This document provides an overview of the structure and cell types of the cerebral cortex. It begins with an introduction to the basic structure of neurons and the central nervous system. It then describes the six layers of the neocortex and the principal cell types found within each layer, including pyramidal cells, stellate cells, and others. The interconnections between neurons and various staining techniques used to visualize cortical components are also summarized. Finally, several common diseases that affect the cerebral cortex are briefly mentioned.
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.
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.
The epithelium lining the respiratory tract from the nasal fossa through the bronchi is called the respiratory mucosa and is characterized by a pseudostratified ciliated epithelium with abundant non-ciliated cells known as goblet cells. - [Source: medcell.med.yale.edu/histology/respiratory_system_lab.php]
The epithelium lining the respiratory tract from the nasal fossa through the bronchi is called the respiratory mucosa and is characterized by a pseudostratified ciliated epithelium with abundant non-ciliated cells known as goblet cells. - [Source: medcell.med.yale.edu/histology/respiratory_system_lab.php]
The nervous system includes the brain, spinal cord, and a complex network of nerves. This system sends messages back and forth between the brain and the body.
The brain is what controls all the body's functions. The spinal cord runs from the brain down through the back. It contains threadlike nerves that branch out to every organ and body part. This network of nerves relays messages back and forth from the brain to different parts of the body.What Are the Parts of the Nervous System?
The nervous system is made up of the central nervous system and the peripheral nervous system:
The central nervous system includes the brain and spinal cord.
The peripheral nervous system includes the nerves that run throughout the whole body.How Does the Nervous System Work?
The nervous system uses tiny cells called neurons (NEW-ronz) to send messages back and forth from the brain, through the spinal cord, to the nerves throughout the body.
Billions of neurons work together to create a communication network. Different neurons have different jobs. For example, sensory neurons send information from the eyes, ears, nose, tongue, and skin to the brain. Motor neurons carry messages away from the brain to the rest of the body to allow muscles to move. These connections make up the way we think, learn, move, and feel. They control how our bodies work — regulating breathing, digestion, and the beating of our hearts.
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.
Objective of the study:- Structure of a typical Neuron, Classification of Neuron based on Polarity, on conduction direction, on neurotransmitters released, on their shape, Glial cells, major type of Glial cells present in CNS and PNS and their functions.
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
MANAGEMENT OF ATRIOVENTRICULAR CONDUCTION BLOCK.pdfJim Jacob Roy
Cardiac conduction defects can occur due to various causes.
Atrioventricular conduction blocks ( AV blocks ) are classified into 3 types.
This document describes the acute management of AV block.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
2. INTRODUCTION
The central nervous system consists of the brain and
spinal cord, which are composed of neurons, the
supporting glial cells and blood vessels.
Basic structure of a neuron consists of
-cell body
-dendrites
-axon
6. CEREBRAL CORTEX
The cerebral hemispheres consists of a convoluted
cortex of grey matter overlying central medullary mass
of white matter.
The grey matter consists of neuron cell bodies and
their dendritic interconnections & glial cells.
The white matter conveys fibers between different
parts of the cortex and from other parts of CNS.
7. Contd..
The cortex is a thin layer of neurons and their inter
connections, measuring few mm and contains 3o
billion neurons.
The evolved cortex in mammals called neocortex
consists of 6 layers of neurons.
10. TYPES OF CORTEX
Neocortex >90 % of our total cortical area.
-6 layered structure.
-Refered to as homogenic cortex.
Paleocortex Covers some parts of the base of the
telencephalon.(olfactory area)
-Forms heterogenic cortex.
archicortex The hippocampal formation.
11. Neuron Cell types
Two principal cell types are present in neo cortex.
1.The pyramidal cell
2.The Stellate cell
Other cells are
3. The cells of Martinotti
4.Fusiform cells
5.Horizontal cells of cajal
14. PYRAMIDAL CELLS
Pyramid shaped cell
bodies.
About 10 microns to 70
microns in diameter.
Axon arises from the
base and the dendrite
from the apex.
The largest of the
pyramidal cells are called
the BETZ cells.
15. Functions of pyramidal cels
The apical dendrites of pyramidal cells are studded
with dendritic spines.
These are numerous small projections that are
the preferential site of synaptic contact.
It has been suggested that dendritic spines may be the sites
of synapses that are selectively modified as a result of
learning.
Most or all pyramidal cells have long axons that leave the
cortex to reach either other cortical areas or to
various subcortical sites.
Therefore, pyramidal cells are the principal output
neurons.
16. STELLATE CELLS
-Also known as granular cells.
-They are the principal interneurons of
cortex .
-These come in a wide
assortment of shapes.
-They are typically small (< 10
micrometres) multipolar neurons.
17. FUNCTIONS OF STELLATE CELLS
The short axons of stellate cells do not leave the
cortex.
Stellate cells are the principal interneurons of the
neocortex.
18. CELLS OF MARTINOTTI
Small polygonal cells.
Have very few short dendrites.
The axon extends towards the surface and bifurcate to
run horizontally in most superficial layers.
Forms synapses with the pyramidal cells.
19. FUSIFORM CELLS
Spindle shaped cells.
They are oriented at right angles to the cortex.
Axon arises from the side of the cell body and passes
superficially.
Dendrites extend from each end of the cell body
branching into deeper and more superficial layers.
Functions are similar to that of pyramidal cells.
20. HORIZONTAL CELLS OF CAJAL (OR)
RETZIUS CAJAL CELLS
Small ,spindle shaped.
