Muscular System Mrs. Hammac Health

What Muscles Do The muscular system allows for voluntary and involuntary movements. Your muscular system allows you to move.

How Muscles Work Functions: Movement Stability When bundles of muscles are stimulated by nerve impulses, or signals, they contract, or shorten. When they relax, the bundles extend, or stretch. Functions: Movement Stability Control of body openings and passages Heat production

Skeletal Muscle

Three Types of Muscle Tissue Types of Muscles Three Types of Muscle Tissue Smooth Muscle Skeletal Muscle Cardiac Muscle

What Muscles Do Involuntary muscle movements help you breathe, make your heart beat, and move food through your digestive system.

Functions of Muscle: Stability Hold bones tightly together Stabilize joints Small muscles hold vertebrae together Stabilize the spinal column

Functions of Muscle: Control of Body Openings and Passages Sphincters Valve-like structures formed by muscles Control movement of substances in and out of passages Example: A urethral sphincter prevents or allows urination

Functions of Muscle: Heat Production Heat is released with muscle contraction Helps the body maintain a normal temperature Moving your body can make you warmer if you are cold

Types of Muscles Smooth muscles are involuntary muscles. Muscles that act on the lining of the body’s passageways and hollow internal organs

Types of Muscle Tissue: Smooth Muscle Multi-unit smooth muscle In the iris of the eye and walls of blood vessels Responds to neurotransmitters and hormones Visceral smooth muscle In walls of hollow organs Responds to neurotransmitters AND Stimulate each other to contract so that muscle fibers contract and relax together in a rhythmic motion – peristalsis

Types of Muscle Tissue: Smooth Muscle (cont.) Peristalsis – rhythmic contraction that pushes substances through tubes of the body Neurotransmitters for smooth muscle contraction Acetylcholine Norepinephrine Will cause or inhibit contractions, depending on smooth muscle type

Types of Muscles Cardiac muscle is involuntary and is responsible for the contraction of your heart. Your heart beats 100,000 times each day. Cardiac muscle A type of striated muscle that forms the wall of the heart

Types of Muscle Tissue: Cardiac Muscle Intercalated discs Connect groups of cardiac muscle Allow the fibers in the groups to contract and relax together Allows heart to work as a pump Self-exciting – does not need nerve stimulation to contract Nerves speed up or slow down contraction

Types of Muscles Most of your muscle tissue is skeletal, and almost all skeletal muscles are under voluntary control. Skeletal muscles Muscles attached to bone that cause body movements

Types of Muscle Tissue: Skeletal Muscle Muscle fibers respond to the neurotransmitter acetylcholine Causes skeletal muscle to contract Following contraction, muscles release the enzyme acetylcholinesterase Breaks down acetylcholine Allows muscle to relax

Apply Your Knowledge True or False: ___ Skeletal muscles are attached to bones by ligaments. __ Contractions of smooth muscle produce movement of organ contents. ___ Cardiac muscle produces atrial and ventricular contractions. ___ Sphincters control movement of substances out of passages. ___ Heat is released as muscles relax.

Apply Your Knowledge RIGHT! ANSWER: True or False: ___ Skeletal muscles are attached to bones by ligaments. __ Contractions of smooth muscle produce movement of organ contents. ___ Cardiac muscle produces atrial and ventricular contractions. ___ Sphincters control movement of substances out of passages. ___ Heat is released as muscles relax. tendons F T T in and out F contract F RIGHT!

What Muscles Do Skeletal muscles work in pairs to produce movement.

Caring for Your Muscles Get regular exercise. Eat high protein foods to build muscle. Practice good posture to strengthen back muscles. Use proper equipment and wear appropriate clothing to protect muscles during any physical activity. Warm up properly and stretch before exercising, and cool down after exercising to prevent injury.

Understanding Muscular Problems Bruises are areas of discolored skin that appear after an injury that causes the blood vessels beneath the skin to rupture and leak.   Large bruises can be treated with an ice pack to reduce initial swelling.

Understanding Muscular Problems Muscle strains or sprains result when muscles are stretched or partially torn from overexertion. Apply ice to strains to reduce swelling, and rest the affected area.

Understanding Muscular Problems Tendinitis can be caused by injury, overuse, or natural aging. Tendinitis The inflammation of a tendon

Understanding Muscular Problems Hernias commonly occur in the abdomen from straining to lift a heavy object. Surgery can usually repair hernias. Hernia An organ or tissue protrudes through an area of weak muscle

Understanding Muscular Problems Muscular dystrophy is an inherited disorder in which skeletal muscle fibers are progressively destroyed. There is no cure, but with early detection, muscle weakness can be delayed through exercise programs.

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

Apply Your Knowledge Good Job! The doctor has told your patient that his son has muscular dystrophy disorder. What is muscular dystrophy? ANSWER: Muscular dystrophy is an inherited disorder characterized by muscle weakness and a loss of muscle tissue. Good Job!

In Summary Skeletal muscles Smooth muscles Cardiac muscles Voluntary control Produce movement in conjunction with skeletal system Help stabilize joints Participate in heat production Smooth muscles Involuntary control Control body openings and passages Cardiac muscles Responsible for pumping action of the heart

Sources http://graphics8.nytimes.com/images/2007/08/01/health/adam/19917.jpg http://www.sport-fitness-advisor.com/images/muscle_anatomy.jpg http://images.encarta.msn.com/xrefmedia/sharemed/targets/images/pho/t790/T790539A.jpg http://clcpages.clcillinois.edu/home/bio567/pages/newtissues/Skeletal%20muscle%2003a.jpg http://www.sciencelearn.org.nz/var/sciencelearn/storage/images/contexts/see_through_body/sci_media/cardiac_muscle/8558-1-eng-NZ/cardiac_muscle_full_size_landscape.jpg