Musculoskeletal system

Question 1

Skeletal muscle

Answer 1

Strained, voluntary, polynucleated

Question 2

Smooth Muscle

Answer 2

Not Strained, automatic, uninucleated, myogenic activity

Question 3

Cardiac Muscle

Answer 3

Strained, automatic, uninucleated or binucleated, myogenic activity

Question 4

Which zone or band in the sarcomere does not change in length during muscle contraction?

Answer 4

The A-band dos not change length during muscle contraction because it is the entire length of the myosin filament. The filaments do not change length, but rather slide over each other; this, the A-band should remain a constant length during contraction

Question 5

What are the events that initiate contraction in order?

Answer 5

Release of acetylcholine from motor neuron > activation of acetylcholine receptors in sarcolemma > depolarization of sarcolemma > spreading of signal using T-tubules > release of calcium from sarcoplasmic reticulum (SR) > binding of calcium to troponin > conformational shift of tropomyosin > exposure of myosin-binding sites > myosin binds to actin

Question 6

What roles does the binding of ATP to the myosin head play in the cross bridge cycle?

Answer 6

ATP binding allows myosin filament to disconnect from actin.

Question 7

What about the dissociation of ADP and inorganic Phosphate from myosin head?

Answer 7

Dissociation of ADP and inorganic phosphate from myosin causes the powerstroke

Question 8

What is tetanus?

Answer 8

Tetanus is the summation of multiple simple twitches that occur too quickly for the muscles to relax. This leads to a stronger and more prolonged contraction of the muscles

Question 9

What does GABA do?

Answer 9

Inhibit motor neurons (thus control muscle contraction)

Question 10

Compact Bone

Answer 10

It is dense and is used for strength; it forms most of the outer layers of a bone.

Question 11

Spongy Bones

Answer 11

Cancellous bone has many spaces between bony spicules called trabecular and is the site of marrow production. It is found in the interior core of bone and also helps distribute forces or pressures on the bone.

Question 12

What are the three structural parts of a bone? Which part contributes most to linear growth?

Answer 12

Diaphysis, metaphases and epiphyses. Growth plates are found in epiphyses and contribute to linear growth. Epiphyseal plate is the site of longitudinal growth that is a disk of cartilaginous cells.

Question 13

What chemicals form most of the inorganic component of bone?

Answer 13

Most inorganic bone is composed of hydroxyapatite crystals

Question 14

Osteoblasts

Answer 14

Build bones

- bone cells involved in the secretion of bone matrix

Question 15

Osteoclasts

Answer 15

Chew bones (break)

Question 16

Chondrocytes

Answer 16

Form cartilage

Question 17

What liquid provides the lubrication for movable joints? What tissue produces it?

Answer 17

Synovial fluid, produced by synovium, lubricates movable joints

Question 18

Articular cartilage

Answer 18

Prevents 2 bones from rubbing against each other

Question 19

periosteum

Answer 19

A fibrous sheath that surrounds long bones, is the site of attachment to muscle tissue. Some periosteum cells are capable of differentiating into bone-forming cells called osteoblasts.

Question 20

2 ways in which bones form

Answer 20

1. endochondral ossification

2. Intramembranous ossification

Question 21

endochondral ossification

Answer 21

It is the replacement of cartilagious skeleton with bone and occurs mostly in long bones

Question 22

Intramembranous ossification

Answer 22

It is the formation of bone from undifferentiated connective tissue cells (mesenchyme) and occurs mostly in skull