Movements of the body are classified as voluntary or involuntary. These movements are controlled by the nervous system which has several divisions such as the ANS (autonomic nervous system), CNS (central nervous system) and PNS (peripheral nervous system). Involuntary movements are controlled by the autonomic nervous system (kind of sounds like automatic). A few involuntary movements would include heart rate (HR). The heart is under autonomic control, we do not tell our hearts to beat, it beats without our input. Peristalsis is another example. This is the autonomic, wavelike movement of the GI tract that serves to propel the food mass through the GI (gastrointestinal) system. Third is the movement of the GE (gastroesophageal) sphinchter which is located at the distal end of the esophagus. The GE sphincter opens to allow food and or fluids into the stomach and closes to prevent gastric contents from splashing back on the esophagus (GERD) gastroesophageal reflux disease or "reflux". Fourth are glandular movements that cause secretion of hormones directly into the bloodstream. The pancreas for example secretes insulin( a hormone) directly into the blood in response to the blood glucose level. Lastly, a seizure is a type of involuntary movement. Seizures like a grand mal seizure is a storm of electrical activity in the brain that causes uncontrollable muscular movements.
It is easier to think about movement related to voluntary muscles, for example walking or talking. People generally do not think about the muscles in the body that are involuntary.
- The pupils in the eyes adjust according to light conditions-they contract very quickly when exposed to light
- The bladder contracts
- Intestines-our intestines contract in order to digest food
- Arteries and veins
- Stomach muscles
There are fewer involuntary movements than there are voluntary ones, but it is still fairly easy to come up with five of these in addition to the voluntary ones from yesterday.
- Heart beat. Your heart is moving when it beats.
- Breathing. Your muscles move so as to allow air to be drawn into and expelled from your lungs.
- Blinking. You can blink voluntarily, but you usually do it involuntarily.
- Hiccups -- we don't even know how to stop them medically, much less voluntarily.
- Coughing -- again, this can be done voluntarily, but it can also be involuntary.
The human body has a wide range of body movements that we can not directly control. (Stomach growling, blinking, sneezing, yawning, passing gas, seizures, heart beating, breathing, and flexing of the ear drum.
The body also has a system of muscles that move food through the esophagus, the stomach, into the small and then large intestine, and then out the colon and rectum. These are involuntary muscles which means they operate upon receipt of a foreign substance which sets their job in motion. Some of human being’s muscles operate while a person is resting and does not even know that action is occurring.