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

2. 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

3. 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

4. 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

5. 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)

6. 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

7. 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

8. 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

9. 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

10. 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

12. Muscle Contraction
Sliding Filament Theory

14. 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

15. 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

16. 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

17. 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

18. 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

19. Let’s watch Hank give his overview
Crash Course – Big Guns

20. 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.

22. 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

23. 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

24. 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

25. 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

26. 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

27. 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

28. 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.

29. 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

30. 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

31. Check out this link to learn more
Interactive Body