Muscular System

myology

study of the different muscles

movement and contraction, gives shape and forms the body, attachment to other organs

functions of muscles

excitability, contractility, extensibility, elasticity

4 basic properties of muscles

excitability

ability to respond to a stimulation

contractility

ability to shorten, done to exert a pull or tension

skeletal muscles

type of muscles that responds through the nervous system

smooth muscles

type of muscles that responds to circulating hormones

connective tissues

what tissue can harness the contractility of a muscle?

extensibility

ability to CONTINUE to contract over a range of resting lengths

smooth muscle

muscle that can be super stretched but still contract on stimulation

elasticity

ability of the muscle to rebound toward its original length after contraction

non striated

appearance of smooth muscles

involuntary

action of smooth muscles

internal/visceral organs

location of smooth muscles

smooth muscle

type of muscles that has the most variations in terms of form and function

regulate the diameter, propel liquids or solids, expel contents

functions of smooth muscle

myocardium

muscular component of the heart

striated

appearance of cardiac muscles

involuntary

action of cardiac muscles

heart

location of cardiac muscles

skeletal muscles

parallel, long, multinucleated fubers

striated

appearance of skeletal muscles

voluntary

action of skeletal muscles

attached to the skeleton

location of skeletal muscles

produce movement, maintains posture, supports soft tissue, guards entrances and exits, maintains body temp

functions of skeletal muscles

epimysium

outer layer of skeletal muscles, entire muscle is covered by this

Epimysium

layer of collagen fibers

separates muscles from surrounding tissues and organs

function of epimysium

epimysial fibers

come together to form tendons that attaches skeletal muscles to the bones

tendon fibers

interwoven into the periosteum of the bone → provides a firm attachment

perimysium

middle layer of skeletal muscles, which contains blood vessels and nerves

perimysium

layer of muscle that contains collagen and elastic fibers

divides the skeletal muscle into series of compartments

function of perimysium

fascicle

the bundle of muscle formed by perimysium

endomysium

found within a fascicle → surrounds each skeletal muscle fiber

ties each muscle fibers together

endomysium function

origin, insertion, belly

parts of a skeletal muscle

origin

more fixed point of attachment, head of the muscle/proximal end

insertion

more movable point, distal end of the muscle

belly

fleshy part of the muscle

unipenniform, bipenniform, multi penniform, spiral, cruciate, triangular

muscles that are oblique to the line of pull

unipenniform

muscles with fibers that are parallel to one another but not along its own axis

bipenniform

muscles with fibers that converge to common tendon

multipenniform

muscles with fibers that run in several directions

spiral

muscles with fibers that are twisted in arrangement

cruciate

muscles that are in a spiral arrangement that has 2 or more planes or fibers

triangular

fan shaped muscles, fibers runs obliquely to a common tendon

quadrilateral, strap like, strap with tendinous insertions, fusiform

muscles that are parallel to the line of pull

quadrilateral

fibers that are largely parallel to the line of pull, flat and short

strap like

same description as quadrilateral BUT it is flat and long

strap with tendinous insertions

muscles with individual fibers that run for over shorter segments

fusiform

muscles that have fibers that are almost parallel to one another, ending in a tendon

prime movers

muscles that produce the actual desired muscular action

antagonist

muscles that oppose the movements of the prime movers

fixators

when prime movers and antagonists contract together → stabilizes the corresponding joint

increased trans articular compression

how does the fixators stabilize the joint

fixators

type of muscle that creates an immobile base where other prime movers may act

synergists

muscles that may individually have different actions but acts a s a group

synergists

assistants in accomplishing the movement

rhomboid

diamond shaped muscles

deltoid

triangular shaped muscles

serratus

serrate muscles

quadratus

square shaped muscles

teres

round shaped muscles

gracilis

slender shaped muscles

lumbrical

worm like muscles

sternocleidomastoid

muscles that are attached to the sternum, clavicle, and mastoid process

coracobrachialis

muscles that are attached to the coracoid process to the arm

sternohyoid

muscles that are attached to sternum to hyoid bone

dorsi

muscles found in theback

abdominis

muscles found in the abdomen

pectoralis

muscles found in the chest

brachii

muscles found in the arm

femoris

muscles found in the thigh

oris

muscles found in the mouth

rectus

muscles that are straight

transverse

muscles that are horizontal

biceps

muscles with 2 heads

triceps

muscles with 3 heads

quadriceps

muscles with 4 heads

digastric

muscles with 2 bellies

superficialis

superficial muscle

profundus

deep muscle

major, magnus

referring to big muscles

minor, minimus

referring to small muscles

latissimus

referring to broadest muscle

longissimus

referring to longest msucle

longus

referring to muscle with long muscle fibers

brevis

referring to muscle with short muscle fibers

tendons

straps of round or oval cross section, cord like or ribbon like, with smooth and glistening surfaces

tendons

strongly attached to bones

connects muscle to bones

function of tendons

synovial bursae

flattened sac of synovial membrane, opposed walls are separated by film or fluid

capillary film

nourishes the lining of synovial cells,

synovial tendon sheaths

where tendons pass under ligamentous bands and retinacula, separated by a thin film of synovial fluid

aponeuroses

broad, thin sheets of connective tissues → carries tensile forces directly or indirectly

connects muscles to muscles

function of aponeuroses

superficial fascia

layer of loose connective tissue of variable thickness, mostly made up of adipose

adipose

foundbetween muscle and skin

attaches muscles to dermis

function of superficial fascia