Muscle List and Function + CHP 9 Notes Lab Exam 3

Frontallis Muscle

Function: elevates eyebrows; wrinkles skin on forehead horizontally

Corrugator supercilii

Function: pulls eyebrows inferiorly and medially(squinting)

Levator labii superioris muscle

Function: elevates the upper lip; exerts and furrows upper like (sneering)

Zygomaticus minor muscle

elevates lateral portion of upper lip (as in smiling)

Zygomaticus major muscle

Function: pulls angle of the mouth superiorly and laterally (as in smiling or laughing)

*Risorius

Function: pulls angle of the mouth laterally to make a closed mouth smile or smirk

Platysma muscle

depresses lower lip and opens mouth by depressing mandible; tenses skin and neck

Occipitallis muscle

Function: pulls scalp posteriorly

Orbicularis oculi muscle

Function: closes eye: pulls skin around eye (blinking and squinting)

Orbicularis oris muscle

Function: closes and protrudes lips

Depressor anguli oris muscle

Function: draws corners of mouth inferiorly (unhappy face)

Depressor labii inferioris muscle

Function- protrudes lower lip (sad or pouting expression)

Mentallis muscle

Function: Protrudes lower lip and chin for drinking and “doubtful” look

Buccinator muscle

Function: pulls cheeks in; produces sucking movements

Superior rectus muscle

Function: elevates (rotates upward) anterior eye, as in looking up

• turns eye medically

Inferior rectus muscle

Function: depression (rotates downward) anterior eye, as in looking down

Turns eye medially

Medial rectus muscle

pulls anterior eye medially, toward the nose

Lateral rectus muscle

Function: pulls anterior eye laterally, as when looking towared the temple

Superior oblique muscle

Function: pulls (and helps rotate) anterior eye. Inferiorly and laterally, as when eye rolls to left and down

Inferior oblique muscle

Function: pulls( and helps rotate) anterior eye superiorly and laterally, as when left eye rolls to up

Levator palpebrae superioris muscle

elevates upper eyelid

Temporalis muscle

Function: elevates and retracts the mandible

Masseter muscle

Function: elevates the mandible

Digastric

Anterior belly and poster movement.

- one of the muscles of swallowing

• the mandible; fixator of the hyoid during swallowing

Mylohyoid

• involved in swallowing

Stylohyoid

• involved in swallowing

• elevates and retracts the hyoid bone and the floor of the mouth

Sternohyoid

• depresses hyoid bone and larynx

• involved in swallowing

Omohyoid (superior belly)

• involved in swallowing

• depresses and retracts hyoid bone

Sternocleidomastoid

flexes head

Genioglossus muscle

depressing tongue

Hyoglossus muscle

protrudes tongue

Styloglossus muscle

retracts and elevates tongue

Stylohyoid muscle

elevates and retractes hyoid and floor of mouth

Mylohyoid muscle

Elevates hyoid and floor of mouth, pushes food toward the pharynx

Geniohyoid

elevates and protracts hyoid

Thyrohyoid muscle

depresses hyoid bone- may elevate larynx

Superior, middle, and inferior pharyngeal constructor muscles

stepwise contraciton squeezes food from top to bottom of pharynx into esophagus

Trapezius muscle

-extends head from bowed position

Spinalis muscle column

• extend vertebral column

Longissimus muscle column

extend vertebral column, laterally flex vertebral column when contracted to one side only

Illocostalis muscle column

• extend vertebral column

• laterally flex vertebral column when contracted to one side only

Diaphragm muscle

dome shaped. main muscle of ventilation

External and internal intercostal muscles

• function in ventilation

• between ribs

• elevate rib cage

• depress the rib cage pull ribs ogether assisting forced expiration

Diaphragm anatomy bonus question

Rectus abdominis muscle (6 pack abs)

• flexes the trunk

rectus sheath

encloses the rectus abdominis. formed by fibers of the other abdominal muscles.

