The document provides information on the nervous system, including its main divisions and components. It discusses:
1) The central nervous system (CNS) which includes the brain and spinal cord, and the peripheral nervous system (PNS) which connects the CNS to the rest of the body and is divided into somatic and autonomic systems.
2) The autonomic nervous system has two divisions - the sympathetic and parasympathetic systems which work in opposition to activate the body during stress and restore it to resting state.
3) The brain is the control center of the body and is made up of the cerebrum, cerebellum, and brain stem. It is protected by meninges and
Neuroanatomy | 1. Introduction to NeuroanatomyAhmed Eljack
This is the first lecture in neuroanatomy presented and taught by Ahmed Eljack to second level medical students at Alneelain University.
This lecture discussed the basics of neuroanatomy regarding anatomical terms, planes of section, anatomical divisions of the nervous system, and cells of the nervous system and their major functions.
Neuroanatomy | 1. Introduction to NeuroanatomyAhmed Eljack
This is the first lecture in neuroanatomy presented and taught by Ahmed Eljack to second level medical students at Alneelain University.
This lecture discussed the basics of neuroanatomy regarding anatomical terms, planes of section, anatomical divisions of the nervous system, and cells of the nervous system and their major functions.
The reference material used to make video is: Principles of Anatomy and Physiology Gerard J. Tortora, Bryan H. Derrickson.
Pons is part of brain stem, present superior to medulla, inferior to mid brain and anterior to cerebellum.
Pons means a bridge. As the name denotes, it connects other areas of brain.
Neurons extending from cerebral cortex to pons makes corticopontine tract.
Pons is connected to cerebellum by middle cerebral peduncle.
Pons has vestibular nuclei, which is part of equilibrium pathways from inner ear to brain.
Pons has also respiratory nuclei. Along with rhythmicity area of medulla, pons controls basal respiratory rhythm.
Pons also contains nuclei for cranial nerve number V, VI,VII, and VIII.
For the video, Kindly visit my you tube channel.
https://www.youtube.com/channel/UC7xXKrK7pDObSfXvk9aOgDA.
Review on Case Hemisection of the Spinal Cord (Brown Sequard Syndrome)
This case is a trigger in Neuroscience Module in Medical Faculty University of Indonesia
Anatomy of Cranial Nerve for BPT class.
Require 10 classes. Require help of brain specimen during the class. Testing of the nerves can also be taken together.
understanding spinal cord, its bransches, lesions, functions and anatomy.
hope to give you better knowledge of spinal cord by the end of it.
plese review ans comment for my future updates and corrections that iw ill be needing in this.
white fibers of the cerebrum, commissural fibers, association fibers and radiation fibers, examples of each types of cerebral fibers, corpus callosum, fornix, habenular commisure, anterior commissure, posterior commissure, superior longitudinal fasciculus, inferior longitudinal fasciculus, occipital fasciculus, uncinate fasciculus, projection fibers, corona radiata, optic radiation
spinal cord, ascending tracts of the the spinal cord, spinocortical tracts, gray matter of spinal cord, white mater of spinal cord, organization of neuron, first order second order and third order neuron, anterolateral spinal tract anteroposterior spinal tract, spinolivary tract, visceral sensory tract, dorsal column tract, spino cerebellar tract , spinorectal pathway, spino olivary pathway, cerebellar peduncles,
enlists and the description of the different descending tracts of the CNS. cortico spinal tract, cortico bulbar tract, extra pyramidal and pyramiddal tracts, homunculus, vestibulospinal tract, reticulo spinal tracts, tectospinal tract, autonomic tract, uppermotor neuron lesion, lower motor neuron lesion, spinal cord injury, brown sequard syndrome. spinal cord infection, degenerative disorders of spinal cord,
BRAINSTEM
The Brainstem lies at the base of the brain and the top of the spinal cord.
The brainstem is located in the posterior cranial fossa.
The brainstem is the structure that connects the cerebrum of the brain to the spinal cord and cerebellum.
Provides a pathway for tracts running between higher and lower neural centers.
Divided into 3 major divisions:
midbrain,
pons, and
medulla oblongata.
It is responsible for many vital functions of life, such as breathing, consciousness, blood pressure, heart rate, and sleep.
It contains many critical collections of white and grey matter.
The grey matter within the brainstem consists of nerve cell bodies and form many important brainstem nuclei. Ten of the twelve cranial nerves arise from their cranial nerve nuclei in the brainstem.
The white matter tracts of the brainstem include axons of nerves traversing their course to different structures. These tracts travel both to the brain (afferent) and from the brain (efferent) such as the somatosensory pathways and the corticospinal tracts, respectively.
Mid Brain
The midbrain is continuous with the cerebral hemisphere.
The upper posterior (i.e. rear) portion of the midbrain is called the tectum, which means "roof."
The surface of the tectum is covered with four bumps representing two paired structures: the superior and inferior colliculi.
The superior colliculi are involved in eye movements and visual processing, while the inferior colliculi are involved in auditory processing.
Another important nucleus, the substantia nigra, is located here.
The substantia nigra is rich in dopamine neurons and is considered part of the basal ganglia.
