Histology Ch. 11: Muscle Tissue

Front 1

The connective tissue layers that surround muscle fibers

Back 1

Endomysium
Perimysium
Epimysium

Front 2

Delicate layer of reticular fibers that surround individual muscle fibers

Back 2

Endomysium

Front 3

Morphologically identical to skeletal muscle but restricted to soft tissues

Back 3

Visceral striated muscle

Front 4

Location of skeletal muscle fiber nuclei

Back 4

sarcolemma(cytoplasm)

Front 5

Thick connective tissue layer that surrounds a group of muscle fibers to form a fascicle

Back 5

Perimysium

Front 6

Layer of dense connective tissue that surrounds a collection of muscle fascicles

Back 6

Epimysium

Front 7

The major vasacular and nerve supply penetrates this layer

Back 7

Epimysium

Front 8

Fibers characterized by oxidative metabolism contain large amounts of?

Back 8

Myoglobin, mitochondria, and electron transport systems

Front 9

Fibers that appear light pink, contain less myoglobin, fewer mitochondria, lots of glycogen, and high anaerobic enzyme activity

Back 9

Type IIb-fast glycolitic fibers: extraocular and digit muscles

Front 10

Fibers that contain many mitochondria and a high myoglobin content. They also contain large amounts of glycogen and can undergo anaerobic glycolysis

Back 10

Type IIa-fast oxidative glycolytic fibers

Front 11

Fibers appear red and cotain large amounts of myoglobin and mitochondria

Back 11

Type I-slow oxidative fibers: Long muscles of the back to maintain erect posture

Front 12

Rank myosin ATPase reaction velocity from slowest to fastest

Back 12

Type I
Type IIa
Type IIb

Front 13

The structural and functional subunit of the muscle fiber

Back 13

Myofibril

Front 14

The individual filamentous polymers of myosin II and actin and its associated proteins

Back 14

Myofilaments

Front 15

Basic contractile unit of striated muscle

Back 15

Sarcomere

Front 16

The functional unit of myofibril

Back 16

Sarcomere-extends from z line to z line.

Front 17

Bifringent band that marks the extent of myosin

Back 17

A band

Front 18

Band that contains only actin filaments. Seperated by the z line.

Back 18

I band- Isotropic

Front 19

Band that bisects the A band and contains only myosin

Back 19

H band

Front 20

Line that bisects myosin and H band

Back 20

M line

Front 21

Primary metabolic substrate in actively contracting muscle

Back 21

Glucose

Front 22

The energy stored in high energy phosphate bonds comes from the metabolism of what?

Back 22

fatty acids and glucose

Front 23

Metabolite formed during muscle exertion that results in ischemic pain (cramp)

Back 23

lactic acid

Front 24

Energy used by recovering or resting muscle comes from?

Back 24

Oxidative phosphorylation. this process closely follows the B-oxidation of fatty acids in mitochondria

Front 25

Smooth endoplasmic reticulum that surrounds myofilaments

Back 25

Sarcoplasmic reticulum

Front 26

molecule that polymerizes to form a double stranded helix, the F-actin filament

Back 26

G actin

Front 27

The positive end of the actin filament

Back 27

bound to the z line by a-actinin

Front 28

The negative end of the actin filament

Back 28

Extends toward the M line and is protected by actin-capping protein

Front 29

Myofilament that runs in a groove between the F-actin molecules

Back 29

Tropomyosin

Front 30

Binds Ca2+ to initiate contraction

Back 30

Troponin-C

Front 31

Key feature of myosin heavy chain

Back 31

Globular head with two binding sites: one for ATP and one for Actin

Front 32

Initiates smooth muscle contraction

Back 32

Phosphorylation by myosin light chain kinase of regulatory light chain

Front 33

the portion of myofilament which does not contain globular heads

Back 33

H band

Front 34

Forms an elastic lattice that anchors thick filaments in the z lines

Back 34

Titin

Front 35

Actin binding protein that anchors thin filaments to z line

Back 35

a-actinin

Front 36

Attached to Z lines and regulates the length of thin filaments during muscle development. Also anchors them.

Back 36

Nebulin

Front 37

Actin-binding protein that caps and regulates the length of actin. Influences physiological properties.

