Main functions of the muscular system are as follows:
Circulation
The heart is a muscle that pumps blood throughout the body. The movement of the heart is outside of conscious control, and it contracts automatically when stimulated by electrical signals..
Respiration
Breathing involves the use of the diaphragm muscle.
The diaphragm is a dome-shaped muscle located below the lungs. When the diaphragm contracts, it pushes downward, causing the chest cavity to get bigger. The lungs then fill with air. When the diaphragm muscle relaxes, it pushes air out of the lungs.
Urination
The urinary system comprises both smooth and skeletal muscles, including those in the:
bladder
kidneys
penis or vagina
prostate
ureters
urethra
Childbirth
Smooth muscles in the uterus expand and contract during childbirth. These movements push the baby through the vagina. Also, the pelvic floor muscles help to guide the baby’s head down the birth canal.
Temperature regulation
Maintaining normal body temperature is an important function of the muscular system. Almost 85 percent of the heat a person generates in their body comes from contracting muscles.
When body heat falls below optimal levels, the skeletal muscles increase their activity to make heat. Shivering is one example of this mechanism. Muscles in the blood vessels also contract to maintain body heat.
Body temperature can be brought back within normal range through the relaxation of smooth muscle in the blood vessels. This action increases blood flow and releases excess heat through the skin.
Organ protection
Muscles in the torso protect the internal organs at the front, sides, and back of the body. The bones of the spine and the ribs provide further protection.
Muscles also protect the bones and organs by absorbing shock and reducing friction in the joints.
Posture
Skeletal muscles help keep the body in the correct position when someone is sitting or standing. This is known as posture.
Vision
Six skeletal muscles around the eye control its movements.
Stability
Muscle tendons stretch over joints and contribute to joint stability. Muscle tendons in the knee joint and the shoulder joint are crucial in stabilization.
