1.2.1 Muscles

biomed quiz 10/07

Muscle Rule #1

muscles must have at least 2 attachments and must cross at least 1 joint

Muscle Rule #2

muscles always pull and shorten, cannot push

Muscle Rule #3

there is an insertion and origin

Insertion

attachment that moves

Origin

attachment that doesn't move

Muscle Rule #4

there are flexors and extensois

Flexors

muscle that decreases the angle between ventral surfaces

Extensois

muscle that increases the angle between ventral surfaces

Muscle Rule #5

muscles work in opposing pairs -> antagonistic pairs

Antagonistic pairs

one muscle contracts and the other relaxes

Muscle Rule #6

muscle striations "point" to the attachment and show direction of pull

Trapezius

classified by shape; trapezoid

Rhomboid

classified by shape; rhombus

Gluteus maximus

classified by size; largest muscle in gluteal muscle group, walking/running, extension, internal rotation of thigh

Gluteus minimus

classified by size; smallest in gluteal muscle group

Frontalis

classified by location; on frontal bone

Temporalis

classified by location; on temporal lobe

Orbicularis oculi

classified by direction of fibers; fibers form a circle

Transverse abdominis

classified by direction of fibers; fibers go transverse/across

Flexor carpi ulnaris

classified by action; flexes hands at wrists

Extensor digitorum longus

classified by action; extends the foot and toes upward

Sterno cleisdomastoid

classified by origin and insertion; origin on sternum and insertion on mastoid process of temporal bone

Brachioradialis

classified by origin and insertion; origin on brachium (arm) and insertion on radius, flexion of lower arm

Biceps brachii

classified by number of origins; two origins on scapular, flexion of elbow

Triceps brachii

classified by number of origins; three origins on scapula and humerus

Adduction

movement towards the midline

Abduction

movement away from midline

Sternocleidomastoid

rotation of head

Rectus abdominus

move trunk

Serratus anterior

lifts ribs and moves scapula forward

Pectoralis major

superficial adduction and internal rotation of shoulder

External obliques

twist trunk

Adductor longus and sartorius

addution thigh at hip

Rectus femoris

main muscle of quadricep group

Vastus medialis and vastus lateralis

knee extensions

Gastrocnemius

calf muscle, walking and posture

Tibialis anterior

dorsal flexsion of foot

Gluteus medius

abduction of hip

Deltoid

ball-and-socket joint

Flexor carpi radialis

wrist flexion

Palmaris longus

most medial, wrist flexion

Lattissimus dorsi

pulls inferior scapula

Bicep femoris

flexion leg knee

Gracilis

helps hip adduction and knee extension