EX 2; Adrenal Gland Flashcards
Where is the adrenal gland located
on top of each kidney
What are the two portions of the adrenal gland
adrenal medulla (inner) adrenal cortex (outer)
This portion of the adrenal gland develops from neural crest cells
medulla
This portion of the adrenal gland is part of the endocrine system (not nervous)
cortex
This portion of the adrenal gland develops from intermediate mesoderm
cortex
This portion of the adrenal gland is part of the sympathetic nervous system
medulla
This portion of the adrenal gland secretes epinephrine and norepinephrine
medulla
This portion of the adrenal gland secretes steroid hormones
cortex
The medulla contains terminals of prganglionic axons which release what
acetylcholine
These types of cells in the medulla have no axons
postganglionic cells (chromaffin cells)
Why is the adrenal medulla classified as a gland
because E and NE are released from chromaffin cells into the blood rather than a synapse
The action of phenyl-N-methyltransferase means that most of the secreted hormone in the medulla is what
epinephrine
Why is NE and E also released from the medulla if it is already stimulated by the sympathetic nervous system
the synapse is quickly shut off and this allows for E to stay in the blood
allows for the release of glucose for “fight or flight”
What are the three zones of the adrenal cortex
zona glomerulosa
zona fasciculata
zona reticularis
This layer of the cortex is the outer most layer
zona glomerulosa
This layer of the cortex is the middle layer
zona fasciculata
This layer of the cortex is the innermost layer (the medulla is deep to it)
zona reticularis
Aldosterone (mineralcorticoid) is secreted in this zona
glomerulosa
DHEA and androstenedione are secreted in this zona
reticularis
Cortisol and corticosterone (glucocorticoids) are secreted in this zona
fasciculata
Steriods are secrete in response to this, except aldosterone secretion is regulated more strongly by other signals
ACTH
Zona glomerulosa contains high levels of what, and is deficient in the enzymes that convert corticosterone to cortisol or androgens
aldosterone synthase
What is the principle action of aldosterone
stimulate Na and H20 retention in the kidney; maintaining blood volume (Na out of the blood)
What three things is aldosterone secretion stimulated by
increase in plasma angiotension II, ACTH, or K
decrease in plasma pH
decrease in blood pressure
Increase sodium intake inhibits what
secretion of aldosterone
Which is more physiologically important, cortisol or corticosterone
cortisol
Glucocorticoid synthesis and secretion is regulated by what
ACTH
ACTH release is stimulated by what in response to neural input
CRH
What kind of feedback mechanism on CRH and ACTH does cortisol have
negative feedback
What are the two major effects of glucocorticoids
increase metabolic fuel availability and use
What are two minor effects of glucocorticoids that become important during a stress response
maintain blood pressure
inhibits non-essential function
This is a precursor of other sex steroids so it serves as a reservoir for conversion in other tissues
DHEA
Where is DHEA also produced
gonads skin brain fat peripheral concentrations indicative of adrenal activity
This is an extragonadal source of testosterone and estradiol that can be made from DHEA, regulated by ACTH
androstenedione
What differs about sex steroid production in pre and post menopausal women
pre; adrenal secretion same as ovarian
post; adrenal is sole source
What three things are influenced by the sex steroids (DHEA, androstenedione)
mood
hair growth
erythropoiesis
This individual was among the first to view the stress response as adaptive, i.e a good thing
Hans Selye
A stress response stimulates what
hypothalamic CRH neurons and input to the SNS
SNS activation results in specific organ responses as well as what
increased circulating epinephrine from the adrenal medulla; rapid response
Activation of the HPA axis results in increased cortisol secretion which increases what
the availability of metabolic fuel and regulation of other functions; this is a delayed response
What are the three primary goals of the human stress response
maintain blood pressure
mobilize metabolic fuel or increase availability
inhibit non-essential functions that would otherwise use energy needed to combat the stressor
Cortisol maintains circulating concentrations of what by stimulating synthesis of liver enzymes needed for gluconeogenesis and glycogenolysis
blood glucose
Gluccocorticoids have what two actions
anti-inflammatory
anti-immune
(inhibitory cytokines)
Effects of chronic SNS activation are confounded or aggravated by the increased action of cortisol, which effects what two conditions
atherosclerosis
hypertension
What turn a short term response into chronic activation
inability to shut off the response
This disease is caused by adrenal insufficiency
Addison’s disease (JFK)
Complete lack of cortisol is what
fatal
What are three causes for primary adrenal insufficiency
disease
congenital disorder
autoimmune disorder
What are two causes for secondary adrenal insufficiency
pituitary problem
glucocorticoid problem
What is a ramification for dentistry involving adrenal insufficiency
hyperpigmentation
What are two symptoms of adrenal insufficiency
low cortisol and high ACTH
hyperpigmentation
How would you treat adrenal insufficiency
exogenous glucocorticoids
Hypercortisolinemia is also know as what
Cushing’s disease
What is the primary cause of Cushing’s disease
pituitary tumor
What are four symptoms of Cushing’s
excess tissue catabolism especially in bone, skin, and fat
diabetes-like symptoms
impaired immune function
threat of hypertension
What is the treatment for Cushing’s
surgical removal of the tumor
What is a ramification of Cushing’s on dentistry
mostly concerned with excess cortisol impairing the immune response after a procedure
