Endocrine Flashcards
Describe endocrine effects of hypothalamus
ADH and oxytocin to posterior pituitary
Release hormones to anterior pituitary
Describe endocrine effects of posterior pituitary
ADH to kidneys
Oxytocin to Breast and uterus
Describe endocrine effects of anterior pituitary
ACTH to adrenals
Oxytocin to breast
FH and LSH to ovaries/testes
GH to bones/tissues
TSH to thyroid
Describe endocrine axis of adrenals
Hypothalamus releases CRH to ant. pituitary which release ACTH to adrenals
Describe layers and products of adrenals
cortex
- zona glomerular: mineralocorticoids
- zona fasciular: glucocorticoids
- zona reticular: androgens
medulla
- adrenaline/noradrenaline
What is acromegaly and what are the causes
increase in GH
pituitary adenoma
cancer releasing GH or GHRH
Visible symptoms of acromegaly
Frontal bossing, protruding jaw
large nose, large tongue
galactorrhoea
Organ dysfunction with acromegaly
HTN
cardiomegaly
diabetes
colorectal cancer
Symptoms of acromegaly caused by pituitary tumour
headaches
bitemporal hemianopia (pressing on optic chiasm)
Diagnosis of aromegaly
Raised IGF-1
OGTT
If GH >1 following glucose +ve
Management of acromegaly
1) transphenoidal surgery to remove
2) Medical management
- somatostatin analogue to inhibit GH release (octreotide)
- GH receptor antagonist (pegvisomant)
- dopamine agonist (bromocriptine)
What is Addisons
primary hypoaldosteronism due to autoimmune dysfunction of adrenals
other causes inc TB, metastatic carcinoma
Describe the RAA pathway
dehydration/low Na causes low blood volume and BP
Reduced renal perfusion causes release of renin by juxtaglomerular cells
Combined with angiotensinogen (liver) produces angiotensin I, combined with ACE (lungs) produces angiotensin II
Causes adrenals to produce aldosterone which increased Na and H20 reabsorption and increases blood volume/BP
Physiological cortisol response to stress
stress causes increased cortisol which causes increased gluconeogenesis in liver
- breakdown of muscle to produce amino acids
- breakdown of adipose tissue to produce free fatty acids
Describe presentation of Addisons where zona glomerular is affected
less aldosterone
- increased K+ and decreased Na
- salt cravings
- N&V
- dizziness
- fatigue
How do you manage an Addisonian crisis
IV hydrocortisone
IV NaCl ± dex
Describe presentation of Addisons where zona fascicular is affected
less cortisol therefore less glucose
- fatigue
- overactive pituitary releases proopiomelanocortin -> melanocyte stimulating hormone->hyperpigmentation
Describe presentation of Addisons where zona reticular is affected
less androgens
- mainly affects females because males also get testosterone from testes
- loss of pubic hair
- decreased sex drive
How do you interpret a 9am cortisol
> 500 addisons unlikely
100-500 do SST
<100 abnormal
How/why does Addisonian crises occur
Major stress creates sudden need for cortisol/aldosterone that cannot be met
- D&V
- pain in back/legs/abdomen
- hypotension
-LOC
How do you diagnose Addisons?
short synacthen test
Given synthetic ACTH, measure cortisol and aldosterone produced, if doesn’t rise then +Ve for adrenal insufficiency
What is Cushings syndrome?
