14. The Endocrine System…. The rest ! Flashcards
The endocrine system
Multiple organs.
Highly integrated.
Secrete hormones to cause the effect
Endocrine diseases
Underproduction
Overproduction
Mass lesions
Areas to be covered
Hypothalamus Pituitary Thyroid Parathyroid Adrenals
Hypothalamus
Located in the brain – above brain stem
Links the Central Nervous system to the Endocrine system
Pituitary gland
Anterior
Posterior
Anterior
Growth hormone Thyroid Stimulating Hormone Adreno-corticotrophic hormone Follicle stimulating hormone Lutenising hormone Prolactin
Posterior
Antidiuretic hormone
Oxytocin
Pituitary Diseases
Hyperpituitarism-related effects
Adenomas
Hypopituitarism-related effectsInjury, surgery, radiation, inflammation
Local mass effectcompressing the optic chiasm
Hyperpiuitarism
Most common cause is an adenoma in anterior lobe.
Other causes:CancerHyperplasia
Pituitary Adenoma (1)
Functional- prolactinoma
Non Functional
Pituitary Adenoma (2)
Macroadenomas ( > 1 cm in diameter )
Microadenomas (
ACTH
Cushing’s disease
Growth hormone
Gigantism (children)
Acromegaly (adults)
Prolactin
Galactorrhea/ amenorrhea
sexual dysfunction
infertility
TSH
Hyperthyroidism
FSH, LH
Hypogonadism, mass effects/hypopituitarism
Hypopituitarism
Occurs with loss of 75% or more of the anterior pituitary parenchyma.
Hypopituitarism: causes
Ischemic necrosis of the pituitary: Sheehan’s syndrome
Non functioning adenomas
Surgery or irradiation
Inflammatory lesions
Grave’s disease (Autoimmune)
Over treatment by thyroxine
Infective – De Quervain’s thyroiditis
Toxic multinodular goitre
Toxic adenoma
Hyperthyroidism: Management
Testing: Clinical + thyroid function tests Treat the cause Carbimazole/propylthiouracil Radioiodine Thyroidectomy
Hypothyroidism causes
Iodine deficiency Autoimmune – Hashimoto’s thyroiditis Iatrogenic: Surgery, radioiodine Pituitary defects Congenital
Hashimoto’s thyroiditis
Autoimmune destruction of the thyroid gland.
Women > men
45 – 60 years old
Hypothyroidism: Management
Thyroxine
Hyperthyroidism symptoms
Intolerance to heat Fine, straight hair Bu;ging eyes Facial flushing enlarged thyroid tachycardia Increase systolic BP Breast enlargement weight loss muscle wasting finger clubbing tremors diahrrhea menstrual changes (amenorrhea) localised edema
Hypothyroidism symptoms
Intolerance to cold receding hair line facial and eyelid edema dull blank expression extreme fatigue thick tongue - slow speech anorexia brittle nails and hair menstrual disturbances hair loss apathy lethargy dry skin muscle aches and weakness constipation
Late clinical manifestations:
subnormal temp, bradycardia, weight gain, decrease LOC, thickened skin, cardiac complications
Thyroid Cancer
Relatively uncommon
Most common type is Papillary carcinoma.
Papillary thyroid carcinoma is a non-functional tumour.
Hypoparathyroidism: Causes
Removal by surgery (Thyroidectomy)
Congenital
Hereditary (autoimmune)
Hypoparathyroidism: Symptoms
Due to low calcium;- Irritability- Tetany- Seizures
Hyperparathyroidism
PRIMARY = Adenoma SECONDARY = Chronic renal failure TERTIARY = After renal transplant
Hyperparathyroidism: Symptoms
Due to hypercalcemia:ConstipationDepressionSeizuresMuscle wastingPolyuriaBone fracturesKidney stones
Hyperaldosteronism
Primary ( Conn’s Disease in > 50 %)
Secondary (due to high renin)
Conn’s Disease: Symptoms
Oedema
Hypertension
High Sodium
Low Potassium
Glucocorticoids: Cortisol
Essential to life Regulates blood sugar Inhibits inflammation Stress response Release is by circadian rhythm (normal) Stress Excess release ------ Cushing’s Syndrome
Cushing’s Syndrome: Causes
ACTH releasing tumour (pituitary/lung)
Steroids
Addison’s disease (adrenal insufficiency)
Multiple causes:
Autoimmune
Infection
Neoplasms
Addison’s disease: Symptoms and signs
GI Symptoms (Anorexia, nausea, vomiting and diarrhoea)
Weight loss
Hyperpigmentation
Low Sodium, High Potassium
Gonadocorticoids (sex hormones)
Testosterone
Oestrogen
Both are also secreted from the gonads
Phaeochromocytoma: Presentation
Hypertension Sweating Palpitations Nervousness Increased metabolic ratio Rapid heart rate
Multiple Endocrine Neoplasia (MEN)
Group of inherited diseases resulting in proliferative lesions of multiple endocrine organs
Different types