Lecture 11 - Adrenal disorders Flashcards
What is the main cause of endocrine disease?
Abnormal amounts of messenger present, causing cells to misbehave
What is the vascular anatomy of the adrenal glands?
Only one vein - left adrenal vein R adrenal vein drains into IVC
Where do the adrenal veins drain into?
LAV drains into renal vein and then into IVC RAV drains straight into IVC
Where is the spleen in relation to the adrenal glands?
Next to the LAG
Why is the location of the spleen important?
It can be easily damaged during a left adrenalectomy So patient must be immunised with HIB and pneumovax
What is HIB and pneumovax?
HIB= Haemophilius Influenzae type b Pneumovax= pneumococcal vaccination against several strains of Streptococcus pneumococcus
How do the hormones pass into the blood?
Arteries that pass through the cortex pick up all the hormones and then deliver it to the central vein
What are the different zones of the adrenal gland from outside to inside?
Glomerulosa - aldosterone Fasciculata - cortisol Reticularis - no real function Adrenal medulla - catecholamines (adrenaline/noradrenaline)
How are steroid hormones manufactured?
Precursor is CHOLESTEROL Remove the side chain and then add OH/oxidising the molecule to form many different molecules
What are the enzymes in steroid synthesis named after?
By the number of carbon that they affect
How is aldosterone produced from cholesterol?
Chol>pregnenolone>progesterone>(21) 11deoxy corticosterone>(11) corticosterone>(18) aldosterone
How is cortisol formed from cholesterol?
Chol>preg>progesterone>(17) 17OHprog>(21) 11 deoxycortisol>(11) cortisol
How is oestrogen formed from cholesterol?
Chol>preg>prog>(17) 17OHprog>sex steroid> androgens> oestrogens
How are the pathways for steroid hormone synthesis decided?
Depends on enzymes present in tissue
What is cortisol controlled by?
ACTH - cortisol is a stress hormone
What is the method of ACTH synthesis?
POMC> ACTH and MSH and endorphins
What is MSH?
Melanocyte stimulating hormone - abnormal levels of ACTH can cause inappropriate tanning, as ^ MSH released
What is the cause of Addison’s disease?
Failure in adrenal glands caused by: Autoimmune disease wiping out adrenal cortex TB of adrenal glands
What is the most common cause of Addison’s in UK?
Autoimmune disease
What is the most common cause of Addison’s worldwide?
TB of adrenal glands
What are the main symptoms of Addison’s?
Darkening of skin in areas of pressure
Autoimmune vitiligo
Low BP - as no aldosterojne production
Weight loss, vomiting, diarrhoea
Muscular weakness
What to do in an Addisonian crisis?
Rehydrate with saline Give dextrose to prevent hypoglycaemia Give hydrocrotisone
What is addison’s?
Cortisol deficiency Salt loss Low BP Eventual death
What are the biological actions of excess cortisol?
Diabetes - due to ^ BGL Weight gain - ^ fat, decreased protein Thin skin & easy bruising Striae Proximal myopathy Mental changes - depression Hypertension Fat redistribution Moon face Interscapular fat pad Hirsuitism and acne
What are the causes of Cushing’s syndrome?
Steroids (oral intake) Pituitary adenoma (^ ACTH production) - Cushing’s DISEASE Ectopic ACTH - lung cancer cells can produce ACTH Adrenal carcinoma/adenoma
What are the clinical signs of Cushing’s syndrome?
LEMON ON STICKS - centripetal obesity
Proximal myopathy, Thin skin
Diabetes, hypertension, osteoporosis
Immunosuppression
Moon face
What is the difference between CS and CD?
CS= collection of symptoms with any cause CD=cause is pituitary adenoma
What are the side effects of steroids?
Similar to Cushing’s syndrome: Hypertension, diabetes, osteoporosis, immunosuppresion, easy bruising, poor wound healing, thin skin
What is Conn’s syndrome?
Aldosterone producing adenoma Tumour of zona glomerulosa
What are the symptoms of Conn’s syndrome?
Aldosterone causes retention of Na and loss of K Hypertension Oedema Low blood K
What is the hypothalamo pituitary axis?
How are the different steroid hormones produced? (simple version)
