A&P Chapter 10 Mucles only

zygomaticus

zygomaticus

Origin: zygomatic bone Insertion: skin and muscle at corner of lips Action: raises corner of mouth

orbicularis oris

Origin: Maxilla and mandible Insertion: Lips Action: Compresses, purses lips

masseter

prime mover of jaw closure (elevates mandible)

• nerve: trigeminal nerve

pharyngeal constrictors

constrict pharynx during swallowing (propels food down esophagus)

sternocleidomastoid

flexes, and laterally rotates head

• nerve: accessory

Splenius

extends head

erector spinae

• spinal extender

• from neck to sacrum

diaphragm

prime mover of inspiration

• flattens on constriction

• 3 holes for the esophagus

• nerve: phrenic nerve

rectus abdominis

flexes and rotates lumbar region of vertebral column

trapezius

scapula mover - adduction (pulling up)

• nerve: accessory nerve

Rhomboids

fixators of the scapula *minor on top, major on bottom

rotator cuff muscles

supraspinatus, infraspinatus, teres minor, subscapularis

pectoralis major

adducts and medially rotates arm

• I: greater tubercle of humerus

latissimus dorsi

rowing muscle

deltoid

Prime mover of arm abduction

biceps

• 2 origins

• prime mover of forearm flex

• synergist for forearm supination

triceps

3 origins

• prime mover of forearm extension

flexor carpi radialis

Flexes and abducts hand

• O: epicondyle of humerus

• I: thumb side of hand

extensor carpi radialis & ulnaris

wrist extenders

extensor digitorum (arm)

prime mover for finger extension

hamstrings

powerful knee flexors cross the knee and hip joint prime movers-flexion biceps femoris semitendinosus semimembranosus

tibialis anterior

prime mover of dorsiflexion and foot inversion

gastrocnemius

Calf muscle O: behind the knee I: into back of calcaneus (achilles tendon)

Flexor pollicis brevis

thumb mover

Quadriceps

Rectus femoris Vastus lateralis and medialis Vastus intermedius

medial pterygoid

protract mandible and side-side grinding movements of teeth

• nerve: trigeminal nerve

lateral pterygoid

protract mandible and side-side grinding movements of teeth

• nerve: trigeminal nerve

Epicranius- over cranium

Occipitalis (occipital belly) Origin: occipital and temporal bones Insertion: epicranial aponeurosis

Raises eyebrows Frontal belly Eyebrow and forehead mover Pulls scalp posteriorly

Origin: epicranial aponeurosis Insertion: skin of eyebrows and root of nose Epicranial aponeurosis Aponeurosis - sheet like tendon

Flexor Carpi Ulnaris

flex and adduct hand

• O: epicondyle of humerus

• I: pinky side of hand

Palmaris Longus

moves fingers (not thumb) *flexor compartment

Pronator Teres

allows arm pronation *flexor compartment

Extensor Retinaculum

piece of tape that wraps tendons around wrist

Carpal Tunnel

a passageway in the wrist that tendons and nerves pass through

Adductor magnuss/longus/brevis

prime movers for leg adduction

Pectineus

flex and adduct thigh

Gracilis

synergist for hip adduction and flexion

Bicep femoris

• sciatic nerve

• rectus femoris antagonist

• sciatic nerve pops and splits at the popliteal fossa

Fibularis Longus/Brevis

prime mover of plantar flexion