Microscopic Anatomy of Skeletal Muscle

Question 1

fibrous connective tissue surrounding fascicle

Answer 1

perimysium

Question 2

dense regular connective tissue surrounding the entire muscle & may blend with fascia

Answer 2

epimysium

Question 3

contractile unit of muscle from Z line to Z line

Answer 3

sacomere

Question 4

a muscle cell

Answer 4

fiber

Question 5

thin connective tissue surrounding each individual muscle fiber

Answer 5

endomysium

Question 6

plasma membrane of the muscle cell

Answer 6

sarcolemma

Question 7

a long filamentous organelle found within muscle cells that has a banded appearance

Answer 7

myofibril

Question 8

actin or myosin containing structure

Answer 8

myofilament

Question 9

cordlike extension of connective tissue beyond the muscle, serving to attach it to the bone

Answer 9

tendon

Question 10

a discrete bundle of muscle cells

Answer 10

fasicle

Question 11

perimysium

Answer 11

fibrous connective tissue surrounding a fascicle

Question 12

epimysium

Answer 12

dense regular connective tissue surrounding the entire muscle & may blend with fascia

Question 13

sacomere

Answer 13

smallest contractile unit of muscle from Z line to Z line which is composed of myofilaments made up of contractile proteins myosin (thick) & actin (thin)

Question 14

fiber

Answer 14

a muscle cell

Question 15

endomysium

Answer 15

thin connective tissue surrounding each individual muscle fiber

Question 16

sarcolemma

Answer 16

plasma membrane of the muscle cell

Question 17

myofibril

Answer 17

a long, filamentous organelle found within muscle cells that has a banded appearance

Question 18

myofilament

Answer 18

actin or myosin containing structure

Question 19

tendon

Answer 19

cordlike extension of connective tissue beyond the muscle, serving to attach it to the bone

Question 20

fascicle

Answer 20

a discrete bundle of muscle cells

Question 21

sarcoplasm

Answer 21

cytoplasm of the cell that is filled with myofibrils & glycogen for stored energy & myoglobin for binding oxygen

Question 22

cytoplasm of the cell

Answer 22

sarcoplasm

Question 23

thick filaments are made of

Answer 23

myosin

Question 24

thin filament are made of

Answer 24

actin

Question 25

contractile proteins

Answer 25

are myosin and actin they do the work of shortening the muscle fiber

Question 26

What proteins shorten the muscle fiber

Answer 26

myosin and actin - contractile proteins

Question 27

Glycogen

Answer 27

a starchlike carbohydrate that provides energy for the cell during heightened levels of exercise

Question 28

a starchlike carbohydrate that provides energy for the cell during heightened levels of exercise

Answer 28

glycogen

Question 29

myoglobin

Answer 29

red oxygen-building pigment which provides some of the oxygen needed for muscular activity found in the sarcoplasm

Question 30

red oxygen-building pigment which provides some of the oxygen needed for muscular activity found in the sarcoplasm

Answer 30

myoglobin

Question 31

sarcoplasmic reticulum (SR)

Answer 31

the smooth endoplasmic reticulum of skeletal muscle which forms a network around each myofibril with dilated end-sacs (terminal cistera) which store calcium

Question 32

the smooth endoplasmic reticulum of skeletal muscle which forms a network around each myofibril with dilated end-sacs (terminal cistera) which store calcium

Answer 32

sarcoplasmic reticulum (SR)

Question 33

Triad

Answer 33

the T tubule, one in the center, and the two terminal cisternae , run alongside the T tubule on the SR

Question 34

the T tubule, one in the center, and the two terminal cisternae , run alongside the T tubule

Answer 34

the Triad

Question 35

Terminal cisternae

Answer 35

crosses the muscle fiber from one side to the other which are dilated end-sacs of the SR which stores calcium

Question 36

crosses the muscle fiber from one side to the other which are dilated end-sacs of the SR which stores calcium

Answer 36

Terminal cisternae

Question 37

Tranverse (T) tubules

Answer 37

tubular infolding in the sarcolemma that penetrate through to the cell's interior at each A band-band junction and emerge on the other side - carries electrical signal into the cell - extension of the sarcolemma

Question 38

tubular infolding in the sarcolemma that penetrate through the cell and emerge on the other side

Answer 38

Tranverse (T) tubules

Question 39

Fibrous actin looks like a beaded necklace

Answer 39

called the "F" actin

Question 40

a string of subunits on the "F" actin

Answer 40

called globular "G" actin

Question 41

active site of the thin filaments which can bind to the head of a myosin molecule

Answer 41

each G actin

Question 42

tropomyosin

Answer 42

a protein on thin filament there are about 40 to 60 molecules

Question 43

a protein on thin filament there are about 40 to 60 molecules

Answer 43

tropomyosin

Question 44

called the "F" actin

Answer 44

Fibrous actin looks like a beaded necklace

Question 45

called globular "G" actin

Answer 45

a string of subunits on the "F" actin

Question 46

each G actin

Answer 46

active site of the thin filaments which can bind to the head of a myosin molecule

Question 47

troponin

Answer 47

calcium binding protein bound to tropomyosin

Question 48

calcium binding protein bound to tropomyosin

Answer 48

troponin

Question 49

elastic filaments

Answer 49

made of huge springy protein called titin which run through the core of each thick filament and anchor it to structures call the Z disc at one end and M line at the other

Question 50

made of huge springy protein called titin which run through the core of each thick filament and anchor it to structures call the Z disc at one end and M line at the other

Answer 50

elastic filaments

Question 51

stabilizes the thick filament, centers it between the thin filaments, prevents over stretching, & recoils like a spring after a muscle is stretched

Answer 51

purpose of titin

Question 52

purpose of titin

Answer 52

stabilizes the thick filament, centers it between the thin filaments, prevents over stretching, & recoils like a spring after a muscle is stretched

Question 53

regulatory protiens

Answer 53

tropomyosin and troponin because they act like a switch to determine when the fiber can contract and when it cannot

Question 54

dystropin

Answer 54

enormous protein located between the sarcolemma and the outermost myofilaments

Question 55

enormous protein located between the sarcolemma and the outermost myofilaments

Answer 55

dystropin

Question 56

"A" band

Answer 56

A - stands for anisotropic - is the dark band - where thick myosin filament are in striated muscles

Question 57

"I" band

Answer 57

I - stands for isotropic - is the light band - where thin actin filaments are in striated muscles - on each side of "A" band - Z disc(band) in center of each "I" band

Question 58

muscle fibers are

Answer 58

cylindrical cells with multiple nuclei, plasma membrane call (sarcolemma), cytoplasm (sarcoplasm), the organelles (sarcoplasmic reticulum & mitochondria) and contractile proteins (myosin & actin) that are responsible for striations

Question 59

cylindrical cells with multiple nuclei, plasma membrane call (sarcolemma), cytoplasm (sarcoplasm), the organelles (sarcoplasmic reticulum & mitochondria) and contractile proteins (myosin & actin) that are responsible for striations

Answer 59

muscle fibers

Question 60

fascia

Answer 60

outer fibrous layer that covers; separates muscles

Question 61

What is Z disc

Answer 61

is the Z line where an I band is bisected by a dark narrow line that provides anchorage for the thin & elastic filaments