Muscles And Muscle Terms

Front 1

What are the main functions of muscle

Back 1

Movement

-heat production

- posture

Front 2

True

Back 2

T or F

the body contains more than 600 skeletal muscles

-40 to 50% of bodyweight skeletal muscle

Front 3

True

Back 3

T or F

the direction of fibers is significant because of its relation to the function

Front 4

Types of muscle contractions

Back 4

reflexive contraction

- tonic contraction

- phasic contraction

-isotonic contraction

Front 5

Reflexive contraction

Back 5

automatic activity

-movement of the diaphragm or movement of a muscle after tapping a tendon with a reflex hammer

Front 6

Tonic contraction

Back 6

continual partial contraction of a muscle at rest

-a small number of muscle fibers contract to produce tightness

- functions to stabilize joints and maintain posture

-absent only when unconscious or with paralysis

Front 7

Phasic contraction

Back 7

There are two types: isotonic and isometric

Front 8

Two types of isotonic contraptions

Back 8

Concentric and eccentric

Front 9

Isotonic contraction

Back 9

Contraction in which the tone or tension within a muscle remains the same as the length of the muscle changes

Front 10

Concentric

Back 10

Muscle shortens as it contracts ex: lifting a cup or pushing a door

Front 11

Eccentric

Back 11

Muscle lengthens while contracting ex: setting objects down, walking, running

Front 12

Isometric contraction

Back 12

Contraction in which muscle length remains the same while muscle tension increases

Front 13

Flaccid

Back 13

muscles with less tone then normal

Front 14

Spastic

Back 14

muscles with more tone than normal

Front 15

Isotonic

Back 15

same tension

Front 16

Isometric

Back 16

same length

Front 17

Functions of muscles

Back 17

Prime mover

- agonist

-antagonist

- synergists

-fixator muscles

Front 18

Prime mover

Back 18

Muscle that directly performs a specific movement

Front 19

Agonist

Back 19

Any mover muscle that directly performs a movement including the prime mover

Front 20

Antagonist

Back 20

Muscles that when contracting directly oppose prime movers

- relax while the prime mover is contracting to produce movement

-provide precision and control during contraction of prime mover

Front 21

Synergists

Back 21

Muscles that contract at the same time as the prime movers

-facilitate prime mover actions to produce a more efficient movement

Front 22

Fixator muscle

Back 22

Joint stabilizers through isometric contraction

- it is a type of synergist

Front 23

True

Back 23

T or F

muscles are composed of bundles of muscle fibers held together by fibrous connective tissue

Front 24

Motor unit

Back 24

Motor neuron plus the muscle fibers to which it attaches

Front 25

The smaller number of fibers in a motor unit

Back 25

the more precise the movements available

Front 26

The larger the number of fibers in a motor unit

Back 26

the more powerful the contraction available

Front 27

Sarcolemma

Back 27

Plasma membrane of the muscle fibers

Front 28

Sarcoplasmic reticulum (SR)

Back 28

contains T tubules(network of tubules and sac found within muscle fibers)

-membrane of the ___continually pumps calcium ions from the sarcoplasm and stores the ions within its sacs for later release

Front 29

Myofibrils

Back 29

Numerous fine fibers packed close together in the sarcoplasm

Front 30

Sarcomere

Back 30

Segment of myofibril between two successive Z disks

-each myofibril consists of many ___________

-the contractile unit of muscle fibers(what makes the muscles contract)

Front 31

Z disks

Back 31

it forms the lateral border of the sarcomere

Front 32

A bands

Back 32

They are the dark stripe, the light H zone runs across the midsection of each dark __ band

Front 33

I bands

Back 33

a dark Z disk extends across the center of each light __ band

Front 34

Myofilaments

Back 34

each myofibril contains thousands of thick and thin _______________

Front 35

The different kinds of protein molecules that make up myofilaments

Back 35

myosins

-actin

-tropomyosin

-troponin

Front 36

Myosins

Back 36

Makes up almost all the thick filament

- heads are chemically attracted to actin molecules

-heads are known as cross bridges when attached to actin

Front 37

Actin

Back 37

Globular proteins that form two fiberous strands twisted around each other to form the bulk of the thin filament

Front 38

Tropomyosin

Back 38

Protein that blocks the active sites on actin molecules

Front 39

Troponin

Back 39

Protein that holds tropomyosin molecules in place

Front 40

Acetylcholine

Back 40

Neurotransmitter released into the synaptic cleft that diffuses across the gap, stimulates the receptors, and initiates an impulse in the sarcolemma

Front 41

Fascicles

Back 41

groups of muscle fibers

Front 42

Origin

Back 42

most proximal

-muscle's attachment to the more stationary bone

Front 43

Insertion

Back 43

most distal

-muscle's attachment to the more movable bone

Front 44

Endomysium

Back 44

layer of connective tissue that covers each individual muscle fiber, over the sarcolemma

Front 45

perimysium

Back 45

a sheath of connective tissue that groups muscle fibers into bundles

Front 46

Epimysium

Back 46

a layer of connective tissue, which covers the entire muscle