2-9-16-The Adrenal Gland (Lopez) Flashcards
What types of hormones does the adrenal cortex secrete?
What types of hormones does the adrenal medulla secrete?
Steroids–> aldosterone, cortisol, androgens
AA derived –> epinephrine and norepinephrine
What are the 3 zones of the adrenal cortex from outer to inner layer?
Glomerulosa, fasciculata, reticularis
What does the zona glomerulosa secrete?
What does the zona fasciculata secrete?
What does the zona reticularis secrete?
Mineralocorticoids (aldosterone)
Glucocorticoids (cortisol) and androgens
Glucocorticoids (cortisol) and androgens
What does the adrenal medulla secrete?
Catecholamines (Epi and norepi)
___ is a transport protein that regulates cholesterol transfer within the mitochondria, which is the rate-limiting step in the production of steroid hormones
StAR (Steroidogenic Acute Regulatory Protein)
__ stimulates synthesis and secretion of adrenal cortical hormones such as glucocorticoids (cortisol) and mineralocorticoids (aldosterone)
ACTH
ACTH is a peptide hormone produced in the anterior pituitary and is derived from post-translational processing of ___
POMC (pro-opiomelanocortin)
The HPA axis is under negative feedback control by ___
Cortisol
List the effect of cortisol secretion on the following:
A-Immune system
B-Liver
C-Muscle
D-Adipose tissue
A-Immune suppression
B-Gluconeogenesis
C-Protein catabolism
D-Lipolysis
The secretory rates of cortisol are highest during ___ and lowest in the ___
Early morning
Late evening
Cushing’s disease is caused by a pituitary tumor or an adrenal tumor and is an example of ____-cortisolism
Hyper-
Addison’s disease can be caused by autoimmune disease of the adrenal gland and is an example of ____-cortisolism
Hypo-
Secondary adrenal insufficiency can be caused by glucocorticoid drugs suppressing the hypothalamus and Pituitary and is an example of ___-cortisolism
Hypo
Rounding of the face, excess fat on the back of the neck, excess weight gain in abdomen, and dark red or purple stretch marks are symptoms of ___
Cushing’s syndrome
Primary hypercortisolism (Cushing’s syndrome) is due to what?
Adrenal tumor that autonomously secretes cortisol (adrenal excess)
Secondary hypercortisolism (Cushing’s disease) is due to what?
Pituitary tumor that autonomously secretes ACTH (pituitary excess)
A pituitary tumor that autonomously secretes ACTH is known as ____
Cushing’s DISEASE –> secondary hypercortisolism, pituitary excess
Describe primary adrenocortical insufficiency
Addison’s disease –> hyposecretion of all adrenal steroid hormones (hypocortisolism)
Describe secondary adrenocortical insufficiency
ACTH deficiency–> chronic exogenous glucocorticoid treatment (hypocortisolism)
Describe the levels of the following in Primary (adrenal) excess: Plasma cortisol- Plasma CRH- Plasma ACTH- Hyperpigmentation-
Plasma cortisol=increase
Plasma CRH=decrease
Plasma ACTH=decrease
Hyperpigmentation=no
Describe the levels of the following in Secondary (pituitary) excess: Plasma cortisol- Plasma CRH- Plasma ACTH- Hyperpigmentation-
Plasma cortisol=increase
Plasma CRH=decrease
Plasma ACTH=increase
Hyperpigmentation=Yes
Describe the levels of the following in Primary cortisol deficiency: Plasma cortisol- Plasma CRH- Plasma ACTH- Hyperpigmentation-
Plasma cortisol=decrease
Plasma CRH=increase
Plasma ACTH=increase
Hyperpigmentation=Yes
Describe the levels of the following in Secondary cortisol deficiency: Plasma cortisol- Plasma CRH- Plasma ACTH- Hyperpigmentation-
Plasma cortisol=decrease
Plasma CRH=increase
Plasma ACTH=decrease
Hyperpigmentation=No
Describe the levels of the following after steroid administration (synthetics other than cortisol) Plasma cortisol- Plasma CRH- Plasma ACTH- Hyperpigmentation-
Plasma cortisol=decrease (but symptoms of excess)
Plasma CRH=decrease
Plasma ACTH=decrease
Hyperpigmentation=no
___ test can be used to detect adrenal gland insufficiency
Cosyntropin (synthetic ACTH) stimulation test
The primary action of aldosterone is ___
Renal sodium reabsorption
List the steps that result in increased Na reabsorption and K secretion due to the action of aldosterone in the DCT
1) aldosterone combines with a cytoplasmic receptor –> 2) hormone-receptor complex initiates transcription in the nucleus –> 3) translation and protein synthesis makes new protein channels and pumps –> 4) aldosterone-induced proteins modulate existing channels and pumps –> 5) result is increase Na reabsorption and K secretion
___ is characterized by excessive release of aldosterone from the adrenal cortex
Primary hyperaldosteronism
__ is due to an adenoma in the adrenal cortex
Conn’s syndrome
___ is due to excessive renin secretion by the juxtaglomerular cells in the kidney
Secondary hyperaldosteronism
___ is due to destruction of the adrenal cortex and leads to defects in aldosterone synthesis and inadequate stimulation of aldosterone secretion
Hypoaldosteronism
What is a possible treatment for Addison’s disease?
