This document provides an overview of a lecture on nervous tissue that will take place on November 21st from 10:30 am to 12:30 pm at the KILIMANJARO CHRISTIAN MMEDICAL UNIVERSITY. The objectives are to learn about the cellular and structural components of nervous tissue, the structure and types of neurons, glial cells, and healing and repair of neurons. The lecture will cover the two main cell types - neurons and glial cells, the parts of a neuron including the cell body, dendrites and axon, myelination, synapses, and the roles of different glial cells.

1. KILIMANJARO CHRISTIAN MMEDICAL UNIVERSITY
COLLEGE
Faculty of Nursing and Rehabilitation Medicine
Department of Anatomy and Neuroscience
Anatomy Lecture for BSc.Nursing and BSc.Physiotherapy
LECTURE 8,9
TOPIC: NERVOUS TISSUE
Date: Nov. 21st 2022, from 10:30 am -12:30pm, GYM – Physiotherapy School
Lecturer: J. S. Kauki, BSc, MSc, on PhD, Email: jskauki@gmail.com.
Office ext. 70 Block C, 3RD Floor, Anatomy dept.

2. Objectives of NS Histology:
At the end of the session, students should be able to:
• Learn about the cellular components and the structural
components of nervous tissue
• Describe the structure and components of neurons
• Classify neurons structurally and functionally
• Describe the structure and function of Glia cells.
• Explain about healing and repair of Neurons

3. CELLS OF THE NERVOUS TISSUE
2 categories
1. Nerve cells/neurons- concerned with
information processing and signalling
2. Glial cells- supporting role. There are 100
billion neurons and may be more glial
cells
Neurons convey information by combined
electrical and chemical
signaling mechanisms
Electrical signals- rapid transmission of
information from one part of
neuron to another
Chemical messengers carry information
between neurons

4. Components of a Neuron
•Cell body= soma/perikaryon [karyon=nucleus]
Fn: Supports metabolic and synthetic needs of the rest of the neuron
•Dendrites : Series of branching tapering processes which receive information from
other neurons via synaptic contacts/synapses
•Axon: One long cylindrical process which conducts information away from cell body.
Gives rise to a series of terminal branches, forming synapses on other neurons

5. • Neuron synthesizes
1. Neuronal enzymes,
2. Structural proteins,
3. Membrane components,
4. Organelles and
5. Some of its chemical
messengers [neurotrnsmitters]

6. Structural classifications of Neurons
Functional classification
• Motor (efferent) neuron
•Sensory (afferent) Neuron
•Relay (inter) neuron

7. The cell body of a neurone
contain the Nucleus.
The Nucleus is large, pale
staining with dispersed
chromatin
Also at the cell body, there
are:
-Abundant RER, free
ribosomes, stacks of Golgi
apparatus and many
mitochondria.

8. • Nissl bodies/Nissl substance- ribosomes, stained intensely
with basic dyes, appear as clumps- prominent in large neurons
• Many mitochondria
• Cytoskeleton composed of microtubules, neurofilaments
[aggregates of these are called neurofibrils] and
microfilaments

9. Dendrites
• Tapered extensions of neuronal body
• Collectively provide a great increase
in surface area available for synaptic
inputs
• In spinal cord, dendritic surface area
may be 30 or more times that of cell
body
• Dendrites of many neurons are
studded with small protuberances
called dendritic spines
• These are preferred sites of some
synaptic contacts

10. Axons
• Is a cylindrical process which arises
abruptly from an axon hillock on one side
of neuronal cell body
• Initial segment has bundles of
microtubules, neurofilaments and
mitochondria- no Nissl substance
• It is electrically most excitable part of a
neuron
• Beyond initial segment, many axons are
encased in spiral wrapping of a membrane
called myelin sheath- greatly increases
speed of propagation of electrical impulses
• Myelinated axon conducts faster (Saltatory)
than unmyelinated axons (Continous
conduction).

11. • Transport of macromolecules and
organelles synthesized by cell body
occurs away from soma[anterograde]
and towards it [retrograde]
• It can be slow or fast
• Microtubules act as ‘railroad tracks’ for
fast transport
• Many peripheral nerves are myelinated
• Myelin sheath between 2 nodes is called
internode- formed by s single Schwann
cell
• Most of smaller axons in peripheral
nerves are unmyelinated- slow
conductors of electrical signals
Axon cont……

12. Myelination and Unmyelination of Neurons

13. Axon Myelination

14. Synapse

15. Types of synapses

16. Tendon
organ

17. Tendon organ

18. NEUROGLIA (Glia cells)
• NEUROGLIA (Glia cells)
– Supporting cells of the CNS and
PNS
– PNS -
–Schwnn cells
–Satellite cells (in ganglia)
– CNS
• Oligodndrocytes
• Astrocytes
• Ependymal cells
• Microglia

19. Glia cells for the PNS

20. Glia cells for the CNS

21. Glia cells for the CNS

23. Relationship between Neurons, Glia cells and Blood vessels
of the CNS.

24. Nerve cells, unlike neuroglial cells, cannot proliferate but can
regenerate their axons, located in the PNS
Nerve injury and Regeneration

27. A Nerve in section

28. Questions

29. Thank you for Listening