linea alba

midline of the rectus sheath

Transversus abdominis muscle

deepest muscle of the abdomen

fibers run horizontal

compress abdominal cavity; urination, defecation, and child birth

external oblique muscle

• fibers run at an angle

internal oblique muscle

• deep to the external oblique muscles

• opposite direction of fibers

• rotate and flex trunk laterally

What are the three bones that make up the pelvis?

ilium, ischium, and pubis

Which organs are found in the pelvic body?

urinary bladder, urethra, colon, rectum and anal canal, reproductive organs

Serratus anterior muscle

• helps protract the scapula

• very powerful “boxer’s muscle”

• rotates scapula superiorly

Pectoralis minor muscle

• assists with scapular protraction

• deep to the pectoralis major muscle

• originates from the third through fifth ribs and inserts into the coracoid process of the scapula

Pectoralis major muscle

• agonist of arm flexion

• adducts and flexes the numerus with coracobrachialis muscle

• flexes and adducts the arm

deltoid muscle

• found mass at shoulder

• abducts the arm

latissimus dorsi muscle

• allows to extend, aduct, and internally rotate the arm

• assisted by teres major muscle

Teres major muscle

Which four muscle are within the rotator cuff muscles?

• teres minor muscle (superior to teres major)

• - supraspinatus muscle )superior to the scapular spine)

• - infrespinatus muscle (inferior to scapular spine)

• subscapularis muscle )anterior surace of the scapula)

example of a muscle abducts the arm?

supraspinatus muscle

Biceps brachii muscle

• largest muscle on the anterior arm

• flexes the forearm

brachialis muscle

• agonist of elbow flexion

• has greater leverage than the biceps brachii muscle to flex the forearm

brachioradialis muscle

lateral forearm

triceps brachii muscle

• three heads

• forearm supination

• extends the forearm

lesser trochanter

medially, inferior to the neck of the femur

iliopsoas muscle

• strongest powerful thigh flexors

• made from the union of iliacus and psoas major

Pectineus muscle

originates on the pubic bone and inserts on the femur

gracilis muscle

• originates from the pelvis and inserts into the proximal tibia

sartorius muscle

• moves leg and thigh

• origin is the anterior superior iliac spine to its insertiol on the medial tibial condyle

• four actions; flexion, abduction, and lateral rotation of the thigh and flexion of the leg

Quadriceps femoris muscle group

• four muscles converge on quadriceps tendon

• tendon becomes patellar ligament and inserts into the tibial tuberosity

• extension of the leg at the knee join

rectus femoris muscle

• originates from the hip

• additional action of thigh flexion

Vastus lateralis

• along diaphysis of the femur

Vastus medialis

• along diaphysis of the femur

Vastus intermedius

• along diaphysis of the femur

Gluteal muscle group: large maximus muscle

Hamstring muscle group

• flex the leg, extend the thigh

Main Dorsiflexors

• tibialis anterior

• extensor digitorum longus longus muscles

Evert foot muscles

fibularis longus and fibularis brevis muscles

• ______ Brevis

• ______ Digitorum

• ______ Hallucis

• ______ Rectus

• ______ Flexor

• ______ Pronator

1. Related to the fingers/toes

2. Straight

3. Short

4. Decreases the angle between bones

5. Turns palm down

6. Related to the hallux (great toe)

A. short

B. related to the fingers/toes

C. related to the hallux

D. straight

E. decreases the angle between bones

F. turns palm down

The action of the biceps brachii muscle on the hinge joint of the elbow is an example of which kind of lever system?

1. First-class

2. Second-class

3. Third-class

4. Fourth-class

3. third class lever

Which function is being fulfilled by a muscle that holds a bone steady during movement?

1. Antagonist

2. Synergist

3. Supinator

4. Fixator

4. fixator

True or False": The main action of the zygomaticus major and minor muscles is to pull the corners of the mouth up to produce smiling

True

The orbicularis oris muscle is located around the eye.

False: located around the mouth

Hamstrings: biceps femoris

• most lateral hamstring muscle

Hamstrings: semitendinosis

Hamstring: semimembranosus

gastrocnemius

plantarflexes the foot