Mrs. Yanac Anatomy & Physiology Muscular System Mrs. Yanac Anatomy & Physiology

Big Ideas Muscle makes us over ½ of the body’s mass Consists of over 600 muscles Consumes a large amount of energy obtained through diet Muscles can ONLY contract & shorten in length Categorized into 3 categories Skeletal, Cardiac, Smooth

Muscle Types Smooth (Involuntary) Cardiac (Involuntary) All body movements are determined by three types of muscles Smooth (Involuntary) cannot be controlled by will Cardiac (Involuntary) control the contractions of the heart Skeletal (Voluntary) can be controlled by will

Functions of Skeletal Muscle Provides voluntary movement of body Enables breathing, blinking, and smiling Allows you to hop, skip, jump, or do push-ups Maintains posture Produces heat http://images.google.com/imgres?imgurl=http://www.justinsokolowski.net/graphics/animatedBlinkingEyeSlowgreen.gif&imgrefurl=http://www.justinsokolowski.net/&h=95&w=95&sz=31&hl=en&start=4&um=1&tbnid=8QMsDOH5nTCixM:&tbnh=80&tbnw=80&prev=/images%3Fq%3Danimated%2Bblinking%26svnum%3D10%26um%3D1%26hl%3Den%26rls%3DGGLB,GGLB:1969-53,GGLB:en%26sa%3DN http://images.google.com/imgres?imgurl=http://www.eyethinkinc.com/rulers/images/blinkingeyes.gif&imgrefurl=http://www.eyethinkinc.com/rulers/blinkingeyes.html&h=148&w=416&sz=34&hl=en&start=58&um=1&tbnid=AmuUAWlJKeLVwM:&tbnh=44&tbnw=125&prev=/images%3Fq%3Danimated%2Bblinking%26start%3D40%26ndsp%3D20%26svnum%3D10%26um%3D1%26hl%3Den%26rls%3DGGLB,GGLB:1969-53,GGLB:en%26sa%3DN http://i81.photobucket.com/albums/j215/Oblivion_fan/Animatedflames.gif

Function of Smooth Muscle Called smooth muscle because they are unmarked by striations, small spindle shaped Unattached to bones, act slowly, do not tire easily and can remain contracted for a long time Not under conscious control so they are also called involuntary muscles Found in walls of internal organs (intestines, bladder, stomach, uterus, blood vessels)

Provides movement of internal organs Moves food through digestive tract (peristalsis) Enables bladder control Causes involuntary actions Reflex actions Adjusts opening of pupils Causes hair to stand on end http://bimari-jankari.mla.iitk.ac.in/image/dsanim.gif http://www.visionsource-arenaeyeworks.com/images/Wild%20Eyes%20-%20animated.gif http://www.search.com/reference/Goose_bumps http://www.ebcl.lib.id.us/ebcl/images/goosebump.gif

Function of Cardiac Muscle Found only in the heart Involuntary muscle Requires a continuous supply of oxygen to function Cardiac muscle cells begin to die after 30 seconds of oxygen cut-off Striated and branched Directs circulation of blood

Special muscles Sphincter (dilator) muscles are openings between the esophagus and stomach the stomach and small intestines walls of the anus, urethra and mouth Open and close to control passage of substances

Characteristics of Muscles All muscles have 4 common characteristics Excitability – ability to respond to a stimulus (ie: nerve impulse) Contractibility – muscle fibers that are stimulated by nerves contract (become shorter) and causes movement Extensibility – ability to be stretched Elasticity – allows the muscle to return to its original shape after it has been stretched

Sources of Heat/Energy When muscles work, they produce heat that our body needs to function properly Major source of this energy is ATP – a compound found in muscle cells ATP requires muscle cells to have oxygen, glucose and other materials circulated by the blood When the muscle is stimulated, ATP is released, thus producing heat

Muscle Contraction Sliding Filament Theory

Attachments & Actions of Skeletal Muscles Actions depend largely on what the muscles are attached to Attachment sites Origin – an attachment site for a less movable bone Insertion – an attachment site for a more moveable bone

