NEURAL \ NERVOUS TISSUE

Question 1

What is the origin of this tissue ?

Answer 1

Ectodermal in origin except microglial cell (mesodermal)

Question 2

What are the major things it includes ?

Answer 2

Brain , spinal cord , nerve , neuron , microglial cell and neuroglial cell.

” Hence , it has the great control over the body.”

Question 3

Give some points in the neuron.

Answer 3

1. Unit of the neural tissue
2. Excitable cell conduct electrical impulse
3. Neuron do not divide after the embryonic stage due to the absence of the centrosome but it grows throughout the life in interphase stage (longest cell)

Question 4

What are the major parts of the neuron ?

Answer 4

1. Cyton \ soma \ cell body \ perikaryon
2. Axon (conduct impulse away from cyton called efferent process)
3. Dendrites or dendrons (number - 1,2 or many){conduct impulse towards the cyton called afferent process}

Question 5

What are the nissals granules ?

Answer 5

1. Made up of the RER and ribosome

2. Present in the cyton and dendrites only

Question 6

What is cyton ?

Answer 6

It’s neuroplasm contains the nucleus , many nissals granules and nerve fibers.

Question 7

What are dendrites ?

Answer 7

From the cyton arises thin processes called the dendrites.

Question 8

What are axon ?

Answer 8

1. From the cyton arises the main cylindrical process called axon having axoplasm.
2. Around the axon present neurilemma which is made up of the Schwann cell (flat cell with bulging nucleus. ensheathed neuron is called nerve fiber)
3. Neurilemma secretes Myelin sheath (lipid + proteins = lycoprotien)around the axon.

Question 9

What is node of Ranvier ?

Answer 9

Myelin sheath absent but the neurilemma is present.

Question 10

What are the two types of the nerve fiber ?

Answer 10

1. Myelinated or medullated nerve fiber

2. Non-myelinated or non-medullated nerve fiber.

Question 11

What are the myelinated or medullated nerve fiber ?

Answer 11

1. Myelin sheath present.
2. White in color.
3. Transmission of the impulse is fast and saltatory(jumping) – from one node of Ranvier to the next
4. Location - Cranial and spinal nerves

Question 12

What are the non-myelinated or non-medullated nerve fiber ?

Answer 12

1. Myelin sheath absent.
2. Gray in color.
3. Transmission of the impulse is slow and smooth
4. Location - Invertebrates , somatic and autonomic neural system

Question 13

LEARN THE STRUCTURE NEURON

Answer 13

DONE :D

Question 14

What is synapse ?

Answer 14

If the axon ending terminate on the dendrites of the another neuron , then the junction is called SYNAPSE