Skeletal muscle

Question 1

What is myology

Answer 1

Study of muscle

Question 2

Muscle cells (fibres) properties

Answer 2

Contractility
Tension

Question 3

what are the three types of muscle

Answer 3

skeletal
smooth
cardiac

Question 4

skeletal muscle

Answer 4

-Attaches to and moves skeleton
-striated (striped) pattern
-under VOLUNTARY control

Question 5

Smooth muscle

Answer 5

Found in walls of hollow organs
Smooth appearance
Under INVOLUNTARY control

Question 6

Cardiac muscle

Answer 6

Has characteristics of both smooth and skeletal muscle

Question 7

what are the characteristics of cardiac muscle

Answer 7

Like skeletal muscle- striations
Like smooth muscle- involuntary control

Question 8

What is syncytium

Answer 8

A large cell-like structure formed by the joining together of two or more cells

Question 9

What are the three actions that work together

Answer 9

Prime mover
Antagonist
Fixators/stabilizers

Question 10

What is the origin

Answer 10

less moveable end of the muscle, usually proximal

Question 11

What is an insertion of a muscle

Answer 11

More moveable end of a muscle, usually distal

Question 12

what is the belly of a muscle

Answer 12

Widest portion of a muscle between origin and insertion

Question 13

Do all muscles insert on bone?

Answer 13

No, most of the muscles that control facial expression originate from bone and insert in the skin

Question 14

what is epimysium?

Answer 14

The epimysium is a dense layer of connective tissue that surrounds the entire muscle. -protects the muscle from friction and helps maintain its shape by connecting it to tendons and bones.

Question 15

What is perimysium

Answer 15

The perimysium is a layer of connective tissue that surrounds and groups muscle fibers into bundles called fascicles. It provides support and carries blood vessels and nerves to the muscle fibers within each fascicle.

Question 16

What is endomysium

Answer 16

The endomysium is a thin layer of connective tissue that surrounds each individual muscle fiber.

Question 17

Are tendons or muscles stronger?

Answer 17

Tendons

Question 18

What is a muscle cell called

Answer 18

Muscle fiber

Question 19

What is found within each muscle fibre

Answer 19

many myofibrils

Question 20

What do myofibrils consist of?

Answer 20

Each myofibril consists of a large array of contractile proteins arranged repeatedly in series.

Question 21

What is each repeated array of contractile proteins in a myofibril called?

Answer 21

sarcomere

Question 22

The two major contractile
proteins of the sarcomere are:

Answer 22

actin (thin) filament
myosin (thick) filament

Question 23

What happens during muscle contraction according to the sliding filament theory?

Answer 23

When a muscle is activated, myosin attaches to actin and, using ATP, pulls the actin to slide over myosin. This shortens the sarcomere and causes muscle contraction.

Question 24

How does blood supply differ between a sedentary person and a person who trains

Answer 24

sedentary- 3-4 capillaries surrounding each muscle fibres
Trained- up to 7 capillaries

Question 25

what is occlusion

Answer 25

Occlusion is the blockage or closing of a blood vessel or hollow organ. It can restrict blood flow or obstruct passage through a body part.

Question 26

at what % does occlusion happen

Answer 26

occlusion happens at 15-20% of max , complete occlusion happens at 50% of max force

Question 27

activation of a muscle fibre can produce:

Answer 27

Max force and max velocity

Question 28

What is a motor unit

Answer 28

A motor unit is the functional unit of a muscle.

Question 29

What does a motor unit consist of?

Answer 29

A motor unit consists of a motor neuron and all the muscle fibers it innervates.

Question 30

Where is the cell body of a motor neuron located?

Answer 30

spinal chord

Question 31

How far can a motor neuron's axon extend?

Answer 31

The axon can extend from the spinal cord to a muscle that may be a few millimeters to a few feet away.

Question 32

What are the two motor units based on contraction speed

Answer 32

fast twitch slow twitch

Question 33

what is slow twitch also called

Answer 33

Slow twitch oxidative (SO) or Type I

Question 34

What is the fast twitch oxidative-glycolytic motor unit also called?

Answer 34

Fast twitch oxidative-glycolytic (FOG) or Type IIa.

Question 35

What is the fast twitch glycolytic motor unit also called?

Answer 35

Fast twitch glycolytic (FG) or Type IIx.

Question 36

what is passive tension

Answer 36

Passive tension is the force generated in a muscle when it is stretched without any active contraction.

Question 37

positive velocity, shortening muscle

Answer 37

concentric contraction

Question 38

velocity is negative, muscle lengthening

Answer 38

eccentric contraction

Question 39

velocity is 0, no change in muscle length

Answer 39

Isometric contraction

Question 40

scaropenia is caused by (5):

Answer 40

Neural apoptosis (cell death) imbalance of muscle protein synth/degradation Physical inactivity hormonal imbalance food intake- insufficient protein

Question 41

sarcopenia enhances: (4)

Answer 41

-loss of physical function -risk of disability -more dependancy towards others -medical care costs

Question 42

prevention of sarcopenia

Answer 42

strength training, hormone therapy, diet, reduction in sedentary time