Write one word in the space provided to complete the second pair of the related words pertaining to the nervous system. Memory: cerebrum:: breathing: Balance: cerebellum:: reasoning:
What are voluntary and involuntary actions? Which part of the nervous system controls them?
Answer
Voluntary action: When an action is produced with the involvement of thoughts, they are called voluntary action. For example, writing an article jumping from heights. These actions are produced consciously by our bodies. Involuntary action: Actions that take place without consciousness or willingness of an individual are called the involuntary action. Digestion, heart beating, sneezing, etc are few examples of involuntary actions.
The cerebral cortex controls our voluntary actions like running and walking etc.
Medulla helps in involuntary actions like a heartbeat, breathing, etc.
The spinal cord has the following functions. 1.It is the center of reflex actions below the neck. 2.It carries messages from the skin and muscles to the brain. 3.All the stimuli and responses are passed from and to the brain through the spinal cord.
What are the nerves? Mention the types of nerves found in humans.
Answer
A bundle of nerve fibers joined together as a tubular sheath that transmits impulses between the brain or spinal cord and other body parts is called a nerve. The nerves constitute the peripheral nervous system. Nerves are of two types in humans: 1.Cranial nerves: They emerge from the brain. There are 12 pairs of cranial nerves. 2.Spinal nerves: They emerge from the spinal cord. There are 31 pairs of spinal nerves.
Central Nervous System (CNS): It consists of the brain and the spinal cord. The brain lies protected inside the skull while the spinal cord is protected within the vertebral column.
Peripheral Nervous System (PNS): It consists of nerves arising from the spinal cord (spinal nerves) and the brain (cranial nerves). These nerves link the central nervous system with the various body organs.