Skeletal system (Rubins)

Question 1

DMD

Answer 1

Severe prog X-linked , progressive degeneration of muscles

Question 2

Most common death of DMD patients

Answer 2

Resp insufficiency due to cardiac arrhythmia and muscular weakness

Question 3

DMD cause

Answer 3

Mutation of Dystrophin short arm of X xsome (Xp21)

Question 4

Dystrophin function

Answer 4

Links sarcolemma the ECM

Question 5

Dermatomyositis

Answer 5

Heliotropic rash on eyelids, elevated CK, inflammation of perimysium

Question 6

MG

Answer 6

Serum antibodies directed against ACh receptors

Question 7

MG Rx

Answer 7

Thymectomy

Question 8

Polymyositis

Answer 8

Inflammation of endomysium, CD8+ T cells, anti Jo-1 antibodies, interstitial liver disease, nonerosive arthritis, Raynaud phenomenon

Question 9

Lambert-Eaton myasthenic syndrome

Answer 9

Serum IgG bodies against calcium channels

Question 10

Myotonic dystrophy

Answer 10

Fixed muscular movements, ptosis, fixed facial expression, slowing muscle relaxation, progressive muscle weakness and wasting

Question 11

Carnityl palmityl transferase deficiency

Answer 11

Inability to transport long-chain fatty acids into the mitochondria

Question 12

Carnityl palmityl transferase deficiency symptoms

Answer 12

Muscular pain after prolonged exercise+ Myoglobinuria

Question 13

Pompe disease

Answer 13

3-month-old boy presents with severe hypotonia and areflexia. His tongue and heart are enlarged. A muscle biopsy displays massive accumulation of membrane-bound glycogen and disappearance of the myofilaments and other sarcoplas- mic organelles. The patient dies after 1 year.

Question 14

Hurler syndrome

Answer 14

Mucopolysaccharide metabolism defect

Question 15

Inclusion body myositis

Answer 15

The pathologic features of inclusion body myositis resemble those of poly- myositis and consist of single-fiber necrosis and regeneration with predominantly endomysial cytotoxic T cells. The inclusions are stained by Congo red and represent a form of intracellular amyloid that can be demonstrated by electron microscopy. The fibers in the electron micrograph shown here represent amyloid filaments. These filaments are immunoreactive for b-amyloid protein—same type of amyloid present in the senile plaques of Alzheimer disease. The pathogenic significance of these inclusions is not understood.

Question 16

Rhabdomyolyssi

Answer 16

Degeneration of the skeletal muscle and release of myoglobin

Question 17

Rhabdomyolysis complications

Answer 17

Acute renal failure and myoglobinuria

Question 18

What are type II muscle fibers suitable for?

Answer 18

Rapid contractions of brief duration and react to strength training with hypertrophy.

Question 19

Type II hypertrophy

Answer 19

Type II muscle fibers are suitable for rapid contractions of brief duration and react to strength training with hypertrophy. Androgenic steroids also induce hypertrophy of type II fibers, and disuse of the mus- cle results in their selective atrophy. Skeletal muscle does not respond to an increased workload by increasing the number of fibers (hyperplasia).

Question 20

Achondroplasia

Answer 20

Fibroblast Growth Factor

Question 21

Blue sclerae

Answer 21

Osteogenesis Imperfecta

Question 22

Osteogenesis Imperfecta

Answer 22

Mutations of COL1A1 and COL1A2 genes, which encode the a1 and a2 chains of type I procollagen, the major structural protein of bone.

Question 23

Lysyl hydroxylase

Answer 23

Ehlers Danlos

Question 24

Fibrillin gene mutation

Answer 24

Marfan’s syndrome

Question 25

High androgen levels lead to

Answer 25

Premature closure of epiphyseal plates and stunted growth