Steroids Flashcards
Which pathway do glucocorticoids act upon
The hypothalamic-pituitary-adrenal axis
What does stress do to influence the HPA axis
It stimulates the hypotlalamus to release corticotrophic releasing hormone (CRH)
What does CRH stimulate in the HPA axis
It stimulates the pituitary gland to release adrenocorticotrophic hormone (ACTH)
WHat des ACTH do in the HPA axis
Causes adrenal cortex above the kidneys, which in turn release cortisol
What does cortisol do in the HPA axis
Decreases immune function
Breakdown of glycogen, proteins and fat
Negative feedback for the pituitary gland and hypothalamus
RESTORES HOMEOSTASIS AFTER STRESS
When is cortisol lowest/highest
Lowest before bed
Highest as you wake up
What is Addisons disease
When the adrenal glands dont produce enough steroid hormones
What are some features of addisons disease
Low BP Hyperpigmentation Fatigue Muscle weakness Hypoglycaemia nausea and vomiting Low Na raised K
What is an addisonian crisis
Very bad hormone deficiency
Collapse, hypoglycaemia, abdominal pain with diarrhoea and vomiting
What is cushings disease
Prolonged exposure to elevated levels of glucocorticoids, affects pituitary gland
Truncal obesity moon face, striae, hypertension, hirsutism (hair grows where it shouldnt) osteoporosis and diabetes
How do glucocorticoids work
They bind to receptors in cytoplasm, move to nucleus and bind to glucocorticoid responsive genes, increasing transcription for anti-inflammatory proteins like IL10 or IL1, and inhibiting inflammatory genes
What MSK condition is associated with glucocorticoid use
Secondary osteoporosis
How can glucocorticoids affect appearance
Truncal obesity, “Moon face”
What infections are more likely on glucocorticoids
Staphylococcal
Gram negative
TB
Listeria
Herpes zoster
Candidiasis
How do glucocorticoids work
By supressing the HPA axis in the same way that cortisol does
