Muscle Physiology - Winden

Question 1

What are the functions of skeletal muscle?

Answer 1

Provides movement, generates heat, stores nutrient reserves, supports soft tissues, maintain posture and body position, guards entrances and exits

Question 2

What are the three different types of CT associated with skeletal muscle?

Answer 2

epimysium
perimysium
endomysium

Question 3

What does epimysium cover?

Answer 3

Covers the entire muscle

Connects to the deep fascia

Question 4

What does the perimysium cover?

Answer 4

Covers the fascicle

Question 5

What does the endomysium cover?

Answer 5

Covers the muscle fiber

Question 6

Describe the difference between a tendon and a aponeurosis

Answer 6

Tendon is the extensions of all the CT from the muscle that is attached to the bone

Aponeurosis is a sheet of the CT extension (ie. on the head)

Question 7

What are characteristics of skeletal muscle?

Answer 7

Voluntary
Striated
Multinucleated 
Long and can be large 
Develop from the fusion of myoblasts

Question 8

Name from smallest to largest the units of skeletal muscle

Answer 8

Myofilament, myofibril, myofiber, fascicle, muscle

Question 9

What is the triad consist of?

Answer 9

Two terminal cisternae and T-tubule

Question 10

What is distinct about the A band?

Answer 10

Length of the thick filament (dark)

Question 11

What is distinct about the I band?

Answer 11

Length between the ends of each thick filament (light)

Question 12

What is distinct about the M line?

Answer 12

Middle of the sarcomere and the center of the A band

Question 13

What is distinct about the H band?

Answer 13

The area of ONLY thick filaments

Question 14

What is distinct about the Z lines?

Answer 14

The center of the I band

Question 15

What is nebulin?

Answer 15

In the thin filament

Holds the two strands of F-actin together

Question 16

What is tropomysosin?

Answer 16

Two strands that block the active sites on the globular actin

Question 17

What is troponin?

Answer 17

Moves tropomyosin when binding with Ca

Question 18

What is titin?

Answer 18

Recoils myosin after contraction

Question 19

What are the components of myosin?

Answer 19

Head and Neck

Has active sites for both actin and ATP

Question 20

What is the sliding filament theory

Answer 20

Thin filaments move toward the M line
Width of the A band stays the same
Z lines move closer together

Question 21

What does contraction duration depend on?

Answer 21

Duration of neural stimulus
Amount of Ca
Avaliability of ATP

Question 22

What occurs with rigor mortis?

Answer 22

After a body has died, there is no ATP but abundant Ca

Cannot rest muscles

Question 23

Twitches have 3 phases:

What are they?

Answer 23

latent- Ca release
contraction- Ca binding
relaxation - Ca decrease

Question 24

What is Treppe?

Answer 24

Repeated stimulation right after relaxation

Question 25

What is Wave?

Answer 25

Stimuli arrives before relaxation has completed

Question 26

What is Tetanus and the two types?

Answer 26

Repeated stimuli with little or no relaxation Incomplete- little relaxation Complete- no relaxation

Question 27

What does skeletal muscle tension depend on?

Answer 27

internal and external tension | total number of muscle fibers

Question 28

What is a motor unit?

Answer 28

All the muscle fibers that are controlled by a single neuron

Question 29

What would you do to get a smooth contraction?

Answer 29

Recruitment

Question 30

What is muscle tone?

Answer 30

The firmness and tension of the muscle fiber at rest

Question 31

What is the difference between isotonic and isometric contraction?

Answer 31

Isotonic (same tension)- muscle changes length | Isometric (same measure)- changes in tension but not in length

Question 32

What is the difference between concentric and eccentric movement?

Answer 32

concentric- tension is larger than the load and muscle lengthens eccentric- tension is less than the load and the muscle shortens

Question 33

What is the difference between slow and fast fibers?

Answer 33

Slow fibers- are red aerobic fibers that are slow to contract and slow to fatigue; contain lots of myoglobin and mitochondria Fast fibers are white anaerobic fibers that are fast to contract and fast to fatigue