Pons
An important pathway for tracts that run from the cerebrum down to the medulla and spinal cord, as well as for tracts that travel up into the brain.
It also forms important connections with the cerebellum via fibre bundles known as the cerebellar peduncles.
Posteriorly, the pons and medulla are separated from the cerebellum by the fourth ventricle.
Home to several nuclei for cranial nerves.
Medulla
The point where the brainstem connects to the spinal cord.
Contains a nucleus called the nucleus of the solitary tract that is crucial for our survival (receives information about blood flow, along with information about levels of oxygen and carbon dioxide in the blood, from the heart and major blood vessels).
When this information suggests a discordance with bodily needs (e.g. blood pressure is too low), there are reflexive actions initiated in the nucleus of the solitary tract to bring things back to within the desired range.
Blood Supply
The brain stem receives its blood supply exclusively from the posterior circulation, including the vertebrae and basilar artery.
The medulla receives its blood supply from the vertebral via medial and lateral perforating arteries.
The pons and midbrain receive their blood from the basilar via the medial and lateral perforating arteries.
The reference material used to make video is: Principles of Anatomy and Physiology Gerard J. Tortora, Bryan H. Derrickson.
Pons is part of brain stem, present superior to medulla, inferior to mid brain and anterior to cerebellum.
Pons means a bridge. As the name denotes, it connects other areas of brain.
Neurons extending from cerebral cortex to pons makes corticopontine tract.
Pons is connected to cerebellum by middle cerebral peduncle.
Pons has vestibular nuclei, which is part of equilibrium pathways from inner ear to brain.
Pons has also respiratory nuclei. Along with rhythmicity area of medulla, pons controls basal respiratory rhythm.
Pons also contains nuclei for cranial nerve number V, VI,VII, and VIII.
For the video, Kindly visit my you tube channel.
https://www.youtube.com/channel/UC7xXKrK7pDObSfXvk9aOgDA.
Review on Case Hemisection of the Spinal Cord (Brown Sequard Syndrome)
This case is a trigger in Neuroscience Module in Medical Faculty University of Indonesia
Anatomy of Cranial Nerve for BPT class.
Require 10 classes. Require help of brain specimen during the class. Testing of the nerves can also be taken together.
understanding spinal cord, its bransches, lesions, functions and anatomy.
hope to give you better knowledge of spinal cord by the end of it.
plese review ans comment for my future updates and corrections that iw ill be needing in this.
white fibers of the cerebrum, commissural fibers, association fibers and radiation fibers, examples of each types of cerebral fibers, corpus callosum, fornix, habenular commisure, anterior commissure, posterior commissure, superior longitudinal fasciculus, inferior longitudinal fasciculus, occipital fasciculus, uncinate fasciculus, projection fibers, corona radiata, optic radiation
spinal cord, ascending tracts of the the spinal cord, spinocortical tracts, gray matter of spinal cord, white mater of spinal cord, organization of neuron, first order second order and third order neuron, anterolateral spinal tract anteroposterior spinal tract, spinolivary tract, visceral sensory tract, dorsal column tract, spino cerebellar tract , spinorectal pathway, spino olivary pathway, cerebellar peduncles,
enlists and the description of the different descending tracts of the CNS. cortico spinal tract, cortico bulbar tract, extra pyramidal and pyramiddal tracts, homunculus, vestibulospinal tract, reticulo spinal tracts, tectospinal tract, autonomic tract, uppermotor neuron lesion, lower motor neuron lesion, spinal cord injury, brown sequard syndrome. spinal cord infection, degenerative disorders of spinal cord,
BRAINSTEM
The Brainstem lies at the base of the brain and the top of the spinal cord.
The brainstem is located in the posterior cranial fossa.
The brainstem is the structure that connects the cerebrum of the brain to the spinal cord and cerebellum.
Provides a pathway for tracts running between higher and lower neural centers.
Divided into 3 major divisions:
midbrain,
pons, and
medulla oblongata.
It is responsible for many vital functions of life, such as breathing, consciousness, blood pressure, heart rate, and sleep.
It contains many critical collections of white and grey matter.
The grey matter within the brainstem consists of nerve cell bodies and form many important brainstem nuclei. Ten of the twelve cranial nerves arise from their cranial nerve nuclei in the brainstem.
The white matter tracts of the brainstem include axons of nerves traversing their course to different structures. These tracts travel both to the brain (afferent) and from the brain (efferent) such as the somatosensory pathways and the corticospinal tracts, respectively.
Mid Brain
The midbrain is continuous with the cerebral hemisphere.
The upper posterior (i.e. rear) portion of the midbrain is called the tectum, which means "roof."
The surface of the tectum is covered with four bumps representing two paired structures: the superior and inferior colliculi.
The superior colliculi are involved in eye movements and visual processing, while the inferior colliculi are involved in auditory processing.
Another important nucleus, the substantia nigra, is located here.
The substantia nigra is rich in dopamine neurons and is considered part of the basal ganglia.
Pons
An important pathway for tracts that run from the cerebrum down to the medulla and spinal cord, as well as for tracts that travel up into the brain.
It also forms important connections with the cerebellum via fibre bundles known as the cerebellar peduncles.
