SKELETAL MUSCLE LAB BIO 137 Anatomy Physiology I

SKELETAL MUSCLE LAB BIO 137 Anatomy & Physiology I

Muscle Attachments • Origin • Anchored, immovable end of muscle • Insertion • Moveable end of muscle • During contraction, the insertion moves toward the origin

Radial tuberosity

MUSCLE ACTIONS

Types of Joint Movements • Flexion • Extension • Dorsiflexion • Plantar Flexion • Hyperextension

Types of Joint Movements • Abduction • Adduction

Types of Joint Movements • Rotation • Circumduction • Supination • Pronation

Types of Joint Movements • Eversion • Inversion • Protraction • Retraction

Types of Joint Movements • Elevation • Depression

Skeletal Muscles • Skeletal muscles usually function in groups • Most movements use more than 1 muscle

Functional groups of muscles • Prime mover (agonist) • Muscle primarily responsible for the action of a movement • Biceps brachii in elbow flexion • Synergist • Muscles that contract and assist the prime mover in an action • Brachialis and brachioradialis in elbow flexion • Antagonist • Muscle that works opposite the prime mover • Triceps brachii that works in the opposite direction as biceps brachii

IDENTIFYING SKELETAL MUSCLES

For each skeletal muscle studied • Identify the muscle • Locate the muscle in the body • Name the action of the muscle

Muscles of Facial Expression • Epicranius • Frontalis • Occipitalis • Orbicularis oculi • Zygomaticus • Orbicularis oris • Buccinator

Frontalis Occipitalis Orbicularis oculi Zygomaticus Orbicularis oris Buccinator

MUSCLES OF MASTICATION n. Masseter n. Temporalis n. Both elevate the mandible §Platysma §Lateral Pterygoid §Both depress the mandible

Temporalis Masseter Platysma

Depression of Mandible Lateral Pterygoid

MUSCLES THAT MOVE THE HEAD Sternocleidomastoid

Sternocleidomastoid

Sternocleidomastoid

MUSCLES THAT MOVE THE PECTORAL GIRDLE Trapezius Pectoralis minor Serratus anterior Closely associated with those that move the arm

Trapezius

Pectoralis minor Serratus anterior

MUSCLES THAT MOVE THE ARM (HUMERUS) Pectoralis major Deltoid Latissimus dorsi (dorsal)

Deltoid Pectoralis major

Latissimus dorsi

MUSCLES THAT MOVE THE FOREARM Biceps brachii Brachialis Brachioradialis Triceps brachii

Biceps brachii Brachialis

Brachioradialis

MUSCLES THAT MOVE THE HAND, WRIST, AND FINGERS Flexor carpi radialis Flexor carpi ulnaris Extensor digitorum

Flexor carpi radialis Flexor carpi ulnaris Ventral View

Extensor digitorum

MUSCLES OF THE ABDOMINAL WALL Rectus abdominis External oblique Internal oblique Transversus abdominis

MUSCLES THAT MOVE THIGH (FEMUR) Gluteus maximus Gluteus medius Adductor longus Gracilis

Gluteus medius Gluteus maximus

Adductor longus Gracilis

MUSCLES THAT MOVE THE LOWER LEG (TIBIA AND FIBULA) Hamstrings – knee flexion Quadriceps - knee extension Sartorius – flexion of hip and lateral rotation

Muscles that flex the knee and move the lower leg: Hamstrings • Knee flexion • Dorsal muscle group • Biceps femoris • Semitendinosus • Semimembranosus

Hamstrings: Knee Flexion Semitendinosus Biceps femoris Semimembranosus Biceps femoris Semitendinosus Biceps femoris

Flexion of the leg at the hip and lateral rotation: Sartorius

Muscles that extend the knee: Quadriceps • Knee extension • Ventral muscle group • Made up of four muscles: • Vastus lateralis • Rectus femoris • Vastus medialis • Vastus intermedius

Rectus femoris Vastus lateralis Vastus medialis Vastus intermedius Deep to other muscles

MUSCLES THAT MOVE THE FOOT AND TOES Gastrocnemius Fibularis longus Tibialis anterior

Muscles that move the foot • Dorsal flexion: Tibialis anterior • Plantar flexion: Gastrocnemius • Eversion: Fibularis longus • Inversion: Tibialis anterior

Fibularis longus Tibialis anterior

Gastrocnemius