Revision lecture Pit Disorders Flashcards
Name 4 investigations for a pituitary disorder
Vision assessment
MRI scan
CAT scan
Blood test for abnormal hormone levels
What are the four layers of the adrenal gland?
From out to in... Zona glomerulosa Zona fasciculata Zona reticularis Adrenal Medulla
What do each of the four layers of the adrenal glands secrete?
Salt, sugar, Sex, Excitement
Zona glomerulosa- Mineralocorticoids
Zona fasciculata- Glucocorticoid
Zona reticularis- Androgens
Adrenal Medulla- Adrenaline and noradrenaline
What are the actions of aldosterone?
Increased water reabsoprtion
So you get an increased number of Na+/K+ ATPase in the kidneys
Whats the action of cortisol? (4)
Increases glucose levels via gluconeogenesis and glycogenolysis
lipolysis
protein breakdown
antiinflammatory effects
Upon what stimulus is cortisol released?
ACTH stimulus
How is cortisol transported and where does it bind to in cells?
Intracellularly, and bound to transcortin
Why would carpal tunnel Syndrome be worse at night?
Cortisol lowest at night
Cortisol has an antiinflammatory effect so more inflammation so pain at night
What is cushing syndrome?
Excessive cortisol
What is the primary cause of cushings syndrome?
Cortisol producing adrenal adenoma
What is the difference between Cushings syndrome and cushings disease?
Cushing disease is where you have a pituitary adenome secreting excessive ACTH leading to raised cortisol
Cushings syndrome is any cause that leads to increased Cortisol (eg. Cortisol producing adrenal adenoma)
What are the signs and symptoms of Cushing Syndrome?
5
Thin arms, legs and purple straie (proteolysis)
Enlarged abdomen and moon face (Due to excessive lipogenesis)
Back pain/osteoporosis (hypocalcaemia)
What is Addisons Disease?
Low cortisol release
Primary cause of addisons disease?
Autoimmune destruction of the adrenal cortex
where is cortisol secreted from?
The adrenal cortex in the zona fasciculata (Sugar)
What is the secondary cause of Addisons Disease?
Low ATCH/CRF release from the hypothalamus or pit gland
What would you see in primary addisons disease?
Low corticosteroids and low mineralcorticoids
What woould you see in secondary addisons disease?
Low corticosteroids, normal mineralocorticoids
What are the signs and symtpoms of addisons disease?
Tiredness
muscle weakness
weight loss
Skin pigmentation (Because raised ACTH and other POMC products one of which being a hormone to stilulate melanocyte to produce melanin
Postural hypotension and dehydratiob (Low aldosterone so low sodium and water retention)
Hypoglycaemic episodes
What are the causes of an addisonian crisis?
Stress, infection trauma
Symptoms of addisonian crisis?
Vomiting, extreme dehydration, confusion
COMA
Treatment for addisonian crisis?
IV cortisol
Fluid replacement
What is Conn’s Syndrome? Symptom?
Aldosterone secreting tumour
Hypertension due to excessive RAAS and water retention
Clinical test for Cushing’s Disease?
Dexamethasone inhibits ACTH secretion
If cushing’s disease it’ll supress plasma corticol by 50%
won’t do in adrenal tumour or ectopic ACTH
Clinical test for Addison’s disease?
Synacthen works as synthetic ACTH
Should increase cortisol
Doesn’t in addisons disease
Where is adrenaline synthesised?
Chromaffin cells in the adrenal medulla
Process of adrenaline production?
Tyrosine–>dopamine–>noradrenaline–>adrenaline
Actions of adrenaline? 4
Increase Heart rate and cardiac output and more flow to muscles
Increased mental alertness
Increased glycogenolysis
Increased lipolysis (Both lead to increased energy for flight or fight
Describe the renin angiotensin aldosterone system
Angiotensinogen released by the liver
renin, released by the kidneys, cleaves angiotensinogen into angiotensin 1
angiotensin 1–>Angiotensin 2 by ACE released by lungs and kidney
Angiotensin 2 causes aldosterone secretion from the adrenal cortex
WHat does angiotensin 2 and aldosterone cause?
Angiotensin 2: Increased sympathetic activity increased water retension in the kidneys aldosterone secretion vasoconstriction ADH secretion from the posterior pit
Aldosterone–> Water retention
