Biology 233 Origin, Insertion & Action

Front 1

Sternocleidomastoid

Back 1

Origin: Sternum & Clavicle

Insertion: Mastoid process of temporal bone

Action: (Bilateral) Flex cervical portion of vertebral column & head; (singly) laterally flex & rotate head to side opposite contracting muscle

Front 2

Trapezius Origin

Back 2

Origin: Occipital bone, ligamentum nuchae, & spinous processes of thoracic vertebrae

Front 3

Trapezius Inserion

Back 3

Insertion: Clavicle & scapula (acromion & scapular spine)

Front 4

Trapezius Action:

Back 4

Action: Elevate, retract, depress, or rotate scapula upward 2. Elevate clavicle 3. Extend neck

Front 5

Latissimus dorsi Origin:

Back 5

Spines of inferior 6 thoracic vertebrae, lumbar vertebrae, crests of sacrum & ilium, inferior 4 ribs, inferior angle of scapula .

Front 6

Latissimus dorsi Insertion:

Back 6

Intertubercular groove of humerus

Front 7

Latissimus dorsi Action:

Back 7

Extends, adducts, & medially rotates arm at shoulder joint; draws arm inferiorly & posteriorly

Front 8

Pectoralis major Origin:

Back 8

Clavicle (clavicular head) sternum, & cartilages of second to 6th ribs (sternocostal head)

Front 9

Pectoralis major Insertion:

Back 9

Greater tubercle and inter tubercular groove of humerus

Front 10

Pectoralis major Action:

Back 10

As a whole, adducts & medially rotates arm at shoulder joint; clavicular head alone flexes arm, & sternocostal head alone extends arm at shoulder joint

Front 11

Rectus abdominis Origin:

Back 11

Pubic crest & pubic symphysis

Front 12

Rectus abdominis Insertion:

Back 12

Cartilage of 5th to 7th ribs & xiphoid process

Front 13

Rectus abdominis Action:

Back 13

Flexes vertebral column, especially lumbar portion, & compresses abdomen to aid in defecation, urination, forces expiration, & parturition (childbirth)

Front 14

Deltoid Origin:

Back 14

Anterior fibers: acromial extremity of clavicle 2. Middle fibers: acromion of scapula 3. Posterior fibers: spine of scapula

Front 15

Deltoid Insertion:

Back 15

Deltoid tuberosity of humerus

Front 16

Deltoid Action:

Back 16

Middle fibers abduct arm at shoulder joint: anterior fibers flex & medially rotate arm at shoulder joint; posterior fibers extend & laterally rotate arm at shoulder joint

Front 17

Biceps brachii Origin:

Back 17

1. Long head: tubercle above glenoid cavity of scapula 2. Short head: coracoid process of scapula

Front 18

Biceps brachii Insertion:

Back 18

Radial tuberosity & bicipital aponeurosis

Front 19

Biceps brachii Action:

Back 19

Flexes forearm at elbow joint, supinates forearm at radioulnar joints, & flexes arm at shoulder joint

Front 20

Triceps brachii Origin:

Back 20

1. Long head: projection inferior to glenoid cavity of scapula 2. Lateral head: lateral & posterior surface of humerus superior to radial groove 3. Medial head: entire posterior surface of humerus inferior to a groove for the radial nerve

Front 21

Triceps brachii Insertion:

Back 21

Olecranon of ulna

Front 22

Triceps brachii Action:

Back 22

Extends forearm at elbow joint & extends arm at shoulder joint

Front 23

Rectus femoris Origin:

Back 23

Anterior inferior iliac spine

Front 24

Rectus femoris Insertion:

Back 24

Patella via quadriceps tendon & then tibial tuberosity via patellar ligament

Front 25

Rectus femoris Action:

Back 25

All 4 heads (of the quadriceps) extend leg at knee joint; rectus femurs muscle acting alone also flexes thigh at hip joint

Front 26

Vastus medialis Origin:

Back 26

Linea aspera of femur

Front 27

Vastus medialis Insertion:

Back 27

Patella via quadriceps tendon & then tibial tuberosity via patellar ligament

Front 28

Vastus medialis Action:

Back 28

All 4 heads (of the quadriceps) extend leg at knee joint; rectus femurs muscle acting alone also flexes thigh at hip joint

Front 29

Vastus lateralis Origin:

Back 29

Greater trochanter & linea aspera of femur

Front 30

Vastus lateralis Insertion:

Back 30

Patella via quadriceps tendon & then tibial tuberosity via patellar ligament

Front 31

Vastus lateralis Action:

Back 31

All 4 heads (of the quadriceps) extend leg at knee joint; rectus femurs muscle acting alone also flexes thigh at hip joint

Front 32

Vastus intermedius Origin:

Back 32

Anterior & lateral surfaces of body of femur

Front 33

Vastus intermedius Insertion:

Back 33

Patella via quadriceps tendon & then tibial tuberosity via patellar ligament

Front 34

Vastus intermedius Action:

Back 34

All 4 heads (of the quadriceps) extend leg at knee joint; rectus femurs muscle acting alone also flexes thigh at hip joint

Front 35

Biceps femoris Origin:

Back 35

Long head arises from ischial tuberosity; short head arises from line aspera of femur

Front 36

Biceps femoris Insertion:

Back 36

Head of fibula & lateral condyle of tibia

Front 37

Biceps femoris Action:

Back 37

(The hamstrings) flex leg at knee joint & extend thigh at hip joint

Front 38

Semitendinosus Origin:

Back 38

Ischial tuberosity

Front 39

Semitendinosus Insertion:

Back 39

Proximal part of medial surface of shaft of tibia

Front 40

Semitendinosus Action:

Back 40

(The hamstrings) flex leg at knee joint & extend thigh at hip joint

Front 41

Semimembranosus Origin:

Back 41

Ischial tuberosity

Front 42

Semimembranosus Insertion:

Back 42

Medial condyle of tibia

Front 43

Semimembranosus Action:

Back 43

(The hamstrings) flex leg at knee joint & extend thigh at hip joint