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Muscle tissue

Muscles

organization levels of the skeletal muscle

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Cardiac muscle

Smooth muscle

Skeletal muscle

cells are long, cylindrical parallel, and multinucleate

attached by tendons

striated-visible banding

voluntary-subject to conscious control

cells are long, cylindrical, branched, has single central nucleus

has striations

forms heart wall

joins to another cell at intercalated disc

involuntary

spindle-shaped cells w/ single central nucleus

has no striations

found mainly in hollow walls of organs and eyes (control size of pupil)

Physiology of muscle contraction

myosin head moves toward M line of sarcomere, pulling actin filaments past myosin

the actin is repeated many times powered by ATP

myosin attaches to actin, forming acting/ myosin cross bridges

Z line gets closer together as actin and myosin filaments slide past each other, and sarcomeres shorten ( H zone disappears) shortening the entire myofibrils

Ca++ binds to actin myofilament, exposing the myosin binding site

Nerve impulse or action potential travels down sarcolemma and into t-tubules causing sarcoplasmic reticulum to release Ca++ into sarcoplasm

Body movement terminology structure

Flexion

hyperextension

extension

rotation

abduction

adduction

circumduction

dorsiflexion

plantar flexion

inversion

eversion

supination

pronation

opposition

movement that decreases angle of joint

movement that increases angle of joint

extension beyond 180 degrees

movement of a bone around a longitudinal axis

movement of limb away from midline

movement of limb towards midline

proximal end of limb is stationary yard distal end moves in circle

lifting the superior surface of foot towards shin

pointing toe

turn sole of foot medially

turn sole of foot laterally

forearm rotates laterally so palm faces anteriorly

forearm rotates laterally so palm faces posteriorly

movement of thumb to touch tips of other finger

Muscle Fiber (cell)

myofibril (complex organelle composed of bundles of myofilaments)

fascicle (a portion of the muscle)

Sarcomere (a segment of a myofibril)

muscle (organ)

Myofilament or filament (extended macromolecular structure)

consists of hundreds of thousands of muscle cells, ct wrappings, blood vessels, and nerve fibers

discrete bundle of muscle cells, segregated from the rest of the muscle by a ct sheath

elongated multinucleate cell, has a banded (striated) appearance

romplex organelle composed of bundles of myofilaments. rodlike contractile element. occupy most of the muscle cell volume. appear banded and bands that are adjacent are aligned. composed of sarcomeres arranged end to end

a segment of a myofibril. the contractile unit, composed of myofiliments made up of contractile proteins

extended macromolecular structure. two types, thick and thin. thick contain bundled myosin molecules. thin contain actin molecules, plus other proteins.the sliding of the thin past the thick produce muscle shortening. elastic maintain the organization of the A band and provide for elastic recoil when muscle contraction ends.

Trunk

Arm

Head

Thigh and Leg

orbicularis oris

zygomaticus

orbicularis oculi

masseter

temporalis

buccinator

sternocleidomastoid

platysma

frontalis

raises eyebrow

closes jaw

blinks and closes eye

close and protucles lips

raises corner of mouth

closes jaw

compressed cheek as in writing and sucking, dos food between teeth during chewing

flexes neck and routes neck

pulls corner of mouth interiorly (below)

trapezius

rectus abdominis

pectorals major

external obliques

latissimus dorsi

erector spinae

primer mover of arm extension powerful arm adductor, medially rates arm

adducts and medially rotates arm, can help in climbing throwing, pushing and forced inspiration

stabilizes and elevates reacts and rotates scapula

flex and rotate lumbar region of vertebral column, stabilize pelvic during wairing

flex vertebral column and compress abdominal wall, trine rotation and lateral flexion

extend the back laterally flex the back and maintain correct posture and curvature of the spinal column

deltoid

flexor carpi radialis

tricep branchii

flexor digitorium superficiali

bicep branchii

flexor carpi ulnaris

extensor digitorium

extensor carpi radialis

flexes and supinates forearm

powerful forearm extensor

prime mover of arm abduction when all its fibers contact at the same time

powerful flexor of hand abducts hand

flexes and and middle phalanges of second to fifth finger

powerful flexor and adductor of hand

prime mover of finger extension

extends hand and adducts hand

gluteus maximus

hamstring

quadriceps group

tibialis anterior

adductor muscles

gastrocnemius

sartorius

extender digitorium longus

iliopsoas

soleus

flexing of the thigh and forward lifting of the pelvis

hip; flex laterally and rotate thigh, Knee; fled leg medially rotates the leg

adduction of thigh at the hip joint flexion and medial rotation of the femur

extensor of knee joint flexor of the hip

major extender of thigh laterally rotates and abducts thigh

flexion of knee extension of hip

prime mover of dorsiflexion, inverse foot

plantor flexes foot downward

prime mover of toe extension dorsiflexes foot

plantar flexes foot downward