Are you strong enough?

MUSCLE= latin ‘musculus’=little mouse

Skeletal muscle makes up about 40% of the mass of the average human body. Muscles are the engine that propels the body. They turn energy into motion and efficient at turning fuel into motion.

They are long lasting, self healing and grow stronger with practice.

Main function is to: Produce heat Produce movement Maintain posture

Muscles are made of elastic fibers. These fibers are like a rubber band that lengthens and shortens. The thick and thin filaments do the actual work of a muscle.A muscle contraction occurs when these fibers

generate tension through the action of actinand myosin cross-bridging.This process describes the sliding of myosin and actin filaments over each other.

Thick filaments are made of protein called myosin.

Thin filaments are made of another protein called actin.

Muscles cannot push- they can only pull.

Even when you push against a wall, each muscle in your body is working by pulling.

When the muscles relax they stop pulling and your arm and another muscle straightens it.

There are over 600 muscles that make up the muscular fibers that are held together by connective tissue

Properties or characteristics of muscles-

Excitability- ability to respond to a nerve impulse

Contractibility- muscle fibers that are stimulated by nerves- they contract or become short and thick

Extensibility- ability to be stretched

Elasticity- allows the muscle to return to its original shape after it has contracted or stretched

Main types of muscles: 1. cardiac 2. visceral-smooth muscles 3. skeletal- striatedCan be described as voluntary and involuntary

Cardiac- These muscles form the walls of the heart

Contract to circulate blood Involuntary- function without us thinking about it

Cardiac muscle is involuntary striated muscle. huge number of mitochondria per cell to make energy.

visceral or smooth- Found in the internal organs of the body such as the digestive system, respiratory system, blood vessels and the eyes

These contract to cause movement in these systems

Involuntary function without conscious control

Smooth muscle is found in your airway, digestive system, blood vessels and in females the uterus.

Smooth muscle can stretch and maintain tension for long periods of time.

It contracts involuntarily without you thinking about it.

Skeletal or striated- Attach to bones Cause body movement Voluntary- person has control over their actions

How muscles attach to bone:1.Tendons- strong tough connective tissue cord

2. fascia- tough sheet-like membrane that hold muscles together,covers and protects tissue

3. Origin and insertion- when muscle attaches to bone one section becomes the origin (which does not move) and one end is the insertion (the end that moves when the muscle contracts)

Actions of the muscles: Adduction- moving a body part toward the midline

Abduction- moving a body part away from the midline

Flexion- decreasing the angle between 2 bones or bending a body part

Extension- increasing the angle between 2 bones or straightening a body part

Actions or movement continued: Rotation- turning a body part around it’s own axis- like turning the head side to side

Circumduction- moving in a circle at a joint

moving one end of a body part in a circle while the other end stays stationary- like swinging the arm in a circle

Seed question- which joints circumduct and which joints rotate?

Actions continued:Supination- a rotation of the arm or foot in which the hand can face up and foot tipped to the outer edge

Pronation- when hand faces down and the foot flattens out so that the arch strikes the ground.

Major muscles of the body: Refer to page 127 in the book: Fill in worksheet on the major muscles of the body

Terms related to muscle: Edema- swelling Hypertrophy of the muscle- increased muscle mass

Atrophy- decreased muscle mass Contracture- muscle shortening Fasciculation- involuntary muscle movement

ROM- range of motion- ability to move the muscle and joint through a full rotation/ extension/flexion smoothly, and without pain or difficulty.

Active isotonic- patient is able to move area by themselves without assistance

Active-assistive- patient can do some, but will need some help, or can assist self

Passive- patient can not do activity independently

Static- isometric- patient can tense muscle without moving joint

Resistive- strength building

fibromyalgia is a chronic condition characterized by widespread pain in your muscles, ligaments and tendons, as well as fatigue and multiple tender points — places on your body where slight pressure causes pain.

Muscular dystrophy- this is an inherited disease that leads to chronic muscle atrophy. It appears in early childhood and most types result in severe disability and early death due to fat tissue replacing the muscle fibers effecting cardiac muscle.

There is no cure, but physical therapy can slow the progression

Signs and symptoms of MD vary according to the type of muscular dystrophy. In general, muscular dystrophy symptoms may include:

Muscle weakness Apparent lack of coordination Progressive crippling, resulting in fixations (contractures) of the muscles around your joints and loss of mobility

Myasthenia gravis- a chronic condition where nerve impulses are not properly transmitted through the muscle. This leads to weakness and paralysis. Any effort gives extreme fatigue.

If the condition affects the respiratory muscles it can lead to respiratory failure and death.

Myasthenia gravis cont.- Symptoms are: Difficulty talking, swallowing, choking

Drooping head and eyes Drooling Difficult breathing Muscle function better after rest Difficulty lifting objects

Rhabdomyosarcoma- tumor of the muscle tissue. This is rare, but prognosis is usually poor. It metastasizes early and leads to advanced malignancy quickly.

Muscle spasm- can occur in the legs and feet due to overexertion, low electrolyte levels or poor circulation

Strain- is an overstretching or injury to a muscle and or tendon. Prolonged or sudden muscle exertion is usually the cause.

Usually symptoms are edema, limited movement and pain.

Treatment is rest, muscle relaxant, pain medication, elevate the extremity and alternate hot and cold applications.

think on this

where is your smallest muscle?

what is the longest muscle?

http://www.sci.sdsu.edu/movies/actin_myosin_gif.html

Are small and not striated They are made up of thick and thin filaments

They have intermediate filaments that cross like fish-net stockings

Intermediate filaments slide across thin filaments and draw the muscle up in all directions