Posteriorly, the pons and medulla are separated from the cerebellum by the fourth ventricle.
Home to several nuclei for cranial nerves.
Medulla
The point where the brainstem connects to the spinal cord.
Contains a nucleus called the nucleus of the solitary tract that is crucial for our survival (receives information about blood flow, along with information about levels of oxygen and carbon dioxide in the blood, from the heart and major blood vessels).
When this information suggests a discordance with bodily needs (e.g. blood pressure is too low), there are reflexive actions initiated in the nucleus of the solitary tract to bring things back to within the desired range.
Blood Supply
The brain stem receives its blood supply exclusively from the posterior circulation, including the vertebrae and basilar artery.
The medulla receives its blood supply from the vertebral via medial and lateral perforating arteries.
The pons and midbrain receive their blood from the basilar via the medial and lateral perforating arteries.
The nervous system is the part of an animal's body that coordinates its behavior and transmits signals between different body areas. In vertebrates it consists of two main parts, called the central nervous system (CNS) and the peripheral nervous system (PNS).
THIS PRESENTATION IS UPLOADED TO HELP THE EDUCATOR OF MEDICAL, NURSING & ALLIE HEALTH SCIENCES TO TEACH THEIR STUDENTS ABOUT THE NERVOUS SYSTEM. IT WILL ALSO CREATE AWARENESS AMONG THE COMMON PEOPLE REGARDING NERVOUS SYSTEM.
Review of Nervous System, Unconsciousness, and CVA. The Nursing Core FunctionsAyinla Kazeem
This presentation was made at several sessions of Mandatory Continuing Professional Development Programme for Nigerian Nurses in Kwara State, and have undergone series of editing till date. While still working on the final editing to totally conform with global standard of practice, I deemed it necessary to share it in this forum.
During my 1st &2nd year of residency period , i used to teach Anatomy and Orthopaedics for foreign undergraduate medical students. At last year i taught Neurology for one batch. so i posted some of my collections for competely educational purpose coz i believe in knowledge ...inseted of deleting these ppts , they may me useful for others so i shared it ....
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
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
263778731218 Abortion Clinic /Pills In Harare ,sisternakatoto
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These simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
Acute scrotum is a general term referring to an emergency condition affecting the contents or the wall of the scrotum.
There are a number of conditions that present acutely, predominantly with pain and/or swelling
A careful and detailed history and examination, and in some cases, investigations allow differentiation between these diagnoses. A prompt diagnosis is essential as the patient may require urgent surgical intervention
Testicular torsion refers to twisting of the spermatic cord, causing ischaemia of the testicle.
Testicular torsion results from inadequate fixation of the testis to the tunica vaginalis producing ischemia from reduced arterial inflow and venous outflow obstruction.
The prevalence of testicular torsion in adult patients hospitalized with acute scrotal pain is approximately 25 to 50 percent
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
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
2. Divisions of the Nervous System
2 main subdivisions:
Central Nervous System
◦ the brain & spinal cord
Peripheral Nervous System -
◦ groups of neurons called ganglia and peripheral
nerves
◦ provides pathways to & from the central nervous
system for electrochemical signals (impulses)
2
3. The Peripheral Nervous System
Composed of 2 divisions:
Somatic
◦ Provides sensory information (voluntary)
◦ Transmits impulses to and from skeletal muscles -
usually conscious actions
Autonomic
◦ motor system for viscera (smooth muscles &
glands-involuntary)
◦ Autonomic is further divided into 2 subdivisions
3
5. The Autonomic Nervous System
2 subdivisions of Autonomic:
Sympathetic
◦ participates in body’s response to stress; fight or flight
Parasympathetic
◦ returns body to resting state & conserves resources
5
6. Orientation of the PNS
Dorsal roots carry sensory info to the spinal cord
Ventral roots carry outgoing motor axons
Peripheral nerves formed from dorsal & ventral roots
Symmetry of PNS
◦ Arranged on 2 axis:
◦ longitudinal: rostral to caudal ( head to tail)
◦ dorsal to ventral (back to front)
Segmented:
◦ 31 pairs of spinal nerves
◦ 12 pairs of cranial nerves
6
7. Neurons
The basic and functional unit of the nervous
system.
Consist of a cell body (perikaryon) and processes
arising from it.
The processes arising from the cell body of a
neuron are called neurites.
Several short branching processes called
Dendrites
One longer process called an Axon
7
9. Synapse
Synapses are sites of junction
between neurons.
Types
axosomatic synapse
axoaxonal synapse
dendro-axonic or dendro-dendritic
somato-dendritic
9
10. NEUROGLIAS:
Supporting cells of nervous system
Non conducting cells of the nervous
systems.
Classification of Neuroglia
Astrocyte
Microglia
Schwann cells
Oligodentrocytes
They provide mechanical support to neurons
Serve as insulators and prevent neuronal impulses
from spreading in unwanted directions.
10
11. The Central Nervous System
Consists of following Regions:
◦ Spinal Cord
◦ Brain
◦ Cerebrum
◦ Cerebellum
◦ Diencephalon: the caudal (posterior) part of the forebrain, containing the epithalamus,
thalamus, hypothalamus, and ventral thalamus and the third ventricle.
