Pathology Flashcards
Where do the adrenal glands sit in relation to the kidneys?
Superior and medial
What are the 2 parts that make up an adrenal gland?
Outer cortex and inner medulla
Which part of the adrenal glands synthesise steroid hormones?
Outer cortex
The synthesis of all corticosteroids in the adrenal cortex begins with what?
Cholesterol
What hormone(s) is/are produced in the zona glomerulosa of the adrenal cortex?
Mineralocorticoids (aldosterone)
What regulates aldosterone?
Angiotensin II and K+ concentrations
What hormone(s) is/are produced in the zona fasciculata of the adrenal cortex?
Corticosteroids (cortisol and corticosterone)
What regulates the glucocorticoids?
ACTH
What hormone(s) is/are produced in the zona reticularis of the adrenal cortex?
Androgens (e.g. DHEA)
What regulates androgens?
ACTH and other unknown factors
Name the different zones of the adrenal cortex in order of outer to inner?
Zona glomerulosa, zone fasciculata, zona reticularis
What 3 things make up the adrenal medulla?
Chromaffin cells, medullary veins, splanchnic nerves
What hormones are secreted from the adrenal medulla?
Catecholamines (adrenaline, noradrenaline)
The RAAS system is activated in response to what?
Decreased BP
How does the RAAS system increase BP?
Production of angiotensin II, causes direct (vasoconstriction) and indirect (aldosterone) methods of BP elevation
Where does aldosterone act?
The mineralocorticoid receptor in the kidneys, salivary glands, gut and sweat glands
What is the action of aldosterone?
K+/H+ excretion and Na+ reabsorption as well as elevated BP
Where do corticosteroids bind?
Intracellular steroid receptors
What happens once corticosteroids have bound to receptors?
The receptor/ligand complex binds to DNA to alter transcription
What are the 6 classes of steroid receptor?
Mineralocorticoid, glucocorticoid, progestin, oestrogen, androgen, vitamin D
What are the CNS effects of glucocorticoids?
Moodswings, decreased libido
How do glucocorticoids accelerate osteoporosis?
Decreased serum calcium and collagen formation
What immunological effects do glucocorticoids have?
Decreased capillary dilatation, leukocyte migration, macrophage activity and inflammatory cytokine production
What metabolic effects do glucocorticoids have?
Increased blood sugar, lipolysis and proteolysis
What are the cardiac effects of glucocorticoids?
Increased cardiac output and BP
What are the renal effects of glucocorticoids?
Increased renal blood flow and GFR
What are the three main uses of corticosteroids?
Suppress inflammation and the immune system, replacement therapy
What innervates the adrenal medulla?
Pre-synaptic fibres from the sympathetic nervous system
What is the main component of the adrenal medulla?
Chromaffin cells
Chromaffin cells secrete what?
Catecholamines
