Muscle 2nd ppt

Parallel muscle

run parallel to the long axis of the muscle

convergent muscle

fascicles are spread out like a fan but coverage at a single tendon

pennate muscles

fascicles attach to a central tendon at an angle

unipennate muscle

attach to one side of the tendon (extensor digitorum longus in the leg)

bipennate muscle

fascicles attach on both sides of the tendon (rectus femoris)

multipennate

several tendons with fascicles attaching at multiple angles (deltoid)

circular muscle

fascicles form a ring around an opening (orbicularis oris)

fusiform

is a variation of parallel muscles with a spindle like shape (biceps brachii)

effort (force) applied

a muscle contracts and pulls on a bone

fulcrum (pivot point)

the joint acts as a fixed point where movement happens

load (resistance)

the weight or resistance must be overcome for movement to occur

origin

stationary end of the muscle

insertion

with the greatest movement (movable)

agonist, synergist, antagonist

3 types of coordination among muscles

agonist (prime mover)

a muscle that produces most of the force durinh a joint action

synergist

small muscle that assists a larger agonist

fixator

stabilizes the origin of a prime mover

antagonist

opposes movement of a particular agonist

location, origin and insertion, fascicle organization, action, structural characteristics

ways of naming skeletal muscles

action

principle action of the muscle

axial muscles

muscles of the head and neck

appendicular muscles

muscles of the shoulders, upper limbs, pelvis and lower limbs

masseter

the strongest jaw muscle

temporalis

helps elevate and retract the mandible

Sternocleidomastoid

cervical vertebrae flex and head extends (contracted left and right)

scarlene muscles

flex the neck

external oblique

stabilized vertebral column; aids in compression of abdominal wall

internal oblique

same function as external oblique

rectus abdominis

rotates lumbar vertebrae; stabilized pelvis for walking