DHO 7.5 muscular system

ability to respond to stimulus

excitability

ability to be stretched

extensibility

ability to become short and thick

contractibility

ability to return to original shape

elasticity

three kinds of muscle

skeletal, visceral, and cardiac

what is the function of skeletal muscles

voluntary muscles that cause body movement

what is the function of visceral or smooth muscle

involuntary muscles that cause movement in organs

what is the function of cardiac muscles

involuntary muscles that form the walls of the heart and contract to regulate blood

voluntary

caused by thought, person is in control

involuntary

not caused by thought, person is out of control

4 functions of skeletal muscles

attach to bone provide movement, help maintain posture, produce heat and energy for the body, and protect internal organs

2 ways skeletal muscles attach to bone

tendons & fascia

adduction

moving toward the midline

abduction

moving away from the midline

flexion

decreasing angles between 2 bones

extension

increasing angles between 2 bones

rotation

turning a body part around its own axis, side to side

circumduction

moving in a circle at a joint, swinging arm

pronation

turning body part downward

supination

turning body part upward

dorsiflexion

bending backward

plantar flexion

bending forward

what is muscle tone

a state of readiness to act

what occurs when muscle atrophy

they shrink in size and lose strength

what causes muscle atrophy

muscles not being used for long periods of time

triceps brachii

muscle of upper arm that flexes lower arm

vastus lateralis

muscles on front of thigh that abducts and flexes leg

trapezius

muscle on upper back and neck that extends head and moves shoulder

intercostals

muscles between ribs used for breathing

tibialis anterior

muscles on front lower leg that flexes and introverts the foot

three muscles used for injection sites

deltoid, gluteus maximus, and vastus lateralis

rectus abdominis

compress the abdomen

pectoralis major

muscle on upper chest that adducts upper arm

sternocleidomastoid

muscle on the side of the neck that turns and flexes head

quadriceps femoris

muscle on front of thigh that extents leg

muscle spasms

sudden, painful, involuntary muscle contractions

muscular dystrophy

inherited diseases that led to chronic, progressive muscle atrophy

myasthenia gravis

chronic condition where nerve impulses are not properly transmitted to the muscles

strain

an overstretching or injury to a muscle or tendon

fibromyalgia

chronic widespread musculoskeletal pain

what is conjuncture

severe tightening of a flexor muscle resulting in bending of a joint