In a nerve impulse, the electrical impulse is caused by:
A nerve impulse is an electrical signal that travels along an axon. There is an electrical difference between the inside of the axon and its surroundings, like a tiny battery. When the nerve is activated, there is a sudden change in the voltage across the wall of the axon, caused by the movement of ions in and out of the neuron. This triggers a wave of electrical activity that passes from the cell body along the length of the axon to the synapse.
Point out the one which is not a reflex action.
All reflex actions are involuntary in nature but all involutary actions are not reflexes. For example - The beating of heart and peristalsis are involuntary actions, but not reflex action.
Reflex actions ar very quick but all involutary actions may not be quick.
Reflex actions are usually at the level of spinal cord whereas the involuntary actions generallly involve brain too
Reflex actions are done to meet emergencies where as an involuntary action is not done for emergencies, but to fulfill a critical life process as circulation of blood, movement of food in food pipe, etc.
Why are reflex arc connections between input and output nerve made at spinal cord?
When we touch any hot object without knowing it is hot, we immediately throughout the object to safe our hand from burning. We have a sensory nerve in our brain to detect the heat. The nerves that are connected to the muscles of the hand are also connected with the sensory nerves. This connection of detecting the signal from the nerves to the muscles for immediate action is called Reflex Arc.
Instant and automatic responses are possible by Reflex Arc. The connection between input and output nerves are connected by Reflex Arc and meets in a bundle in the spinal chord. All the nerves on their way to brain meet in a bundle in the spinal chord to send the information to the brain.
The largest cell in the body is:
The longest cells in the human body are neurons.
Neurons or the nerve cells form the basic components of the nervous system. A typical neuron possesses a cell body called as soma, hair like structures called as dendrites and an axon. Neurons are specialized in transmitting information throughout the body. Three types of neurons are sensory neurons, motor neurons and interneurons. Neurons possess a membrane that is designed to send information to other cells. Neurons synthesise chemicals called as neurotransmitters which help in transmission of information.
The part of a neuron where information is acquired is:
Dendrites of the neutron receive the information and it is nothing but it requires information that are part of the neuron family.
Likewise, the Axon of the neuron information travels as fast as electrical impulse taken by the dentritis action.
It has been emerged with neuron information and travels through the Axon.