Muscles

Question 1

to move the body and things within the body –> Contraction

Answer 1

Function of Muscle

Question 2

Name the 3 types of Muscle

Answer 2

Smooth, Skeletal and Cardiac

Question 3

One muscle Cell

Answer 3

Fiber

Question 4

plasma (cell) membrane of muscle cell/fiber

Answer 4

Sarcolemma

Question 5

cytoplasm of muscle cell/fiber

Answer 5

Sarcoplasm

Question 6

smooth endoplasmic reticulum of muscle cell, storage area for fiber

Answer 6

Sarcoplasmic reticulum

Question 7

: prefix for muscle terms (e.g., myocyte = muscle cell)

Answer 7

Myo

Question 8

Not striated
Cells are spindle shaped
Centrally located nucleus
Regulated by the ANS
Visceral organs
Involuntary: not under conscious control
Found in hollow viscera, eye, attached to hairs (arrector pili)

Answer 8

Smooth Muscle

Question 9

Found only in the heart
Regulated by ANS
Striations from light and dark bands
Elongated branching cells
Ends of the cells join at intercalated disc
Highly specialized cell membrane –> facilitates transmission of electrical impulse

Answer 9

Cardiac Muscle

Question 10

Makes up majority of muscle mass in body
Striated
Do not branch, no intercalated disk
Innervated by cranial and spinal nerves
Multinucleated cells
Peripherally located nuclei
Voluntary: usually contracts only under conscious control
Exception: reflexes
Required nerve impulse for stimulation

Answer 10

Skeletal Muscle

Question 11

least movable attachment, usually proximal and/or medial

Answer 11

Origin

Question 12

most movable attachment, usually distal and/or lateral

Answer 12

Insertion

Question 13

___________ of the muscle brings origin and insertion closer together

Answer 13

Contraction

Question 14

Skeletal muscle types—action

Answer 14

Extensors, Flexors, Adductors, Abductors, Constrictors (sphincters), Dilators, Agonist and Antagonists

Question 15

extend or increase angle between body parts

Answer 15

Extensors

Question 16

flex or decrease angle between body parts

Answer 16

flexors

Question 17

pull limb toward median plane

Answer 17

Adductors

Question 18

move limb away from median plane

Answer 18

Abductors

Question 19

surround circular opening, close it when they contract

Answer 19

Constrictors (sphincters)

Question 20

surround circular area, open it when they contract (uncommon in mammals)

Answer 20

Dilators

Question 21

muscles that promote a given movement

Answer 21

Agonists

Question 22

muscles that inhibit a given movement, prevent hyperextension, etc.

Answer 22

Antagonists

Question 23

More myoglobin (Mb): oxygen storage
More glycogen: glucose storage
More mitochondria: ATP production
Slow twitch: slower to contract but fatigue slowly
Red muscles are used for endurance

Answer 23

Red Muscle Fibers

Question 24

Fast twitch: contract quickly but fatigue faster
Example: Rabbits have a quick burst of activity, not for endurance.

Answer 24

White Muscle Fibers

Question 25

Parallel, Pennate, Fleshy, Oblique

Answer 25

Muscle Fibers Arrangements in Muscle

Question 26

tendon comes off ends of fibers to attach to bone Example: pectoralis muscle

Answer 26

Parallel Muscle Shape

Question 27

feather-like with central tendon, wide at the top and converges at the tendon Example: biceps

Answer 27

Pennate Muscle Shape

Question 28

appears to attach directly to bone, but has short (microscopic) tendons between muscle fibers and bone

Answer 28

Fleshy Muscle Shape

Question 29

circular or convergent (abdomen)

Answer 29

Oblique Muscle Shape

Question 30

Loose C.T. around muscle cells

Answer 30

endomysium

Question 31

Loose C.T. around muscle bundles (fascicles) of muscle cells

Answer 31

perimysium

Question 32

Dense irregular to regular C.T. around whole muscle

Answer 32

epimysium

Question 33

Endomysium, perimysium and epimysium all meet at ends (or center for pennate muscles) to become

Answer 33

Tendons to attach to bones -->transfers movement and energy of contraction to bones

Question 34

Endomysium, perimysium and epimysium are.....

Answer 34

C.T. harnessing muscle

Question 35

Muscle cell (fiber) composed of

Answer 35

Myofibrils

Question 36

These are composed of protein myofilaments and have Myosin and Actin

Answer 36

Myofibrils

Question 37

thick filament

Answer 37

Myosin

Question 38

thin filament

Answer 38

Actin

Question 39

Arrangement makes units called ______ along myofibril Banding pattern—striations

Answer 39

sarcomeres

Question 40

Banding pattern

Answer 40

striations

Question 41

length of myosin filament, includes overlap with actin, stains dark Always he same length

Answer 41

A band

Question 42

actin only, does not include area of overlap with myosin, stains light Change with contractions and relaxation (length)

Answer 42

I band

Question 43

myosin only without actin overlap Change with contractions and relaxation (length)

Answer 43

H band

Question 44

ends of sarcomere, connects actin filaments

Answer 44

Z line

Question 45

middle of sarcomere, connects myosin filaments

Answer 45

M line

Question 46

Protein filament Individual myosin filaments resemble golf clubs, fit together with heads at ends sticking out all around No heads in middle of filament Head is heavy meromyosin (HMM) Neck is light meromyosin (LMM)

Answer 46

Myosin Filament

Question 47

Protein myofilament 3 parts Individual actin molecules are globular (G-actin) and fit together like beads on a string --> 2 strands of G-actins twisted around each other make the actin filament Groove of actin filament (between actin strands) has a different strand of protein --> tropomyosin Tropomyosin has a globular protein, troponin, spaced along it Has binding sites for myosin heads along filament, in relaxation tropomyosin covers these binding sites so that actin and myosin do not interact

Answer 47

Actin Filament

Question 48

Synapse of a motor neuron on a skeletal muscle fiber Cell bodies of motor neurons in ventral horns of spinal cord One motor neuron usually branches to synapse on many skeletal muscle cells One motor unit: one motor neuron + all skeletal muscle fibers it innervates (synapses with)

Answer 48

Neuromuscular junction or motor endplate