Chapter 11- Musculoskeletal System

Question 1

Skeletal muscle

Answer 1

Involved in support and movement. Propulsion of blood in the Venus system.
Thermal regulation.
Striated.
Under voluntary or somatic control. Polynucleated.

Question 2

What are the two types of fibers in skeletal muscle?

Answer 2

Slow twitch fibers that carry out oxidative phosphorylation. White fast twitch fibers that rely on anaerobic metabolism.

Question 3

Myoglobin

Answer 3

An oxygen carrier that uses iron in a heme group to bind oxygen. Present in slow and fast twitch fibers. More numerous in slow twitch fibers.

Question 4

Smooth muscle

Answer 4

Present in the respiratory reproductive cardiovascular and digestive systems. Non-striated.
Under involuntary or autonomic control.
Uninucleated.
Can display myogenic activity (contraction without neural input)

Question 5

Cardiac muscle

Answer 5

The contractile tissue of the heart. Striated.
Under involuntary or autonomic control.
Uninucleated,sometimes binucleated. Can display myogenic activity (contraction without neural input). Cells are connected with intercalated discs that contain a gap junctions. (Allows for full of ions directly between cells it allows for rapid uncoordinated depolarization of muscle cells)

Question 6

Sarcomere

Answer 6

The basic contractile units of striated muscle. Contains thick myosin and thin actin filaments.

Question 7

What are the bodyguards of actin filaments?

Answer 7

Troponins and tropomyosin that both are found on the thin filament of actin

Question 8

M line of the sarcomere

Answer 8

Located in the middle of the sarcomere

Question 9

I – band of the sarcomere

Answer 9

Contains only thin filaments

Question 10

H zone of the sarcomere

Answer 10

Consists of only thick filaments

Question 11

A band of the sarcomere

Answer 11

Contains thick filaments in their entirety. The only part of the sarcomere that does not change size during contraction.

Question 12

Myocyte

Answer 12

Muscle cell/muscle fiber

Question 13

Sarcomeres attach end to end to become what?

Answer 13

Myofibril. Each muscle cell or muscle fiber contains many myofibrils.

Question 14

What surrounds myofibrils?

Answer 14

Sarcoplasmic reticulum And sarcolemma

Question 15

Sarcoplasmic reticulum

Answer 15

A calcium containing modified endoplasmic reticulum.

A network of specialized smooth endoplasmic reticulum and transmits the electrical impulse as well as the storage of calcium ions.

Question 16

Sarcolemma

Answer 16

Cell membrane of a myocytes or muscle cells/muscle fiber

Question 17

T tubules transverse tubules

Answer 17

Allows for distribution of the action potential to all sarcomeres in a muscle. Oriented perpendicularly to myofibrils

Question 18

Where does muscle contraction begin?

Answer 18

The neuromuscular junction.

Question 19

Neuromuscular junction

Answer 19

Where the motor neuron releases acetylcholine that binds to receptors on the sarcolemma causing depolarization.

Question 20

What causes depolarization in the musculoskeletal system?

Answer 20

Release of acetylcholine that binds to receptors on the sarcolemma 

Question 21

Depolarization and muscle cells leads to what action?

Answer 21

Depolarization spreads down the sarcolemma to the T tubules and triggers release of calcium ions.

Question 22

Calcium binds to what to expose the myosin binding sites on the actin thin filament?

Answer 22

Binds to troponin which causes tropomyosin to expose the myosin binding site.

Question 23

Myosin binding to what molecule allows for the binding and release of myosin to the actin filament?

Answer 23

ATP

Question 24

What causes the relaxation of muscles?

Answer 24

Muscle relaxes when acetylcholine is degraded by acetylcholinesterase. The signals and allows calcium to be brought back into the Sarco plasmic reticulum. ATP binds to the myosin head and it releases from actin.

