Chapter 4.
Muscular System
Muscle tissue is unique in its ability to shorten or contract. Smooth muscle is used to push things through many internal organs, and it is also used to regulate the pressure and flow of blood throughout the body.
Cardiac muscle is formed into a hollow structure that is used to pump blood. Skeletal muscle is the voluntary muscle tissue that is typically attached to the skeleton on for movement. Skeletal muscles are striated (they have a cross stripped appearance).
Most muscles are grouped in pairs of antagonistic (opposite) functions.
The actions of the muscles are:
Flexion (to decrease the angle of a joint);
Extension (to increase the angle of a joint);
Adduction (to move closer to the midline);
Abduction (to move away from the midline);
Pronation (to turn the palm down);
Supination (to turn the palm up);
Dorsiflexion (to elevate the foot);
Plantar flexion (to lower the foot);
Rotation (to rotate a bone around its longitudinal axis).
Suggested videos:
- Three types of muscle | Circulatory system physiology | NCLEX-RN | Khan Academy (about 12 minutes)
- Thermoregulation by muscles | Integumentary system physiology | NCLEX-RN | Khan Academy (about 9 minutes)
Back to Introduction Ch. 3 – Skeletal System Ch. 5 – Cardiovascular System