1. Pain is transmitted by two types of nerve fibers: fast pain via A-delta fibers and slow pain via C fibers. Fast pain is sharp and localized while slow pain is dull and poorly localized.
2. Pain receptors are free nerve endings that respond to mechanical, thermal, and chemical stimuli. They are present mainly in the skin, joints, and blood vessels.
3. Pain pathways involve the transmission of pain stimuli from receptors to the spinal cord and then to the brain. This involves both neospinothalamic and paleospinothalamic tracts.
Physiology of Pain, Characteristic of pain, Basic consideration of nervous system, Pain receptor, Mechanism of pain causation, Theories of pain, Pathways of pain, Pain Receptors
Physiology of Pain, Characteristic of pain, Basic consideration of nervous system, Pain receptor, Mechanism of pain causation, Theories of pain, Pathways of pain, Pain Receptors
Pain is defined as an “unpleasant emotional experience usually initiated by a noxious stimulus and transmitted over a specialized neural network to the central nervous system where it is interpreted as such”.
Free nerve endings – responsible for carrying noxious stimulus from both superficial as well as deep somatic and visceral pain sensations therefore reffered as nociceptors
According to type of impulses they carry second order neuron can be classified as –
LOW THRESHOLD MECHANOSENSORY( ligth touch, pressure and Proprioception)
NOCIOCEPTIVE SPECIFIC ( Noxious stimulation)
WIDE DYNAMIC RANGE ( wide range of stimulus intensities from nonnoxious to noxious.
SILENT NOCICEPTORS (It is an afferent neuron that appear to remain or silent to any mechanical stimulation .These neuron become active with tissue injury and add to the nociceptive input entering the CNS.
Knowledge of pain physiology is very important in understanding of electrotherapy prescription. So, this slide may be useful in understanding the background of the pain processes.
Gait control theory of pain given by Melzack & Wall in 1965. This is very much helpful for those medical/paramedical professionals who deal with subjects having pain.
Enteric nervous system - GIT physiology, EXTRINSIC AND INTRINSIC NERVE SUPPLY, Meissner's and myenteric's plexus.
local reflex, short reflex. Parasympathetic and sympathetic nerve supply of GIT. Functions of the plexuses.
Pain is one of the most commonly experienced symptom . It is often spoken of as a protective mechanism since it is usually manifested when an environmental change occurs that causes injury to responsive tissue
Pain is one of the most commonly experienced symptom . It is often spoken of as a protective mechanism since it is usually manifested when an environmental change occurs that causes injury to responsive tissue
Thigh - Anterior Compartment Anatomy contains many muscles and important Triangle the Femoral triangle. This slide gives you a diagramatic representation of the Ant.Compt and also Apllied anatomy facilitating Integrated Teaching.
Anatomy of thalamus,Nuclei of thalamus,functional classification of thalamic nuclei,afferent and efferent connections of thalamus,motor function of thalamus,alertness and arousal in thalamus,thalamus and emotional behavior,Thalamic syndrome,Korsakoff's Syndrome
Pain is defined as an “unpleasant emotional experience usually initiated by a noxious stimulus and transmitted over a specialized neural network to the central nervous system where it is interpreted as such”.
Free nerve endings – responsible for carrying noxious stimulus from both superficial as well as deep somatic and visceral pain sensations therefore reffered as nociceptors
According to type of impulses they carry second order neuron can be classified as –
LOW THRESHOLD MECHANOSENSORY( ligth touch, pressure and Proprioception)
NOCIOCEPTIVE SPECIFIC ( Noxious stimulation)
WIDE DYNAMIC RANGE ( wide range of stimulus intensities from nonnoxious to noxious.
SILENT NOCICEPTORS (It is an afferent neuron that appear to remain or silent to any mechanical stimulation .These neuron become active with tissue injury and add to the nociceptive input entering the CNS.
Knowledge of pain physiology is very important in understanding of electrotherapy prescription. So, this slide may be useful in understanding the background of the pain processes.
