ENDOCRINE END OF BLOCK TEACHING ROOM TUTORIAL Flashcards
What hormone is known as anti-diuretic hormone? Where is ADH produced and stored?
Vasopressin Produced in the hypothalamus and stored in the posterior pituitary gland
Name of a hypothalamic hormone also known as prolactin inhibiting factor?
Dopamine
A hormone stored in the posterior pituitary whose target organs are the breast and uterus? What does it cause in the breast and uterus?
Oxytocin - rpdocued in hypothalamus and stored in posterior pituitary Stimulates prolactin release causing nipple stimulation Also causes uterine contractions
Along with FSH, which other hormone from the anterior pituitary targets the ovaries or testes?
LH
What hormone is produced to excess in acromegaly? Which hormone is used in the short synacthen test in Addison’s?
Growth hormone is produced Synthetic ACTH
What two bone conditions are associated with increase alkaline phosphatase?
Osteomalacia and paget’s disease
What are two common complications of thyroid surgery?
Recurrent laryngeal nerve palsy Hypoparathyroidism
Patient with normal calcium, phosphate and alk phos, presents with a Colle’s fracture What is the cause? What direction is the angulation?
Osteoporosis Dorsal angulation
60 year old man has back pain, elevated calcium levels and lytic lesions on X-ray What is this?
Multiple myeloma
Bitemporal hemianopia is caused by a lesion in the optic chiasm What is the difference in the way in which pituitary adenomas and craniopharyngiomas typically cause a bitemporal hemianiopia?
upper quadrant defect > lower quadrant defect = inferior chiasmal compression, commonly a pituitary tumour lower quadrant defect > upper quadrant defect = superior chiasmal compression, commonly a craniopharyngioma
A 41 year old man presents with headache and visual loss. Your history elicits symptoms of lethargy, loss of libido and impotence. On examination you find a bitemporal hemianopia and galactorrhea. What do you suspect this to be?
Prolactinoma
Why does prolactinoma cause a decreased production of gonadotrphins?
Prolactin has an inhibitory effect on the GnRH causing a decrease in the gonadotrophic hormone production leading to the loss of libido and impotence in the patient
A 50 year old women presents with lethargy and weakness. Her past medical history includes type 1 diabetes mellitus and pernicious anaemia. On examination you find she is hypotensive, with hyperpigmentation of her palmar creases and buccal mucosa? What is the likely cause of her findings? What causes the hypotensive and hyperpigmentation?
Addison’s disease Hypotensive due to lack of the mineralocorticoid hormone aldosterone which causes low sodium resorption into blood and therefore low water resorption into the blood causing a low blood volume - hypotension Hyperpigmenation due to excess ACTH being produced due to the lack of aldosterone and cortisol - ACTH contains the sequence for MSH and therefore when broken down this cause the pigmentation
What is pernicious anaemia?
Autoimmune disorder where the body doesnt produce enough intrinsic factor (Pernicious anaemia causes your immune system to attack the cells in your stomach that produce the intrinsic factor) which is a protein produced by the stomach which combines with vitamin B12 which is required for the formation of healthy red blood cells Therefore you become anaemic
A 28 year old female develops polyuria, with a urine output greater than 400ml/hour. She suffered a subarachnoid haemorrage two days previously, and underwent surgery to clip an aneurysm in the anterior communicating artery. What is the most likely cause of the clinical findings?
Cranial diabetes insipidus
A 49 year old man complains of tightening of his shoes and visual loss. On examination you note macroglossia, plus spade like hands and feet What is the most likely cause of the clinical findings?
Acromegaly due to a growth hormone producing pituitary adenoma
What drug is used for the treatment of cranial diabetes insipidus?
Desmopressin aka vasopressin
What anti-thyroid drug can cause agranulocytosis?
Carbimazole Sore throat, ulcers, cough means stop taking drug and go to doctors
Which drug can be used to control the symptoms of cushings syndrome?
Metyrapone and ketaconazole - inhibit steroid genesis (inhibit cortisol synthesis)
What drug should be the first-line short term treatment of a pheochromocytoma?
Alpha blocker Phenoxybenzamine - non selective alpha blocker to lower BP given before beta blocker
Which drug may be used in the treatment of hyperprolactinaemia?
Cabergoline or bromocryptine
An 18 year old man comes to see you, his GP, complaining of a 3month history of polydipsia, polyuria, nocturia and unexplained weight loss What endocrine disorder do you believe could be the cause? List two other potential causes?
Type 1 diabetes mellitus or diabetes insipdus or hypercalcaemia
Explain how the underlying pathophysiology of diabetes mellitus relates to the symptoms polyuria and polydipsia?
Autoimmune disorder reacting against islet cells of pancreas Causes insulin not to be be produced therefore glucose does not get taken up by tissue Hyperglycaemia causes high urine output which will cause an osmotic drift leading to poluria This will cause thirst
What are the criteria for diagnosing type 1 diabetes?
Random glucose over 2 occasions - 11.1mmol/L Fasting - greater than 7mmol/L HbA1c - greater than 48mmol/L (6.5%)
What advice would be given for treating type 1 diabetes?
