Endocrinology Flashcards
Cheat sheet for these diseases?
Diabetes =
Thyroid disorders =
Cushing’s =
Acromegaly =
Conn’s syndrome =
Addison’s =
Diabetes = too much blood glucose / not enough insulin
Thyroid disorders = too much or too little thyroid hormone
Cushing’s = too much cortisol
Acromegaly = too much growth hormone
Conn’s syndrome = too much aldosterone
Addison’s = too little cortisol and too little aldosterone
Cheat sheet for these diseases?
Diabetes insipidus =
SiADH =
Hyperkalaemia =
Hypercalcaemia =
Parathyroid disorder =
Diabetes insipidus = not enough ADH
SiADH = too much ADH
Hyperkalaemia = too much potassium
Hypercalcaemia = too much calcium
Parathyroid disorder = too much or too little parathormone
Describe the pituitary gland?
Lies just inferior to the optic chiasm
Connected to the hypothalamus via pituitary stalk
Formed of separate anterior and posterior parts
Describe the anterior pituitary?
- Recieves blood from portal venous circulation of hypothalamus
- Contains 5 types of hormone producing cell which together produce 6 hormones
- Hormone production is stimulated by the hypothalamus
Describe the CRH axis?
Hypothalamus > CRH > Ant. pituitary > ACTH > Adrenal cortex > glucocorticoids (cortisol)
Describe the GRH axis?
Hypothalamus > GRH > Ant. Pituitary > LH/FSH > gonads > various effects inc production of testosterone and oestrogen
Describe the GHRH axis?
Hypothalamus > GHRH > Ant. Pituitary > GH > Liver > IGF-1
Describe the TRH axis?
Hypothalamus > TRH > Ant. Pituitary > TSH > thyroid > T3 and T4
Describe the dopamine axis?
Hypothalamus > Dopamine > Ant. Pituitary > DECREASED prolactin
Describe the posterior pituitary?
Hormones are produced in the hypothalamus and stored in the posterior pituitary for release
The only two hormones are:
- Oxytocin
- ADH (vasopressin)
Symptoms of hyperthyroidism?
Symptoms:
Diarrhoea
Weight loss
Sweats
Heat intolerance
Palpitations
Tremor
Anxiety
Menstrual disturbance
Signs of hyperthyroidism?
Tachycardia Thin hair Lid lag Onycholysis Lid retraction Exophthalmos
Investigation of hyperthyroidism?
Thyroid function tests
Primary = low TSH, high T3/T4
Secondary = high TSH, high T3/T4
Thyroid autoantibodies
Radioactive iodine isotope uptake scan
Treatment for hyperthyroidism?
Beta blockers for rapid symptom control
Carbimazole = antithyroid drug
Radioiodine therapy
Thyroidectomy
Pathology and aetiology of Graves disease?
aetiology: Associated with other autoimmune diseases
pathology: Increased levels of TSH Receptor Stimulating Antibody (TRAb) - causes excess TH secretion from the thyroid
What is Graves’ Ophthalmology?
- Extraocular muscle swelling
- Eye discomfort
- lacrimation
- Diplopia
What is the investigation and treatment for Graves’ disease
Same as normal hyperthyroidism but with emphasis on TRAb (Ix)
Aetiology of hypothyroidism?
Hashimoto’s thyroiditis
Iodine deficiency
Previous radioiodine therapy
Over-treatment of hyperthyroidism
Symptoms of hypothyroidism
Fatigue Cold intolerance Weight gain Constipation Myalgia Constipation Menorrhagia
Signs of hypothyroidism?
Bradycardic
Bradycardia Reflexes relax slowly Ataxia Dry thin hair/skin Yawning Cold Hands Ascites Round puffy face Defeated demeanor Immobile Congestive HF
What is is acromegaly?
Increased production of growth hormone occurring in adults after fusion of epiphyseal plates
What is gigantism?
Increased production of growth hormones occurring in children
Aetiology of acromegaly?
Mainly a pituitary adenenoma
Very slow insidious onset over many years
Signs of acromegaly?
Massive growth of hands and feet Big tongue and widely spaced feet Darkening skin Obstructive sleep apnoea Deep voice
What is acroparaesthesia?
pins and needles
What are the symptoms of acromegaly?
Acroparaesthesia Sweating Headache Arthralgia Decreased libido
Investigation of acromegaly?
Not a random gH test because GH is a pulsatile protein and levels may vary throughout the day
ORAL GLUCOSE TOLERANCE TEST
- normally a rise in blood glucose will suppress GH levels
- Give glucose then test GH, if still high this is diagnostic for acromegaly
MRI the pituitary fossa for adenomas
Treatment for acromegaly?