Gait control theory of pain given by Melzack & Wall in 1965. This is very much helpful for those medical/paramedical professionals who deal with subjects having pain.
Enteric nervous system - GIT physiology, EXTRINSIC AND INTRINSIC NERVE SUPPLY, Meissner's and myenteric's plexus.
local reflex, short reflex. Parasympathetic and sympathetic nerve supply of GIT. Functions of the plexuses.
Pain is one of the most commonly experienced symptom . It is often spoken of as a protective mechanism since it is usually manifested when an environmental change occurs that causes injury to responsive tissue
Pain is one of the most commonly experienced symptom . It is often spoken of as a protective mechanism since it is usually manifested when an environmental change occurs that causes injury to responsive tissue
Thigh - Anterior Compartment Anatomy contains many muscles and important Triangle the Femoral triangle. This slide gives you a diagramatic representation of the Ant.Compt and also Apllied anatomy facilitating Integrated Teaching.
Anatomy of thalamus,Nuclei of thalamus,functional classification of thalamic nuclei,afferent and efferent connections of thalamus,motor function of thalamus,alertness and arousal in thalamus,thalamus and emotional behavior,Thalamic syndrome,Korsakoff's Syndrome
this is a series of notes on clinical pathology, useful for undergraduate and post graduate pathology students. Notes have been prepared from standard textbooks and are in a format easy to reproduce in exams.
rft is described in detail . function of kidney, objectives of doing the test. the various test available for assessing the renal function with clinical interpretation is available.
Physiology of Pain (PPT) Nervous System PhysiologyShaista Jabeen
https://www.youtube.com/channel/UCrrAABI7QDRCJ1yMrQCip_w/videos
https://www.facebook.com/ShaistaJabeeen/
https://www.facebook.com/Human-Physiology-Lectures-100702741804409/
Physiology of Pain (PPT)
Nervous System Physiology
INTRODUCTION
BENEFITS OF PAIN SENSATION
COMPONENTS OF PAIN SENSATION
PATHWAYS OF PAIN SENSATION
FROM SKIN AND DEEPER STRUCTURES
FROM FACE
FROM VISCERA
FROM PELVIC REGION
VISCERAL PAIN
CAUSES OF VISCERAL PAIN
REFERRED PAIN
DEFINITION
EXAMPLES OF REFERRED PAIN
MECHANISM OF REFERRED PAIN
NEUROTRANSMITTERS INVOLVED IN PAIN SENSATION
ANALGESIA SYSTEM
ANALGESIC PATHWAY
GATE CONTROL THEORY
APPLIED PHYSIOLOGY
Short Notes
pdf ppt
Pain helps as to known that there is a problem or damaged to our organs or our mind and we need very attension for seeking a medical advices or to learn from the pain.
New product dedisions provide a dear path to the business. New product development
astep by step process. A Complete idea is required behind new product.
1 1deal Generation: The development of a product starts with the concept and idea.
The remaining process is depending on that idea.
2 Screening of Idea: This step is cruial to ensure that unsuitable ideas, for whatever
reason, are rejected as soon as possible. Ideas need to be considered objectively,
ideally by a group or committee.
3. Concept Development and Testing: After having an idea, next is the sreening
stage. The idea should now convert into concept. It has depth information which can
be visualizing by the consumer.
4. Anaysis of business: After finalization of concept, a business case needs to be kept
algTStogether to consider whether the new service /product will be gainful.
2665.Product Development If the nev product is approved, it will be approved to the
2marketing and technical development step.
6. Test Marketing: Market testing (test marketing or) is different to consumer testing.
in that it introduces the product that follows proposed plan of marketing.
od7. Commercialization: When the concept has been tested and developed, final
0decisions are required to move the product to its introduction into the market.
8. Launch: A detailed plan of launch is required for this step. This is the important
stage for success of a product
New Drug Development
So In present business atmosphere, it is more important to take smart decisions for
business. Innovative approaches and new products can put an organization on proper
pathway and to make a big success if appropriately analyzed and executed. Make it simpler
(Fig.2.1).0
Following parameters should keep in mind for a better decision:
Analyzing existing service and product portfolio frequently.