Attachments & Actions (cont.) Movement usually produced by a group of muscles Prime mover – muscle responsible for most of the movement Synergists – muscles that help the prime mover by stabilizing joints Antagonist (agonist) – produces movement opposite to prime mover Relaxes when prime mover contracts

Attachments & Actions: Body Movements Flexion – bending a body part Extension – straightening a body part Hyperextension – extending a body part past the normal anatomical position Dorsiflexion – pointing the toes up Plantar flexion – pointing the toes down Abduction – moving a body part away from the anatomical position Adduction – moving a body part toward the anatomical position

Attachments & Actions: Body Movements (cont.) Circumduction – moving a body part in a circle Pronation – turning the palm of the hand down Supination – turning the palm of the hand up Inversion – turning the sole of the foot medially Eversion – turning the sole of the foot laterally Retraction – moving a body part posteriorly Protraction – moving a body part anteriorly

Attachments & Actions: Body Movements (cont.) Elevation – lifting a body part; for example, elevating the shoulders as in a shrugging expression Depression – lowering a body part; for example, lowering the shoulders

Let’s watch Hank give his overview Crash Course – Big Guns https://www.youtube.com/watch?v=jqy0i1KXUO4

Major Skeletal Muscles The muscle name indicates Location Size Action Shape OR Number of attachments of the muscle As you study muscles, you will find it easier to remember them if you think about what the name describes.

MUSCLES YOU SHOULD KNOW THE FUNCTIONS OF: Biceps – flexes lower arm Deltoid – abducts arm; injection site Sternocleidomastoid – turns head Gastrocnemius – flexes sole of feet Latissimus dorsi – extends & adducts upper arm Pectoralis major – adducts and flexes upper arm Intercostals – moves ribs for breathing

Trapezius – extends head, moves shoulder Triceps – extends lower arm Gluteus maximus – extends thigh; injection site Sartorius – abducts thigh, flexes leg Vastus lateralis – extends leg Rectus abdominus – compresses the abdomen Rectus femoris – flexes thigh & extends lower leg Tibialis anterior – flexes and inverts foot

Muscle Strains and Sprains Strains – injuries due to over-stretched muscles or tendons Sprains – more serious injuries that result in tears to tendons, ligaments, and/or cartilage of joints RICE is recommended treatment for either Rest Ice Compression Elevation

Muscle Strains and Sprains (cont.) Prevention Warm up muscles A few minutes before an intense activity raises muscle temperature and makes muscle more pliable Stretching Improves muscle performance and should always be done after the warm-up or after exercising Cooling down or slowing down Before completely stopping prevents pooling of blood in the legs and helps remove lactic acid from muscles

Aging and the Musculoskeletal System Contractions become slower and not as strong Dexterity and gripping ability decrease Mobility may decrease Assistive devices helpful Routine exercise Swimming Physical therapy

Diseases and Disorders of the Muscular System Description Botulism Affects the gastrointestinal tract and various muscle groups Fibromyalgia Fairly common condition that causes chronic pain primarily in joints, muscles, and tendons Muscular Dystrophy Inherited disorder characterized by muscle weakness and a loss of muscle tissue Myasthenia gravis Autoimmune condition in which patients experience muscle weakness

Diseases and Disorders of the Muscular System (cont.) Description Tennis/Golfer’s elbow Tendon damage in the area of the elbow from repeated use of forearm Tendonitis Painful inflammation of a tendon and the tendon-muscle attachment to a bone Carpal Tunnel Syndrome Compression in nerves in the wrist leads to tingling and pain in the hand, wrist, & forearm Fibromyalgia Chronic, widespread pain in specific muscle site; numbness and tingling in arms or legs; headaches. Cause unknown.

Problems from lack of movement Contractures Tightening and shortening of a muscle resulting in a permanent flexing of a joint Muscle atrophy Muscles become weak and joints become stiff Circulatory impairment Blood clots and pressure ulcers can develop Mineral loss Especially calcium from the bones making bones brittle and easily to be fractured Other problems Poor appetite; constipation; urinary infections; respiratory problems; and pneumonia

Point to Ponder: Everyone has a 'risk muscle.' You keep it in shape by trying new things. If you don't, it atrophies. Make a point of using it at least once a day. ~Roger von Oech

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