Endo Flashcards
Where is aldosterone produced / secreted?
Zona glomerulosa of the adrenal cortex
Where is cortisol produced / secreted ?
Zona fasciculata of the adrenal cortex
Where are androgens produced / secreted?
Zona reticularis of the adrenal cortex
In a pt with T2DM, who is already on Metformin but who’s blood glucose levels are not well managed, what is their second line treatment option?
Add a sulphonylurea to their metformin, eg Gliclazide
What is the mechanism of action of Metformin?
- Reduces gluconeogenisis in the liver
- Increases insulin sensitivity by increasing glucose uptake / use in skeletal muscle
What is the mechanism of action of Gliclazide?
A sulphonylurea
Bind to the ATP dependent K+ channels on pancreatic beta cells to promote insulin secretion
What is the mechanism of action of Sitagliptin?
DPP4 inhibitor
Increases the levels of incretins by decreasing their peripheral breakdown, therefore allowing the production of more insulin
What is the mechanism of action of Canagliflozin?
SGLT-2 inhibitor
Reversibly inhibits sodium glucose co-transporter 2 in the renal proximal convoluted tubule to reduce glucose reabsorption
What is the diagnostic criteria for DKA?
Blood glucose >11mmol/L
Plasma ketones >3mmol/L
Blood pH <7.3
Bicarbonate <15mmol/L
What is the most common subtype of thyroid carcinoma?
Papillary (70%)
Often young females, very good prognosis
What is the second most common type of thyroid carcinoma?
Follicular (20%)
Well differentiated, worse prognosis than papillary
Give an example of an exogenous cause of Cushing’s Syndrome
Prolonged glucocorticoid use, e.g. Prednisolone, Hydrocortisone
Give two examples of endogenous, corticotropin (ACTH) dependent cause of Cushing’s Syndrome
- Pituitary adenoma
- Small cell lung cancer causing ectopic production of cortisol
Give two examples of endogenous, corticotropin (ACTH) independent causes of Cushing’s Syndrome
- Adrenal adenoma
- Adrenal carcinoma
What TSH, T3, T4 levels are expected to diagnose Grave’s disease?
Low TSH
High T3/T4
What kind of antibody is involved in Grave’s disease?
IgG
Describe the pathology of Graves’ disease
Serum IgG antibodies bind to TSH receptors on the thyroid. Increased T3 and T4 production and secretion. Hyperplasia of the thyroid follicular cells. Hyperthyroidism and goitre.
What phrase is used to remember the symptoms of hypercalcaemia?
Painful bones, renal stones, psychiatric moans, abdominal groans
What is the gold standard diagnostic test for carcinoid syndrome?
Serum Chromagranin-A (raised in carcinoid syndrome)
And an octreotide scan
What is the gold standard investigation for Addison’s disease?
Synacthen test (ACTH stimulation test)
No rise in cortisol = Addison’s
What ECG changes are expected in hyperkalaemia?
Absent P waves, long PR interval, wide QRS complex, tall tented T wave
List 4 causes of pitting oedema
- pregnancy
- low serum albumin
- venous insufficiency
- cardiac failure
What are 3 clinical features of PCOS?
- hirtuitsm
- acne
- oligoamenorrhoea
List 5 clinical features of DKA
- abdo pain
- polyuria
- polydipsia
- Kussmaul’s respiration
- acetone/pear drop smell to breath
Describe the immediate management of DKA
- fluid replacement (isotonic saline)
- insulin
- potassium
What hormones are secreted by the anterior pituitary?
FLAT PiG
-FSH
-LH
-ACTH
-TSH
-Prolactin
-GH
What is the function of glucagon?
- glycogenolysis
- gluconeogenesis
- lipolysis
Describe the secretion of glucagon
Secreted by α cells in the islets of Langerhans in response to low blood glucose
Describe the action of glucagon
- acts on the liver to convert glycogen to glucose
- stimulates lipolysis and muscle breakdown -> glucose formation from lactic acid and amino acids
What is the function of PTH? (4)
- indirect stimulation of osteoclasts / direct stimulation of osteoblasts to re absorb bone and increase serum calcium
- increase calcium reabsorption in the kidney
- increase calcium absorption in the small intestine via activation of vitamin D
- decreases phosphate reabsorption in the kidney / increased phosphate loss
What are the contents of the spermatic cord?
RULE OF THREE
3 arteries:
- testicular artery
- deferential artery
- cremasteric artery
3 nerves:
- genital branch of the genitofemoral nerve
- cremasteric nerve
- sympathetic nerve fibres
3 fascias:
- external spermatic fascia
- cremasteric fascia
- internal spermatic fascia
3 others:
- ductus deferens
- processus vaginalis
- lymphatic vessels
What is the GS diagnostic test for Addisons?
