabolism, suppress the immune response (anti-inflammatories) and helps resist mental and physical stress
describe the the zona reticularis of the cortex.
what does it secrete
when does this zone become present
- makes up 10 % of the cortex
- inner layer
+ secretes sex hormones.. specifically estrogen and androgens which promote development of reproductive organs and bones
- @ 4 yrs
the medulla is related to what nervous system in the body
is it essential for life?
sympathetic nervous system… responsible for flight or fight
not essential
in general, what type of hormones does the medulla release?
list the specific hormones it releases and there effect on the body
catecholamines
-epinephrine/adrenaline
+ dilutes coronary vessels
+ constricts skin and renal vessels
-norepinephrine
+ constricts all arteries except coronary vessels
whats the body’s response to catecholamines
- increases heart rate, BP (due to constriction), blood sugar, blood flow to muscles, respiration
- dilates respiratory passages
- slows digestions
whats the purpose of performing a blood test for adrenal function
measures cortical function
whats the purpose of performing a urine test for adrenal function
measures medulla function
describe the echogenicity and echo texture of the adrenals in adults
homogenous and hypoechoic
describe the echogenicity of the adrenals in kids
when should child adrenals show and adult appearance
thin echogenic core (medulla) and less echogenic rim (cortex)
-age 1
why is it more difficult to see the adrenals in adults then children
they have more perirenal fat surrounding them
which 4 structures can commonly mimic the adrenal glad on US
- crus of the diaphragm
- panc tail
- lymphadenopathy
- gastric fundus
whats the best way to interrogate the R adrenal
where should the sound beam be directed if scanning the adrenal transversely
intercostally using liver of R kidney as a window… patient usually in supine
+ towards the IVC and should be scanning from the renal hilum to the liver
whats the best way to interrogate the L adrenal
whats an alternate way to scan the L adrenal
intercostal scanning using spleen or L kidney as a window… patient in decube or RAO
- patient in LPO and scan through the liver, IVC and AO
