Muscle Histology & Skeletal Muscle Identification

characteristics of muscle tissue

excitability, contractility, extensibility, elasticity

functions of muscle tissue

-providing body movement

-supporting organ structure

-protection

-thermogenesis

-blood circulation

Another name for muscle cells is a ________.

myocyte

The three types of muscle tissue are ______, ______, and _______.

skeletal, cardiac, smooth

skeletal muscle function

responsible for body movement

skeletal muscle location

attached to bones

skeletal muscle is under ____ control

voluntary

skeletal muscle is ______-nucleated

multi-nucleated

skeletal muscle is

a. striated

b. un-striated

a. striated

skeletal muscle

cardiac muscle function

pump blood

cardiac muscle location

forms the bulk of the heart

cardiac muscle is under ________ control

involuntary

cardiac muscle is _____-nucleated

mono-nucleated (1 nucleus)

cardiac muscle is

a. striated

b. un-striated

a. striated

cardiac muscle

smooth muscle function

propels substances or objects along internal passageways

smooth muscle location

forms walls of hollow organs (ex: esophagus, GI tract)

smooth muscle is under ______ control

involuntary

smooth muscle is _____-nucleated

mono-nucleated (1 nucleus)

smooth muscle is

a. striated

b. un-striated

b. un-striated

smooth muscle

intercalated discs

junctions between cells anchor cardiac cells

epimysium

covers the entire skeletal muscle group (outermost layer)

perimysium

surrounds fascicles (middle layer)

endomysium

Connective tissue surrounding a muscle fiber (innermost layer)

fasicle

a discrete bundle of muscle cells

muscle fiber (cell)

bundle of myofibrils

sarcolemma

plasma membrane of a muscle fiber

myofibril

tightly packed filament bundles found within skeletal muscle fibers

sarcomere

contractile unit of a muscle fiber

sarcomeres run from __- disc to __- disc

z-disc

z-disc

sarcomere boundary

a-band

area of contraction and relaxation

i-band

actin filaments (thin)

h-band

myosin filaments (thick)

origin

attachment at the stationary end

insertion

attachment at the moving end

action

the effect produced by the muscle (produce or prevent movement)

agonist (prime mover)

produces most of force

synergist

assistant to agonist

antagonist

opposes prime mover

fixator

prevents movement of bone

frontalis

elevates eyebrows and scalp

orbicularis oculi

closes the eye (blink, squint, flow of tears)

orbicularis oris

moves lips

buccinator

compresses cheek (whistle, blow, drink through straw, chew)

masseter

elevates mandible to close mouth

sternocleidomastoid

laterally flexes; rotates head

trapezius

draw head back

rectus abdominus

sitting up

external oblique

twisting, bending to the side

pectoralis major

brings elbows together

deltoid

lifts arms at shoulder

latissimus dorsi

arm movement

biceps brachii

bicep curl

triceps brachii

extends forearm

gluteal group

gluteus maximus

gracilis

moves thighs together

hamstring

-biceps femoris, semitendinosus, semimembranosus

-all bend the knee (hamstring curls)

biceps femoris

semitendinosus

semimembranosus

rectus (quadriceps) femoris

gastrocnemius

flexes foot and knee, jumping, running, walking

soleus

steadies leg on ankle when standing

tibialis anterior

dorsiflexion of the ankle (raising toes and clears foot off ground when running/walking)