Question

A. Multiple Choice Questions (MCQs)
1. Vomiting immediately after eating something wrong is an example of
coordination.
a. Nervous
b. Chemical
c. Physical.
d. Mental


2. The outer part of cerebrum is lightly convoluted with
a. Ridges
b. Grooves
c. Both a and b
d. None

3. Which part of the neuron contains nucleus?
a. Cyton
b. Dendrite
c. Axon
d. None

4. How many pairs of spinal nerves emerge from the spinal cord?
a. 30
b. 31
c. 32
d. 33
5. Which of the following surrounds the axon?
a. Cyton
b. Dendrite
c. Neuron

d. Myelin sheath​

Answer 1

Answer:

1 = b

2 =a

3 = c

4 =c

5= c

Explanation:

hope it helps u

Answer 2

Answer:

1. a. Nervous

2. c. Both a and b

3. a. Cyton

4. b. 31 pairs

5. d. Myelin sheath​

Explanation:

• 1. The sense organs, nerves, spinal cord and brain participate in nervous coordination. The neural system controls actions such as voluntary, involuntary and reflex actions.

• Reflex action is the result of the coordination of the peripheral nervous system with the spinal cord.        

• Both the spinal cord and brain are involved in voluntary actions and coordinate with PNS to generate necessary movements.

• Both involuntary and voluntary actions are controlled by the same parts of the brain. Hindbrain and midbrain control involuntary actions such as salivation, vomiting, etc.

• The vomiting or throwing out immediately after eating something wrong is controlled by two distinct brain centres, the vomiting centre and the chemoreceptor trigger zone, both located in the medulla oblongata. Hence, it is nervous coordination.

• 2. The outer layer of cerebral hemispheres is called the cerebral cortex which is formed of grey matter and contains millions of neurons.

• The cerebral cortex is highly convoluted in order to increase the surface area. The ridges of these convolutions are called gyri and depressions (grooves) in between are called sulci.
• Hence, the outer part of the cerebrum is highly convoluted with both ridges and grooves.

• 3. A neuron refers to a cell in the nervous system which receives and transmits information.
• Neurons are made up of three major components: a cell body (cyton), or soma, which contains the nucleus of the cell and keeps the cell alive; a branching treelike fibre known as the dendrite and a long, segmented fibre known as the axon.

• 4. There are 31 pairs of spinal nerves, arising in pairs from the spinal cord. They possess double root origin and are of mixed type.

• 5. An axon is a tube-like structure that propagates the integrated signal to specialized endings called axon terminals.

• It is a long, segmented fibre which transmits information away from the cell body toward other neurons or to the muscles and glands.

• Some axons are myelinated, which acts as an insulator to minimize the dissipation of the electrical signal as it travels down the axon, greatly increasing the speed of nerve impulse conduction.    

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