◦ Brain Stem
◦ Midbrain
◦ Medulla
◦ Pons
11
12. Protection of the Brain & CNS
The skull & spinal column
The Meninges
◦ 3 layers of tissue protecting brain
◦ Dura mater
◦ outer tough layer
◦ Subdural space – normally small
◦ Arachnoid membrane
◦ next to dura mater
◦ Subarachnoid space - spongy layer filled with cerebrospinal fluid and
blood vessels
◦ Pia mater
◦ membrane that covers the brain
Cerebrospinal fluid (CSF) - cushions brain; circulates around the brain &
spinal cord
12
13. VENTRICULAR SYSTEM
13
The ventricles are a communicating network
of cavities.
The adult derivatives of the open space or
lumen of the embryonic neural tube
14. LATERAL VENTRICLE
14
The largest of these spaces
One within each of the cerebral hemispheres)
Volume increases with age
Best seen in frontal sections, where their
◦ ventral surface is usually defined by the basal
ganglia,
◦ dorsal surface by the corpus callosum, and
◦ medial surface by the septum pellucidum
16. THIRD VENTRICLE
16
Forms a narrow midline space
between the right and left thalamus
Runs through the midbrain
The anterior surface contains two
protrusions:
◦ Supra-optic recess
◦ Infundibular recess
17. FOURTH VENTRICLE
17
The last in the system
It lies within the
brainstem, at the junction
between the pons and
medulla oblongata.
18. BOUNDARIES
18
Lateral boundary- superior and inferior
cerebellar peduncles
Roof- Superior part is formed by medial superior
cerebellar peduncle, inferior part by inferior
medullary velum.
Floor- Formed by posterior surface of pons and
cranial halves of medulla. Divided by median
sulcus
19. COMMUNICATION
19
Lateral Ventricle Lateral Ventricle
Third ventricle
Fourth ventricle
Cisterna Magna
Median aperture (Magendie)
Intervertebral foramen
of Monro
Intervertebral foramen
of Monro
Lateral aperture
(Lushka)
Lateral aperture
(Lushka)
Cerebral aqueduct
22. CHOROID PLEXUS
22
Lined by ependymal cells
Located in the ventricles produce
Cerebrospinal fluid (CSF), which fills the
ventricles and subarachnoid space,
following a cycle of constant production
and reabsorption.
It forms the barrier between blood and
CSF
23. CEREBROSPINAL FLUID
23
Found in the ventricles of the brain and in the subarachnoid space around the
brain and spinal cord
The circulation is aided by the arterial pulsations of the choroid plexuses and by
the cilia on the ependymal cells lining the ventricles.
The main sites for the absorption of the cerebrospinal fluid are the arachnoid
villi that project into the dural venous sinuses, especially the superior sagittal
sinus
Functions…….
24. CLINICAL RELEVANCE
24
Hydrocephalus is defined as an abnormal collection of CSF within
the ventricles of the brain.
Chronic hydrocephalus causes raised intracranial pressure, and
consequently cerebral atrophy
There are 2 basic clinical classifications
COMMUNICATING (NON-OBSTRUCTIVE HYDROCEPHALUS)
NON-COMMUNICATING (OBSTRUTIVE HYDROCEPHALUS)
25. 25
COMMUNICATING
(NON-OBSTRUCTIVE HYDROCEPHALUS)
Abnormal collection of CSF in the absence of any
flow obstruction in the ventricles.
Common causes usually involve the functional
impairment of the arachnoid granulations, such as
fibrosis of the subarachnoid space following a
haemorrhage.
27. 27
BLOCKAGE OF CSF CIRCULATION
Obstruction can arise in the interventricular foramen,
median aperture or cerebral aqueduct.
Occurs due to tumor
Causes distention of the ventricles
28. 28
HYDROCEPHALUS EX VACUO
Refers to ventricular expansion, secondary to brain
atrophy.
Occur due to loss of adjacent brain parenchyma
Often seen in patients with neurodegenerative
conditions, such as Alzheimer’s disease.
29. 29
INCREASED CSF PRESSURE
Caused by an intracranial tumor
Compresses the thin walls of the retinal vein as it
crosses the extension of the subarachnoid space to
enter the optic nerve.
Results in congestion of the retinal vein, bulging
forward of the optic disc, and edema of the disc; the last
condition is referred to as papilledema.
Both eyes exhibits papilledema. Persistent papilledema
leads to optic atrophy and blindness.
30. The Spinal Cord- gross anatomy and internal structure
The spinal cord is roughly cylindrical in shape.
It begins superiorly at the foramen magnum
in the skull.
It terminates inferiorly in the adult at the level
of the lower border of the L1.
In the young child, it usually ends at the upper
border of L3.
30
31. Spinal Cord (cont’d)
ENLARGEMENTS
Cervical & lumbar enlargements
In the cervical region, it gives origin to the brachial
plexus
In the lower thoracic and lumbar regions, it gives
origin to the lumbosacral plexus
CONUS MEDULLARIS:
Inferiorly, the spinal cord tapers off into the conus
medullaris.