Synacthen test
‘Lean, tanned, tired, tearful’ =?
Addison’s
What electrolyte imbalance does SIADH cause?
Hyponatraemia
What electrolyte imbalance is associated with salbutamol?
Hypokalaemia
What test is used to differentiate between cranial and nephrogenic diabetes insipidus?
Desmopressin test
What are the acromegaly investigations, in order
- IGF-1
- Oral glucose tolerance test
- Pituitary function tests
- MRI pituitary
What are the two main causes of primary hyperaldosteronism?
1 = bilateral idiopathic adrenal hyperplasia
2 = adrenal adenoma
What are the 3 main features of primary hyperaldosteronism?
- hypertension
- hypokalaemia
- metabolic alkalosis
What is the first line investigation for primary hyperaldosteronism?
Aldosterone to renin ratio
What are the 4 causes of primary hyperparathyroidism?
- solitary adenoma
- hyperplasia
- multiple adenoma
- carcinoma
45F presents with hirtuism, central obesity, striae.
Low ACTH, no cortisol suppression following high dose dexamethasone suppression.
Most likely diagnosis?
ACTH independent cause of Cushing’s syndrome.
76F, presents with polyuria, polydipsia.
Bloods:
Fasting glucose = normal
Ca2+ = high
Phosphate = low
PTH = normal
ADH = normal
Most likely diagnosis?
Primary hyperparathyroidism
35M. Postural hypotension, headaches, increased sweating, palpitations.
Urine sample: high carecholamines and metanephrines.
Most likely diagnosis and GS diagnostic investigation?
Pheochromocytoma
Elevated plasma free metanephrine
What are the typical signs of Graves’ disease?
- tremor
- palpitations
- pretibial myxoedema
- ophthalmology
- weight loss
What is the acute management of DKA, in order?
1 = IV fluids
2 = insulin
3 = electrolyte correction
Hypothyroidism symptoms?
- weight gain
- cold intolerance
- constipation
- menorrhagia
Pt forgot to take Crohn’s meds while away on holiday.
Symptoms: tired, loss of appetite, postural hypotension.
What is the cause of her symptoms?
Secondary adrenal insufficiency due to sudden corticosteroid withdrawal
List 5 cancerous causes of SIADH
- small cell carcinoma
- prostate cancer
- pancreatic cancer
- lymphoma
- cancer of the thymus
What ECG changes are seen in hyperkalaemia?
- tall tented T waves
- absent/flat P wave
- prolonged PR interval
- wide QRS complex
- bradycardia
State 5 signs/symptoms of hyperkalaemia
- Muscle weakness/ Painful cramping / Paraesthesia
- Neurological derangement/ irritability/ anxiety
- Palpitations
- Abdo cramping and diarrhoea
- Dyspnoea
- Hyperreflexia
What symptoms are caused by a GH secreting pituitary adenoma?
- large hands/feet
- coarsening of facial features
- large tongue
- excessive sweating
Give 3 complications of Acromegaly
- obstructive sleep apnoea
- T2DM
- cardiomyopathy
- hypertension
- IHD/stroke
- colorectal cancer
What is the first line investigation for Acromegaly
Serum IGF-1
Will be raised in acromegaly
What is the curative treatment of Acromegaly?
Transsphenoidal resection of the pituitary gland
Apart from resection, what other treatments can be used in Acromegaly?
- Somatostatin analogues e.g. octreotide
- Growth hormone antagonists e.g. Pegvisomant
- DA agonists e.g. Cabergoline
- Stereotactic gamma knife
Polyuria, polydipsia. DD? (6)
- Diabetes mellitus
- Diabetes insipidus
- SIADH
- Primary polydipsia
- Hypercalcaemia
- Primary hyperparathyroidism
What is the most common cause of primary hyperparathyroidism?
Solitary adenoma
Give 5 symptoms of primary hyperparathyroidism
- Bone pain
- Renal stones
- GI upset e.g. gastric ulcer, diarrhoea
- depression
- polyuria
- constipation
What is the most common cause of Cushing’s Syndrome
Exogenous, corticosteroid use
30F. Generalised fatigue, headaches, paraesthesia. Muscle cramps in legs, polyuria, polydipsia.
Give 3 DD
- primary hyperaldosteronism
- SIADH
- DM
- renal artery stenosis
- DI
What electrolyte imbalance is associated with primary hyperaldosteronism?