Oriented parallel to the surface.
Least common cell type.
Found only in most superficial layer.
Axons pass laterally to synapse with dendrites of
pyramidal cells.
They are prominent during development, but
disappear after birth.
21. LAYERS OF NEOCORTEX
Differing in neuron morphology, size and population density, there
are 6 layers in the neocortex.
1.plexiform or molecular layer
2.outer granular layer
3.outer pyramidal cell layer
4.inner granular layer
5.inner pyramidal cell layer/ganglion cell layer
6.multiform cell layer
-The six neocortical layers are not equally prominent
everywhere. They form granular & agranular layers.
22.
23. 1.PLEXIFORM LAYER
Most superficial layer.
Contains many dendritic
and axonal synapses with
one another.
Sparse nuclei are seen
that belongs to
neuroglia.
Occasional horizontal
cells of cajal are seen.
24. 2.OUTER GRANULAR LAYER
Dense population of
small pyramidal cells
and stellate cells.
Also contains various
axons and dendritic
connections.
25. 3.PYRAMIDAL CELL LAYER
Moderate sized pyramidal
cells predominate.
Large pyramidal cells are
present in further deeper
layers.
Martinotti cells are also
present.
27. 5.GANGLIONIC LAYER
Large pyramidal cells
Stellate cells (few)
Cells of martinotti
Huge pyramidal Betz
cells of motor cortex are
present. Hence the name
ganglion cell layer.
28. 6.MULTIFORM CELL LAYER
All morphological forms are found in this layer.
Fusiform cells in deeper and other cells are present
superficially in this layer.
34. INTERCONNECTIONS OF CORTEX
Afferent fibers synapse high(superficially) in the
cortex with dendrites of efferent neuron.
Efferent fibers, typically the axons of pyramidal cells
tend to give off branches.
These branches pass back into the superficial layers
to communicate with their own dendrites.
This can be via interneuronal connectins or involving
other cortical cell types.
36. Contd…
Afferent Input Efferent Output
Association nuclei(Thalamus) - corticothalamic fibers
Other cortical areas - corticocortical fibers
Intralaminar nuclei(Thalamus) - corticostriate fibers to
brainstem & spinal cord
37. NEUROGLIAL CELLS
In addition to neurons, the cortex contains supporting
neuroglial cells.
They are-
1. Astrocytes
2. Oligodendroglial cells
3. Microglial cells
4. Ependymal cells
38. ASTROCYTES
Function(s):
.
Most numerous glial cells in
..Supply of nutrients to
the grey matter. neurons.
The nucleus is round to oval ..Removes excess
with open chromatin and neurotransmitters
..Maintains appropriate balance
peripheral nucleoli. of Ca2+ and K+
The cytoplasm is highly ions (which are important in
passing nerve
branched that occupy most impulses at synapses).
of the neuropil - ..Helps migration of neurons
during braindevelopment.
protoplasmic astrocytes
..Aids formation of the
The foot process act as BBB blood-brain barrier.
called glia limitans.
39.
40.
41. OLIGODENDROCYTES
-Found mainly adjacent to
neurons/axon.
-FUNCTION- myelination of
neurons.
-They develop an artifactural
vacuolisation around nuclei thus
a halo appears around the
nucleus.
-They are relatively large cells
with dispersed nuclear chromatin
and perinuclear halo.
-They also aggregate around nerve
cell bodies in grey matter and
function as supporting cells.
42. MICROGLIAL CELLS
Small cells of mesenchymal
origin.
- Have elongated nuclei and
relatively little cytoplasm.
- The cytoplasm forms fine,
highly branched processes.
- In response to tissue damage,
they transform into large
amoeboid phagocytic cells.
Protects neurons from
disease process.
- They function as scavengers
of nervous system.
- CNS representatives of
macrophage monocyte
defence system.
43. EPENDYMAL CELLS FUNCTIONS
-Protection: Forms lining of the
ventricles of the brain and
-Forms the epithelial lining of central canal of the spinal cord.
ventricles and spinal cord. Forms cerebrospinal fluid (CSF).
-Aids circulation of cerebrospinal
-Cuboidal or low columnar in fluid (CSF).
shape.
-cells are bound at the luminal
surface by epithelial
junctional complexes.
–The bases of cells taper and
break into fine branches which
ramify into underlying layer of
astrocytic processes.
44. Staining of components of nervous
system
NEURON:
General architecture -routine H&E stain.
Hematoxylin & von Giesan stain
- highlights vascular changes.
- emphasises myelin staining.
- provides cellular cytology.
Nissl’s substance-basic dyes-methylene blue,
toluedene blue,
neurtal red,
cresyl violet
46. HEAVY METAL IMPREGNATION TECHNIQUE WITH GOLD
HMI techniques with gold
and silver are valuable in the
study of neuronal
morphology.
Cajal and Golgi are the
pioneers of neuroanatomy
who employed these
techniques.
47. Contd..
IHC OF NEURONS
Anti-neurofilament antibody staining- Nf 70, Nf 150,
Nf 200(cytoskeletal protiens)
Ab to neuron specific enolase(cytoplasmic protiens)
Protiens associated with neurosecretory granules
Chromogranin A
Synaptophysin
62. REFERENCE
WHEATERS functional histology – Page399,123-127 5th
edition.
Text book of histology- I.B.SINGH
JOHN D.BANCROFT- theory and practice of histological
techniques-5th edition.
ROBBINS & COTRAN-8th edition
INTERNET