31
32. FILUM TERMINALE:
From the apex of conus medullaris
Prolongation of the pia mater, descends to be attached to the posterior
surface of coccyx.
FISSURE & SULCI
In the midline anteriorly, the anterior median fissure.
On the posterior surface, a shallow furrow, the posterior median sulcus.
32
33. SPINAL NERVES
Along the entire length of the spinal cord are attached 31 pairs of spinal nerves
Cervical …… 8
Thoracic …… 12
Lumbar …… 5
Sacral …… 5
Coccygeal …..1
Each connects to the spinal cord by 2 roots – dorsal and ventral.
Each root forms from a series of rootlets that attach along the whole
length of the spinal cord segment.
Ventral roots are motor while dorsal roots are sensory.
The 2 roots join to form a spinal nerve prior to exiting the vertebral column.
Almost immediately after emerging from its intervertebral foramen, a spinal nerve will divide
into a dorsal ramus, a ventral ramus, and a meningeal branch that re-enters and innervates the
meninges and associated blood vessels.
Each ramus is mixed.
Joined to the base of the ventral rami of spinal nerves in the thoracic region are the rami communicantes. These are sympathetic fibers.
Dorsal rami supply the posterior body trunk whereas the thicker ventral rami supply the rest of the body trunk and the limbs.
33
34. Plexuses
Except for T2 to T12, all ventral rami branch extensively and join one another lateral to the
vertebral column forming complicated nerve plexuses.
Within a plexus, fibers from different rami criss cross each other and become redistributed.
Internal Structure:
The spinal cord is composed of an inner core of gray matter, which is surrounded by an outer
covering of white matter.
GRAY MATTER
On cross section; the gray matter is seen as an H-shaped pillar with anterior and posterior gray
columns, or horns, united by a thin gray commissure containing the small central canal.
A small lateral gray column or horn is present in the thoracic and upper lumbar segments of the
cord.
The amount of gray matter present at any given level of the spinal cord is related to the amount
of muscle innervated at that level.
Thus, its size is greatest within the cervical and lumbosacral enlargements of the cord.
34
35. Grey and White Matter of Spinal Cord
35
WHITE MATTER
• The white matter, may be divided into anterior,
lateral, and posterior white columns or
funiculi.
• The anterior column on each side lies
between the midline and the anterior nerve
roots;
• The lateral column lies between the anterior
and the posterior nerve roots;
• The posterior column lies between the
posterior nerve roots and the midline.
43. 43
Amyotrophic Lateral Sclerosis, ALS (or
Lou Gehrig’s Disease
• Upper and lower motor
neuron disease
– with gradual degeneration of
motor neurons
– Progressive weakening of
skeletal muscles occurs
• atrophy and fasciculation (fine
twitching) occur
• May involve genetic factor
– Mutation of SOD1 gene (on
xsome 21) reported
– FALS runs in family
• Symptoms starts around 40-
60 years (more in men)
• Patient may die from
respiratory failure
– due to paralysis of diaphragm
44. The Brain
Remaining 6 areas of the CNS are part of the brain
The control center of the body
◦ Regulates body activity; enables you to think
Surface is gray matter - 6 x 106 cell bodies / cc
Under gray matter is white matter - formed of myelinated
axons.
Surface of the brain (neocortex) is convoluted
◦ Increases surface area
◦ ridges = gyri
◦ grooves = sulci
44
46. The Cerebral Hemispheres
Largest region of brain; 7/8 by weight - Includes:
◦ Cerebral cortex – outer surface of gray matter
◦ underlying white matter
◦ 3 nuclei (clusters of related neurons):
◦ the basal ganglia
◦ the hippocampal formation
◦ the amygdala
◦ these are masses of gray matter at the base of the cerebrum
that serve the motor cortex
◦ paired cavities = lateral ventricles
◦ Divided into 2 ‘half spheres’ = hemisheres
46
47. The Cerebral Cortex
The convoluted outer surface
◦ grooves = sulci
◦ elevated regions = gyri
Composed of gray matter
2-5 mm thick
Contains ~ 12 billion neurons
Most of the cerebral cortex is concerned with processing sensory
information or motor commands
2 bands of tissue – one sensory, one motor
Divided into primary, secondary, & tertiary
47
48. The Forebrain
Telencephalon
◦ Olfactory bulb
◦ Cerebral cortex
◦ Basal telencephalon (basal ganglia)
◦ Corpus callosum
◦ commissure between cerebral hemispheres
◦ Internal capsule
◦ connections with brain stem
◦ Lateral ventricles
48
49. Lobes of the Cerebrum
2 sides called hemispheres
Joined by a bridge = Corpus Callosum
Separated by a deep fissure front to back
Like 2 mirror images (but not quite)
Divided into 4 lobes
◦ 1. Frontal
◦ 2. Parietal
◦ 3. Temporal
◦ 4. Occipital
49
50. Lobes of the Cerebrum
Parietal Lobe
Temporal Lobe
Frontal Lobe
Limbic Lobe
Occipital Lobe
50
62. White matter of Cerebral hemisphere
The surface of the cerebral hemisphere is covered by a thin layer of grey
matter called the cerebral cortex.
