Musculoskeletal system

Question 1

What are osteocytes and what are their function?

Answer 1

bone cells; they help maintain bone by signaling osteoblasts and osteoclasts to form and reabsorb bone

Question 2

What are osteoblasts and what are their function?

Answer 2

bone forming cells; lay down new bone and become osteocytes that are embedded into bone

Question 3

What are osteoclasts and what are their function?

Answer 3

bone reabsorbing cells; responsible for remodeling. Contain lysosomes filled with enzymes. have ruffled borders

Question 4

What is the function of proteoglycans?

Answer 4

strengthen bone by forming compression resistant networks between collagen fibrils; control transport and distribution of calcium

Question 5

What is the function of bone albumin?

Answer 5

transports essential elements such as hormones, ions, and other metabolites to and from the bone cells and maintains the osmotic pressure of bone fluid.

Question 6

How are calcium and phosphate important in bone matrix?

Answer 6

they are the major inorganic components of the bone matrix. calcification begins when extracellular calcium enters the matrix vesicles and forms hydroxyapatite

Question 7

What are the 3 phases of bone remodeling?

Answer 7

phase 1: activation
phase 2: resorption
phase 3: formation

Question 8

Describe activation phase of bone remodeling (phase 1)

Answer 8

stimulus activates programmed osteocyte death, the apoptotic osteocytes provides osteoclasts with information about where to begin resorbing bone

Question 9

Describe resorption phase of bone remodeling (phase 2)

Answer 9

osteoclasts form a cutting cone that gradually resorbs bone, leaving behind an elongated cavity

Question 10

Describe formation phase of bone remodeling (phase 3)

Answer 10

laying down of new “secondary bone” by osteoblasts

Question 11

What are the differences between compact (cortical) bone and spongey (cancellous) bone?

Answer 11

Compact bone is strong and highly organized. Contains haversian system. Spongey bone is less complex, lamellae are arranged by trabeculae.

Question 12

Fibrous joints

Answer 12

immovable (synarthrosis); skull sutures, tibia/fibula or radial/ulnar, teeth held into jaw bone

Question 13

Cartilaginous joints

Answer 13

ribs to sternum, between vertebrae, connection of pubic bones

Question 14

Synovial joints

Answer 14

spheroid- shoulder
hinge - elbow
gliding - hand

Question 15

What is a motor unit?

Answer 15

lower motor neurons in the anterior horn connect to muscle fibers by its axon.
The higher the ratio (1 motor axon to 200 muscle fibers) the greater its endurance (calf muscle)
The lower the ratio (1 motor axon to 3 muscle fibers) the more precision

Question 16

Describe the 4 step process for muscle contraction: Excitation, coupling, contraction, and relaxation

Answer 16

Excitation: Action potential causing depolarization of T tubules and releases of Ca
Coupling: Ca ions attract troponin and tropomyosin, leaving actin and myosin free to bind with each other
Contraction: Actin slides toward myosin and muscle shortens CROSS-BRIDGES
Relaxation: sarcoplasmic reticulum absorbs the Ca removing them from interaction with troponin. muscle relaxes

Question 17

Comminuted fracture

Answer 17

bone breaks into more than two fragments

Question 18

Linear fracture

Answer 18

runs parallel to the long axis of the bone

Question 19

Oblique fracture

Answer 19

slanted fracture of the shaft of bone

Question 20

Spiral fracture

Answer 20

encircles the bone, seen in child abuse

Question 21

Transverse fracture

Answer 21

straight across the bone

Question 22

Green-stick fracture

Answer 22

perforates the cortex and splinters in the spongey bone.

Question 23

Torus fracture

Answer 23

cortex buckles but does not break

Question 24

Bowing fracture

Answer 24

longitudinal force is applied to bone. Common in children in radius-ulna or tibia-fibula

Question 25

Stress fractures

Answer 25

in bone subject to repeated forces

Question 26

Describe difference between subluxation and dislocation

Answer 26

Dislocation: displacement of bone from its original position
Subluxation: contact between joint surfaces is only partially lost

Question 27

Pathophysiology of sprain and strain

Answer 27

inflammatory exudate between torn ends; granulation tissue containing macrophages, fibroblasts and cap buds to begin repair process; collagen formation interweaves with tendon/ligament fibers

Question 28

Pathophysiology of bursitis

Answer 28

inflammation from overuse or excessive pressure. becomes engorged and can spread to adjacent tissues.

Question 29

What are the different types of epicondylitis?

Answer 29

lateral (tennis elbow) radial condyle

medial (golfer’s elbow) at humeral condyle

Question 30

What is rhabdomyolysis? Include patho and clinical manifestations

Answer 30

rapid breakdown of muscle that releases protein myoglobin. Classic triad of muscle pain, weakness and dark urine

Question 31

Osteoporosis and types

Answer 31

old bone is being reabsorbed faster than new bone is being made causing bone to lose density.
primary - postmenopausal
secondary- hormonal imbalances, medications, tabacco

Question 32

Clinical manifestations of osteoporosis

Answer 32

kyphosis (hunchback), shortened height, fractures of long bones

Question 33

Characteristics of metastatic bony tumors

Answer 33

??

Question 34

What is inflammatory joint disease and what are the clinical manifestations?

Answer 34

arthritis: damage or destruction in the synovial membrane or articular cartilage and systemic signs of inflammation.

Question 35

Rheumatoid arthritis

Answer 35

autoimmune disease distinguished by joint swelling and tenderness and destruction of synovial joints, presence of antibodies. warm joints, still painful after 1 hour from awakening

Question 36

Osteoarthritis and clinical manifestations

Answer 36

degenerative joint disease, bone spurs, enlargement of joint

Question 37

Ankylosing Spondylitis

Answer 37

Inflammatory joint disease of the spine or
sacroiliac joints causing stiffening and fusion
of the joints, scar tissue ossifies and calcifies. Loss of lumbar curvature, low back pain stiffness

Question 38

Clinical presentation of fibromyalgia

Answer 38

Wide spread joint and muscle pain, Increased sensitivity to touch, absence of
inflammation, fatigue, sleep disturbances

Question 39

How does juvenile arthritis differ from RA in adults?

Answer 39

less insidious onset, joint pain not as severe, large joints affected, rheumatoid nodules just just in subcutaneous tissue but also located in heart lungs and eyes.

Question 40

Osgood-Schlatter disease and clinical manifestations

Answer 40

tendinitis of anterior patellar tendon; pain and swelling in patellar tendon region and becomes prominent

Question 41

Legg-Calve-Perthes disease and clinical manifestations

Answer 41

osteochondrosis of hip caused by recurrent interruption of the blood supply to the femoral head. Pain often referred to knee, spasm on inward rotation of hip and limited abduction

Question 42

Pathophysiology of Duchenne muscular dystrophy

Answer 42

X linked, absent dystrophin, large calves consisting of fat and connective tissue rather than muscle.