Muscle Functions Flashcards
Orbicularis Oris
Protrudes the lips and compresses them against the teeth, while shaping them during speech.
Levator labii superioris
Raises the upper lip and is innervated by the facial nerve.
Depressor labii inferioris
Depresses/ Lowers the lower lip
Buccinator
Compresses the cheeks, like when playing the trumpet or blowing air. During chewing it moves food back across the teeth inside the cheeks.
Mentalis
When one pouts, the skin of the chin is elevated and the lower lip is protruded.
Orbicularis Oculi
Allows one to close the eyelid and to blink, squint, and perform other movements to protect the eye.
Levator palpebrae superioris
Operates when one raises the upper eyelid
Nasalis
Elevates the corners of the nostrils
Masseter
Elevates the mandible
Sternocleidomastoid
Flexes and bends the neck towards the shoulder
Temporalis
Important muscle in mastication (chewing) as it elevates the mandible when the lower jaw moves
Scalene Muscles
Aid in breathing
Trapezius
Elevates the clavicle and scapula to extend the head.
Rectus abdominis
Depresses the ribs and permits flexion at the waistline
Tranversus abdominis
Compresses the abdominal wall.
Pectoralis Major
Flexes the arm and adducts it
Deltoid
Prime abductor of the arm
Pectoralis Minor
Thin muscles close to the pectoralis major
External Intercostals
Elevates the ribs during inspiration
Internal Intercostals
Decreases the size of the thorax during forced expiration
Subscapularis
Rotates the arm in the medial direction
Teres Major
Extends the arm
Biceps brachii
A main flexor of the forearm
Pectineus
Flat muscle that adducts and flexes the thigh
Sartorius
One of the body’s longest muscles; holds everything in
Rectus femoris
A superficial thigh muscle that extends the knee and flexes the thigh at the hip joint
Latissimus Dorsi
Acts antagonistically to the pectoralis major; it extends the arm
Flexor carpi radialis
Flexes the wrist and abducts the palm of the hand
Flexor carpi ulnaris
This muscle flexes and adducts the wrist
Brachioradialis
Its primary function is to flex the forearm
Supinator
Supinates the arm
Pronator teres
Anatagonistic to the supinator
Semitendinosus
This muscle flexes the knee and can also extend the thigh at the hip
Gluteus maximus
Largesst and most posterior of the muscles
Gastrocnemius
This muscle adducts the foot and flexes the leg