Exam 2 Flashcards
(359 cards)
What are the two parts of the adrenal (suprarenal) glands
Cortex
Medulla
Function of cortex in the adrenal glands
Secretes corticosteroids derived from cholesterol
Function of medulla in the adrenal glands
Secretes catecholamines derived from tyrosine
Corticosteroids released from the adrenal cortex (3)
Glucocorticoids (eg- Cortisol) Mineralcorticoids (ex- Aldosterone) Sex steroids (testosterone)
Catecholamines secreted from the adrenal medulla (2)
Epinephrine and norepinephrine
Layers of the adrenal cortex (superficial to deep)
Zona glomerulosa
Zona fasciculata
Zona Reticularis
Layers of the adrenal glands
Capsule
Adrenal cortex
Adrenal medulla
Zona glomerulosa is ____% of the adrenal cortex thickness
15%
What does the Zona glomerulosa secrete? What is the primary hormone?
Mineralocorticoids
Primary hormone = aldosterone
What stimulates aldosterone release?
Angiotensin II and Potassium
Function of Aldosterone
Controls blood pressure and blood volume
Controls electrolyte balance through the kidney
Causes reabsorption of Na, Cl, H20
And excretion of K and H
______% of adrenal cortex thickness is the Zona fasciculata
75%
Zona fasciculata secretes:
Its primary hormone is:
Glucocorticoids
Primary hormone is cortisol (stress hormone)
The zona fasciculata is under what control?
Hypothalamic-pituitary axis control (CRH and ACTH)
Cortisol provides negative feedback to the hypothalamus and the anterior pituitary
______% of thickness in the adrenal cortex that is the zona reticularis
10%
What does the zona reticularis secrete?
Primary hormones?
Adrogens
DHEA (dehydroepiandosterone) and androstenedione
Zona Reticularis control mechanism is influenced by:
ACTH
Dihydrotesterone and estradiol synthesis occur where?
In peripheral tissues and gonads
How is pregnenolone made?
Cholesterol enters mitochondria of cells and is cleaved by cholesterol desmolase (P-450scc)
Rate limiting step in adrenal steroid production .
Why?
Synthesis of pregnolone
It can be converted into any of the other steroid hormones
Adrenal cholesterol is most provided by:
Blood LDL
Adrenal cholesterol is obtained by:
Receptor mediated endocytosis (rate influenced by ACTH)
______ release cholesterol from the endosomes
Lysosomes
Synthesis of hormones occurs where?
In mitochondria and ER