Anatomy: Muscles and Bones

Skeletal Muscle

moves bones and controls body movement

controls voluntary movement

striated microscopic appearance

Cardiac Muscle

pumps blood through the heart

involuntary

smooth microscopic appearance

contracts slowly and rhythmically

Movement

muscles pull on bones to create motion

Posture

maintain upright seating and standing

Circulation

pumping blood in cardiovascular system

Thermoregulation

muscle contraction generates heat to maintain body temperature

Muscle Growth

1. resistance training create tears in muscle fibers

2. muscle stem cells, called satellite cells, rush to repair the microtrauma

3. repaired muscle fibers are thicker + stronger

Progressive Overload

gradually increasing weight to keep challenging tissue

Fuel

consuming dietary protein and fiber

Rest

muscles rebuild and grow while sleeping, not during the workout

Extensibility

ability to stretch/extend

loss leads to muscles becoming stiff, leading to muscles rigidity or post-stroke spasticity

stretching cold muscles increases joint risks and joint dislocations

Elasticity

ability to return to its original length after being stretched

therapists use plylometric drills to retrain recoil

chronic tearing causes scar tissue, repairing elastic tissue with collagen scar tissue

Excitability

ability to be stimulated by a nerve and respond

a nerve releases acetylcholine into the synaptic gap to trigger contraction

relies on precise balances of Sodium, Potassium, Calcium

Contractility

ability to shorten and contract

microscopic protein fibers called Actin and Myosin slide past each other like pulling ropes

immobilized or casted limbs suffer from severe Atrophy

severe overexertion can trigger Rhabdomylosis, causing damaged muscle fibers to burst and release toxic myoglobin into the kidneys

Pectoralis Major/Minor

pecs

Deltoids

shoulder

Biceps

arm

Triceps

arm

Rectus Abdominis

abs

Obliques

thoracic cavity

Quadriceps

legs

Gastrocenemius

calf muscle

Agonist

contracts

Relaxes

antagonist

Joints

point where 2 bones meet

Pivot Joints

rotational movement

Ball and Socket Joints

widest range of motion

Gliding Joints

bones glide past one another in any direction along the plane of the joint

Hinge Joint

a door hinge has back and forth movement

Jobs of skeletal system

support - our bodies need framework against gravity

movement

protection

Muscles

made of fibers that shorten

Tendons

connect muscles to bones

Ligaments

connect bones to bones

Lever Action

muscle - effort

joint - fulcrum

bone - support

Joint Movement

immovable (skull structures)

slightly movable (vertebrae)

freely movable (knee/hip)

Skull

absorbs impacts, thick bones and non-movable joints allow for minor movement + shock absorption

Ribcage

protects the thoracic organs

flexible for breathing

Spine

protects the spinal chord

discs help with shock absorption

Cranium

skull

Mandible

jawbone

Scapula

shoulder blade

Rib Cage

thoracic cavity

Humerus

funny bone

Radius

forearm

Pelvis

groin area

Ulna

forearm

Carpals

hand

Femur

thighs

Clavicle

collarbone

Fibula

leg

Tibia

leg

Metatarsals

foot