Disorders Flashcards
What is Cushing’s disease?
Hypersecretion of cortisol due to a defect in the negative feedback system of CRH and ACTH
What is the normal treatment procedure for Cushing’s disease?
Surgery through the nose
What causes Gigantism and Acromegaly?
Over production of GH without pulsatility: increasing IGF levels as a result
Treat with long acting somatostatin analogues or surgical removal
What are the different types of hypothyroidism?
- Primary: thyroid gland failure
- Secondary: pituitary failure
- Tertiary: hypothalamic failure
- Peripheral resistance to action
What are the signs and symptoms of hypothyroidism?
- symptoms: fatigue, coldness, weight gain, constipation, low voice
- signs: cool skin, dry skin, swelling of face, slow reflexes, myxedema
What is Hashimoto’s disease?
An autoimmune disease caused by hypothyroidism
- will typically see goiter in younger patients
- the immune system attacks and gradually destroys the thyroid gland
How is Hashimoto’s disease treated?
With T4 analogue
What causes Grave’s disease?
Overproduction of thyroid hormone
- causes enlargement of the thyroid, heat intolerance
- results in immune system producing anti TSH receptor antibodies
How is Grave’s disease treated?
Anti-T4 compounds
Radioactive iodine
Subtotal thyroidectomy
What is a thyroid storm?
Acute events that cause hypersecretion of T4 resulting in hypermetabolism and excessive responses to catecholamines
- can result from thyroid surgery, trauma, severe illness
- anti-thyroid drugs and beta blockers are used for treatment
What is rickets?
Softening and bending of the bones in chlidren (weak bones)
What is osteopetrosis?
Marble bone
- increase in bone density due to defective osteoclasts
- bones become more brittle
What is osteoporosis?
Excess osteoclast function
- frequent fractures in areas with trabecular bone
What is involutional osteoporosis?
Loss of bone density with age
What is associated with hyperparathyroidism?
Associated with loss of tumour suppressor genes (MEN1 and MEN2A)
- primary parathyroidism is characterized by increased parathyroid cell proliferation and PTH secretion
What characterizes hypercalcemia?
- Renal salt and water loss
- Anorexia, nausea, vomitting due to ECF volume contraction
How is osteoporosis being treated now?
By using recombinant PTH to increase bone density
- PTH induces RUNX2 expression in osteoblasts
- prolongs osteoblast survival
- increases structural integrity of bones
How does hypoparathyroidism occur?
Failure to secrete PTH, altered responsiveness to PTH, Vitamin D deficiency or resistance to Vitamin D
What is the relationship between calcitonin and PTH?
Calcitonin secretion is stimulated by a rise in serum Ca2+, which suppresses secretion of PTH
- hypocalcemia stimulates PTH release and releases calcitonin
How does Vitamin D toxicity occur?
Overdose either therapeutically or accidentally
Treat by reducing calcium, vitamin and cortisol intake
What are the causes of Cushing’s disease?
- CRH producing tumour
- ACTH producing tumour
- lack of feedback control from cortisol
- iatrogenic
What does Cushing’s disease affect?
inhibits Ca2+ uptake and osteoblasts
increase glucocorticoid activity
What is Addison disease?
Due to the destruction of the adrenal gland by an autoimmune response
What is Conn’s disease?
Hypersecretion of aldosterone usually caused by adrenal hyperplasia or tumour
- excess excretion of K+ and H+: serum alkalosis and neuropathy
- increased water retention: increased Na, increased BP
What causes congenital adrenal hyperplasia?
hyperplasia of the adrenal glands before birth leading to excessive androgen production
- masculinization of genitilia
What are the most common autoimmune dieases?
Autoimmune thyroid diseases and T1DM
What are some organ specific autoimmune diease?
- T1DM
- Good pasture’s syndrome
- MS
- Grave’s disease
- Hashimoto’s thyroiditis
What are some systemic autoimmune disorders?
- Rheumatoid arthritis
- Scleroderma
- Systemic Lupus
- Primary Siogren’s syndrome
- Polymyositis
What is rheumatoid arthritis?
Inflammation which may lead to bone erosion by activating osteoclasts
What mispairings may occur during sexual differentiation?
SRY gene may be transferred to X chromosome - producing a sperm with X+SRY : XX male
Y chromosome might have an abnormal SRY: deleted or mutated SRY: XY female
What effects does defects in testosterone have?
Phenotypic female (XY female)
- testosterone is not functional
- scrotum does not develop
- DHT is not produced
What is CAH?
- leads to masculinization of external genitilia at birth: enlarged clitorits, excessive androgen production
- no AMH, no SRY gene
What disturbances can occur in the menstrual cycle?
Primary amenorrhea: genetic defects in gonadal maturation, depletion of follicles Secondary amenorrhea (failure to ovulate in a 6 month period): excessive androgen production, pituitary disease
What is Laron syndrome?
Dwarfism which is caused by elevated GH levels leading to impaired growth
- deletion is exon 3,5,6
What is Prader Willi Syndrome?
- Inability to feel satiated
- ghrelin is continously secreted
What is Cretinism?
Caused by maternal hypothyroidism leading to stunted growth