Hypokalaemia
What is the first line investigation of hyperaldosteronism and how do you distinguish between primary and secondary?
Aldosterone to renin ratio
Primary = high ratio
Secondary = low ratio
What ECG changes can be seen in hypercalcaemia?
Shortening of the QT interval
Name 2 signs on clinical examination that can be seen on hypocalcaemia
Chvostek’s sign - tap over the facial nerve causes spasm of the facial muscles
Trousseau’s sign - inflate the BP cuff to 20mmHg above systolic for 5 mins and the hand should form a claw
From which artery does the superior thyroid branch from?
External carotid artery
Give 4 functions of parathyroid hormone
- Binds to osteoblasts which signal to osteoclasts to cause resorption of bone and release calcium.
- Active reabsorption of calcium and magnesium from the distal convoluted tubule. Decreases reabsorption of phosphate.
- Increases activated vitamin D via calcitonin
- increases intestinal calcium absorption via activated vitamin D
Give 3 generalised symptoms of a pituitary adenoma
• Headaches
• Vision problems (double vision, vision loss)
• Nausea or vomiting
• Changes in behavior, including hostility, depression and anxiety
• Changes in the sense of smell
• Nasal drainage
• Sexual dysfunction
• Infertility
• Fatigue (extreme tiredness)
• Unexplained weight gain or loss
• Achy joints or muscle weakness
What is carcinoid syndrome?
usually occurs when metastases are present in the liver and release serotonin into the systemic circulation
may also occur with lung carcinoid as mediators are not ‘cleared’ by the liver
Give 3 signs / symptoms of carcinoid syndrome
flushing (often the earliest symptom)
diarrhoea
bronchospasm
hypotension
Abdominal cramps
What drug is commonly used to reduce thyroid hormone production?
Describe its mechanism of action
Carbimazole
Blocks thyroid peroxidase from coupling and iodinating the tyrosine residues on thyroglobulin
Causing decreased thyroid hormone production
Provide 4 signs and/or symptoms of a patient experiencing DKA
• Nausea/Vomiting
• Abdominal Pain
• Recued Conscious Levels
• Kussmauls Breathing
• Fruity Breath
• Polydipsia/Polyuria
• Hypotension
• Tachycardia
What cells are pheochromocytomas composed of
Chromaffin cells
3 symptoms of pheochromocytoma?
Hypertension
Tachycardia/Palpitation
Diaphoresis
Hypertensive Retinopathy
Pallor
Diabetes
Name 2 causes of Acromegaly
Benign pituitary adenoma (GH secreting)
Ectopic carcinoid tumour (GH secreting) e.g. small cell lung cancer
Give 3 signs of Acromegaly
- skin darkening
- coarsening face
- wide node
- large supraorbital ridge
- interdental separation
- deep voice
- large tongue
- headaches
- excessive sweating
- hands/feet growth
Name 2 investigations for diagnosing Acromegaly and the result of each.
- Oral glucose tolerance test: raised
- Serum IGF-1: raised
Why would measuring plasma growth hormone levels alone not be diagnostic of Acromegaly?
GH secretion is pulsatile
GH levels can also be elevated in pregnancy, stress, puberty
Name 2 types of drug used in the treatment of Acromegaly and give examples
- Somatostatin analogues e.g. IM octreotide
- GH receptor antagonist e.g. SC Pegvisomant
- Dopamine agonist e.g. oral cabergoline
List the tests and diagnostic criteria for DKA (5)
Blood glucose >11.1 mol/L
Plasma ketones >3mmol/L
Ketonuria >2 on dipstick
venous pH <7.35
HCO3- <15.0mmol/L
Name 3 RFs for DKA
- stopped insulin
- infection e.g. UTI
- pancreatitis
- undiagnosed DMT1
- MI
- surgery
Name 3 potential complications of DKA
- hypotension
- coma
- cerebral oedema
- hypothermia
- DVT
- pneumonia
What aspect on a urine dipstick would indicate DI instead of DM
Glucose negative in DI
What test us used to differentiate cranial and nephrogenic DI and what result would indicate cranial?
IM desmopressin test
Urine becomes concentrated in cranial
Pt found to have cranial DI. What class of medication is given and give an example
ADH analogue e.g. desmopressin
In pts with nephrogenic DI you give them NSAIDs, what is the physiology behind this?
Inhibits prostaglandins which stops their inhibition of ADH action
What type of hypersensitivity reaction in Graves’ disease?
Type II
What causes hyperparathyroidism in Graves?
Pathological stimulation of TSH receptors by IgG autoantibodies
Why ask about vitiligo/Addisons in a Graves history?
