The cerebellum is located in the posterior cranial fossa at the back of the brainstem. It is divided into three lobes - anterior, middle and flocculonodular. The cerebellum coordinates movement and controls balance through connections with the spinal cord and vestibular system. Damage to the midline of the cerebellum causes imbalance and trunk ataxia, while damage to the hemispheres causes incoordination of the contralateral limbs.
Thalamus-Anatomy,Physiology,Applied aspectsRanadhi Das
Thalamus is a very important relay station.
All general and special sensory impulses (except smell) & afferent impulses from RAS are integrated here.
Thalamus however is the center of pain and protopathic sensations.
It has other non sensory functions as well, like motor control, sleep, wakefulness.
It is the largest structure deriving from the embryonic diencephalon, the posterior part of the forebrain situated between the midbrain and the cerebrum.
The thalamus is part of a nuclear complex structured of 4 parts, the hypothalamus, epithalamus, prethalamus (formerly called ventral thalamus) and dorsal thalamus.
Thalamus-Anatomy,Physiology,Applied aspectsRanadhi Das
Thalamus is a very important relay station.
All general and special sensory impulses (except smell) & afferent impulses from RAS are integrated here.
Thalamus however is the center of pain and protopathic sensations.
It has other non sensory functions as well, like motor control, sleep, wakefulness.
It is the largest structure deriving from the embryonic diencephalon, the posterior part of the forebrain situated between the midbrain and the cerebrum.
The thalamus is part of a nuclear complex structured of 4 parts, the hypothalamus, epithalamus, prethalamus (formerly called ventral thalamus) and dorsal thalamus.
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 fibers present in the cerebellar peduncles
the applied anatomy of the cerebellum
the microscopic structure of the cerebellum, mossy, and climbing fibers
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 fibers present in the cerebellar peduncles
the applied anatomy of the cerebellum
the microscopic structure of the cerebellum, mossy, and climbing fibers
The cerebellum which stands for “little brain”, is a structure of the central nervous system.
It has an important role in motor control.
In particular, it is active in the coordination, precision and timing of movements, as well as in motor learning.
The surface of the cerebellum is marked by a series of small infoldings called folia. It consists of two hemispheres separated by a vermis.
A dural in folding called the tentorium cerebelli separates the superior surface of the cerebellum from the inferior surface of the occipital lobe. Three peduncles connect the cerebellum to other neural structures.
Anatomical Location:
The cerebellum is located at the back of the brain,
immediately inferior to the occipital and temporal lobes.
It is separated from the cerebral lobes by the tentorium cerebelli, a tough layer of dura mater.
It lies at the same level and posterior to the pons, from which it is separated by the fourth ventricle.
The cerebellum consists of grey matter and white matter.Grey matter – located on the
surface of the cerebellum. It is tightly folded, forming the cerebellar cortex.
White matter – located underneath the cerebellar cortex.
parts of Cerebellum :
There are three parts
Anatomical lobes,
zones and
functional divisions
There are three anatomical lobes;
the anterior lobe, the posterior lobe and the flocculonodular lobe.
These lobes are divided by two fissures – the primary fissure and posterolateral fissure.There are two cerebellar zones.
In the midline of the cerebellum is the vermis.
Either side of the vermis is the intermediate zone.
Lateral to the intermediate zone are the lateral hemispheres/lateral zone.The cerebellum has 3 parts:
Archicerebellum (vestibulocerebellum): It includes the flocculonodular lobe, which is located in the medial zone. The archicerebellum helps maintain equilibrium and coordinate eye, head, and neck movements; it is closely interconnected with the vestibular nuclei.
Midline vermis (paleocerebellum)/spinocerebellum: It helps coordinate trunk and leg movements. Vermis lesions result in abnormalities of stance and gait. It is involved in regulating body movements by allowing for error correction. It also receives proprioceptive information.
Lateral hemispheres (neocerebellum)/cerebrocerebellum: They control quick and finely coordinated limb movements, predominantly of the arms and hands.
THE CEREBELLUM IS INVOLVED IN THE FOLLOWING FUNCTIONS:
Maintenance of balance and posture. postural adjustments in order to maintain balance
Coordination of voluntary movements. Most movements are composed of a number of different muscle groups acting together in a temporally coordinated fashion.
Motor learning. The cerebellum is important for motor learning. The cerebellum plays a major role in adapting and fine-tuning motor programs to make accurate movements through a trial-and-error process (e.g., learning to hit a baseball).
Cognitive functions. involved in certain cognitive function
Anatomy of Human Brain Presented by Dr Arman MD (Resident) Physical Medicine & Rehabilitation, Dhaka Medical College, Dhaka, Bangladesh. reference taken from latest book & journal.
White matter of cerebral hemisphere corpus callosum Dr Lovely Jain
White matter of cerebral hemisphere corpus callosum is a very imporant topic for theory & viva in neuroanatomy.i try to made easy to understand for all student of medical field.
The brain stem is a critical part of the human brain that connects the brain to the spinal cord.
It plays a vital role in basic life functions and serves as a bridge between the higher brain centers (such as the cerebral cortex) and the rest of the body.
The brain stem is responsible for essential functions such as breathing, heart rate, blood pressure, and basic reflexes.
