Origin: Frontal and maxillary bones

Insertion: Skin near the eye

Action: Closes the eye and wrinkles the skin around the eye

​ ​ (a)  

Origin: Maxillary bone and mandible

Insertion: Skin and muscle around the mouth

Action: Closes the lips and wrinkles the skin around the mouth

​ (b)  

Origin: Zygomatic arch

Insertion: Mandible

Action: Elevates the jaw, closes the jaw, and grinds food in the molars

​ ​ (a)  

What are the 2 muscles that synergize with one another to perform mastication?

​ ​ 1) Primary mastication muscle​ (a)  

​ 2) Accessory muscle for mastication ​ (b)  

Smiling muscles

1) Origin: Zygomatic bone

Insertion: Skin near the corner of the mouth

Action: Raises the corners of the mouth and forms a smile

​ ​ ​ ​ (a)  

2) Origin: Zygomatic bone

Insertion: Skin near the corner of the mouth

Action: elevates the upper lip

​ ​ (b)  

Origin: Sternum and clavicle

Insertion: Mastoid process of the temporal bone

Action: Flexes the neck and rotates the head to the opposite side.

​ ​ ​ (a)  

Origin: Clavicle, sternum, and costal cartilages

Insertion: Humerus

Action: Flexes, adducts, and rotates arm medially

​ ​ (a)  

Origin: Spinous processes of T6-L5 vertebrae, iliac crest, sacrum, and lower 3 or 4 ribs

Insertion: Intertubercular groove of the humerus

Action: Adducts, extends, and rotates arm medially

​ ​ (a)  

​ ​

Origin: Lateral third of clavicle, acromion process of scapula, and spine of scapula

Insertion: Deltoid tuberosity of humerus

Action: Abducts, flexes, and extends arm at the shoulder.

​ ​ (a)  

​ ​

Origin: Pubic crest and symphysis

Insertion: Xiphoid process and costal cartilages of ribs 5-7

Action: Flexes vertebral column and compresses the abdomen

​ ​ ​ (a)  

​ ​

Origin: Short head: coracoid process of the scapula. Long head: supraglenoid tubercle of the scapula

Insertion: Tuberosity of the radius and the bicipital aponeurosis (a tendinous sheath)

Action: Flexes the forearm at the elbow and supinates the forearm

​ (a)  

​ ​

Origin: Long head: infraglenoid tubercle of the scapula. Lateral head: posterior humerus. Medial head: posterior humerus

Insertion: Olecranon process of the ulna

Action: Extends the forearm at the elbow

​ ​ ​ (a)  

​ ​

Origin: Lateral epicondyle of the humerus

Insertion: Extensor expansions (tendons that spread out to the fingers) of the fingers

Action: Extends the fingers and wrist.

​ ​ ​ ​ (a)  

Origin: Medial epicondyle of the humerus

Insertion: Palmar aponeurosis (a tendinous sheath in the palm of the hand)

Action: Flexes the wrist

​ ​ (b)  

​ ​

​ ​Origin: Anterior inferior iliac spine

Insertion: Base of the patella and the quadriceps tendon

Action: Flexes the hip and extend the knee

​ ​ (a)  

Origin: Ischial tuberosity

Insertion: Head of the fibula

Action: Flexes the knee and extends the hip

​ ​ (b)  

These two muscles assist in supporting the body in an upright position.

1) Extends and laterally rotates the hip

​ ​ (a)  

2) Abducts the hip, and medially rotates the hip when it is flexed

​ ​ (b)  

Action: Plantar flexes the ankle

​ ​ ​ (a)  

​ Action: Dorsiflexes the ankle and inverts the foot

​ ​ (b)  

Gastrocnemius plantar flexes the ankle

This muscle synergizes with the gastrocnemius and also planter flexes the ankle

​ ​ (a)