This document summarizes the cellular organization of the nervous system. It describes the main cell types: neurons, which are the basic functional units, and neuroglia, which provide support. Neurons have a cell body, dendrites, and an axon. Neuroglia include astrocytes, oligodendrocytes, microglia, and ependymal cells. Astrocytes regulate the neuronal microenvironment and form part of the blood-brain barrier. Oligodendrocytes and Schwann cells myelinate axons to increase conduction speed. The document also notes that glial cells can give rise to brain tumors since they continue to divide in adulthood, unlike most neurons.
Cells of the Nervous System- Glial cells I Macroglia and Microglia I Nervous ...HM Learnings
Cells of the Nervous System- Glial cells I Macroglia and Microglia I Nervous System Physiology I
This video will be about
1. Types of cells in nervous system
2. Glial cells
3. Types of glial cells- macroglia and microglia
4. Oligodendrocytes
5. Schwann cells
6. Astrocytes
7. Ependyma cells
8. Microglia
You can also watch the same topic on HM Learnings Youtube channel.
You can also follow HM Learnings on facebook, instagram and twitter for daily updates
Cells of the Nervous System- Glial cells I Macroglia and Microglia I Nervous ...HM Learnings
Cells of the Nervous System- Glial cells I Macroglia and Microglia I Nervous System Physiology I
This video will be about
1. Types of cells in nervous system
2. Glial cells
3. Types of glial cells- macroglia and microglia
4. Oligodendrocytes
5. Schwann cells
6. Astrocytes
7. Ependyma cells
8. Microglia
You can also watch the same topic on HM Learnings Youtube channel.
You can also follow HM Learnings on facebook, instagram and twitter for daily updates
This slides gives a brief description about the structure of neuron, information flow in neurons and also how transcription takesplace and protein synthesis in the cell. This presentation also explain the types of glia and non glial cells.
Lecture notes and diagrams to help high school anatomy and physiology students learn the general functions of the nervous system and types of glial support nerve cells, types of neurons and anatomy of typical neurons.
Nervous System is a uniquely designed organ system of our body. This presentation is highlighting over the cellular configuration of this system. Neurons & Neuroglia are the two main players of the system. Neuron is the structural & functional unit of the system, while, Neuroglia are the supporting elements. At the end of this presentation, the young learner would be able to recognize different cell types of the Nervous system & their exclusive function.
Structure of Neuron
Neuron contents ,neuron parts and processes
Classification of neurons according to function, according to
processes, according to shape
Histology of neuron
NERVE CELLS FINAL( NEURON AND GLIAL CELLS.pptx FOR NURSING STUDENTSWINCY THIRUMURUGAN
THE NERVOUS SYSTEM CONTAINS TWO MAIN TYPES OF CELLS.
A neuron is a nerve cell that is the basic building block of the
nervous system.
Neurons are the structural and functional unit of the nervous
system.
Neurons are specialized to transmit information throughout the
body.
They constitute the communication network of the nervous system and transfer electrical impulses between the central nervous system and sensory organs such as eye,ear.nose,tongue and skin.
There are Approximately 86-100 billion neurons in the brain.
DENDRITES
Dendrites are the tree-like branched structures that arise from the nerve cell body.
Apart from the main dendrite branches, dendrites may contain additional protrusions
known as dendrite spines.
The axon hillock is a specialized region from which the
axon extends.
The axon is a single elongated tubal structure that extends from the Axon Hillock.
Each neuron has a single axon that extends and branches at its end.
The inner most Plasma membrane around the axon is Axolemma.
Neurilemma is the plasma membrane of schwann cells .
The spaces/gaps between the Schwann cells are known as the nodes of Ranvier and they serve to propagate electrical signals along the axon.
The branched end of the axon is known as the axon terminal[arborization] and
branches at the middle of the axon is axon collaterals .
This is the distal part of the axon that comes in contact with other cells. Also called as terminal boutons.
This part of the axon is largely involved in the release of the neurotransmitter.The cell body, also called the soma, is the spherical part of the neuron that contains the nucleus ,cytoplasm and organelles.
The cell body connects to the dendrites, and send information to the
axon depending on the strength of the signal.
The neuronal cytoplasm have the following
The Nucleus,
Nucleolus,
Endoplasmic Reticulum,
Golgi Apparatus,
Mitochondria,
Ribosomes,
Lysosomes,
Endosomes,
And Peroxisomes. A bipolar neuron is a type of neuron which has two extensions (one axon and one dendrite).
A multipolar neuron is a type of neuron that possesses a single axon and many dendrites (and dendritic branches), allowing for the integration of a great deal of information from other neurons.