The greater part of the cerebral hemisphere deep to the cortex is occupied by
white matter within which are embedded certain important masses of grey
matter.
These fibres may be:
Association fibres that interconnect different regions of the cerebral cortex.
Projection fibres that connect the cerebral cortex with other masses of grey
matter; and vice versa.
Commissural fibres that interconnect identical areas in the two hemispheres.
62
63. Internal capsule
The internal capsule may be divided into the following parts.
The anterior limb lies between the caudate nucleus medially, and the anterior part of the
lentiform nucleus laterally.
The posterior limb lies between the thalamus medially, and the posterior part of the
lentiform nucleus on the lateral side.
In transverse sections through the cerebral hemisphere the anterior and posterior limbs
of the internal capsule are seen to meet at an angle open outwards. This angle is called
the genu (genu = bend).
Some fibres of the internal capsule lie behind the posterior end of the lentiform nucleus.
They constitute its retrolentiform part.
Some other fibres pass below the lentiform nucleus (and not medial to it). These fibres
constitute the sublentiform part of the internal capsule
63
65. The Primary Sensory & Motor Cortex
Primary Motor Cortex:
◦ controls voluntary movements of limbs & trunk
◦ contains neurons that project directly to spinal cord to
activate somatic motor neurons
Primary Sensory Areas
◦ receive information from peripheral receptors with only a
few synaptic relays interposed
65
66. Brodmann Areas
Cytoarchitectural areas of neocortex
Regions with similar cell structure
Numbered
◦ each represents a functionally distinct area
Examples:
◦ Area 17 is the primary visual cortex
◦ at the caudal pole of the occipital lobe
◦ Area 4 is the primary motor cortex
◦ primary auditory cortex on left side of temporal lobe near language center
66
67. Secondary & Tertiary Areas
Surrounding primary areas are higher order (secondary & tertiary)
sensory & motor areas
◦ Process & integrate info coming from the primary sensory areas.
Higher order motor areas send complex info required for motor
actions to primary motor areas
67
68. Association Areas
Three other large regions of cortex surround the primary,
secondary & tertiary areas Called association areas
In primates, association areas are majority of cortex
68
71. Integration of Brain Functions
Interactions of all areas sensory, motor & motivational systems is
essential for behavior.
Example: throw a ball - info about motion of ball, impact of ball,
position of arms, legs, hands, etc. - sensory, motor, motivational
systems
Anatomical organization of each major functional system (sensory,
motor, motivational) follows 4 principles
71
72. Principles of Anatomical Organization
Each system contains relay centers
◦ These don’t just transmit info; also modify it
◦ Most important relay center is the thalamus
◦ almost all sensory info to cerebral cortex processed
by thalamus
Each system is composed of several distinct
pathways
◦ Example: touch & pain
72
73. Principles of Anatomical Organization (Cont.)
Each pathway is topographically organized
◦ neural map - clustered functions
Most pathways cross the body’s midline
◦ Thus each hemisphere controls the actions/sensations of the
opposite side.
◦ Left side dominates language; right side -spatial perception,
musical ability
73
74. Diencephalon
Thalamus & hypothalamus taken together
Important structures found in the cerebrum
Between the midbrain & cerebral hemispheres
◦ Thalamus
◦ Hypothalamus
◦ Third ventricle
Retina and optic nerves
◦ develop from optic vesicle that pouches off from
diencephalon during development
74
75. The Thalamus & Hypothalamus
Thalamus
◦ relay center - processes & distributes almost all sensory & motor info
going to the cerebral cortex
◦ links nervous & endocrine system
◦ emotional control
Hypothalamus
◦ under the thalamus
◦ regulates autonomic nervous system
◦ connects to thalamus, midbrain & some cortical areas
◦ Controls body temperature, thirst, hunger, emotional behavior
75
76. Cerebellum
The cerebellum consists of a part lying near the midline called the vermis, and
of two lateral hemispheres.
two surfaces, superior and inferior
Dorsal to the pons & medulla
Mostly white matter covered with a thin layer of gray matter
Pleated surface; divided into several lobes
Receives sensory input from the spinal cord, motor info from the cerebral
cortex & input about balance from receptors in the inner ear
Therefore, can coordinate planning & timing of voluntary muscle movement &
maintain balance.
76
78. The Medulla Oblongata & Pons
Medulla Oblongata
◦ Bottom (rostral) region of the brainstem
◦ Regulates blood pressure and respiration; controls
breathing, swallowing, digestion, heart & blood
vessels.
