Chapter 11

Question 1

Universal characteristics of muscles:

Answer 1

1. Excitability
2. Conductivity
3. Contractility
4. Extensibility
5. Elasticity

Question 2

Skeletal muscle characteristics

Answer 2

1. Produce movement
2. Maintain posture and body position, support soft tissues
3. Control of body openings and passages
4. Maintain body temperature - produce heat
5. store nutrients
6. Glycemic control

Question 3

Connective tissue sheaths provide…

Answer 3

Routes for blood vessels and nerves to enter the muscle, stabilize their positions

Question 4

Fascia =

Answer 4

Sheet of connective tissues that separates neighboring muscles or groups from each other or subcutaneous tissue

Question 5

Epimysium

Answer 5

Dense irregular connective tissue

Question 6

Perimysium

Answer 6

Surrounds fascicles (usually bundles of 2-60 fibers)

Question 7

Endomysium

Answer 7

Delicate, loose connective tissue sheath, chemical environment is important for muscle function

Question 8

Sarcolemma

Answer 8

Plasma membrane

Question 9

Sarcoplasm

Answer 9

Cytoplasm

Question 10

Myofibrils

Answer 10

Long protein cords

Question 11

Mitochondria

Answer 11

Aerobic cellular respiration

Question 12

Triads

Answer 12

Transverse tubule and terminal cisternae of sarcoplasmic reticulum

Question 13

Myofibiril are long chains of sarcomeres that ___ during contraction

Answer 13

Shorten

Question 14

Actin and myosin are considered _____ proteins

Answer 14

Contractile

Question 15

Tropomyosin and troponin are considered _____ proteins

Answer 15

Regulatory

Question 16

What links actin to the sarcolemma?

Answer 16

Dystrophin

Question 17

How do we get contraction of all the sarcomemeres within a muscle fiber at once?

Answer 17

Excitation- contraction coupling

Question 18

Membrane potential =

Answer 18

Voltage across the membrane

Question 19

voltage =

Answer 19

Electrical potential energy due to separation of oppositely charged particles (in our case ions!)

Question 20

High concentration OUTSIDE the cell =

Answer 20

-sodium (Na+)
-chloride (Cl-)

Question 21

High concentration OUTSIDE the cell =

Answer 21

-sodium (Na+)
-chloride (Cl-)

Question 22

Higher concentration INSIDE the cell:

Answer 22

• potassium (k+)
• protein anions

Question 23

Electrical gradient =

Answer 23

Ions are attracted to opposite charges, repelled by like charges

Question 24

There are more __ channels than __ channels

Answer 24

K+ , Na+

Question 25

Area where signal is received =

Answer 25

Motor end plate, contains chemically-gated channels

Question 26

Space that separates axon terminal from motor end plate =

Answer 26

Synaptic cleft

Question 27

Action potential =

Answer 27

A large change in membrane potential that spreads rapidly over long distances within a cell

Question 28

What affects the amount of tension produced?

Answer 28

1. Length of the sarcomere at the start of contraction
2. The frequency of the stimulus
3. Which motor units are contracting
4. Total number of motor units contracting