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प्रश्न
‘A’ is a cylindrical structure that begins from the lower end of the medulla and extends downwards. It is enclosed in bony cage ‘B’ and covered by membranes ‘C’. As many as ‘D’ pairs of nerves arise from the structure ‘A’.
(i) What is A?
(ii) Name (a) bony cage ‘B’ and (b) membranes ‘C’
(iii) How much is D?
उत्तर
- A is the spinal cord.
- (a) Bony cage is Vertebral column
(c) is Meninges - D is 31 pairs of spinal nerves.
APPEARS IN
संबंधित प्रश्न
Answer the following questions briefly:
How are the cytons and axons placed in the brain and the spinal cord?
Name the following:
The third neuron that is involved in reflexes, other than simple reflex.
Name the following:
Neuron only with axon.
Write whether the following is true or false:
Neurotransmitters are either broken down or reabsorbed after they have conducted an impulse.
Assertion: The imbalance in concentration of Na+, K+ and proteins generates action potential.
Reason: To maintain the unequal distribution of Na+ and K+, the neurons use electrical energy.
At the end of repolarization, the nerve membrane gets hyperpolarized. Why?
A neuron contains all cell organelles except ______.
Classify neurons based on their structure.
Our body contains a large number of cells ‘L’ which are the longest cells in the body. L has long and short branches called ‘M’ and ‘N’ respectively. There is a gap ‘O’ between two ‘L’ cells, through which nerve impulse transfer by the release of chemical substance ‘P’.
(i) Name the cells L?
(ii) What are M and N?
(iii) What is the gap O?
(iv) Name the chemical substance P?
Which cells form a single layer of squamous or columnar often ciliated epithelial cells lining the ventricle?
______ is the gap between the axon of one terminal neuron and the dendrites of next neuron.
The longest fibre on the cell body of a neuron is called ____________.
Assertion: Impulse travels from dendrite to cell body and then along the axon to its end.
Reason: Information acquired at the end of the dendrite tip of a nerve cell sets of an electric impulse.
In a neuron, conversion of electrical signal to a chemical signal occurs at/in
Which of the following statements about transmission of nerve impulse is incorrect?
Chemicals which are released at the synaptic junction are called ______.
Any factor that can bring a change in the body of an organism is called ______.
Name the following:
Three main parts of the neuron
Define the following term:
Synaptic cleft
Give reason:
Neurotransmitters are broken down by an enzyme just after passing an impulse from one neuron to the other.