Pons
◦ Above medulla
◦ links cerebellum to cerebrum; relays info from
cerebral hemispheres to cerebellum
78
79. The Midbrain
Mesencephalon
◦ Tectum (roof)
◦ superior colliculus + inferior colliculus
◦ Tegmentum (floor)
◦ Cerebral aqueduct
Controls responses to sight (e.g. eye movements)
Relay station of auditory & visual signals
Motor control of some skeletal muscles
79
80. The Brainstem
Anatomically, from the bottom up:
◦ Medulla Oblongata
◦ Pons
◦ Midbrain
Taken together = brainstem
◦ Contains all the nerves that connect the spinal cord with the cerebrum
◦ Receives sensory info from head, face, & neck
◦ Motor neurons control muscles of head & neck
◦ 12 pairs of cranial nerves carry input & output
◦ Also involved in hearing, taste & balance
80
81. The Limbic System
A functional & evolutionary division, rather than anatomical
Group of structures in center of the brain above the brainstem:
◦ hypothalamus
◦ pituitary
◦ hippocampus
◦ important role in memory
◦ hippocampal gyrus
◦ amygdala
◦ coordinates actions of the autonomic & endocrine systems
◦ involved in emotions
81
82. Functions of the Limbic System
Sometimes called the “mammalian brain because most highly developed in
mammals
One of the oldest areas of brain from an evolutionary standpoint
Maintains homeostasis: e.g. helps maintain temperature, blood pressure,
heart rate, blood sugar
Also involved in emotional reactions needed for survival
4 F’s: fleeing, fighting, feeding.
82
85. Ipsilateral/Contralateral
The cerebral hemispheres are involved with inputs and outputs from
the contralateral side of the body
◦ Damage to neocortex causes problems on the opposite side
◦ In patients with epilepsy, surgeons occasionally cut corpus callosum
to relieve seizures. Flash different pictures in each eye, patients
could describe what they saw with right eye, but not left, but could
pick out object - example: Heart = ART.
The cerebellum is involved with the control of movement on the
ipsilateral side of the body.
◦ Damage to the cerebellum causes motor deficits on the same side.
85
86. Injury Mechanisms
The brain is a complex and delicate organ, and one that is
vulnerable to injury from a variety of different traumas. These
include:
Frontal Lobe Injury
Occipital Lobe Injury
Temporal Lobe Injury
Side Impact Injury
Coup/Contre-coup Injury
Diffuse Axonal Injury
Epidural Hematoma
Subdural Hematoma
86
87. Frontal Lobe Injury
The frontal lobe of the brain can be injured
from direct impact on the front of the head.
During impact, the brain tissue is accelerated
forward into the bony skull. This can cause
bruising of the brain tissue and tearing of
blood vessels.
Frontal lobe injuries can cause changes in
personality, as well as many different kinds of
disturbances in cognition and memory.
87
88. Occipital Lobe Injury
Occipital lobe injuries occur from
blows to the back of the head.
This can cause bruising of the
brain tissue and tearing of blood
vessels.
These injuries can result in vision
problems or even blindness.
88
89. Temporal Lobe Injury
The temporal lobe of the brain is
vulnerable to injury from impacts of
the front of the head.
The temporal lobe lies upon the bony
ridges of the inside of the skull, and
rapid acceleration can cause the brain
tissue to smash into the bone, causing
tissue damage or bleeding.
89
90. Side Impact Injury
Injuries to the right or left side of the brain
can occur from injuries to the side of the
head.
Injuries to this part of the brain can result
in language or speech difficulties, and
sensory or motor problems.
90
91. Coup/Contre-coup Injury
A French phrase that describes bruises
that occur at two sites in the brain.
When the head is struck, the impact
causes the brain to bump the opposite
side of the skull. Damage occurs at the
area of impact and on the opposite
side of the brain.
91
92. Diffuse Axonal Injury
Brain injury does not require a direct head
impact. During rapid acceleration of the
head, some parts of the brain can move
separately from other parts. This type of
motion creates shear forces that can
destroy axons necessary for brain
functioning.
These shear forces can stretch the nerve
bundles of the brain.
92
93. Diffuse Axonal Injury
The brain is a complex
network of interconnections.
Critical nerve tracts can be
sheared and stressed during
an acceleration-type of injury.
Diffuse axonal injury is a very
serious injury, as it directly
impacts the major pathways of the
brain.
93
94. Epidural Hematoma
An epidural hematoma is a blood clot
that forms between the skull and the
top lining of the brain (dura).
This blood clot can cause fast changes in
the pressure inside the brain.
When the brain tissue is compressed, it
can quickly result in compromised blood
flow and neuron damage.
94
95. Subdural Hematoma
A subdural hematoma is a blood clot
that forms between the dura and the
brain tissue.
The clot may cause increased pressure
and may need to be removed surgically.
When the brain tissue is compressed, it
can quickly result in compromised blood
flow and tissue damage.
95
97. Introduction
The brain is one of the most metabolically
active organs in the body, receiving 17% of
the total cardiac output and about 20% of
the oxygen available in the body.
The brain receives it’s blood from two
pairs of arteries, the carotid and vertebral.
About 80% of the brain’s blood supply
comes from the carotid, and the remaining
20% from the vertebral.
97
98. These arteries arise in the neck, and ascend to
the cranium.
Within the cranial vault, the terminal branches
of these arteries form an anastomotic circle,
called the Circle of Willis. From this circle,
branches arise which supply the majority of the
cerebrum.
Other parts of the CNS, such as the pons and
spinal cord, are supplied by smaller branches
from the vertebral arteries.
98
99. Internal Carotid Arteries
The internal carotid arteries (ICA) originate at the bifurcation of the left and right common carotid arteries, at
the level of the fourth cervical vertebrae (C4).
