MUSCULAR SYSTEM Chapter 7 NAMING SKELETAL MUSCLES Location

MUSCULAR SYSTEM Chapter 7

NAMING SKELETAL MUSCLES Location Size Direction of fibers Number of origins Location of origins and insertion Action flexor Extensor Levator and depressor

MUSCLES OF THE HEAD AND NECK Muscles of the head and neck control human facial expressions Muscles of mastication control the mandible (lower jaw)

FACIAL EXPRESSIONS frontalis Expression: Surprise Location: Either side of forehead Function: Raises eyebrow and wrinkles forehead Depressor anguli oris Expression: doubt, disdain, contempt Location: along side of chin Function: depresses corner of mouth

FACIAL EXPRESSIONS Orbicularis oris Expression: doubt, disdain, contempt Location: ring-shaped muscle found around mouth Function: compresses and closes the lips Platysma Expression: horror Location: broad, thin muscular sheet covering the side of neck and lower jaw Function: draws corners of mouth downward and backward

FACIAL EXPRESSIONS Zygomaticus major Expression: laughing or smiling Location: extends diagonally upward from corner of mouth Function: raises corner of mouth Nasalis Expression: Muscles of nose Location: over nasal bones Function: closes and opens nasal openings

FACIAL EXPRESSIONS Orbicularis oculi Expression: sadness Location: Surrounds eye orbit underlying the eyebrows Function: Closes the eyelid and tightens the skin on the forehead

MASTICATION Masseter Location: Covers the lateral surface of mandible Function: Closes the jaw Temporalis Location: Located on the temporal fossa of the skull Function: Raises the jaw, closes the mouth, and draws back the jaw

NECK Sternocleidomastoid Location: large muscles extending diagonally down sides of neck Function: flexes head; rotates head toward opposite side from muscle

MUSCLES OF THE UPPER EXTREMITIES Muscles of the upper extremity help to move the: Shoulder (scapula) Arm (humerus) Forearm Wrist Hand Fingers

UPPER EXTREMITIES Trapezius Location: a lg triangular muscle located on the upper surface of the back. Function: Moves the shoulder; extends the head Deltoid Location: a thick triangular muscle that covers the shoulder joint Function: Abducts the upper arm

UPPER EXTREMITIES Pectoralis major Location: anterior part of chest Function: Flexes upper arm and helps to abduct the upper arm. Serratus Location: anterior chest Function: Moves scapula forward and helps to raise the arm.

UPPER EXTREMITIES Biceps brachii Location: upper arm to radius Function: flexes the lower arm Triceps brachii Location: posterior arm to ulna Function: extends the lower arm

UPPER EXTREMITIES Extensor and flexor carpi Location: extends from the anterior and posterior forearm to hand Function: moves the hand Extensor and flexor digitorum Location: extends from the anterior and posterior forearm to fingers Function: moves the fingers

MUSCLES OF THE TRUNK Trunk muscles control breathing and the movements of the abdomen and the pelvis External intercostals Diaphragm Rectus abdominis External oblique Internal oblique

TRUNK External intercostals Location: found b/w the ribs Function: raises the ribs to help in breathing Diaphragm Location: dome-shaped muscle separating the thoracic and abdominal cavities Function: control breathing

TRUNK Rectus abdominis Location: extends from the ribs to the pelvis Function: compresses the abdomen. External oblique Location: anterior inferior edge of the last 8 ribs Function: depresses ribs, flexes the spinal column, compresses the abdominal cavity

TRUNK Internal oblique Location: beneath the external oblique, fibers running the opposite direction Function: depresses ribs, flexes the spinal column, compresses the abdominal cavity

MUSCLES OF THE LOWER EXTREMITIES Assist in the movement of the thigh, leg, ankle, foot, and toes Gluteus maximus - Tibialis anterior Gluteus medius - Gastrocnemius Tensor fasciae - Soleus Peroneus longus - Sartorius Rectus femoris

LOWER EXTREMITIES Gluteus maximus Location: forms the buttocks Function: extends femur and rotates it outward. Gluteus medius Location: extends from deep femur to buttocks Function: abducts and rotates the thigh

LOWER EXTREMITIES Tensor fasciae Location: flat muscle found along the upper lateral surface of thigh Function: flexes, abducts, medially rotates thigh. Rectus femoris Location: anterior thigh Function: flexes thigh and extends lower leg

LOWER EXTREMITIES Sartorius Location: long, straplike muscle that runs diagonally across the anterior and medial surface of the thigh Function: flexes and rotates the thigh and leg Tibialis anterior Location: front of tibia bone Function: dorsiflexes the foot; permits walking on the heels

LOWER EXTREMITIES Gastrocnemius Location: calf Function: points toes and flexes lower leg. Soleus Location: broad flat muscle found beneath calf Function: extends foot

LOWER EXTREMITIES Peroneus longus Location: superficial muscle found on the lateral side of the leg Function: extends and everts the foot and supports the arches.

HOW EXERCISE AND TRAINING CHANGE MUSCLES Effect of training on muscle efficiency: Improved coordination Improvement of the respiratory and circulatory system Elimination or reduction of excess fat Improved joint movement

HOW EXERCISE AND TRAINING CHANGE MUSCLES Effects of Training on Muscle Strength Increase in muscle size Improved antagonistic muscle coordination Improved functioning in the cortical brain region

INTRAMUSCULAR INJECTIONS Injections are made into the muscle, usually the deltoid muscle of the upper arm, vastus lateralis (anterior thigh), dorsal gluteal or ventral gluteal or buttocks

MUSCULOSKELETAL DISORDERS Atrophy Fibromyalgia Strain Hernia Abdominal hernia Inguinal hernia Hiatal hernia Spasm Myalgia

MUSCULOSKELETAL DISORDERS Flatfeet Mysathenia Tetanus gravis Recreational injuries Torticollis Muscular dystrophy Tennis elbow Shin splints Rotator cuff disease