Unit 6:5 Muscular System

Myasthenia gravis

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

Muscular Dystrophy

A group of inherited diseases that lead to chronic, progressive muscle atrophy.

Extensibility

Ability to be stretched.

Contractability

Ability to become short and thick.

Excitability

Ability to respond to a stimulus.

Elasticity

Ability to return to its original shape.

4 functions of skeletal muscles

Attach to bones to provide voluntary movement, produce heat and energy, help maintain posture, and protect internal organ.

3 main kinds of muscles

Cardiac, Smooth, and Skeletal

Fibromyalgia

Chronic, widespread pain in specific muscle sites.

Flexion

Decreasing the angle between two bones.

Extension

Increasing the angle between two bones.

Abduction

Moving a body part away from the midline.

Circumduction

Moving a body part in a circle on its joint.

Adduction

Moving a body part toward the midline.

Biceps brachii

Muscle of upper arm that flexes lower arm.

Tibialis anterior

Muscle on front of lower leg that flexes and inverts the foot.

Sartorius

Muscle on front of thigh that abducts and flexes leg.

Quadriceps femoris

Muscle on front of thigh that extends leg.

Sternocleidomastoid

Muscle on side of neck that turns and flexes head.

Trapezius

Muscle on upper back and neck that extends head and moves shoulder.

Pectoralis major

Muscle on upper chest that adducts upper arm.

Rectus Abdominus

Muscle that compresses the abdomen.

Intercostals

Muscles between ribs used for breathing.

Strain

Overstreching of or injury to a muscle and/or tendon.

Muscle Tone

State of partial contraction.

Muscle Spasms

Sudden, painful, involuntary muscle contractions.

2 ways skeletal muscles attach to bones

Tendons and Fascia

Rotation

Turning a body part on its own axis.

Gluteus Maximus and Deltoid

Two muscles that can be used as injection sites.