neuron .pdf

Ppt on neuron

1. RANI DULLAIYA SMRITI AYURVED PG COLLEGE & HOSPITAL
BHOPAL
PRESENTED BYGUIDED BY
Name-
Roll no.-
Batch -
Dr. ABHILASHA AGRAWAL
Dr. PRASHANT THAKUR
Topic-
2020-21
63
RAHUL TALE
(MD)
(BDS)
NEURON

3. NEURON

4. or is defined as the stuctural
. functional unit of nervous system.However, it is
different from other cells by two ways:
1.Neuron has branches or processes called axon and dendrites
2.Neuron does not have centrosome. So, it cannot undergo
division.
Introduction
Neuron nerve cell

5. CLASSIFICATION OF NEURON
Neurons are classified by three different methods

A. Number of poles
B. Function
C. Length of axon.

6. A. Number of poles
1. Unipolar Neuron.
2. Bipolar Neuron
3. Multipolar Neuron



Unipolar
Bipolar Multipolar

7. B. Function
1.Motor or efferent
2. Sensory or Afferent

8. C. Length of Axon
1. Golgi type 1 neuron

have long axons.
The cell body of these neurons is in central nervous
system and their axons reach the remote peripheral
organs.

9. 2. Golgi type 2 neuron
have short axon.

These neurons are present in cerebral
cortex and spinal cord.

10. STRUCTURE OF NEURON
Neuron is made up of three parts:
1. Nerve cell body
2. Dendrite
3. Axon.

11. 1. NERVE CELL BODY
• Also known as soma or perikaryon.

• Irregular in shape.
• It is constituted by a mass of cytoplasm called
neuroplasm,which covered by a cell membrane

12. 2. AXON
• Single
• the longest process of the cell body
• carries nervous impulses away from the
cell body. out side the CNS
• the axons(nerve fibers) runs in groups
forming the nerves of the body

13. 3. DENDRITE
• are multiple.
• the short processes of the cell body
• which carry impulses towards the nerve cell body.

14. • Many axons together form a bundle called fasciculus.
• many fasciculi together form a nerve.
Organization of nerve :
Covering of nerve
• Epineurium
• Perineurium
• Endoneurium

15. Cross section of nerve

16. MYELIN SHEATH
•Myelin sheath is a thick lipoprotein sheath that
insulates the nerve fiber
•It is absent at regular intervals.
•Myelin sheath is responsible for the white color
of the nerve fibers

18. -Myelinated nerve fiber
The nerve fibers which are insulated by myelin
sheath.
-Nonmyelinated nerve fiber
The nerve fiber is not covered by myelin sheath.

19. Function of Myelin sheath:
1- Faster conduction faster conduction of impulse
2 - Insulating capacity restricts the nerve impulse
within the single nerve fiber

20. NEURILEMMA
It is a thin membrane,which sorrounds the axis cylinder.
Also called Neurilemmal sheath or sheath of schwann
In non-myelinated nerve fiber, the neurilemma surrounds
axolemma continuously. In myelinated nerve fiber, it
covers the myelin sheath.

21. Function of neurilemma
In non-myelinated nerve fiber, the neurilemma
serves as a covering membrane.
it is necessary for the formation of myelin sheath
(myelinogenesis).