Chapter 9 Muscles And Muscle Tissue

Front 1

epimysium

Back 1

surrounds the whole muscle and is made of dense irregular connective tissue

Front 2

muscle fibers

Back 2

elongated muscle cells

Front 3

myo or mys

Back 3

root word meaning muscle in reference to muscle

Front 4

sarco

Back 4

root word meaning flesh in reference to muscle

Front 5

skeletal muscle tissue

Back 5

Muscle composed of cylindrical multinucleate cells with obvious striations; the muscle(s) attached to the body's skeleton; voluntary muscle. responsible for mobility

Front 6

smooth muscle

Back 6

Spindle-shaped cells with one centrally located nucleus and no externally visible striations (bands). Found mainly in the walls of hollow organs. involuntary muscle. moves fluids and substances

Front 7

cardiac muscle

Back 7

specialized muscle of the heart striated involuntary contractions controlled by the brain

Front 8

voluntary muscle

Back 8

muscle under strict nervous control; skeletal muscle

Front 9

involuntary muscle

Back 9

Muscle that cannot ordinarily be controlled voluntarily (e.g., smooth and cardiac muscle).

Front 10

Excitability (irritability or responsiveness)

Back 10

Ability to respond to stimuli.

Front 11

Contractility

Back 11

Muscle cell’s ability to move by shortening.

Front 12

connective tissue sheaths

Back 12

what muscle fibers are wrapped in and held together by. they support and reinforce the muscle

Front 13

epimysium

Back 13

sheath of dense irregular fibrous connective tissue surrounding the whole muscle

Front 14

perimysium

Back 14

sheath of fibrous connective tissue enveloping bundles of muscle fibers called fascicles

Front 15

fascicles

Back 15

Bundle of nerve or muscle fibers bound together by connective tissue

Front 16

endomysium

Back 16

sheath of connective tissue surrounding each muscle cell. fine areolar connective tissue

Front 17

insertion attachment

Back 17

movable attachment of muscle

Front 18

origin attachment

Back 18

Attachment of a muscle that remains relatively fixed during muscular contraction.

Front 19

direct attachment

Back 19

fused connection between epimysium of muscle to periostium of bon

Front 20

indirect attachment

Back 20

epimysium of muscle extends in ropelike tendon or sheetlike aponeurosis both anchor muscle to bone or other muscles

Front 21

tendon

Back 21

Cord of dense fibrous tissue attaching muscle to bone

Front 22

Sarcolemma

Back 22

The plasma membrane surface of a muscle fiber

Front 23

Sarcoplams

Back 23

The nonfibrillar cytoplasm of a muscle fiber.

Front 24

Glycosomes

Back 24

Granules of stored glycogen that provide glucosed during periods of muscle cell activity

Front 25

Myoglobin

Back 25

A red pigment that stores oxygen

Front 26

Myofibrils

Back 26

Rodlike bundle of contractile filaments hat occupy most of the muscle fiber (cell) volume

Front 27

Striations

Back 27

series of dark and light bands along the length of the myofibril

Front 28

A Bands

Back 28

Dark bands in the striations of the myofibril. They have a light midsecton called HZone w/ darker M Lines. Thick filaments span its width

Front 29

I Bands

Back 29

Light bands in the striations of the myofibril. They are interrupted by Z discs in the middle. Thin filaments span I Band and are partway in A Band also.

Front 30

H Zone

Back 30

Lighter region in the midsection of A Band

Front 31

M Lines

Back 31

Vertically bisecting dark lines of the H Zone formed by molecules of the protein myomesin. hold adjjacent thick filaments together

Front 32

Z Discs

Back 32

Midline intterruption of the I Band that anchors thin filaments

Front 33

Sarcomere

Back 33

Smalles contractile uinit of muscle consisting of the section between 2 Z Discs

Front 34

Myofilaments

Back 34

Filament that constitutes myofibrils. Of two types: actin (thick) and myosin (thin)

Front 35

Actin

Back 35

A contractile protein of muscle. thin filaments mostly composed of same

Front 36

Myosin

Back 36

One of the principal contractile proteins found in muscle.
thick filaments mostly composed of same.

Front 37

thick filaments

Back 37

central myosin containing filaments that spann the A Band

Front 38

thin filaments

Back 38

lateral actin containing filaments that spann the I band and part of the A band

Front 39

elastic filaments

Back 39

span the z disc and runs withing thick filaments forming its core and connecting one myofibril to the next

Front 40

cross bridges

Back 40

are formed when thick and thin filaments link togetther

Front 41

tropomyosin

Back 41

rod shaped protein that spirals about actin core of thin filaments that stiffen ans stabalizes it. block binding sites when muscle is relaxed.

Front 42

troponin

Back 42

globular protein in thin filaments that helps control myosin-actin interactions and helps position tropomyosin to actin of thin filaments

Front 43

titin

Back 43

a gian protein that elastic filaments are made of. holds thick filaments in place and helps muscle sping back into shape after being stretched

Front 44

Sarcoplasmic Reticulum

Back 44

Specialized endoplasmic reticulum of muscle cells responsible for regulating intracellular levels of ionic calcium

Front 45

T Tubules

Back 45

Extension of the muscle cell plasma membrane (sarcolemma) that protrudes deeply into the muscle cell and sends the message to every myofibril to contract.

Front 46

Terminal Cisternae

Back 46

tubules of sr @ A and I band junctions

Front 47

somatic motor neurons

Back 47

nerve cells that activate skeletal muscle

Front 48

axons

Back 48

long threadlike extensions of neurons that branch off to form neuromuscular junctions w/ single muscle cells. they carry impulses away from nerve cell body

Front 49

axon terminals (synaptic knob)

Back 49

bulbous distal endings of the teminal branches of an axon

Front 50

synaptic cleft

Back 50

fluid filled space at a synapse. located in extracellular space between axon terminal and sarcolemma.

Front 51

synaptic vesicles

Back 51

small membranous sacs containing neurotransmitter

Front 52

acetylcholine (ACh)

Back 52

Chemical transmitter substance released by some nerve endings.

Front 53

Junctional Folds

Back 53

the part of the sarcolemma that forms the neuromuscular junction that is highly folded to increase surface area

Front 54

Ach Receptors

Back 54

located in sarcolemma. Ach binds to them to open ion channels allowing Na+ into muscle and K+ out.

Front 55

Acetylcholinesterase

Back 55

Enzyme present at the neuromuscular junction and synapses that degrades acetylcholine and terminates its action

Front 56

Action Potential

Back 56

A large transient depolarization event, including polarity reversal, that is conducted along the membrane of a muscle cell or a nerve fiber

Front 57

Depolarization

Back 57

Loss of a state of polarity; loss or reduction of negative membrane potential.

Front 58

end plate potential

Back 58

local depolarization

Front 59

repolarization

Back 59

sarcolemma restored to intitial polarized state and is a consequence of change in membrane permeability

Front 60

refractory period

Back 60

stimulation is impossible becasue repolarization is occuring