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
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The prostate is an exocrine gland of the male mammalian reproductive system
It is a walnut-sized gland that forms part of the male reproductive system and is located in front of the rectum and just below the urinary bladder
Function is to store and secrete a clear, slightly alkaline fluid that constitutes 10-30% of the volume of the seminal fluid that along with the spermatozoa, constitutes semen
A healthy human prostate measures (4cm-vertical, by 3cm-horizontal, 2cm ant-post ).
It surrounds the urethra just below the urinary bladder. It has anterior, median, posterior and two lateral lobes
It’s work is regulated by androgens which are responsible for male sex characteristics
Generalised disease of the prostate due to hormonal derangement which leads to non malignant enlargement of the gland (increase in the number of epithelial cells and stromal tissue)to cause compression of the urethra leading to symptoms (LUTS
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
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
Explore natural remedies for syphilis treatment in Singapore. Discover alternative therapies, herbal remedies, and lifestyle changes that may complement conventional treatments. Learn about holistic approaches to managing syphilis symptoms and supporting overall health.
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.
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
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
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
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
2. The cerebellum is
situated in the
posterior cranial
fossa. It is the largest
part of the hindbrain
and lies posterior to
the fourth ventricle,
the pons, and the
medulla oblongata.
3. CEREBELLUM
The cerebellum is located
behind the dorsal aspect of
the pons and the medulla.
A midline portion, the
vermis, separates two
lateral lobes, or cerebellar
hemispheres.
The cerebellum consists of
the cerebellar cortex and
the underlying cerebellar
white matter
Four paired deep
cerebellar nuclei are
located within the white
matter of the cerebellum
4. The cerebellum is
divided into three main
lobes:
the anterior lobe
the middle(posterior)
lobe
the flocculonodular
lobe.
A deep horizontal fissure that is found
along the margin of the cerebellum
separates the superior from the
inferior surfaces; it is of no
morphologic or functional significance
5.
6.
7. Structure of the Cerebellum
The cerebellum is composed of
an outer covering of gray matter
called the cortex and inner white
matter.
8. A section made through the cerebellum parallel
with the median plane divides the folia at right
angles, and the cut surface has a branched
appearance, called the arbor vitae.
9. The gray matter of the
cortex throughout its
extent may be divided into
three layers:
(1) an external layer, the
molecular layer
(2) a middle layer, the
Purkinje cell layer
(3) an internal layer, the
granular layer .
10.
11. Functional Areas of the Cerebellar Cortex
Clinically it is possible to divide up the cerebellar cortex
into three functional areas.
1.The cortex of the vermis influences the movements of
the long axis of the body, namely, the neck, the
shoulders, the thorax, the abdomen, and the hips.
2.Immediately lateral to the vermis is a so-called
intermediate zone of the cerebellar hemisphere. This
area has been shown to control the muscles of the
distal parts of the limbs, especially the hands and feet.
3.The lateral zone of each cerebellar hemisphere
appears to be concerned with the planning of sequential
movements of the entire body and is involved with the
conscious assessment of movement errors.
12. Intracerebellar Nuclei
Four masses of gray matter are embedded in the white
matter of the cerebellum on each side of the midline.
From lateral to medial, these nuclei are the dentate, the
emboliform, the globose, and the fastigial.
13. White Matter
There is a small amount of white matter in
the vermis; it closely resembles the trunk
and branches of a tree and thus is termed
the arbor vitae . There is a large amount of
white matter in each cerebellar
hemisphere.
The white matter is made up of three
groups of fibers:
(1) intrinsic,
(2) afferent,
(3) efferent.
14. Cerebellar Peduncles
The cerebellum is linked to
other parts of the central nervous
system by numerous efferent and
afferent fibers that are grouped
together on each side into three
large bundles, or peduncles.
The superior cerebellar
peduncles connect the cerebellum
to the midbrain,
the middle cerebellar
peduncles connect the cerebellum
to the pons, and
the inferior cerebellar peduncles
connect the cerebellum to the
medulla oblongata.
15.
16.
17. CEREBELLAR FUNCTIONS
The cerebellum has several main functions:
coordinating skilled voluntary movements by
influencing muscle activity,
controlling equilibrium and muscle tone through
connections with the vestibular system and the
spinal cord.
There is a somatotopic organization of body parts
within the cerebellar cortex.
In addition, the cerebellum receives collateral input
from the sensory and special sensory systems.
18. Each cerebellar hemisphere is connected by
nervous pathways principally with the same
side of the body; thus, a lesion in one
cerebellar hemisphere gives rise to signs
and symptoms that are limited to the same
side of the body.
19. Diagnosis of Cerebellar disorders
The main clinical features of cerebellar disorders include
incoordination, imbalance, and troubles with stabilizing eye
movements.
There are two distinguishable cerebellar syndromes –
1. midline and
2.hemispheric.
1.Midline cerebellar syndromes are characterized by
imbalance.
Persons are unsteady, they are unable to stand in with eyes
open or closed, and are unable to well perform tandem gait.
trunkal ataxia .
"titubation" or a bobbing motion of the head or trunk.
also often affect eye movements.
There may be nystagmus, ocular dysmetria.
20. Hemispheric cerebellar syndromes are characterized by
incoordination of the limbs.
There may be decomposition of movement, dysmetria, and
rebound.
Dysdiadochokinesis is the irregular performance of rapid
alternating movements.
Intention tremors may be present on an attempt to touch an
object.
A kinetic tremor may be present in motion.
The finger-to-nose and heel-to-knee tests are classic tests of
hemispheric cerebellar dysfunction.