Endocrine System Flashcards
Hypothalamus
Located in the brain – above brain stem
Links the Central Nervous system to the Endocrine system
Anterior Pituitary gland produces
Growth hormone
Thyroid Stimulating Hormone
Adreno-corticotrophic hormone
Follicle stimulating hormone
Lutenising hormone
Prolactin
Posterior Pituitary gland produces
Antidiuretic hormone
Oxytocin
Pituitary Diseases
Hyperpituitarism-related effects
Adenomas
Hypopituitarism-related effectsInjury, surgery, radiation, inflammation
Local mass effect compressing the optic chiasm
Hyperpituitarism
Most common cause is an adenoma in anterior lobe.
Other causes:Cancer Hyperplasia
Pituitary Adenoma
Functional- prolactinoma
Non Functional
Macroadenomas ( > 1 cm in diameter )
Microadenomas (
Pituitary Adenoma over production of ACTH
Cushing’s disease
Pituitary Adenoma over production of growth hormone
Gigantism (children)
Acromegaly (adults)
Pituitary Adenoma over production of prolactin
Galactorrhea/ amenorrhea sexual dysfunctioninfertility
Pituitary Adenoma over production of TSH
Hyperthyroidism
Pituitary Adenoma over production of FSH, LH
Hypogonadism, mass effects/hypopituitarism
Hypopituitarism
Occurs with loss of 75% or more of the anterior pituitary parenchyma.
Causes:
Ischemic necrosis of the pituitary: Sheehan’s syndrome
Non functioning adenomas
Surgery or irradiation
Inflammatory lesions
Hyperthyroidism causes
Grave’s disease (Autoimmune) Over treatment by thyroxine Infective – De Quervain’s thyroiditis Toxic multinodular goitre Toxic adenoma
Hyperthyroidism management/ treatment
Testing: Clinical + thyroid function tests
Treat the cause
Carbimazole/propylthiouracil
Radioiodine
Thyroidectomy
Hypothyroidism
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
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 causes
PRIMARY Adenoma SECONDARY chronic renal failure TERTIARY After renal transplant
Hyperparathyroidism symptoms
Due to hypercalcemia: Constipation Depression Seizures Muscle wasting Polyuria Bone fractures Kidney 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