Diet treatment Basal bolus insulin regime - basal is long lasting and bolus is short acting for each meal
What is the type 2 diet diabetes treatment? (pharmacogical steps)
Diet and exercise 1. Metformin - a biguanide increases insulin sensitivity 2. Sulphonylurea - increases insulin secretion 3. SGLT2 inhibtors or DPP4 inibitors - DPP-4 inhibitors slow the inactivation and degradation of GLP-1, a hormone involved in glucose removal from the gut. 4. TZDs (thiazolidinediones eg the glitazones) - activate PPARy (causes weight gain, osteoporosis and heart failure)
What are the long term microvascular and macrovascular complications?
Macrovascular - stroke and MI Microvascular - Retinopathy, neuropathy and nephropathy Severe complication can be limb ischaemia
How is diabetes insipidus diagnosed?
To diagnose give water deprivation test - deprive of water for 8 hours and see if * The body’s normal response to dehydration is to conserve water by concentrating the urine. Those with DI continue to urinate large amounts of dilute urine in spite of water deprivation * Therefore urine osmolality does not increase to above a certain level (>600mOsmol/kg) after 8 hours
How is diabetes insipidus differentiated between cranial and nephrogenic?
Give patient desmorpressin (vasopressin analogue): * In nephro - will not resorb water and therefore serum osmalility will remain high * In cranial (Central) - will cause a decrease in serum osmolalilty as increased water resoprtion
Six months, the 18 year old man presents to A&E with a 12-hour history of nausea, vomiting and abdominal pain. On examination, his respirations are deep and sighing with a respiratory rate of 22, a heart rate of 110beats/min, a blood pressure of 100/70mmHg, and he appears to be confused. BM glucose taken by the nurse is 24. What diagnosis do you suspect?
Diabetic ketoacidosis (DKA)
Explain how the underlying pathophysiology of your answer for DKA relates to his hyperventilation? What is the name for this type of hyperventilation?
Known as Kaussmaul breathing Basically, not enough insulin to convert glucose to glucagon for energy therefore body needs energy and breaks down fat to fatty acids insteads, excess fatty acid causes ketones which causes acidosis Metabollically acidotic and therefore body tries to blow of CO2
What are the diagnostic criteria for diabetic ketoacidosis?
2 out of 3 of Ketones - urine ketones positive Bicarb 14
What is the treatment process of diabetic ketoacidosis?
After ABC Give IV fluids within 30minutes IV insulin in first hour and potassium after first hour
Should the person stop insulin diabetic ketoacidosis?
No as no insulin will continue to cause ketones to be produced
A 55-year old woman presents with symptoms of palpitations, diarrhoea and feeling warm and sweaty. She has lost two stone in the last 6 weeks What is the probable diagnoses?
Hyperthyroidism Could be pheochromocytoma
What is the building blocks of T4?
Iodine and tyrosine residues
What blood test results would you expect to see in hyperthyroidism?
High T4 Low TSH TSH receptor antibody (TRab)
What are the pharmacological and non-pharmacologcial management options for hyperthyroidism?
For symptomatic relief - beta blockers Carbimazole, propylthiouracil if carbimazole contraindicated Surgery + ablation and radio iodine to detect metastases
When is carbimzole contraindicated as treatment for hyperthyroidism?
When pregnant Give propylthiouracil for first trimester instead
Failure of medical management meant that this patient underwent surgery. One year after surgery the patient presents to her GP complaining of weight gain, lethargy and a dislike for cold. What is your new diagnosis?
Hypothyroidism
What are other symptoms of hypothyroidism? What test results would you expect to support your answer for the diagnosis?
Myxoedema, heavy periods, decreased appetite, greasy hair Low T3,4 High TSH
What treatment would you initiate in hypothyroidism? How long for and how would you assess this? What are possible complications specific to the surgery? (how long to notice hypoparathyroidism)
Give T4 (levothyroxine) 50-100mg, lifelong and assess by measuring TSH levels Recurrent laryngeal nerve palsy Hypoparathyrodism - usually within a day or two Hypocalcaemia - Troussea or Chovstek sign
A 70 year old woman is admitted with nausea, polyuria and drowsiness. Her serum calcium is 4.2mmol/L (normal is 2.25 - 2.5) What is she suffering from?
Hypercalcaemia
How would you manage hypercalcaemia? List 6 diseases associated with hypercalcaemia
Could give calcitonin or biphosphonates Non small cell lung cancer, bones cancers Hyperparathyrodiism, hyperthyrodiism Sarcoidosis, MENs syndromes, vit D failure
Name 4 causes of adrenal insufficiency?
Addison’s disease Hypopituitarism Congenital 21-OH deficiency Trauma to hypothalamus
What is the difference between primary and secondary addisons? What is the treatment of Addisons and addisonian crisis?
Primary addison - adrenal origin therefore high ACTH and hyperpigmentation Secondary - low ACTH and no pigmentation Treatment - hydrocortisone for corticosteroid replacement - cortisol fludrocortisone for mineralocorticoid replacement - aldosterone
