Chapter 9

Question 1

what are the three types of muscle tissues?

Answer 1

skeletal, cardiac and smooth

Question 2

what are the four basic properties of the muscle tissues?

Answer 2

excitability, contractility, extensibility, and elasticity

Question 3

what are the five functions of skeletal muscle?

Answer 3

produce skeletal movement, maintain posture and body position, support soft tissues, regulate entering and exiting of material, maintain body temperature

Question 4

what are the three layers of the connective tissue of muscle?

Answer 4

epimysium, perimysium, endomysium

Question 5

what is the epimysium?

Answer 5

dense irregular connective tissuelayer that surrounds the entire skeletal muscle

Question 6

what is the perimysium?

Answer 6

divides the muscle into a series of internal compartments.

Question 7

a bundle of muscle fibers is called?

Answer 7

fascicle

Question 8

what is the endomysium?

Answer 8

a delicate network of reticular fibers that surrounds each skeletal muscle fiber

Question 9

what are the two functions of the endomysium?

Answer 9

binds each muscle fiber to its neighbor, supports capillaries that supply individual fibers

Question 10

what do satellite cells do?

Answer 10

repair damaged muscle tissue that lie between endomysium and the muscle fibers

Question 11

what are aponeuroses?

Answer 11

think, flattened sheets formed by tendons

Question 12

sacrolemma

Answer 12

cell membrane

Question 13

sacroplasm

Answer 13

cytoplasm

Question 14

what is a myofibril?

Answer 14

cylindical structure that is responsible for skeletal muscle fiber contraction

Question 15

what are myofilaments?

Answer 15

protein filaments consisting of the proteins actin and myosin

Question 16

actin filaments are found where?

Answer 16

in thin filaments

Question 17

myosin filaments are found where?

Answer 17

in thick filaments

Question 18

actin and myosin filaments are organized into what?

Answer 18

sacromeres

Question 19

sacroplasmic reticulum is…

Answer 19

a sleeve made up of membranes surrounding each myofibril

Question 20

sacromeres are the … functional units of the muscle fibers

Answer 20

smallest

Question 21

thick filaments lie in the center of the sacromere linked by proteins of the…

Answer 21

M line

Question 22

what are Z lines?

Answer 22

filaments at either end of the sacromere attached to interconnecting proteins and extend toward the m line

Question 23

what is the zone of overlap?

Answer 23

thin filaments that pass between the thick filaments

Question 24

what is the A band?

Answer 24

area containing thick filaments

Question 25

what does the A band include?

Answer 25

the M line, the H band, and the zone of overlap.

Question 26

what is the I band?

Answer 26

the region between the A band and the Z line and containas oly thin filaments

Question 27

what does a thin filament contain?

Answer 27

the proteins tropomyosin and troponin

Question 28

what are the actinins?

Answer 28

open meshwork created by proteins

Question 29

myosin heads are also known as what?

Answer 29

cross bridges

Question 30

what is the sliding filament theory?

Answer 30

sliding occurs when the myosin heads of thick filaments bind to active sites on thin filaments

Question 31

what are the four features of the sliding filament theory?

Answer 31

the H and I band get smaller, the zone of overlap gets larger, Z lines move closer together and the width of the A band remains constant through contraction

Question 32

what is the immediate trigger of a contraction?

Answer 32

the appearance of free calcium and ions in the sacroplasm

Question 33

electrical impulses is distributed by what?

Answer 33

transverse tubules that extend deep into the sacroplasm of the muscle fiber

Question 34

what cocks the myosin head and prepares it for binding to an active site on actin

Answer 34

ATP

Question 35

describe the axon

Answer 35

extends to the periperphy, to reach the neuromuscular junction of that muscle fiber

Question 36

what is the synaptic terminal?

Answer 36

expanded tip of the axon at the neuromuscular junction

Question 37

what are synaptic vesicles?

Answer 37

mitochondria and dmall secretory vesicles

Question 38

acetylcholine is an example of what?

Answer 38

neurotransmitter

Question 39

the amount of muscle tension produced depends on what two factors?

Answer 39

the frequency of stimulation and the number of motor units involved

Question 40

what is the all or none principal?

Answer 40

each muscle fiber either contracts completely or does not contract at all