Knowing the position of functions of business, projects of departments and
initiatives.
Understanding the distribution of funds and assessing efficiency.
Having understanding of market for new opportunities and possible competition.
2.B PRODUCT BRANDING, PACKAGING AND LABELLING DECİSIONs
2.8.1 Branding
Branding has its existence from ancient era. According to Nilson (2000), the first example
of branding is found in the oil lamps' manufacture on the Greek islands thousands of years
back. Brand elements are name, sign, term, symbol, design or distinguishing characteristics.
Brand is not only a graphical design or a logo; it is the unique identity of the product.
By American Marketing Association, Brand can be defined as name, term, sign, symbol
or design, or a combination of them intended to identijy the goods and services of one seller or
group of sellers and to diferentiate them from those of other sellersa54
Branding is a process, where a company generates loyalty among consumers in the
market. Brands are designed with a motive to communicate customers the reason for the
existence of their product. Brand should have a strong connection with customers;
Pain sensation is an unpleasant sensation produced by damaged tissues.
It differs from other sensations because its purpose is not to inform the higher centers about the quality of pain.
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
Model Attribute Check Company Auto PropertyCeline George
In Odoo, the multi-company feature allows you to manage multiple companies within a single Odoo database instance. Each company can have its own configurations while still sharing common resources such as products, customers, and suppliers.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
Synthetic Fiber Construction in lab .pptxPavel ( NSTU)
Synthetic fiber production is a fascinating and complex field that blends chemistry, engineering, and environmental science. By understanding these aspects, students can gain a comprehensive view of synthetic fiber production, its impact on society and the environment, and the potential for future innovations. Synthetic fibers play a crucial role in modern society, impacting various aspects of daily life, industry, and the environment. ynthetic fibers are integral to modern life, offering a range of benefits from cost-effectiveness and versatility to innovative applications and performance characteristics. While they pose environmental challenges, ongoing research and development aim to create more sustainable and eco-friendly alternatives. Understanding the importance of synthetic fibers helps in appreciating their role in the economy, industry, and daily life, while also emphasizing the need for sustainable practices and innovation.
Honest Reviews of Tim Han LMA Course Program.pptxtimhan337
Personal development courses are widely available today, with each one promising life-changing outcomes. Tim Han’s Life Mastery Achievers (LMA) Course has drawn a lot of interest. In addition to offering my frank assessment of Success Insider’s LMA Course, this piece examines the course’s effects via a variety of Tim Han LMA course reviews and Success Insider comments.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
Acetabularia Information For Class 9 .docxvaibhavrinwa19
Acetabularia acetabulum is a single-celled green alga that in its vegetative state is morphologically differentiated into a basal rhizoid and an axially elongated stalk, which bears whorls of branching hairs. The single diploid nucleus resides in the rhizoid.
2. PAIN
• An unpleasant sensory and emotional
experience associated with actual or potential
tissue damage, or described in terms of such
damage.
– (International association for the study of pain
1979)
3. Damaged tissues release proteolytic enzymes, K+
&histamine .Proteolytic enzymes act on globulins in the
interstitial Fluid to release kinins.
e.g bradykinin, K+ and histamine stimulate pain receptors
Pain is a protective sensation.
4.
5. Pain receptors . Free nerve endings
Three types
1. Mechanical pain Receptors.: stimulated by
mechanical injurious stimuli.
2. Thermal pain Receptors. : discussed before.
3. Chemical pain Receptors.: stimulated by
chemical stimuli.
Chemical stimuli include:
bradykinin (most important) serotonin, histamine
& K+.
6. Distribution of pain receptors
- More : Skin, periosteum, arteries, joint surfaces, &
tentorium cerebelli and cranial sinuses.
- Less : deep tissues.
- Absent : liver parenchyma, lung alveoli and brain.
