Endocrine system

Question 1

Name the 3 categories of endocrine disease

Answer 1

Underproduction
Overproduction
Mass lesions

Question 2

Hypothalamus

Answer 2

located in the brain, links CNS to endocrine system
> anterior pituitary = multiple hormones
> posterior pituitary = oxytocin, ADH

Question 3

Pituitary gland

Answer 3

Anterior = growth hormone, TSH, adreno-corticotrophic hormone, FSH, LH, prolactin
Posterior = ADH, oxytocin

Question 4

Hyperpituitarism

Answer 4

common causes are adenomas in the anterior lobe, cancer, hyperplasia
adenoma can be functional (prolactinoma) or non-functional, and can be macro (<1cm) or micro (<1cm)
ACTH = Cushing’s disease
Growth hormone = gigantism, acromegaly
Prolactin = infertility/sexual dysfunction
TSH = hyperthyroidism
FSH/LH = hypogonadism, hypopituitarism

Question 5

Hypopituitarism

Answer 5

causes:
injury, surgery, radiation, inflammation
ischaemic necrosis of the pituitary = Sheehan’s syndrome
non-functioning adenomas

Question 6

Thyroid gland

Answer 6

butterfly shaped, 4 parathyroid glands

• hypothalamus releases TRH from the anterior pituitary, causing TSH to be released
• causes thyroid gland to release T3 and T4 = increased metabolism, growth and development, increase catecholamine effect
• also causes negative feedback to the hypothalamus

Question 7

Hyperthyroidism

Answer 7

Causes:
> Grave's disease (autoimmune)
> over treatment by thyroxine
> infective - De Quervain's thyroiditis 
> toxic multi nodular goitre
> toxic adenoma
Symptoms: intolerance to heat, enlarged thyroid, tachycardia, increased systolic BP, weight loss and muscle wasting, menstrual changes
Management = clinical and thyroid function tests
- Carbimazole
- treat cause
- radioiodine
- thyroidectomy

Question 8

Hypothyroidism

Answer 8

Causes:
> iodine deficiency
> Hahimato's thyroiditis (autoimmune) - destruction of thyroid gland
> surgery/radioiodine
> pituitary defects
> congenital
Symptoms: intolerance to cold, facial oedema, anorexia, muscle aches and weakness, constipation, hair loss
Management = thyroxine

Question 9

Thyroid cancer

Answer 9

most common is papillary carcinoma (non-function tumour)

Question 10

Parathyroid glands

Answer 10

calcium regulation by parathyroid hormone

Question 11

Hypoparathyroidism

Answer 11

causes:
> removal by surgery
> hereditary
> congenital
symptoms: due to decreased calcium are irritability and seizures

Question 12

Hyperparathyroidism

Answer 12

primary - adenoma
secondary - chronic renal failure
tertiary - after renal transplant
symptoms: due to increased calcium are constipation, depression, seizures, muscle wasting, bone fractures, kidney stones

Question 13

Adrenal gland

Answer 13

3 zones:
1 = sex hormones eg testosterone, oestrogen
2 = glucocorticoids eg cortisol
> essential to life, regulate blood sugars, inhibits inflammation, stress response
> release is by circadian rhythm
> excess release = Cushing’s syndrome
3 = mineralocorticoids eg aldosterone

Question 14

Cushing’s syndrome (adrenals)

Answer 14

causes:

• ACTH releasing tumour in pituitary or lung
• steroids

Question 15

Addison’s disease (adrenals)

Answer 15

adrenal insufficiency
multiple causes:
- autoimmune
- infection
- neoplasms
signs and symptoms: GI symptoms including anorexia, nausea, vomiting and diarrhoea, weight loss, hyperpigmentation, decreased sodium increased potassium

Question 16

Phaeochromocytoma (adrenals)

Answer 16

presents as: hypertension, sweating/palpitations, nervousness, increase metabolic rate and HR

Question 17

Multiple Endocrine Neoplasia (adrenals)

Answer 17

group of inherited diseases = proliferative lesions of multiple endocrine glands