Exam #3 Chapter 9 Muscular system (histology & physiology) part 1

Question 1

though skeletal muscle fibers don’t divide what DO they do and what is that?

Answer 1

hypertrophy- increase in size

Question 2

what are myofibrils composed of?

Answer 2

protein fibers (myofilaments)

Question 3

where is smooth muscle located?

Answer 3

walls of hollow organs, blood vessels, eyes, glands and skin

Question 4

what is the cell shape of smooth muscle?

Answer 4

spindle shaped

Question 5

what is a neuromuscular junction?

Answer 5

a few enlarged presynaptic (axon terminals separated from the fiber by a small synaptic cleft

Question 6

what do nerves do in a muscle fiber?

Answer 6

enter a muscle, branch and contract each muscle fiber near the middle.

Question 7

what does the myosin heads do?

Answer 7

they bind the actin active site and are an ATPase enzyme

Question 8

what is the endonysium?

Answer 8

a delicate structure that surrounds each muscle fiber

Question 9

do skeletal muscles have special cell-to-cell attachments and if so what are they?

Answer 9

no

Question 10

if you cut a nerve from skeletal muscle what will happen?

Answer 10

the muscle will never contract again

Question 11

what type of tissue does skeletal muscle contain?

Answer 11

connective tissue

Question 12

what is contractility?

Answer 12

the ability for the muscle to shorten forcefully or contract?

Question 13

what is the knowledge of skeletal muscle fiber structure required to understand?

Answer 13

the muscle contraction

Question 14

where is the muscular fascia located/

Answer 14

superficial to the epimysium

Question 15

are any of the muscle tissues capable of spontaneous contraction?

Answer 15

yes, cardiac muscle and some smooth muscle tissue

Question 16

what is the plasma membrane of a fiber called?

Answer 16

the sarcolemma

Question 17

what are T Tubules continous with?

Answer 17

the sarcolemma

Question 18

what are the tube-lie extensions of the sarcolemma into the cytoplasm of a fiber called?

Answer 18

transverse (T) tubules

Question 19

what is the sarcomere?

Answer 19

the functional unit of a muscle (the smallest structure that can contract)

Question 20

what type of nucleus does smooth muscle have and where?

Answer 20

single, centrally located

Question 21

what are Z disk composed of?

Answer 21

proteins to which the thin filaments attach in an ordered way

Question 22

what is extensibility?

Answer 22

when a muscle can be stretched beyond its normal resting length and still be able to contract.

Question 23

what is another word for nerves?

Answer 23

somatic motor neuron axons

Question 24

in muscle fibers what is the extensive smooth endoplasmic retiuculum called?

Answer 24

sarcoplasmic reticulum

Question 25

what is the cell shape of skeletal muscle?

Answer 25

very long and cylindrical

Question 26

which muscle tissues are voluntary and which are involuntary?

Answer 26

skeletal is both voluntary and involuntary (reflexes) and smooth and cardiac are involuntary

Question 27

what are some function of smooth muscle? (6) (MERCCM)

Answer 27

1) moving food through the digestive system 2) emptying the urinary bladder 3) regulating blood vessel diameter 4) changing pupil size 5) contracting many gland ducts 6) moving hair

Question 28

besides the mitochondria and glycogen granules what else does sarcoplasm contain?

Answer 28

many rod-like organelles called myofibrils

Question 29

how many cells is a muscle fiber?

Answer 29

one cell

Question 30

what do skeletal muscle look like?

Answer 30

1) long 2) cylindrical 3) multinucleate 4) striated cells

Question 31

what is an example of contractility?

Answer 31

lifting a textbook requires certain muscles to contract.

Question 32

which muscle tissue enables us to breath?

Answer 32

skeletal

Question 33

in muscle fibers what is the postsynaptic membrane?

Answer 33

the muscle fiber sarcolemma

Question 34

what do skeletal muscle fibers develop from?

Answer 34

the fusion of many myoblasts

Question 35

what are myosin molecules composed of?

Answer 35

2 myosin protein chains

Question 36

does cardiac muscle tissue have special cell-to-cell attachments and if so what are they?

Answer 36

yes, intercalated disks join cells to one another

Question 37

what does thin filaments also contain besides titin?

Answer 37

two strands of tropomyosin molecules

Question 38

what is the cell shape of cardiac muscle?

Answer 38

cylindrical and branched

Question 39

which muscle tissue moves substances?

Answer 39

all of them

Question 40

what is the muscular fascia?

Answer 40

separates individual muscles or group of muscles

Question 41

what else is in the sacrcomere ?

Answer 41

other proteins to regulate the interaction between thick and thin filaments and others to stabilize the ordered structure of the sarcomere

Question 42

what type of nucleus does skeletal muscle have and where?

Answer 42

multiple nuclei (peripherally located)

Question 43

what does the rest of the A band contain?

Answer 43

thick and thin filaments

Question 44

how do muscles function?