Graves is associated with other autoimmune diseases
Graves diagnosis: TSH , T3/4 levels?
TSH low
T3/4 raised
If left untreated, what is a possible complication of Graves?
Thyroid storm
What rare but serious adverse effect of Carbimazole needs to be monitored?
Agranulocytosis
What class of meds is prescribed for bulging eyes in Graves?
High dose glucocorticoids
Why would an oral glucose tolerance test help diagnose acromegaly?
Growth hormone is normally inhibited by glucose
Growth hormone will stay high in an OGTT
In a healthy person GH would fall in an OGTT
What is IGF-1?
- insulin like growth factor 1
- produced by the liver
- endocrine hormone
- promotes growth in most cells
- production is stimulated by GH
Hyperkalaemia management? 1st and 2nd steps
1=Calcium gluconate
2=Insulin and dextrose
What electrolyte imbalance can be caused by ectopic ACTH from small cell lung cancer?
Hypokalaemia
What hormone imbalance can lithium cause?
elevated TSH
Teenage Male
Headache, double vision, drowsiness, polyuria, polydipsia.
Low FT4, low 0900 cortisol, positive pregnancy test
Diagnosis?
Germinoma
T1DM hypoglycaemia symptoms?
- palpitations
- poor concentration
- shaking
- sweating
What is the most specific antibody to Graves’ disease?
TSH receptor antibody
What blood volume and sodium levels are found in SIADH?
Normovolaemia
Hyponatraemia
What drug can be used to treat the hyponatraemia in SIADH?
Tolvaptan
What symptoms does phaeochromocytoma present with?
- raised BP
- raised HR
- sweating
- pallor
What is phaeochromocytoma?
Adrenal medulla tumour that secretes chatecholamines
What is the first line management of phaeochromocytoma?
Αlpha blockers e.g. Penoxybenzamine
What is the genetic defect in Klinefelter’s syndrome?
What symptoms does it cause?
What hormones are raised?
47 XXY
Learning difficulties, male phenotype, small testicles
Raised LH and FSH
(Hypergonadotrophic hypogonadism)
Central obesity, weight gain, purple striae.
Most likely diagnosis?
Cushing’s syndrome
Widely spaced nipples, delayed menarche, webbed neck
Diagnosis?
Turner’s syndrome
List 6 symptoms/signs of hypocalcaemia
- Trousseau’s sign
- Chvosteks sign
- Convulsions
- Arrhythmia
- Tetany
- Numbness
First line treatment for hypocalcaemia?
Calcium gluconate
What is the difference between exocrine and endocrine ?
exocrine glands secrete substances into a ductal system to an epithelial surface, endocrine glands secrete products directly into the bloodstream
What blood pressure should be aimed for in diabetes mellitus?
130/80 mmHg
Name a test that could be done to assess potential organ damage from hypertension in diabetes. Also say what the test would show.
Echo or ECG- to see left ventricular hypertrophy or past myocardial infarction
Urine analysis- shows proteinuria to check kidney function
Fundoscopy- assess hypertensive retinopathy
What is the triad of ketoacidosis?
- hyperglycaemia
- ketonaemia
- acidaemia
Describe how ketoacidosis occurs
In absence of insulin
Unrestrained increase in hepatic gluconeogenesis/ peripheral uptake by tissues is reduced
Ketones produced as bodies require glucose in cells/ ketone bodies accumulate
5 signs of Graves’ disease
- Graves opthalmology
- tachycardia
- hyperreflexia
- goitre
- clubbing
- AF
- dyspnoea
Briefly describe the pathophysiology of Graves’ disease
- TSH receptor autoantibodies cause increased stimulation of the thyroid gland, causing increased T3/T4
What is the Tx of graves?
- Carbimazole
- Radioiodine therapy
- thyroidectomy
What is the immediate management of hyperthyroidism?
Βeta blocker e.g. Propanolol
Graves: medication used to TREAT ?
Thionamides e.g. Carbimazole
Serious side effect of carbimazole ?
Agranulocytosis
What is HLA B27 typically associated with?
Seronegative spondyloarthridities eg Ankylosing spondylitis
What is anterior uveitis? What are some common symptoms?
Inflammation of the anterior portion of the eves - iris and ciliary body
Symptoms: red eye, photophobia, blurred vision, pain
Which uncontrolled metabolic process causes DKA/
Uncontrolled lipolysis resulting in an excess of free fatty acids which are converted to ketone bodies
Presenting with recurrent renal stones. Bloods tests show increased calcium and decreased phosphate.
Likely diagnosis?
Hyperparathyroidism - increases PTH