TYPES OF NEURON:
A unipolar neuron is a type of neuron in which only one process called a neurite extends from the cell body. A pseudounipolar neuron is a type of neuron which has one extension from its cell body. This type of neuron contains an axon that has split into two branches; one branch travels to the PNS and the other to the CNS.They are three types of neurons based on the function as follows Sensory Neuron
Inter-Neuron
Motor Neuron
Interneurons are the central nodes of neural circuits, enabling communication between sensory or motor neurons and the (CNS).
Glial cells (named from the Greek word for "glue") are non- neuronal cells that
provide support and nutrition,
maintain homeostasis,
form myelin,
and participate in signal transmission.
This slides gives a brief description about the structure of neuron, information flow in neurons and also how transcription takesplace and protein synthesis in the cell. This presentation also explain the types of glia and non glial cells.
Lecture notes and diagrams to help high school anatomy and physiology students learn the general functions of the nervous system and types of glial support nerve cells, types of neurons and anatomy of typical neurons.
Nervous System is a uniquely designed organ system of our body. This presentation is highlighting over the cellular configuration of this system. Neurons & Neuroglia are the two main players of the system. Neuron is the structural & functional unit of the system, while, Neuroglia are the supporting elements. At the end of this presentation, the young learner would be able to recognize different cell types of the Nervous system & their exclusive function.
Structure of Neuron
Neuron contents ,neuron parts and processes
Classification of neurons according to function, according to
processes, according to shape
Histology of neuron
NERVE CELLS FINAL( NEURON AND GLIAL CELLS.pptx FOR NURSING STUDENTSWINCY THIRUMURUGAN
THE NERVOUS SYSTEM CONTAINS TWO MAIN TYPES OF CELLS.
A neuron is a nerve cell that is the basic building block of the
nervous system.
Neurons are the structural and functional unit of the nervous
system.
Neurons are specialized to transmit information throughout the
body.
They constitute the communication network of the nervous system and transfer electrical impulses between the central nervous system and sensory organs such as eye,ear.nose,tongue and skin.
There are Approximately 86-100 billion neurons in the brain.
DENDRITES
Dendrites are the tree-like branched structures that arise from the nerve cell body.
Apart from the main dendrite branches, dendrites may contain additional protrusions
known as dendrite spines.
The axon hillock is a specialized region from which the
axon extends.
The axon is a single elongated tubal structure that extends from the Axon Hillock.
Each neuron has a single axon that extends and branches at its end.
The inner most Plasma membrane around the axon is Axolemma.
Neurilemma is the plasma membrane of schwann cells .
The spaces/gaps between the Schwann cells are known as the nodes of Ranvier and they serve to propagate electrical signals along the axon.
The branched end of the axon is known as the axon terminal[arborization] and
branches at the middle of the axon is axon collaterals .
This is the distal part of the axon that comes in contact with other cells. Also called as terminal boutons.
This part of the axon is largely involved in the release of the neurotransmitter.The cell body, also called the soma, is the spherical part of the neuron that contains the nucleus ,cytoplasm and organelles.
The cell body connects to the dendrites, and send information to the
axon depending on the strength of the signal.
The neuronal cytoplasm have the following
The Nucleus,
Nucleolus,
Endoplasmic Reticulum,
Golgi Apparatus,
Mitochondria,
Ribosomes,
Lysosomes,
Endosomes,
And Peroxisomes. A bipolar neuron is a type of neuron which has two extensions (one axon and one dendrite).
A multipolar neuron is a type of neuron that possesses a single axon and many dendrites (and dendritic branches), allowing for the integration of a great deal of information from other neurons.
TYPES OF NEURON:
A unipolar neuron is a type of neuron in which only one process called a neurite extends from the cell body. A pseudounipolar neuron is a type of neuron which has one extension from its cell body. This type of neuron contains an axon that has split into two branches; one branch travels to the PNS and the other to the CNS.They are three types of neurons based on the function as follows Sensory Neuron
Inter-Neuron
Motor Neuron
Interneurons are the central nodes of neural circuits, enabling communication between sensory or motor neurons and the (CNS).
Glial cells (named from the Greek word for "glue") are non- neuronal cells that
provide support and nutrition,
maintain homeostasis,
form myelin,
and participate in signal transmission.
This is the ppt that describes about organization of nerve in central nervous system. It also classify the nerves in various ways. Functions of different nerves and its characteristics are also described in this ppt.
It is a brief account on neurons. Neurons are simply brain cells. They have the ability to process and transmit information as electrical and chemical signals.These signals between neurons occur via synapses.
1. CELLULAR ORGANIZATION OF THE
NERVOUS SYSTEM
DR. BRIAN LISHENGA
DEPT. OF MEDICAL PHYSIOLOGY
EGERTON UNIVERSITY
2. NEURONS
• Neurons are the functional unit of the
communication network.
• Parts of a neuron:
Soma or cell body: contains the nucleus and
nucleolus and a well-developed biosynthetic
apparatus for manufacturing membrane
constituents, synthetic enzymes,
neurotransmitters.