Answer 44

by forcefully shortening

Question 45

how are the myofilaments organized?

Answer 45

into a highly organized and repeating structures called sarcomeres

Question 46

besides titin and tropomyosin what else does thin filaments contain?

Answer 46

troponin molecules

Question 47

what is the cytoplasm in a muscle cell called?

Answer 47

sarcoplasm

Question 48

what are the thick myofilaments composed of?

Answer 48

mostly myosin

Question 49

which muscle tissue produces body movement?

Answer 49

skeletal

Question 50

what does titin do?

Answer 50

it keeps the ends of the thick filaments in position

Question 51

what does the presynaptic terminals contain?

Answer 51

vessicles with the neurotransmitter acetylcholine (ACh)

Question 52

when an action potential comes down the axon what does the axon terminals release?

Answer 52

aCh

Question 53

what do Z lines (disks) do?

Answer 53

separate individual sarcomeres (boxcars filaments attach in an ordered way)

Question 54

what is the function of skeletal muscle

Answer 54

body movement

Question 55

what is the sarcoplasmic reticulum?

Answer 55

a compartment for calcium storage

Question 56

what are the epimysium, perimysium and endomysium made of?

Answer 56

connective tissue

Question 57

what is the perimysium?

Answer 57

surrounds a group of fiber muscles (fascicle) and is fibrous

Question 58

where in the sarcomere are the thick filaments located?

Answer 58

in the center and positioned by proteins of the M line in an ordered array

Question 59

what do all muscle tissues display? (4) (ECEE)

Answer 59

1) electrical excitability 2) contractility 3) extensibility 4) elasticity

Question 60

what is elasticity?

Answer 60

the ability of a muscle to spring back to its original resting length after it has been stretched.

Question 61

what functions does muscle tissue have? (5) (BSEGM)

Answer 61

1) body movements 2) stabilizes our body position 3) enables us to breath and to communicate 4) generates heat 5) moves substances in our body

Question 62

what type of connective tissue is the epimysium?

Answer 62

dense irregular collagenous connective tissue

Question 63

what does motor neuron axons carry?

Answer 63

action potential to muscle fibers at the neuromuscular junction to produce contraction

Question 64

what are the 3 subunits of troponin do??

Answer 64

bind G actin, tropomyosin and calcium

Question 65

what is excitablility?

Answer 65

the capacity of a muscle to respond to an electrical stimulus.

Question 66

where is the H Zone located in the sarcomere?

Answer 66

in the center

Question 67

what is caused when the ACh diffuses across the synaptic cleft and binds with ligand-gated channels?

Answer 67

causes an action potention in the sacrolemma

Question 68

what do muscle only do when contracting?

Answer 68

shorten, they never lengthen

Question 69

does the thin filaments reach the M line?

Answer 69

only part of the way

Question 70

what are the thin myofilaments composed of?

Answer 70

mostly actin

Question 71

what does the sarcoplasm contain?

Answer 71

the mitochondria and glycogen granules

Question 72

what type of nucleus does cardiac muscle have and where?

Answer 72

single, centrally located

Question 73

where does the light or I band extend from?

Answer 73

the ends of the thick filaments in one or more sarcomere to the ends of the thick filaments in the adjacent sarcomere (z disk in middle)

Question 74

which muscle tissues are striated?

Answer 74

skeletal and cardiac

Question 75

what does the thin and thick filaments produce?

Answer 75

they are aligned producing alternating dark and light bands (striations)

Question 76

what is the entire skeletal muscle surrounded by?

Answer 76

the epimysium

Question 77

what is the part of the sarcomere that contains the thick filament?

Answer 77

dark or A band

Question 78

what does skeletal muscle fibers NOT do?

Answer 78

divide

Question 79

what does the rod-like portion of mysoin form?

Answer 79

the thick filament with heads facing out

Question 80

which muscle tissue stabilizes our body position (posture)?

Answer 80

skeletal

Question 81

what do the 2 myosin protein chains composed from mysoin look like?

Answer 81

they have a rod-like portion and a hinged head

Question 82

what does the H zone only contain?

Answer 82

thick filaments

Question 83

what are thin filaments composed of?

Answer 83

two strands of G actin monomers

Question 84

what does troponin and tropomyosin regulate?

Answer 84

the interaction between mysoin and actin

Question 85

what does the ACh do when it's released by the axon terminals?

Answer 85

it diffuses across the synaptic cleft, binds to the ligand-gated channels

Question 86

what do blood vessels do in a muscle fiber?

Answer 86

branch and form capillaries around each fiber

Question 87

which muscle tissue generates heat?

Answer 87

all of them

Question 88

what are thick filaments composed of?

Answer 88

myosin molecules

Question 89

does smooth muscle tissue have special cell-to-cell attachments and if so what are they?

Answer 89

yes, gap junctions join SOME visceral smooth muscle cells together

Question 90

what does each G actin monomer each have?

Answer 90

an active site to which myosin binds