Lab Unit 13: Gross Anatomy of the Muscular System

Vocabulary flashcards covering skeletal muscle classifications and the primary origin, primary insertion, and primary actions of muscles across the human body for Lab Unit 13.

Origin

The muscle attachment end that is immovable.

Insertion

The muscle attachment end that is movable; it is pulled toward the origin point(s) when the muscle contracts (shortens).

Belly

The thicker, middle region of a muscle, located between the origin and insertion.

Prime Mover (Agonist)

The muscle primarily responsible for producing an action.

Synergists

Muscles that contract and assist prime movers.

Antagonists

Muscles that resist the prime mover's action and cause movement in the opposite direction.

Fixator

A muscle that stabilizes the origin of the prime mover, allowing the prime mover to act more efficiently.

Frontalis

Origin: Epicranial aponeurosis. Insertion: Skin of eyebrows. Actions: Raises eyebrows; wrinkles skin of forehead horizontally.

Occipitalis

Origin: Occipital bone. Insertion: Epicranial aponeurosis. Action: Pulls scalp posteriorly.

Orbicularis oculi

Origin: Frontal bones; maxilla. Insertion: Skin of orbital area; skin of eyelids. Actions: Closes eyelids; blinking; winking.

Zygomaticus major

Origin: Zygomatic bone (anterior surface). Insertion: Orbicularis oris (corners). Actions: Elevates and draws corners of mouth laterally, elevates upper lip (smile, laugh).

Zygomaticus minor

Origin: Anterior surface of zygomatic bone. Insertion: Orbicularis oris (corners). Actions: Elevates and draws corners of mouth laterally, elevates upper lip (smile, laugh).

Orbicularis oris

Origin: Maxilla Insertion: Skin of lips. Actions: puckers lip edges ('kissing muscle').

Buccinator

Origin: maxilla. Insertion: Orbicularis oris (lateral portion of upper & lower lips, angle of mouth). Actions: Compresses cheeks inward (blowing air, whistling)

Platysma

Origin: Fascia covering lower neck and upper chest. Insertion: Inferior border of mandible. Actions: depresses mandible. (Not on the model!)

Masseter

Origin: Zygomatic arch and zygomatic bone. Insertion: Ramus (lateral surface) of mandible. Action: Elevates mandible (forced closure of mouth).

Temporalis

Origin: Temporal bone. Insertion: Anterior ramus of mandible. Action: Elevates mandible.

Medial pterygoid

Origin: Pterygoid process of sphenoid bone Insertion: Medial surface of mandibular ramus. Actions: Elevates mandible (Not on the model!)

Lateral pterygoid

Origin: Pterygoid process of sphenoid bone. Insertion: Mandibular condyle (anterior surface). Actions: Depresses mandible (Not on the model!)

Sternocleidomastoid

Origin: clavicle. Insertion: Mastoid process of temporal bone. Actions: flexes neck

Trapezius (Superior Section)

Origin: Occipital bone Insertion: Clavicle Action: Extends head (draws it backwards).

Trapezius (All Sections)

Origin: Occipital bone. Insertion: Clavicle Actions: Extends head (draws it backwards)

Rectus abdominis

Origin: Superior aspect of pubic bones. Insertion: Costal cartilages of lower ribs. Actions: Flexes trunk

External oblique

Origin: Lower 8 ribs. Insertion: Iliac crest Actions: Flexes trunk

Internal oblique

Origin: Iliac crest Insertion: linea alba Actions: Flexes trunk

Transversus abdominis

Origin: Lower 6 costal cartilages Insertion: Linea alba Action: Compresses abdominal cavity.

Levator scapulae

Origin: Transverse processes of cervical vertebrae (C1-C4). Insertion: Medial margin of scapula (above scapular spine). Action: Elevates scapula.

Rhomboid major

Origin: Spinous processes of thoracic vertebrae (T2-T5). Insertion: Medial border of scapula. Action: Retracts scapula.

Rhomboid minor

Origin: Spinous process of C7 through T1. Insertion: Medial border of scapula. Action: Retracts scapula.

Pectoralis minor

Origin: Sternal ends of ribs 3-5. Insertion: Coracoid process of scapula. Actions: protracts scapula.

Serratus anterior

Origin: Lateral surfaces of first 9 ribs. Insertion: Medial border of scapula. Actions: Protracts scapula

Pectoralis major

Origin: Clavicle Insertion: Intertubercular groove (sulcus) of humerus. Actions: adducts arm

Latissimus dorsi

Origin: Spinous processes of lumbar Insertion: Intertubercular groove of humerus. Actions: Adducts arm

Deltoid

Origin: the clavicle. Insertion: Deltoid tuberosity of humerus. Actions: Abducts arm.

