Muscles enable us to walk, stand, smile, blink, etc.Muscular system controls movements of our body. There are over 600 muscles inthe human body, and they are classified in three big categories: cardiacmuscles, smooth muscles and skeletal muscles. Skeletal muscles enable us tomake voluntary movement. Smooth and heart muscles are muscles designed forinvoluntary movements, and we can find them lining the stomach walls, intestinewalls and other hollow organs. They are controlled by the autonomous nervoussystem. Finally, cardiac muscles are unique muscles in the body, and they canbe found only in the heart. They are also controlled by the autonomous nervoussystem.
Mobility is one of the main functions of the muscularsystem. When moving, our central nervous system sends signals to our muscles,and they start to congest and relax. Considering that central nervous systemcontrols these skeletal muscles, these movements are considered as voluntaryfunctions. Voluntary muscle movementenables us to jump, walk, run, sit up and sit down, dance, climb, etc.
Stability & Posture
Skeletal muscles are in command when it comes to keeping thestability and posture. They are attached with the bones via ligaments andtendons. These muscles are also essential for keeping the balance andcoordination of the body.
Involuntary movements of digestive tract muscles enable usto digest our food. These movements are considered as involuntary, sincethey are controlled via the autonomous nervous system. The smooth muscles(found in the walls of the intestine) contract and relax and permit the swallowedfood to be mixed in the stomach and then the intestines. As the food getsprocessed, smooth muscles send waste to the rectal part of colon where the wastegets to be discharged.
Because we are warm blooded creatures, our body needs tomaintain a constant temperature level in the body. By contracting, musclesproduce an adequate amount of heat required by the body.
Because we are warm blooded, a continuous body temperaturemust be kept in the body with the help of the temperature regulationmechanisms. Heat is maintained in the body when the muscles contract, thus, asbody temperature falls, the muscles start involuntary contractions in order toproduce heat. These involuntary contractions are called shivering. This is thebody’s way to keep the temperature level high enough.
Pumping and circulation of the blood through the whole bodyis performed by smooth muscles. This is an involuntary function as it iscongesting and relaxing the heart muscles and pumping the blood into the blood vessels.Blood circulation enables transfer of the different substances through the bodyand that way keeps our body in function.