The voluntary and involuntary movements are the voluntary or involuntary actions performed by the human being. The movements or voluntary responses are given under conscious control. An example of this response would be walking or getting out of bed. On the other hand, movements or involuntary responses do not require conscious attention, such as heartbeats.
There are two types of involuntary movements: autonomous and reflex. Autonomous responses regulate the organism. Reflexes mainly affect those muscles that are normally under voluntary control. Reflexes are involuntary movements that occur after an external stimulus. For example, close your eyes after sneezing.
Voluntary movements are the expression of thought through action. The planning occurs in the motor cortex, signals are sent to the motor cortex, from this to the spinal cord and finally to the extremities to perform the movements. Examples of voluntary movements are playing tennis, talking with someone or taking some object.
Voluntary movements
All voluntary activities involve the brain, which sends motor impulses that generate movement.
These motor signals are initiated by thought and most also involve a response to the sensory stimulus. For example, people use sight and a sense of position to help coordinate the action of walking.
The cerebral cortex processes the sensory information and sends these impulses to the muscles. The basal ganglia plays a secondary role in this process; These masses of gray matter help control coordinated movements, such as walking.
The cerebellum monitors the sensory information of the body's position, putting the final touches to the motor impulses of the nerves from the cerebral cortex in order to coordinate the movement.
General sequence of voluntary movement
Visual information is required to locate the target, such as holding a cup with your hand. Then the motor areas of the frontal lobe of the brain plan the range and order the movement.
The vertebral spine carries information to the limb of the body, as towards the hand in this case. Then the motor neurons carry the message to the muscles of the hand and the forearm and take the cup.
The sensory receptors of the fingers send the message that the cup has been grasped towards the sensory cortex. Afterwards, the spinal cord carries this sensory information to the brain.
The basal ganglia judge the grip strength and the cerebellum corrects movement errors. Finally, the sensory cortex receives the message that the cup has been grabbed.
Involuntary movements
Involuntary movements are those movements in which the body moves in an uncontrollable and unwanted way. These movements occupy a wide range, from epileptic attacks to the movements that the body needs so that the heart keeps beating.
There are many neurological disorders in which the body makes involuntary movements. These movements can occur in almost any part of the body, including the neck, face and bodily limbs.
There are several types of involuntary movements and different causes. These movements can be transient or can occur in only one part of the body, while in other cases the movements are a continuous problem that gets worse over time.
Autonomous answers
The autonomic nervous system is in charge of the internal environment of the body without conscious intervention; helps regulate vital functions such as blood pressure or heartbeat.
The two types of autonomic nerves: sympathetic and parasympathetic, have opposite effects but are mutually balanced. At certain times, such as during exercise or sometimes stress, a system dominates.
Everyone starts in the cerebral cortex. Autonomous responses are processed here or in the spinal cord. The impulses of sympathetic nerves are transmitted by the spinal nerves; the impulses of parasympathetic nerves are transmitted by the cranial nerves.
Division of the autonomous system
The information collected by the internal receptors travels through the sensory nerves to the spinal cord and the cerebral cortex so that they can be processed. The sympathetic and parasympathetic responses travel in separate ways.
The sympathetic and parasympathetic nerves produce different responses in a particular organ. Sympathetic responses prepare the body to cope with stressful situations; the parasympathetic responses conserve energy.
For example, the pupils dilate in the sympathetic response but contract in the parasympathetic response. Also, the rhythm of the heart increases during the sympathetic response but decreases during the parasympathetic response.
Reflexes
A reflex is an involuntary response to a stimulus, such as removing your hand from a hot surface before you realize it is hot.
Most reflexes are processed in the spinal cord although some, like blinking, are processed in the brain.
In a spinal reflex, the stimulus signal travels through the sensory nerve to the spinal cord and a response signal travels back as a motor nerve.
Spinal reflexes involve the simplest nerve pathways: motor and sensory neurons are directly connected in the spinal cord.
In summary: each impulse of the sensory nerve is processed in the spinal cord, which sends a direct signal to the correct muscle.
Examples of Involuntary Movements
Dystonia
These are sustained and repeated muscle contractions that often produce an abnormal posture.
Myoclonus
They are short and rapid arrhythmic spasms similar to a shock. They can occur naturally when we sleep or when we are suddenly frightened.
Sometimes they can occur when there is a more serious health condition, such as epilepsy or Alzheimer's.
Tics
They are paroxysmal muscle contractions that can often be suppressed. They can be simple (occur in a single group of muscles) or complex (in several groups).
Basically they are sudden and repeated movements. An example of a simple tic may be an excessive shrug or flexing of a finger. An example of a complex tic may be repeatedly hit on the arm.
This often occurs with Tourette's syndrome or with Parkinson's disease. Although sometimes it can happen in adults due to traumas or the use of certain drugs.
Tremors
They are rhythmic oscillations in a particular part of the body caused by intermittent muscle contractions. Many people experience tremors due to factors such as low blood glucose, alcohol withdrawal and fatigue.
Occasionally, tremors can also occur in Parkinson's disease or multiple sclerosis.
References
- What causes involuntary movements. Retrieved from healthline.com
- Voluntary movement. Recovered from lik.springer.com
- Introduction to involuntary movements. Retrieved from standfordmedicine25.standford.edu
- Function: voluntary and involuntary responses. Recovered from aviva.co.uk
- Voluntary movement. Recovered from uvm.edu
- Voluntary movement. Retrieved from medical-dictionary.thefreedictionary.com