15 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 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
Functional- prolactinoma
Non Functional
Pituitary Adenoma
Macroadenomas ( > 1 cm in diameter )
Microadenomas (
Pituitary adenomas
Hormone - Syndrome
ACTH - Cushings Disease
Growth hormone -
Gigantism (children)
Acromegaly (adults)
Prolactin - Galactorrhoea/amenorrhea
sexual dysfuntion
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
Hyperthyroidism causes
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
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
Glucocorticoids: Cortisol
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
Summary
Hypothalmus Pituitary Thyroid Parathyroid Adrenals