Back 37

Tropomodulin

Front 38

Holds thick filaments in register at m line

Back 38

Myomesin

Front 39

Links laminin of the external lamina to muscle cell actin filaments

Back 39

Dystrophin

Front 40

Rigor mortis is initiated by?

Back 40

Lack of ATP

Front 41

What occurs during the power stroke?

Back 41

ADP is lost

Front 42

What causes the myosin head to release from actin?

Back 42

Binding of ATP

Front 43

Rod shaped protein with a short head and long tail that is bound by F-actin

Back 43

Dystrophin

Front 44

Links dystrophin to the extracellular matrix proteins laminin and agrin

Back 44

alpha and beta dystroglycans

Front 45

Mutations in the genes found on x chromosome encoding sarcoglycans

Back 45

limb-girdle muscular dystrophy

Front 46

Function and location of terminal cisternae

Back 46

Reservoirs for Ca2+ located at the AI junction in the sarcoplasmic reticulum

Front 47

Invaginations of the plasma membrane that propagate action potentials

Back 47

T-tubules

Front 48

Complex of a T-tubule and two terminal cisternae

Back 48

Triad of skeletal muscle

Front 49

Depolarization of T-tubules activates what proteins that open what?

Back 49

Voltage-sensor proteins that undergo a conformational change to open gated Ca2+ channels of the terminal cisternae.

Front 50

What occurs directly after Ca2+ binds to Troponin-C

Back 50

TnI disassociates from actin

Front 51

At what point is the myelin sheath absent, and the axon is covered by only a thin portion of the neurilemmal cell and its external lamina?

Back 51

Neuromuscular junction

Front 52

A single neuron along with its the specific muscle fibers that it innervates

Back 52

motor unit

Front 53

Loss of innervation to a muscle fiber results in what?

Back 53

atrophy

Front 54

Transmits information about the degree of stretch of a muscle to the brain

Back 54

Muscle spindle cells

Front 55

Regulates the sensitivity of the stretch receptor

Back 55

Gamma efferent fibers from the brain and spinal cord. When skeletal muscle is stretched, nerve endings of sensory nerves become activated. They convey their impulses to the CNS, which modulates the activity of motor neurons

Front 56

Tendon organs contain only what type of fibers?

Back 56

afferent

Front 57

Myoblasts are derived from what?

Back 57

A self-renewing population of multipotential myogenic stem cells that originate in the embryo from unsegmented paraxial mesoderm

Front 58

Myoblasts express what during early embryonic development

Back 58

MyoD transcription factor

Front 59

Responsible for the skeletal muscles ability to regenerate

Back 59

Satellite cells begin expressing MRF's and become myoblasts as long as the external lamina is intact.

Front 60

External lamina disruption

Back 60

During muscle injury, external lamina disruption causes fibroblast repair, and scar formation

Front 61

Histological characteristics of cardiac muscle

Back 61

Intercalated disks, Single central nucleus, endomysium connective tissue

Front 62

Components of atrial granules

Back 62

Atrial natriuretic factor and brain natriuretic factor

Front 63

Attachment sites between adjacent cells

Back 63

Intercalate disks

Front 64

Holds the cardiac muscle cells at their ends to form the functional cardiac muscle fiber

Back 64

Fascia adherens: The site at which the then filaments in the terminal sarcomere anchor onto the plasma membrane

Front 65

Provide ionic continuity between adjacent cardiac muscle cells

Back 65

gap junctions

Front 66

Bind individual muscle cells to one another and help prevent the cells from pulling apart under the strain of contractions

Back 66

Maculae adherentes(desmosomes)

Front 67

Characteristics of T-tubules of cardiac muscle that differ from skeletal muscle

Back 67

T tubules much larger and carry external lamina into cell. Located at the z disk. T-tubule does not have surrounding terminal cisternae, but instead a diad.

Front 68

How many t-tubules per sarcomere in cardiac muscle?

Back 68

one

Front 69

Explain cardiac muscle depolarization

Back 69

Long lasting depolarization activates voltage sensor proteins which become Ca2+ channels that allow Ca2+ from the lumen into the sarcoplasm. The Ca2+ then activates gated Ca2+ release channels of the sarcoplasmic reticulum which allows release of Ca2+ from sER into the sarcoplasm