Steroid replacement therapy for life
What is a likely treatment for Conn’s dyndrome (adrenal adosteronoma)?
Surgery
WHat is a likely treatment option for bilateral adrenal hyperplasia?
Spironolactone (K-sparing diuretics)
___ responds to stress such as hypoglycemia/exercise and influences energy metabolism and cardiac output
Epinephrine
What is the initial substrate (amino acid) in the formation of norepi and epi?
Tyrosin
In order for tyrosine hydroxylase to convert Tyrosine to DOPA, what else needs to happen?
Sympathetic stimulation with Ach
In order for Dopamine to be converted to Norepinephrine via dopamine-beta-hydroxylase, what needs to happen?
Sympathetic stimulation via Ach
The synthesis of catecholamines is under the control of the __ axis
CRH-ACTH-Cortisol axis
___ stimulates synthesis of DOPA
___ increases PNMT enzyme
ACTH
Cortisol
This enzyme catalyzes the formation of epinephrine from norepinephrine
PNMT plus cortisol
Where is Epi synthesized?
In the cytosol from NE
What is the rate-limiting step in the formation of catecholamines?
Tyrosine hydroxylase catalyzing TYROSINE –> DOPA
DOPA is converted to DOPAMINE by the cytoplasmic enzyme ___ and is then transported into this secretory vesicle ___
Aromatic Amino Acid Decarboxylase
Chromaffin granule
Within the chromaffin granule, dopamine is converted to NE by the enzyme ___
Dopamine-beta-hydroxylase
Epinephrine gets transported back into the chromaffin granule by ___
Vesicular monoamine transporters (VMAT)
___ are multimolecular complexes, thought to decrease the osmotic burden of storing individual molecules of epinephrine within chromaffin granules.
Chromogranins
Circulating ___ can be used as a marker of sympathetic paraganglion-derived tumors (paragangliomas)
Chromogranins
Epinephrine –> dihydroxymandelic acid
MAO
Epi –> metanephrine is catalyzed by ____
NE –> normetanephrine is catalyzed by ___
COMT
COMT
Metanehprine –> Vanillylmandelic acid (in urine)
MAO
The adrenal medulla is of ___ origin
The adrenal cortex is of ___ origin
Ectodermal
Epidermal
___ receptor(s) respond better to norepi than epi
___ receptor(s) respond equally to norepi and epi
Epi is more potent than norepi for the ___ receptor(s)
Alpha and beta3
Beta1
Beta2
List which adrenergic receptor types result with an increase in cAMP
List which adrenergic receptor types result with a decrease in cAMP
List which adrenergic receptor types result in an increase in IP3 and Ca, and DAG
Beta1/2/3
Alpha2
Alpha1
___ is a tumor of chromaffin tissue and results in an excess production of catecholamines. Symptoms include hypertension, orthostatic hypotension, headaches, sweating, anxiety, palpitations, chest pain, and flushing
Pheochromocytoma
