Disorders

Question 1

What is Cushing’s disease?

Answer 1

Hypersecretion of cortisol due to a defect in the negative feedback system of CRH and ACTH

Question 2

What is the normal treatment procedure for Cushing’s disease?

Answer 2

Surgery through the nose

Question 3

What causes Gigantism and Acromegaly?

Answer 3

Over production of GH without pulsatility: increasing IGF levels as a result
Treat with long acting somatostatin analogues or surgical removal

Question 4

What are the different types of hypothyroidism?

Answer 4

• Primary: thyroid gland failure
• Secondary: pituitary failure
• Tertiary: hypothalamic failure
• Peripheral resistance to action

Question 5

What are the signs and symptoms of hypothyroidism?

Answer 5

• symptoms: fatigue, coldness, weight gain, constipation, low voice
• signs: cool skin, dry skin, swelling of face, slow reflexes, myxedema

Question 6

What is Hashimoto’s disease?

Answer 6

An autoimmune disease caused by hypothyroidism

• will typically see goiter in younger patients
• the immune system attacks and gradually destroys the thyroid gland

Question 7

How is Hashimoto’s disease treated?

Answer 7

With T4 analogue

Question 8

What causes Grave’s disease?

Answer 8

Overproduction of thyroid hormone

• causes enlargement of the thyroid, heat intolerance
• results in immune system producing anti TSH receptor antibodies

Question 9

How is Grave’s disease treated?

Answer 9

Anti-T4 compounds
Radioactive iodine
Subtotal thyroidectomy

Question 10

What is a thyroid storm?

Answer 10

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

Question 11

What is rickets?

Answer 11

Softening and bending of the bones in chlidren (weak bones)

Question 12

What is osteopetrosis?

Answer 12

Marble bone

• increase in bone density due to defective osteoclasts
• bones become more brittle

Question 13

What is osteoporosis?

Answer 13

Excess osteoclast function

- frequent fractures in areas with trabecular bone

Question 14

What is involutional osteoporosis?

Answer 14

Loss of bone density with age

Question 15

What is associated with hyperparathyroidism?

Answer 15

Associated with loss of tumour suppressor genes (MEN1 and MEN2A)
- primary parathyroidism is characterized by increased parathyroid cell proliferation and PTH secretion

Question 16

What characterizes hypercalcemia?

Answer 16

• Renal salt and water loss

- Anorexia, nausea, vomitting due to ECF volume contraction

Question 17

How is osteoporosis being treated now?

Answer 17

By using recombinant PTH to increase bone density

• PTH induces RUNX2 expression in osteoblasts
• prolongs osteoblast survival
• increases structural integrity of bones

Question 18

How does hypoparathyroidism occur?

Answer 18

Failure to secrete PTH, altered responsiveness to PTH, Vitamin D deficiency or resistance to Vitamin D

Question 19

What is the relationship between calcitonin and PTH?

Answer 19

Calcitonin secretion is stimulated by a rise in serum Ca2+, which suppresses secretion of PTH
- hypocalcemia stimulates PTH release and releases calcitonin

Question 20

How does Vitamin D toxicity occur?

Answer 20

Overdose either therapeutically or accidentally

Treat by reducing calcium, vitamin and cortisol intake

Question 21

What are the causes of Cushing’s disease?

Answer 21

• CRH producing tumour
• ACTH producing tumour
• lack of feedback control from cortisol
• iatrogenic

Question 22

What does Cushing’s disease affect?

Answer 22

inhibits Ca2+ uptake and osteoblasts

increase glucocorticoid activity

Question 23

What is Addison disease?

Answer 23

Due to the destruction of the adrenal gland by an autoimmune response

Question 24

What is Conn’s disease?

Answer 24

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

Question 25

What causes congenital adrenal hyperplasia?

Answer 25

hyperplasia of the adrenal glands before birth leading to excessive androgen production - masculinization of genitilia

Question 26

What are the most common autoimmune dieases?

Answer 26

Autoimmune thyroid diseases and T1DM

Question 27

What are some organ specific autoimmune diease?

Answer 27

- T1DM - Good pasture's syndrome - MS - Grave's disease - Hashimoto's thyroiditis

Question 28

What are some systemic autoimmune disorders?

Answer 28

- Rheumatoid arthritis - Scleroderma - Systemic Lupus - Primary Siogren's syndrome - Polymyositis

Question 29

What is rheumatoid arthritis?

Answer 29

Inflammation which may lead to bone erosion by activating osteoclasts

Question 30

What mispairings may occur during sexual differentiation?

Answer 30

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

Question 31

What effects does defects in testosterone have?

Answer 31

Phenotypic female (XY female) - testosterone is not functional - scrotum does not develop - DHT is not produced

Question 32

What is CAH?

Answer 32

- leads to masculinization of external genitilia at birth: enlarged clitorits, excessive androgen production - no AMH, no SRY gene

Question 33

What disturbances can occur in the menstrual cycle?

Answer 33

``` 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 ```

Question 34

What is Laron syndrome?

Answer 34

Dwarfism which is caused by elevated GH levels leading to impaired growth - deletion is exon 3,5,6

Question 35

What is Prader Willi Syndrome?

Answer 35

- Inability to feel satiated | - ghrelin is continously secreted

Question 36

What is Cretinism?

Answer 36

Caused by maternal hypothyroidism leading to stunted growth