Nissl bodies, (found in the soma) are stacks
of RER, and a prominent Golgi apparatus.
The soma also contains numerous
mitochondria and cytoskeletal elements,
including neurofilaments and microtubules.
3. NEURONS
• Parts of a neuron:
Dendrites: Extensions of the neuronal cell body.
They can be more than 1 mm long, and can
account for more than 90% of the surface
area. They contain Nissl bodies, neurofilaments
and microtubules.
Axon: Arises from the soma (or sometimes from
a dendrite) in a specialized region called the
axon hillock.
Doesn’t have Nissl bodies so it degenerates
when disconnected from the soma.
Its length varies with neuron type from a few
mm to greater than a meter.
4. NEURON
Schematic diagram of an idealized neuron and its major components. Most afferent
input from axons of other cells terminates in synapses on the dendrites (d), although
some may terminate on the soma (S). Excitatory terminals tend to terminate more
distally on dendrites than do inhibitory ones, which often terminate on the soma
5. NEUROGLIA
• These are supportive cells.
• Neuroglial cells in the human CNS
outnumber neurons by an order of
magnitude: there are about 10 trillion
neuroglia and 1 trillion neurons.
• Neuroglial cells in the peripheral nervous
system (PNS) include;
Schwann cells and satellite cells,
• In the central nervous system (CNS) they
include;
Astrocytes, oligodendroglia, microglia and
ependymal cells.
6. Schematic representation of nonneural elements in the central nervous system. Two astrocytes (darker colour)
are shown ending on a neuron's soma and dendrites. They also contact the pial surface and/or capillaries. An
oligodendrocyte (lighter colour) provides the myelin sheaths for axons. Also shown are microglia (darker colour)
and ependymal cells (lighter colour). (Redrawn from Williams PL, Warwick R: Functional neuroanatomy of man,
Edinburgh, 1975, Churchill Livingstone.)
7. ASTROCYTES
• Astrocytes (named for their star shape) regulate the
microenvironment of neurons in the CNS. They can
actively take up K+ ions and neurotransmitter substances,
which they metabolize
• Astrocytes form part of the BBB. They have foot
processes that contact the capillaries and the pia mater.
These foot processes may help limit the free diffusion of
substances into the CNS. The processes also surround
groups of synaptic endings and isolate these from adjacent
synapses.
• Astrocytes provide mechanical support to the CNS. The
cytoplasm of astrocytes contains glial filaments, which
provide mechanical support for CNS tissue.
• After injury, the astrocytic processes that contain these
glial filaments hypertrophy and form a glial "scar."
8. OLIGODENDROGLIA AND SCHWANN CELLS
• Oligodendrocytes myelinate nerve axons in the
CNS while Schwann cells provide myelin sheath
in the PNS.
• Myelin increases the speed of action
potential conduction, in part by limiting the
flow of ionic current during action potentials to
the nodes of Ranvier (the unmyelinated
portions of the axon at the junctions between
adjacent sheath cells).
• This action results in saltatory conduction,
which is the skipping of nerve impulses from
node to node
9. OTHER NEUROGLIA
• Satellite cells:
• Encapsulate dorsal root and cranial nerve ganglion cells and
regulate their microenvironment in a fashion similar to that
employed by astrocytes.
• Microglia are latent phagocytes. When the CNS is damaged,
the microglia help remove the cellular products of the damage.
They are assisted by neuroglia and by other phagocytes that
invade the CNS from the circulation.
• Ependymal cells form the epithelium that separates the CNS
from cerebrospinal fluid (CSF) in the ventricles. Many
substances diffuse readily across the ependyma, which lie
between the extracellular space of the brain and the CSF.
• CSF is secreted by specialized ependymal cells of the choroid
plexuses, located in the ventricular system.
10. CLINICAL CORRELATES
• Most neurons in the adult nervous system are postmitotic cells
(although there may also remain some precursor neurons or stem cells).
• Many glial precursor cells are present in the adult brain, and they
can still divide and differentiate.
• Therefore, the cellular elements that give rise to most intrinsic brain
tumors in the adult brain are the glial cells. For example: Astrocyte
Tumors: Vary in malignancy from the slowly growing astrocytoma to the
rapidly fatal glioblastoma multiforme
• Oligodendroglia Tumours Oligodendroglioma,
• Ependymal cells: Ependymoma.
• Meningeal cells can also give rise to slowly growing tumors
(meningiomas) that compress brain tissue,
• Schwann cells (e.g., "acoustic neurinomas," which are tumors formed by
Schwann cells of the eighth cranial nerve).
• In the brain of infants, neurons that are still dividing can sometimes
give rise to neuroblastomas (e.g., of the roof of the fourth ventricle) or
retinoblastomas (in the eye).
Editor's Notes
The nervous system is an aggregate of 2 cellular systems; A communications network and a supportive matrix.