MUSCULAR SYSTEM

skeletal muscles

• organs of the muscular system

• most of them are attached to bone

functions of the muscular system

• Locomotion

• Posture 

• Respiration

• Communication

• Constriction 

• Heartbeat

• Body heat regulation

nervous system

• Primary coordinating and controlling system of the body

• divided into central and peripheral

properties of muscle

• Extensibility

• Elasticity 

• Contractility 

insertion

movable attachment of a muscle

origin

immovable attachment of a muscle

agonists

group of muscles producing an action

antagonists

opposing group of muscles

buccinator and epicranius

compresses cheeks inward

frontal belly

elevates eyebrows and wrinkles forehead

occipital belly

pulls scalp posteriorly

orbicularis oculi

closes eye

orbicularis oris

closes eye and puckers lips; shapes lips during speech

platysma

draws angle of the mouth inferiorly

zygomaticus

elevates corners of mouth (smiling)

elevates mandible

masseter and temporalis

trapezius

elevates clavicle

abducts and elevates scapula

extends head

rhomboid major and minor

adducts and elevates scapula

levator scapulae

elevates scapula

serratus anterior

depresses, protracts, and rotates scapula

pectoralis minor

depresses and protracts scapula

scapular muscles

stabilizes the scapula when the shoulder complex is loaded

moving and positioning the scapula to facilitate movement

pectoralis major

abducts, flexes, and medially rotates arm

deltoid

abducts, flexes, and extends arm

latissimus dorsi

adducts, extends, and medially rotates arm

teres major

same as latissimus dorsi

supraspinatus

abducts arm

laterally rotates arm

infraspinatus and teres minor

subscapularis

medially rotates arm

biceps brachii

rotates forearm and supination, also flexes arm

brachialis

flexes forearm

brachioradialis

flexes forearm

flexes forearm

brachialis and brachioradialis

triceps brachii

extends forearm, also extends arm

flexor carpi radialis

flexes and abducts wrist

flexor capri ulnaris

flexes and adducts wrist

palmaris longus

flexes wrist

extensor carpi radialis longus

extends and abducts wrist

extensor carpi ulnaris

extends and adducts wrist

extensor digitorum

extends fingers

rectus adonis

tightens abdominal wall; flexes the vertebral column

external and internal oblique

tightens abdominal wall

rotation and lateral flexion of the vertebral column

transversus abdominis

tightens abdominal wall

diaphragm

forms floor of thoracic cavity

depresses during contraction, causing inspiration

external intercostals

elevates and protracts ribs during inspiration

internal intercostals

depresses and retracts ribs during expiration

flexes thigh

illiacus and psoas major

gluteus medius

abducts and medially rotates thigh

tensor fasciae latae

flexes and abducts thigh

adducts, flexes, and laterally rotates thigh

adductor longus and adductor magnus

extends leg and flexes thigh

quadriceps femoris

rectus femoris

extends leg

vastus lateralis

vastus medialis

vastus intermedius

biceps femoris

flexes and laterally rotates leg

extends thigh

flexes and medially rotates thigh

semitendinosus

semimembranosus

gracilis

adducts thigh

flexes leg and locks knee

sartorius

flexes thigh and leg

abducts and laterally rotates thigh

gastrocnemius

plantar flexes foot and flexes leg

solenus

plantar flexes foot

fibularis longus

plantar flexes and everts foot

supports arch

tibialis anterior

dorsiflexes and inverts foot

extensor digitorum longus

dorsiflexes and everts foot

extends toes

concentric contraction

muscle shortens

produces tension while shortening to overcome external resistance

eccentric contraction

muscle lengthens

produces tension while lengthening

bringing weight down

isometric contraction

muscles stay the same length as they contract

ends of the muscles stay the same distance apart

stabilizing muscles hold parts of the body steady

periostium

at the bone where the fibers of the tendon are embedded