Musculoskeletal Muscle Histology

Front 1

What is the plasma membrane of muscle cells?

Back 1

Sarcolemma

Front 2

What is the cytoplasm for muscle cells?

Back 2

Sarcoplasm

Front 3

What is the fascia surrounding the entire muscle?

Back 3

Epimysium

Front 4

What is a bundle of muscle fibers?

Back 4

Fasicle

Front 5

What surrounds each fasicle?

Back 5

Perimysium

Front 6

What surrounds each individual muscle cell?

Back 6

Endomysium

Front 7

How many muscle cells make up 1 fiber?

Back 7

1 cell

Front 8

What is a cell that is made up of many myofibrils?

Back 8

Myofiber

Front 9

Which band is the dark band?

Back 9

A band

Front 10

Which band is the light band in the spaces between the A bands?

Back 10

I band

Front 11

What bisects the I bands?

Back 11

Z-disks

Front 12

How many sarcomeres make up a muscle fiber?

Back 12

Many

Front 13

What is the light area in the middle of the A band?

Back 13

H band

Front 14

What is in the middle of the H band and sarcomere?

Back 14

M line

Front 15

What is a protein that fastens thin filaments to Z disks?

Back 15

Alpha Actin

Front 16

What is responsible for muscle contraction?

Back 16

Actin & Myosin (Actomyosin)

Front 17

What is wrapped around the actin?

Back 17

Tropomyosin

Front 18

What forms the I bands?

Back 18

Actin (thin filaments)

Front 19

What shape do thin filaments have?

Back 19

Helical shape

Front 20

What forms the A band?

Back 20

Myosin (thick filaments)

Front 21

What part of the myosin is the ATPase?

Back 21

Heavy meromyosin

Front 22

What is a rod-like protein that makes up the backbone of the thick filament?

Back 22

Light Meromyosin

Front 23

What connects the thick filaments together?

Back 23

Creatine Phosphate

Front 24

Which band disappears during contraction?

Back 24

H band disappears

Front 25

When the muscle is stretched which bands increase in width?

Back 25

I band and H band increase

Front 26

Where do T-tubules begin?

Back 26

At the interface between the A & I bands

Front 27

What is responsible for carrying a depolarization completely within a muscle fiber so that the muscle contracts all together?

Back 27

T-tubules

Front 28

What is the combination of two Sarcoplasmic reticulum complexes and the T-tubules?

Back 28

Triad

Front 29

What is structural syncytium also known as?

Back 29

Skeletal Muscle

Front 30

What happens during super contractions?

Back 30

thin filaments will bunch up in the center forming a new band

Front 31

What hormone is especially responsible for creating white muscle?

Back 31

Testosterone

Front 32

What cells help regenerate skeletal muscle?

Back 32

Satellite cells

Front 33

What type of muscle cells are lots of individual cells held together end-to-end to form fibers?

Back 33

Cardiac myocytes

Front 34

What holds together the Cardiac muscle cells?

Back 34

Intercalated Disks

Front 35

What two configurations are cardiact myocytes found in?

Back 35

Transverse and Longitudinal configuration

Front 36

What holds the transverse components of Cardiac myocytes together?

Back 36

Desmosomes and Fascia Adherens

Front 37

What does the longitudinal component of cardiac myocytes have that allows the wave of depolarization to travel?

Back 37

Gap Junctions

Front 38

What do the gap junctions ability to allow the cardiac myocytes to operate as if they are a single cell called?

Back 38

Functional Syncytium

Front 39

Where are the nuclei of cardiac myocytes?

Back 39

centered (not off to the side like skeletal muscle)

Front 40

Which muscle cells are branched?

Back 40

Cardiac myocytes

Front 41

T/F
Satellite cells present in the heart regenerate myocytes

Back 41

False
There are no satellite cells in the heart and so there is no regeneration/division

Front 42

T/F
T-tubules are found in cardiac muscles at the A/I band junction

Back 42

False
A/I junction is skeletal muscle

Cardiac is at the Z line

Front 43

T/F
Cardiac myocytes have diads

Back 43

True
Diads are only one Sarcoplasmic Reticulum associated with the T-tubule

Front 44

What is known as the wear and tear pigment in cardiac myocytes?

Back 44

Lipofuscin is from the waste products of lysosomal digestion. It accumulates in nerves but does not seem to affect function.

Front 45

What type of muscle consists of long Spindle-Shaped cells that taper at the end and have a nucleus in the center?

Back 45

Smooth muscle

Front 46

T/F
Smooth muscle cells are striated

Back 46

False
They have NO sarcomeres

Front 47

Since smooth muscle does not have sarcomeres do they lack myosin and actin?

Back 47

No, they are just organized differently

Front 48

How dow smooth muscle cells contract?

Back 48

They twist and shorten like a twisted towel

Front 49

T/F Smooth muscle have T-tubules and sarcoplasmic reticulum

Back 49

False
Instead they have small vesicles along the membrane that hold and release Ca++

Front 50

What muscle cells are linked by gap junctions?

Back 50

Smooth Muscle and Cardiac Muscle

Front 51

T/F
Smooth muscle is able to divide and it is stronger than skeletal muscle

Back 51

True

Front 52

Which muscle cells are the smallest?

Back 52

Smooth muscle cells

Front 53

Which muscle cells are the largest?

Back 53

Skeletal muscle cells
(multinucleated)