Teres major

Origin: Posterior part of scapula. Insertion: Intertubercular sulcus of humerus. Actions: Extends, adducts, rotates arm medially.

Coracobrachialis

Origin: Coracoid process of scapula. Insertion: Medial surface of humerus shaft. Actions: Adducts arm.

Teres minor

Origin: Lateral border of scapula. Insertion: Greater tubercle of humerus. Action: Rotates humerus laterally. (Rotator cuff muscle)

Supraspinatus

Origin: Supraspinous fossa of scapula. Insertion: Greater tubercle of humerus (superior portion). Action: Abducts the arm. (Rotator cuff muscle)

Infraspinatus

Origin: Infraspinous fossa of scapula. Insertion: Greater tubercle of humerus (posterior to insertion of supraspinatus). Action: Rotates humerus laterally. (Rotator cuff muscle)

Subscapularis

Origin: Anterior of scapula. Insertion: Lesser tubercle of humerus. Actions: Rotates humerus medially. (Rotator cuff muscle)

Biceps brachii

Origin: Coracoid process Insertion: Radial tuberosity of radius. Actions: Flexes forearm at elbow

Brachialis

Origin: Anterior shaft of humerus (distal half). Insertion: Coronoid process of ulna. Action: Flexes forearm at elbow.

Brachioradialis

Origin: Lateral epicondyle of humerus. Insertion: Base of radial styloid process. Actions: Flexes forearm at elbow

Triceps brachii

Origin: Lateral and medial surfaces of the humerus. Insertion: Olecranon process of the ulna. Action: Extends the forearm at the elbow.

Pronator teres

Origin: Medial epicondyle of humerus Insertion: Lateral surface of radius. Actions: pronates forearm and hand.

Supinator

Origin: Lateral epicondyle of humerus Insertion: Lateral surface of radius (proximal area). Actions: supinates forearm and hand.

Sartorius

Origin: Anterior superior iliac spine. Insertion: Tibia. Actions: Flexes the leg at knee.

Adductor magnus

Origin: Pubis. Insertion: Linea aspera of the femur. Actions: Adduction

Adductor longus

Origin: Pubis. Insertion: Linea aspera of femur. Actions: Adduction and flexion of thigh.

Gracilis

Origin: Pubis. Insertion: Tibia (medial surface). Actions: Adducts thigh; flexes leg at knee.

Rectus femoris

Origin: Acetabulum Insertion: Patella Actions: Extends leg at knee (Quadriceps femoris group)

Vastus lateralis

Origin: Greater trochanter Insertion: Patella Actions: Extends leg at knee; stabilizes knee. (Quadriceps femoris group)

Vastus medialis

Origin: Linea aspera of femur. Insertion: Patella Actions: Extends leg at knee; stabilizes knee. (Quadriceps femoris group)

Vastus intermedius

Origin: Femur. Insertion: Patella Action: Extends leg at knee. (Quadriceps femoris group)

Gluteus maximus

Origin: Posterior iliac crest Insertion: Femur Actions: Extension of femur.

Gluteus medius

Origin: Ilium (lateral surface). Insertion: Greater trochanter of femur. Actions: Abduction and medial rotation of thigh.

Gluteus minimus

Origin: Ilium (lateral surface). Insertion: Greater trochanter of femur. Actions: Abduction and medial rotation of thigh. (Not on the model!)

Tensor fasciae latae

Origin: Iliac crest Insertion: Iliotibial tract. Actions: Abducts and medially rotates thigh.

Biceps femoris

Origin: linea aspera of femur. Insertion: head of fibula. Actions: flexes leg at knee. (Hamstring group)

Semitendinosus

Origin: Ischial tuberosity. Insertion: Tibia. Actions: flexes leg at knee(Hamstring group)

Semimembranosus

Origin: Ischial tuberosity. Insertion: Medial condyle of tibia. Actions: flexes leg at knee (Hamstring group)

Tibialis anterior

Origin: Proximal tibia. Insertion: Metatarsal I; medial cuneiform. Actions: Dorsiflexion

Gastrocnemius

Origin: Medial and lateral condyles of femur. Insertion: Calcaneus (via Achilles' tendon). Actions: Plantar flexes foot

Soleus

Origin: Tibia Insertion: Calcaneus (via Achilles' tendon). Action: Plantar flexes foot.