• 45% body weight
• Over 600 muscles
• Muscles are bundles of muscle fibers held together by connective tissue
• Takes 17 muscles to smile, 43 to frown, every
2000 frowns creates a wrinkle

• Skeletal
• Smooth
• Cardiac
Application: Make a trifold and in each column draw and describe the 3 types of muscle.
Include where located and how controlled
(voluntary vs. involuntary)

• Attach to bones of skeleton
• Striped or striated
• Also called voluntary
• Bundles of muscle cells
• Each cell is multinucleate
• Fleshy body parts, provide movement
• Most attach to bones: facial to skin

1. Attach to bones to provide voluntary movement and involuntary movement
2. Produce heat and energy for the body
3. Help maintain posture
4. Protect internal organs

• Small, short, spindle shaped
• 1 nucleus located in center of cell
• Do not have any striations – appear smooth
• Unattached to bones, act slowly, do not tire easily, can remain contracted for a long time
• INVOLUNTARY
• Walls of internal organs
(except heart)

• Found only in heart
• Branched, striated, interconnected chains
• 1 nucleus
• Involuntary
• No independent cell contraction
• Requires constant oxygen supply
• > 30 seconds w/o oxygen
– cells die

• https://www.khanacademy.org/science/healt hcare-and-medicine/heart-musclecontraction/v/three-types-of-muscle

• Excitability: ability to respond to a stimulus such as a nerve impulse
• Contractibility: muscle fibers stimulated by nerves contract or become short and thick causing movement
• Extensibility: ability to be stretched
• Elasticity: allows muscle to return to its original shape after it has contracted or stretched

• Muscles are attached at both ends
• Can be attached to bones, ligaments, cartilage, tendons, skin, to other muscles
• Fascia: touch, sheetlike membrane that covers and protects

• When muscle attaches to bone, end that does not move is called the origin
• End that moves when muscle contracts is insertion
Belly – central body of muscle

• Using DHO, define the following:
• Adduction
• Abduction
• Flexion
• Extension
• Rotation
• Circumduction

• Adduction: moving a body part toward the midline
• Abduction: moving a body part away from the midline
• Flexion: decreasing the angle between 2 bones, bending a body part
• Extension: increasing the angle between 2 bones, straightening a body part
• Rotation: turning a body part around its own axis
(head)
• Circumduction: moving in a circle at a joint (swinging arm)

• State of partial contraction
• State of readiness to act
• Muscles are partially contracted at all times
• Loss of muscle tone occurs in paralysis
• Lack of use causes atrophy (shrink)
• Contracture – severe tightening of flexor muscle

• Using Body Structures and Functions, explain how the muscles are a source of heat and energy. Be sure to include how ATP is involved in this process.

Muscle need energy to function
Adenosine Triphosphate - ATP – major source of energy
Cells bring in oxygen, glucose, etc
Muscle stimulated ATP released producing heat for our body and energy for muscle contracting

• During process of ATP release creating energy/heat: lactic acid (byproduct of cellular metabolism) builds up
• Increased lactic acid levels in muscles cause muscle fatigue
• WHY? Vigorous exercise – blood can’t transport enough oxygen to complete oxidation of glucose in muscles – muscles contract anaerobically
• So why does resting help a cramp?

• Chronic, widespread muscular pain
• S&S: muscle stiffness, numbness, tingling in arms or legs, fatigue, sleep disturbances, memory and mood issues, headaches and depression
• Causes:unknown
• Tx: pain relief, PT, massage, exercise, stress reduction, pain meds, muscle relaxers

• A group of inherited diseases that lead to chronic,progressive muscle atrophy. Usually begins in childhood
• S&S: muscle atrophy including heart and respiratory system muscles leading to total disability and early death.
• Causes: inherited- genetic defect
• Tx: PT

• Living with Muscular Dystrophy

• Chronic condition where nerve impulses are not properly transmitted to the muscles leading to progressive muscle weakness and paralysis.
• S&S: eye weakness, drooping eyelids, altered speech, difficulty swallowing or chewing
• Causes: unknown but may be autoimmune
• Tx: no cure but cholinesterase inhibitors seems to increase communication bw muscles and nerves, corticosteroids limit antibody production, immunosuppressants, plasmapharesis

• also known as cramps. Sudden, painful, involuntary muscle contractions
• S&S: cramps
• Causes: overexertion, dehydration, low electrolyte levels, poor circulation
• TX: gentle pressure and massage, stretching of muscle to relieve spasm

• Overstretching of or an injury to a muscle or tendon
• S&S: myalgia, swelling, limited movement
• Causes: prolonged or sudden exertion
• Tx: rest, muscle relaxers, pain meds, ibuprofen, elevation, compression, hot/cold applications

• Inflammation of the tendon that connects the arm to the elbow
• S&S: pain at elbow
• Causes: repetitive use of arm
• Tx: pain relief, ice packs

• Injury to muscle tendon in front of shin
• S&S: pain in shin
• Causes: running/jogging
• Tx: proper fitting shoes with arch support

• Inflammation of group of tendons that surround shoulder joint
• S&S: repetitive swinging action of joint
• Causes: pain at shoulder
• Tx: rest, PT, surgery

• Rotator Cuff Surgery
• 3 Signs of Rotator Cuff injury by PT