Question 25

Frequency summation

Answer 25

Addition of multiple simple twitches before the muscle has an opportunity to fully relax

Question 26

Tetanus

Answer 26

A more prolonged and stronger contraction caused when simple twitches occur so frequently and do not allow the muscle to relax at all.

Question 27

How do cells reduce oxygen debt?

Answer 27

Muscle cells have additional energy reserves to avoid being in a situation where the amount of oxygen needed is more than the amount of oxygen present.

Question 28

Creatinine phosphate

Answer 28

Can you transfer a phosphate group to ADP to form ATP

Question 29

Myoglobin

Answer 29

A human containing proteins that is a muscular oxygen reserve

Question 30

What are the two divisions of the human skeletal system?

Answer 30

The axial and appendicular skeleton

Question 31

Axial skeleton

Answer 31

Consists of structures in the midline such as the skull vertebral column rib cage and hyoid bone

Question 32

Appendicular skeleton

Answer 32

Consist of the bones of the limbs the pectoral girdle and the pelvis.

Question 33

Where is bone derived from?

Answer 33

From embryonic mesoderm includes both compact and spongy types

Question 34

Compact bone

Answer 34

Provide strength and his dense

Question 35

Spongy or cancellous bone

Answer 35

Has the loudest like structure consisting of bony spy tools known as trabeculae. Cavities are filled with bone marrow.

Question 36

Long bones

Answer 36

Contain shafts called diaphysis that flare to form metaphyses and terminate in the epiphyses

Question 37

What part of the bone allows for linear growth of the bone?

Answer 37

The epiphyseal or growth plate within the epiphyses

Question 38

What is the layer of connective tissue that surrounds the bone

Answer 38

Periosteum

Question 39

Tendons versus ligaments

Answer 39

Tendons connect bones to muscles. Ligaments connect muscle to muscle

Question 40

Bone matrix

Answer 40

Where the strength of compact bone comes from. Contains both organic and inorganic components. Organic components include collagen glycoproteins and other peptides. Inorganic components include calcium phosphate and hydroxide ions which harden together to form hydroxyapatite crystals

Question 41

Lamellae

Answer 41

Bone organized into concentric rings. Organize around a central Haversian or Volksmann canal. Structural unit known as an osteom.

Question 42

Where do osteocytes reside?

Answer 42

Between lamellar rings.

Question 43

Canaliculi

Answer 43

Connected with lacunae and allow for nutrient and waste transfer

Question 44

Osteoblasts

Answer 44

Build bone

Question 45

Osteoclasts

Answer 45

Reabsorb bone

Question 46

What hormone is involved in the reabsorption of bone/promotes osteoclasts activation.

Answer 46

Parathyroid hormone. Increases reabsorption of bone increases calcium and phosphate concentrations in the blood. Essentially breaks down bone

Question 47

Vitamin D’s role in the musculoskeletal system

Answer 47

Increases reabsorption of bone, increases turnover and subsequently the production of stronger bone

Question 48

Calcitonins role in the musculoskeletal system

Answer 48

Increases bone formation decreasing calcium concentrations in the blood

Question 49

Cartilage

Answer 49

A firm elastic material secreted by chondrocytes. Matrix is called chondrin. Avascular and not innervated

Question 50

Endochondral ossification

Answer 50

Development of fetal bones from cartilage.

Question 51

Intramembranous ossification

Answer 51

Formation of bone, example: the skull form directly from undifferentiated tissue (mesenchyme)

Question 52

Immovable joints

Answer 52

Joints that are fused together to form sutures or similar fibrous joints. Found primarily in the head where the anchor bones of the skull together. 

Question 53

Movable joints

Answer 53

Strengthen by ligaments and contain a synovial capsule. A layer of soft tissue secretes synovial fluid (into the synovium) which lubricates the movement of structures in the joint space.

Question 54

Antagonistic pairs of muscles

Answer 54

Muscles that serve opposite functions when one muscle contracts the other lengthens