Transphenoidal surgery to remove the adenoma
GH antagonist e.g. pegvisomant
Define: hyperaldosteronism
Excess production of aldosterone independent of the RAAS system
Aldosterone works in the kidney to cause potassium loss, excess causes hypokalaemia and sodium and water retention
2/3 - conns syndrome
1/2 - bilateral adrenocortical hyperplasia
Symptoms of hyperaldosteronism?
Symptoms of hyperaldosteronism = symptoms of hypokalaemia
- constipation
- weakness and cramps
- paraesthesia
- polyuria and polydipsia
Also causes hypertension due to increased bv
Investigation of hyperaldosteronism?
U&E
- decreased renin
- increased aldosterone
ECG flat T, long PR, long QT, U waves
Adrenal CT
Treatment of hyperaldosteronism?
Conn’s: laproscopic adrenalectomy
Spirolactone - aldosterone anatagonist
Describe the action of PTH?
Increased bone resorption by osteoclasts
Increased intestinal calcium absorption
Activates 1,25 dihydroxyVD in kidney
Increased calcium reabsorption and phosphate excretion in the kidney
Aeitology of hyperparathyroidism?
80% solitary adenoma
20% = parathyroid hyperplasia
rare = parathyroid cancer
Symptoms of hyperparathyrodism?
Symptoms of hyperparathyroidism = symptoms of hypercalcaemia
Bones stones groans moans
Investigation of hyperparathyroidism?
Bloods:
Primary: ↑PTH, ↑Ca, ↓Phosph
Secondary: ↑PTH, ↓Ca, ↑Phosph
Tertiary: ↑everything (progression of secondary)
Increased 24hr urinary calcium excretion DEXA bone scan for osteoporosis
Treatment of hyperparathyroidism?
Fluids, surgically treat underlying cause, bisphosphates
Aetiology, S+S and Tx of hypoparathyroidism?
Aeitology: autoimmune destruction of PT, congenital, surgical removal (secondary) Mg/VD deficiency
S+S = hypocalcaemia = SPASM
Tx = Ca supplement, calcitriol, synthetic PTH
Pseudohypoparathyroidism
Decreased response to PTH
Bloodwork shows low Ca, high PTH
Treat as normal hypoparathyroid
The initial treatment for someone having a thyrotoxic storm is:
a )IV 0.9% saline
b) Propanolol
c) Salbutamol
d) Carbimazole
e) Omeprazole
B) propanolol
Which autoantibody will be present in Graves’ disease?
a) Thyroid Peroxidase (TPO)
b) TSH Receptor Stimulating Antibody (TRAb)
c) Graves Related Thyroid Antibody (GRTA)
d) Eutonic Auto Thyroid-Fascicle Automatic Renal Thyroid (EAT-FART)
e) T3 Mimicking antibody (TMA)
b) TSH Receptor Stimulating Antibody (TRAb)
Describe hypokalemia?
[K+] <3.5 mmol/L
Which causes…
- Low K+ in the serum (ECF) causes a water concentration gradient out of the cell (ICF)
- Increased leakage from the ICF causing hyperpolarisation of the myocyte membrane
Investigation of hypokaelemia?
ECG!
U got no Pot and you got no T but a long PR and and long QT
U waves
No T waves
Long PR
long QT
Treatment of hypokalemia?
Not enough potassium - give some
Mild = oral K+ Severe = IV K+
Hyperkalemia investigation?
ECG
Tall tented ECG
Small P
Wide QRS
Treatment of hyperkalemia?
non urgent - polystyrene sulphonate resin - binds the K+ in the gut decreasing uptake
urgent - calcium gluconate - decreases VF risk in the heart
Insulin - drives K+ into the cells
Things that cause
HYPOkalemia
HYPERkalemia
HYPOkalemia - fasting, anorexia
HYPERkalemia - excessive consumption at a fast rate: IV fluids
Hyperokalemia on muscles?
Smooth- constipation
Skeletal - weakness/cramps
Cardiac - arrhythmias and palpitations
Hyperkalemia on muscles?
Smooth - cramping
Skeletal - weakness/flaccid paralysis due to overcontraction of muscles becoming totally drained of energy
Cardiac - arrhythmias and arrest
Potassium excretion issues?
HYPO (high secretion) = high aldosterone
HYPER (low secretion) = low aldosterone, adrenal insufficiency
AKI decreased filtration rate so more K+ os maintained in the blood
Describe hypokalemia internal balance issues?
insulin = excess
pH = alkalosis
B2 receptor = B2 agonists
Describe hyperkalemia internal balance issues?
insulin = deficiency pH = acidosis B2 = beta blocker
Where is calcium stored?
99% of calcium is stored in bone calcium as calcium phosphate
What is calcium balance controlled by?
Parathyroid: PTH
Thyroid: Calcitonin