Increased cortisol
Physiological effects of cortisol
1) gluconeogenesis
2) increased sensitivity of peripheral blood vessels to adrenaline
3) decreased immune response
Causes of Cushing Syndrome
Exogenous: steroids
Endogenous: pituitary adendoma (Cushings disease), SCLC, adrenal adenoma/carinoma
Symptoms of Cushings syndrome
excess muscle/bone breakdown
-muscle wasting, thin skin, bruising, fractures
Increased glucose, increased insulin, increased adipose tissues
- buffalo hump, moon face, central obesity
- Diabetes
Increased periperal sensitivity to adrenaline
- HTN
- infections
Imagining in Cushings
MRI pituitary
CT adrenal
CT TAP (malignancy)
Management of Cushings
Exogenous: gradually reduce steroids
Pituitary adenoma: surgery
Adrenal steroid inhibitors e.g. ketoconazole
Risk factors for endometrial cancer
Increased oestrogen
- nulliparity
- early menache
- late menopause
- unopposed oestrogen
metabolic
-obesity
- PCOS
- Diabetes
Protective factors for endometrial cancer
multiparity
COCP
smoking
Presentation of endometrial cancer
PMB
Investigation and management of endometrial cancer
TV US
Hysteroscopy + biopsy
Surgery
Symptoms of uterine fibroids
menorrhagia
abdo pain, bloating, LUTS
subfertility
Diagnosis and management of uterine fibroids
TVUS
Medical: GnRH antagonists
Surgical: myomectomy, endometrial ablation, hysterectomy
Types of urinary incontinence
1) urge: detrusor overactivity
2) stess: when laughing/coughing
3) Overflow
4) Functional
5) mixed: urge/stress
Management of urge incontinence
bladder retraining 6/52
antimuscarinics (oxybutynin)
mirabegron (elderly)
Management of stress incontinence
Pelvic floor exercises 3/12
surgery
duloxetine
Features of PCOS
subfertility, infertility
menstrual disturbance
hirsutism, acne
obesity
acanthosis nigricans
Diagnosis of PCOS
requires 2 out of the following 3
1) infrequent or no mestration
2) signs of increased androgens e.g hirsutism, acne, increased testosterone
3) polycystic ovaries on USS
Causes of hypothyrodism
primary
- hashimotos thyroiditis
-de Quervains
- Riedel
- thyroidecomy
- lithium, amiodarone
Secondary
- pituiarty failure
Conditions associated with hypothyroidism
Downs
Turners
Coeliac
Symptoms of hypothyroid
Hair loss, dry skin
weight gain, fluid gain
fatigue
constipation
cold sensitive
Investigations of hypothryoidism
primary: low T3/T4 high TSH
Secondary: Low T3/T4 low TSH
Management of hypothyroidism
levothyroxine - titrate until normal TSH
Increase in pregnancy
SE of levothyroxine
AF, worsening angina, reduced bone mineral density
What is de Quervains
Sub acute thyroiditis following viral infection
How does de Quervains present
Phase 1: 3-6 weeks
-hyperthyroid, goitre, raised ESR
Phase 2 1-3 weeks: euthyroid
Phase 3 weeks/months Hypothyroid
Phase 4: normal
How do you diagnose de Quervains
thyroid scintigraphy - decreased iodine 131 uptake
How do you manage de Quervains
self limiting, steroids if severe
What is subclinical hypothyroidism
High TSH, normal T3/T4 with no symptoms
How do you manage subclinical hypothyroidism
If TSH >10 on 2 occasions more than 3 months apart - give levo
If TSH 5.5-10 on 2 occasions more than 3 months apart and symptomatic - give levo
if TSH 5.5-10 and >65 repeat in 6 months
What causes thyroid eye disease
Graves
inflam of muscles behind eye
How do you prevent/manage thyroid eye disease
Prevent: stop smoking
Treat: steroids, topical lubricants, radiotherapy, surgery
Causes of hyperthyroidism
Graves
Toxic multinodular goitre
Pituitary/hypothalamic pathology
Symptoms of hyperthyroidism
Heat intolerance, sweating
weight loss
tachycardia
loose stools
How does Graves present?
hyperthyroid symptoms
+ diffuse goitre, eye disease, pretibial myxoedema
What is a thyroid storm
triggered by trauma. infection, contrast
-pyrexia
- N&V
- tachycardia
- Hypertension
-Delerium
Thyroid storm management
fluids, b blockers, steroids, anti-arrhythmics
Management of hyperthyroidism
1) carbimazole
2) propylthiouracil - less used because risk of hepatic injury
3) radioactive iodine, surgery + levo
Causes and management of subclinical hyperthyroidism
multinodular goitre
excessive thyroxine
m:: low dose anti thyroid agent 6 months
How do you diagnose and treat toxic multinodular goitre
patchy update on nuclear scintigraphy
mx: radioiodine therapy
