Anatomy and Physiology Chapter 6 Muscular System

Muscular System The body system that covers, shapes, and supports the skeletal tissue It contracts and moves various parts of the body

Cosmetologists Limited to: Voluntary muscles Arms, hands, lower legs, feet

Myology The science of the nature, structure, function, and diseases of the muscles

Muscle 600 muscles 40% of body’s weight Fibrous tissue that have the ability to stretch and contract according to the demands of the body’s movements

Striated Muscles Skeletal or voluntary muscles Striped Legs, arms, face etc. Striped What we work over and are concerned about Attached to the bones and are controlled by will Create heat and energy for the body during muscle contractions Assist in maintaining posture Protect some internal organs

Nonstriated Muscles Involuntary, visceral Smooth (not striped) Diaphragm etc. Smooth (not striped) Function automatically, without conscious will, without thought or control Found in internal organs of digestive and respiratory systems

Cardiac Muscle Involuntary muscle that is the heart Not found anywhere else in the body

Origin Part of the muscle that does not move Fixed attachment to a bone or ligament Direction of movement is from the insertion of the muscle to the origin of the muscle

Insertion Part of the muscle at the more movable attachment to the bone or ligament

Belly or Body Middle part of the muscle

Muscle tissue can be stimulated by: Massage Electrical current Light rays Dry heat Moist heat Nerve impulses Chemicals

Muscles of the scalp Epicranius – broad muscle that covers the top of the skull Occipitalis – back of the head draws the scalp backward Frontalis – front of head muscle that raises the eyebrows Draws the scalp forward Causes wrinkles across the forehead

Superior – above Inferior – below Anterior – front Posterior - back

Muscles of the ear Auricularis superior – Auricularis Anterior – Muscle above the ear that draws the ear upward Auricularis Anterior – Muscle in front of the ear that draws the ear forward Auricularis Posterior – Muscle behind the ear that draws the ear backward

Muscle of Mastication (chewing) Masseter – Long broad muscle on the sides of the chin - in front of the ear, to aid in chewing Temporalis – Muscle on sides of head above the ear and behind the eyes to aid the masseter in chewing

Muscles of the Neck Platysma – Sternocleidomastoideus – Broad muscle extending from the chest and shoulder muscles to the side of the chin Responsible for lowering the lower jaw and lip Sternocleidomastoideus – Muscle of the neck that lowers and rotates the head

Muscles of the Eyebrow Corrugator – Orbicularis oculi – located beneath the frontalis and orbicularis oculi Draws the eyebrow down Wrinkles the forehead vertically Orbicularis oculi – Ring of muscle of the eye socket Enables you to close your eyes

Muscles of the Nose Procerus Other – Covers the bridge of the nose Lowers the eyebrows Causes wrinkles across the bridge of the nose Other – Nasal muscles contract and expand the opening of the nostrils

Muscles of the Mouth Mentalis Orbicularis Oris Elevates the lower lip Raises and wrinkles the skin of the chin Orbicularis Oris Flat band around the mouth Compresses, contracts, puckers and wrinkles the lips - kissing

Risorius Triangularis Zygomaticus Muscle that draws the corner of the mouth out and back as in grinning Triangularis Muscle extending alongside the chin Pulls down the corner of the mouth Zygomaticus Muscles extending from the zygomatic bone to the angle of the mouth Elevate the lip as in laughing

Muscles that attach the arms to the body Latissimus Dorsi Broad, flat superficial muscle covering the back of the neck and upper and middle region of the back Controlling the shoulder blade and the swinging movements of the arm

Pectoralis major/pectoralis minor Muscles of the chest that assist the swinging movements of the arm Serratus Anterior Muscle of the chest that assists in breathing and in raising the arm

Trapezius Muscle that covers the back of the neck and upper and middle region of the back Rotates and controls swinging movements of the arm

Muscles of the Shoulder and Arm Biceps Two (2) headed muscle Muscle producing the contour of the front and inner side of the upper arm Lift the forearm Flex elbow Turn the palms outward

Deltoids Large triangular muscle covering the shoulder joint Allows the arm to extend outward and to the side of the body

Triceps Three (3) headed muscle Large muscle that covers the entire back of the upper arm Extends the forearm

Forearm muscles Extensors Flexors Muscles that straighten the wrist, hand, and fingers to form a straight line Flexors Extensor muscles of the wrist Involved in bending the wrist

Pronators Muscle that turn the hand inward so that the palm faces downward Supinators Muscle of the forearm that rotates the radius outward and the palm upward

Muscles of the Hand Abductors Adductors Opponent muscles Muscle that separate the fingers Adductors Muscles at the base of each finger that draw fingers together Opponent muscles Muscles in the palm that act to bring the thumb toward the fingers

Muscles of the Lower Leg and Foot Extensor Digitorum Longus Bends the foot up and extends the toes Tibialis Anterior Covers the front of the shin Bends the foot upward and inward

Peroneus Longus Peroneus Brevis Covers the outer side of the calf Inverts the foot Turns it outward Peroneus Brevis Originates in the lower surface of the fibula Bends the foot down and out

Gastrocnemius Soleus Attached to the lower rear surface of the heel Pulls the foot down Soleus Originates in the upper portion of the fibula Bends the foot down

Muscles of the Foot Extensors Digitorum Brevis Abductor Hallucis Flexor Brevis Abductor Muscles move the toes and help maintain balance while walking and standing