The a voluntary muscle contracts involuntarily, you will see a little movement through your skin. These movements are often called Tics, Twitches, and Spasms.
If the involuntary contractions are widespread and very energetic, they may be called, "Seizures".
Smooth muscle (non-striated) and cardiac muscles (heart muscle) contract involuntarily.
spasm
Flexion
Babies happen
When a muscle cramp occurs, the muscle contracts forcibly and involuntarily and doesn't relax for the time the cramp lasts. The cramp can last from few seconds up to few minutes.
Muscle fibers generates throught the action of actin and myosin. Contraction of Voluntary muscles occurs as a result of conscious effort originating in the brain. The brain sends signals, in the form of action potentials,through the nervous system to the motor neuron that innervates the muscle fiber. Involuntary muscles like the heart or smooth muscles in the gut contracts as a result of unconscious brain activity stimuli endogenous to the muscle itself.
yes it is known as peristalisis. it occurs throughout the tract due to rythemic contractions and ralaxations
A spasm is described as a muscle which quickly contracts involuntarily and suddenly. This can be painful. According to the part of the body where the spasm occurs, the cause can stem from various factors. However, in general a spasm will occur if a muscle is overused, therefore running out of energy.
Food is pushed down the oesophagus by a series of contractions. The part of the oesophagus just above the ball of food contracts and pushes it down. then it relaxes and the next part of the oesophagus contracts. this wavelike movement, controlled by muscles, is called peristalsis. It occurs all the way down the alimentary canal.
A spasm is described as a muscle which quickly contracts involuntarily and suddenly. This can be painful. According to the part of the body where the spasm occurs, the cause can stem from various factors. However, in general a spasm will occur if a muscle is overused, therefore running out of energy.
This particular reflex is autonomic as the affected muscle, constrictor pupillae muscle, is a smooth muscle and not under conscious control. Typically if you can consciously contract the muscle, any reflex associated with that muscle is somatic in nature.
The bicep muscle relaxes. It is vice-versa when the bicep muscle contracts.
Internal rotation of the shoulder
dilation