LAB 6 MUSCULAR SYSTEM: UPPER MUSCLES

know the location of each muscle and the action

MUSCLES OF MASTIFICATION

• masseter

• temporalis

(1) masseter

(2) temporalis

Massester

elevates mandible

Temporalis

elevates mandible

MUSCLES OF THE ANTERIOR TRIANGLE OF THE NECK

• digastric

• sternohyoid

• sternothyroid

• thyrohyoid

• sternocleidomastoid

(3) digastric

(4) sternohyoid

(5) sternothyroid

(6) thyrohyoid

(7) sternocleidomastoid

Digastric

depresses mandible

Sternohyoid

depresses hyoid

Sternothyroid

depress thryoid cartilage (larynx)

Thyrohoid

-elevates larynx

-depresses hyoid bone

Sternocleidomastoid

-flexes the head

-rotates the head

MUSCLES THAT ACT ON THE CLAVICLE AND HEAD

• clavo-trapezius

(8) clavo-trapezius

clavo-trapezius

-flexes neck laterally

-elevates clavicle

MUSCLES THAT ACT ON THE SCAPULA

• acromio-trapezius

• spino-trapezius

• pectoralis minor

• levator scapulae

• serratus anterior

• rhomboideus

(9) acromio-trapezius

(10) spino-trapezius

(11) pectoralis minor

(12) levator scapulae

(13) serratus anterior

(14) rhomboideus

acromio-trapezius

adducts scapula

spino-trapezius

depresses scapula

Pectoralis Minor

-steadies the scapula

-depresses the scapula

Levator Scapulae

elevates the scapula

Serratus Anterior

anterior rotation of scapula

Rhomboideus

adducts and elevates scapula

MUSCLES THAT ACT ON THE ARM (HUMERUS)

• pectoralis major

• clavo-deltoid

• acromio-deltoid

• spino-deltoid

• infraspinatus

• supraspinatus

• subscapularis

• latissimus dorsi

• teres major

(15) pectoralis major

(16) clavo-deltoid

(17) acromio-deltoid

(18) spino-deltoid

(19) infraspinatus

(20) supraspinatus

(21) subscapularis

(22) latissimus dorsi

(23) teres major

Pectoralis Major

-flexes the humerus

-adducts the humerus

clavo-deltoid

-flexes the humerus

-adducts the humerus

acromio-deltoid

abducts the humerus

spino-deltoid

extends the humerus

infraspinatus

lateral rotation of the humerus

supraspinatus

abducts humerus

subscapularis

medial rotation of the humerus

latissimus dorsi

adducts the humerus

teres major

medial rotation of the humerus

MUSCLES THAT ACT ON THE FOREARM (RADIUS AND ULNA)

• triceps brachii (medial, lateral, and long heads)

• biceps brachii (short and long heads)

• brachialis

• brachioradialis

• pronator teres

• supinator

(24) triceps brachii (medial, lateral, and long heads)

(25) biceps brachii (short and long heads)

(26) brachialis

(27) brachioradialis

(28) pronator teres

(29) supinator

triceps brachii (medial, lateral, and long heads)

extends the forearm

biceps brachii (short and long heads)

flexes the forearm

brachialis

flexes the forearm

brachioradialis

flexes the forearm

pronator teres

pronation

supinator

supination

MUSCLES THAT ACT ON THE WRIST, HAND AND FINGERS

• extensor carpi radialis longus

• extensor carpi radialis brevis

• extensor digitorum (extensor digitorum communis in cats)

• extensor digiti minimi (extensor digitorum lateralis in cats)

• extensor carpi ulnaris

• flexor carpi radialis

• palmaris longus

• flexor carpi ulnaris (two heads in cats)

• flexor digitorum superficialis (very small in cats)

• flexor digitorum profundus (five heads in cats)

• abductor pollicis brevis (absent in cats)

(30) extensor carpi radialis longus

(31) extensor carpi radialis brevi

(32) extensor digitorum (extensor digitorum communis in cats)

(33) extensor digiti minimi (extensor digitorum lateralis in cats)

(34) extensor carpi ulnaris

(35) flexor carpi radialis

(36) palmaris longus

(37) flexor carpi ulnaris (two heads in cats)

(38) flexor digitorum superficialis (very small in cats)

(39) flexor digitorum profundus (five heads in cats)

(40) abductor pollicis brevis (absent in cats)

extensor carpi radialis longus

extends wrist

extensor carpi radialis brevis

extends wrist

extensor digitorum

extends digits 2-5

extensor digiti minimi

extends digit 5

extensor carpi ulnaris

extends the wrist

flexor carpi radialis

flexes wrist

palmaris longus

flexes the wrist

flexor carpi ulnaris

flexes the wrist

flexor digitorum superficialis

flexes middle phalanges 2-5

flexor digitorum profundus

flexes distal phalanges 2-5

abductor pollicis brevis

abducts thumb