1. Muscular System
Mrs. Hammac
Health

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

3. 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

4. Skeletal Muscle

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

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

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

8. 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

9. 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

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

11. 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

12. 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

13. 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

14. 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

15. 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

16. 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

17. 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.

18. 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!

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

20. 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.

21. 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.

22. 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.

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

24. 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

25. 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.

26. 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

27. 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

28. 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

29. 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!

30. 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

31. Sources