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NERVOUS TISSUE.pdf

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JuliusKauki1

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 cells of the nervous tissue including neurons and glial cells, the components of neurons, classifications of neurons, structures of the neuron cell body, dendrites, axons, synapses, myelination, neuroglia, and the relationship between neurons, glia cells and blood vessels.

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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.
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
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
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
Neuron synthesizes 1. Neuronal enzymes, 2. Structural proteins, 3. Membrane components, 4. Organelles and 5. Some of its chemical messengers [neurotrnsmitters]
Structural classifications of Neurons Functional classification Motor (efferent) neuron Sensory (afferent) Neuron Relay (inter) neuron
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.
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
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
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).
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
Myelination and Unmyelination of Neurons
Axon Myelination
Synapse
Types of synapses
Tendon organ
Tendon organ
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
Glia cells for the PNS
Glia cells for the CNS
Glia cells for the CNS
NERVOUS TISSUE.pdf
Relationship between Neurons, Glia cells and Blood vessels of the CNS.
Nerve cells, unlike neuroglial cells, cannot proliferate but can regenerate their axons, located in the PNS Nerve injury and Regeneration
NERVOUS TISSUE.pdf
NERVOUS TISSUE.pdf
A Nerve in section
Questions
Thank you for Listening

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NERVOUS TISSUE.pdf

  • 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
  • 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
  • 29. Thank you for Listening