A&P I Lab Practial 3 (Origins, Insertions, Actions)

What is the origin, insertion, and action of Masseter?

Origin: Zygomatic arch, Insertion: Angle or ramus of mandible, Action: Elevates or closes mandible

What is the origin, insertion, and action of Temporalis?

Origin: Temporal fossa, Insertion: Coronoid process or ramus of mandible, Action: Elevates or closes mandible

What is the origin, insertion, and action of Sternocleidomastoid?

Origin: Manubrium of sternum, clavicle, Insertion: Mastoid process of temporal bone, Action: Abducts, rotates or flexes head; laterally flexes neck to same side and rotates head to opposite side; pulls head forward and down; aids in forceful inhalation

What is the origin, insertion, and action of Zygomaticus major?

Origin: Zygomatic bone. Insertion: Corner of mouth, Action: Elevates corner of mouth

What is the action of Zygomaticus minor?

Elevates corner of mouth as in smiling and laughing

What is the action of Buccinator?

Compresses cheek

What is the action of Occipitofrontalis (frontal belly)?

Raises eyebrows, draws scalp anteriorly

What is the action of Occipitofrontalis (occipital belly)?

Retracts scalp

What is the action of Mentalis?

Protrudes lower lip; elevates and wrinkles chin

What is the action of Orbicularis oris?

Closes lips; protrudes lips

What is the action of Orbicularis oculi?

Closes eyelids; aids in flow of tears

What is the origin, insertion, and action of Trapezius?

Origin: Posterior occipital bone or nuchal ligament; spinous processes C7–T12, Insertion: Clavicle; acromion or spine of scapula, Action: Extends head; rotates/adducts scapula; elevates and depresses scapula

What is the origin, insertion, and action of Latissimus dorsi?

Origin: Spinous processes T7–T12, L1–L5, iliac crest, ribs 10–12, Insertion: Intertubercular sulcus of humerus
Action: Extends, adducts, medially rotates humerus

What is the origin, insertion, and action of Pectoralis major?

Origin: Clavicle, sternum, ribs 1–7; aponeurosis of external oblique, Insertion: Intertubercular sulcus of humerus, Action: Flexes, adducts, medially rotates humerus

What is the origin, insertion, and action of Pectoralis minor?

Origin: Ribs 3–5, Insertion: Coracoid process of scapula, Action: Depresses scapula; draws it forward; elevates ribs

What is the origin, insertion, and action of Rectus abdominis?

Origin: Pubic crest, pubic symphysis, Insertion: Costal cartilage 5–7 or xiphoid process, Action: Flexes spine; compresses abdominal wall

What is the action of Serratus anterior?

Abducts and rotates scapula; protracts scapula

What is the action of External oblique?

Compresses abdominal wall; rotates and flexes vertebral column

What is the action of Internal oblique?

Compresses abdominal wall; rotates and flexes vertebral column

What is the action of Transversus abdominis?

Compresses abdominal wall; rotates and flexes vertebral column

What is the action of Diaphragm?

Inspiration; compresses abdominal viscera

What is the action of External intercostals?

Elevates ribs; increases thoracic volume

What is the action of Internal intercostals?

Elevates and depresses ribs; compresses thoracic cavity

What is the origin, insertion, and action of Deltoid?

Origin: Acromion and spine of scapula, clavicle, Insertion: Deltoid tuberosity of humerus, Action: Flexes, abducts, extends, and rotates arm

What is the origin, insertion, and action of Biceps brachii?

Origin: Glenoid cavity or coracoid process, Insertion: Radial tuberosity, Action: Flexes arm; flexes and supinates forearm

What is the origin, insertion, and action of Triceps brachii?

Origin: Glenoid cavity of scapula, humerus, Insertion: Olecranon of ulna, Action: Extends elbow

What is the origin, insertion, and action of Brachioradialis?

Origin: Humerus, Insertion: Styloid process of radius, Action: Flexes forearm

What is the action of Brachialis?

Flexes forearm; prime mover of elbow flexion

What is the origin, insertion, and action of Teres major?

Origin: Inferior angle of scapula, Insertion: Intertubercular sulcus of humerus, Action: Extends, adducts, medially rotates arm

What is the origin, insertion, and action of Supraspinatus?

Origin: Supraspinous fossa, Insertion: Greater tubercle, Action: Abducts arm

What is the origin, insertion, and action of Infraspinatus?

Origin: Infraspinous fossa, Insertion: Greater tubercle, Action: Laterally rotates arm

What is the origin, insertion, and action of Teres minor?

Origin: Lateral border of scapula, Insertion: Greater tubercle, Action: Laterally rotates arm

What is the origin, insertion, and action of Subscapularis?

Origin: Subscapular fossa, Insertion: Lesser tubercle, Action: Medially rotates arm

What is the action of Extensor digitorum (upper limb)?

Extends wrist and fingers; spreads digits

What is the action of Palmaris longus?

Anchors skin; weakly flexes hand

What is the action of Flexor carpi ulnaris?

Flexes and adducts wrist

What is the action of Extensor carpi radialis longus?

Extends and abducts wrist

What is the action of Extensor carpi radialis brevis?

Extends and abducts wrist

What is the action of Pronator teres?

Pronates and flexes forearm

What is the origin, insertion, and action of Biceps femoris?

Origin: Ischial tuberosity, linea aspera, Insertion: Head of fibula, Action: Flexes knee; extends hip

What is the origin, insertion, and action of Semitendinosus?

Origin: Ischial tuberosity, Insertion: Tibia, Action: Flexes knee; extends thigh

What is the origin, insertion, and action of Semimembranosus?

Origin: Ischial tuberosity, Insertion: Medial condyle of tibia, Action: Flexes knee; extends thigh

What is the origin, insertion, and action of Iliopsoas (iliacus, psoas major)?

Origin: Iliacus - iliac crest and fossa, Psoas major - transverse processes and intervertebral discs of T12-L5 vertebrae, Insertion: Lesser trochanter, Action: Flexes thigh; flexes trunk

What is the origin, insertion, and action of Rectus femoris?

Origin: Ilium, acetabulum, Insertion: Patella, tibia, Action: Flexes thigh; extends leg

What is the origin, insertion, and action of Vastus intermedius?

Origin: Femur, Insertion: Patella, tibia, Action: Extends knee

What is the origin, insertion, and action of Vastus lateralis?

Origin: Femur, Insertion: Patella, tibia, Action: Extends knee

What is the origin, insertion, and action of Vastus medialis?

Origin: Greater trochanter/linea aspera of femur, Insertion: Patella, tibial tuberosity, lateral and medial condyles of tibia, Action: Extends knee

What is the action of Sartorius?

Flexes hip and knee; abducts and laterally rotates thigh

What is the action of Piriformis?

Laterally rotates and abducts hip

What is the action of Gracilis?

Flexes and medially rotates leg; adducts thigh

What is the origin, insertion, and action of Gluteus maximus?

Origin: Ilium, sacrum, coccyx, Insertion: Femur, iliotibial tract, Action: Extends thigh

What is the origin, insertion, and action of Gastrocnemius?

Origin: Femur, Insertion: Calcaneus, Action: Plantar flexion; flexes knee

What is the action of Soleus?

Plantarflexion; steadies leg

What is the origin, insertion, and action of Tibialis anterior?

Origin: Lateral condyle of tibia/proximal tibia, Insertion: Metatarsal I/medial cuneiform, Action: Dorsiflexes foot

What is the action of Extensor digitorum longus?

Extends toes; dorsiflexes foot

What is the action of Iliotibial tract?

Stabilizes hip and knee

What is the action of Calcaneal tendon?

Plantar flexion