They move superiorly within the carotid sheath, and enter the brain via the carotid canal of the temporal bone.
They do not supply any branches to the face or neck.
Once in the cranial cavity, the internal carotids pass anteriorly through the cavernous sinus. Distal to the
cavernous sinus, each ICA gives rise to:
◦ Ophthalmic artery
◦ Posterior communicating artery
◦ Anterior cerebral artery
The internal carotids then continue as the middle cerebral artery, which supplies the the lateral portions of the
cerebrum.
99
101. Vertebral Arteries
The right and left vertebral arteries arise from the subclavian arteries, medial
to the anterior scalene muscle. They then ascend up the posterior side of the
neck, through holes in the transverse processes of the cervical vertebrae,
known as foramen transversarium.
The vertebral arteries enter the cranial cavity via the foramen magnum.
Within the cranial vault, some branches are given off:
◦ Meningeal branch
◦ Anterior and posterior spinal arteries
◦ Posterior inferior cerebellar artery
After this, the two vertebral arteries converge to form the basilar artery
101
103. Arterial Circle of Willis
The terminal branches of the vertebral and internal carotid arteries all anastamose to form a
circular blood vessel, called the Circle of Willis.
There are three main (paired) constituents of the Circle of Willis:
◦ Anterior cerebral arteries: These are terminal branches of the internal carotids.
◦ Internal carotid arteries: Present immediately proximal to the origin of the middle
cerebral arteries.
◦ Posterior cerebral arteries: These are terminal branches of the vertebral arteries.
To complete the circle, two ‘connecting vessels’ are also present:
◦ Anterior communicating artery: This artery connects the two anterior cerebral arteries.
◦ Posterior communicating artery: A branch of the internal carotid, this artery connects the
ICA to the posterior cerebral artery.
103
105. Regional Blood Supply to the Cerebrum
There are three cerebral arteries; anterior, middle and
inferior. They each supply a different portion of the
cerebrum.
◦ The anterior cerebral arteries supply the anteromedial
portion of the cerebrum.
◦ The middle cerebral arteries are situated laterally,
supplying the majority of the lateral part of the brain.
◦ The posterior cerebral arteries supply both the medial
and lateral parts of the posterior cerebrum
105
107. Anterior Spinal Artery, provides
sulcal branches which penetrate
the ventral median fissure and
supply the ventral 2/3 of the spinal
cord.
Posterior Spinal Arteries, each
descends along the dorsolateral
surface of the spinal cord and
supplies the dorsal 1/3.
107
Spinal cord blood supply
109. Radicular arteries, originating from
segmental arteries at various levels,
which divide into anterior and
posterior radicular
arteries as they move along ventral and
dorsal roots to reach the spinal cord.
Here they reinforce spinal arteries and
anastomose with their branches.
From these varied sources of blood supply, a series of circumferential
anastomotic channels are formed around the spinal cord, called the arterial
vasocorona, from which short branches penetrate and supply the lateral parts
of the cord
109
110. The radicular arteries provide the main
blood supply to the cord at the thorasic,
lumbar and sacral segments. There are a
greater number on the posterior (10-23)
than anterior (6-10 only) side of the cord.
One radicular artery, noticeably larger than the others, is called
the artery of Adamkiewicz, or the artery of the lumbar
enlargement. Usually located with the lower thorasic or upper
lumbar spinal segment on the left side of the spinal cord.
110
111. The spinal cord lacks adequate collateral supply in some areas,
making these regions prone to ischemia after vascular occlusions.
The upper Thorasic (T1-T4) and first lumbar segments are the most
vulnerable regions of the cord.
111
112. There are several arteries that reinforce
the spinal cord blood supply and are
termed segmental arteries
1. The Vertebral arteries, spinal branches
which are present in the upper cervical
(~C3-C5) levels
2. Ascending Cervical arteries, present in
the lower cervical areas
3. Posterior Intercostal, present in the
mid-thorasic region
112
113. Clinical Relevance: Disorders of Arterial Supply
Stroke
◦ The brain is particularly sensitive to oxygen starvation. A stroke is a acute
development of a neurological deficit, due to a disturbance in the blood supply of
the brain.
◦ There are four main causes of a cerebrovascular accident:
◦ Thrombosis – Obstruction of a blood vessel by a locally forming clot.
◦ Embolism – Obstruction of a blood vessel by an emboli formed elsewhere.
◦ Hypoperfusion – Underperfusion of the brain, due to systemically low blood pressure (e.g shock).
◦ Haemorrhage – An accumulation of blood within the cranial cavity.
◦ Out of these four, the most common cause is embolism. In many patients, an
athlerosclerotic emboli will arise from the vessels of the neck.
113
114. Clinical Relevance: Disorders of Arterial Supply
Intracerebral Aneurysms
◦ An aneurysm is a dilation of an artery, which is greater than
50% of the normal diameter. They most likely to occur to occur
in the vessels contributing to the Circle of Willis. They are
particularly dangerous – producing no symptoms until they
rupture.
◦ Once the artery wall has ruptured, it is a medical emergency,
and the patient is likely to die unless treated swiftly. Treatment
of an intracerebral aneurysm is surgical.
114