A&P Chapter 10 Mucles only

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