►Nerve fibres: A delta and C fibres.
►Adaptation: Slowly (static-tonic) or nonadaptive
receptors.
7. Types of pain
Pain is classified according to the:
(a) Site of pain
1. Cutaneous pain.
2. Deep pain.
3. Visceral pain.
(b) Quality of pain
1. Epicritic i.e sharp pricking pain.
2. Protopathic i.e dull aching pain.
3. Burning pain.
8. Pain nerve fibers – fast pain and slow pain
• From the pain receptors, the pain stimulus is
transmitted through peripheral nerves to the
spinal cord and from there to the brain. This
happens through two different types of nerves
fibers:
• A-delta "fast pain” and
• C-fibers “slow pain” nerve fibers.
9. What is “fast pain” and “slow pain”?
• A pain stimulus, e.g. if you cut yourself,
consists of two sensations.
• first “fast pain” sensation-is experienced as
sharp.
• “slow pain”, more a dull and burning.
• Occurs after a short time
• lasts a few days or weeks,
• Chronic pain-if inappropriately processed by
the body, it can last several months
10. Fast pain
• nerves are called A-delta fibers.
• relatively thick size nerve fibers allow the pain
stimulus to be transferred very fast (at a speed
of five to 30 meter/second), hence the name
• This is all to make the body withdraw
immediately from the painful and harmful
stimulus, in order to avoid further damage.
11. Slow Pain
• starts immediately after the fast pain
• is transmitted by very thin nerve fibers, called
C-nerve fibers (their diameter is between 0.2
to 1 thousandth of a millimeter).
• pain impulse can only be transmitted slowly to
the brain, at a speed of less than 2 meters per
second.
• Body response -immobilization (guarding,
spasm or rigidity), so that healing can take
place.
12. (1) Cutaneous Pain
• Fast (Immediate, acute
• sharp or pricking)
• Felts within 0.1 sec ond .
• Short-duration.
• Mechanical &Thermal R.
• A delta fibres.
• Ends in cerebral cortex.
• Well localized.
• Not felt in deep tissues
• Blocked by hypoxia & pressure
• Neospinothalamic tract
• Neurotransmitter:
• Glutamate .
• Slow (Chronic, burning, aching
throbbing nauseous)
After one second .
Prolonged;annoying,intolerable.
Elicited by All types of R.
C fibres
Ends in non specific thalamic
nuclei & Reticular formation.
Poorly localized .
Occurs in skin & deep tissues
Blocked by local anesthesia.
Paleospinthalamic tract
Neurotransmitter
Substance P.
13. Nociceptive Pathways
• Fast
• A Delta Fibers
• Glutamate
• Neospinothalamic
• Mechanical, Thermal
• Good Localization
• Sharp, Pricking
• Terminate in VB
Complex of Thalamus
• Slow
• C Fibers
• Substance P
• Paleospinothalamic
• Polymodal/Chemical
• Poor Localization
• Dull, Burning, Aching
• Terminate; RF
– Tectal Area of Mesen.
– Periaqueductal Gray
14. Nociceptive Pathways
• Spinothalamic - Major
– Neo- Fast (A Delta)
– Paleo- Slow (C Fibers)
• Spinoreticular
• Spinomesencephalic
• Spinocervical (Mostly Tactile)
• Dorsal Columns (Mostly Tactile)
15.
16. PAIN
• A-DELTA→ Noxious Stimulation → change in
Membrane Potential → Receptor Potential → A. P.
• C-FIBERS: Damaged Cell → Proteolytic Enzymes
Circulating Gamma Globulins
Bradykinin, Substance P
Stimulation of Nerve Ending
17. Fast pain is transmitted by A delta fibers (5-15
m/sec.) from skin
(mainly), parietal pleura, peritoneum a &
Synovial membrane.
20. Appreciation of pain
- Fast pain; is appreciated in thalamus and cortex.
- Slow pain; is appreciated mainly in thalamus.
Functions of the cortex in pain appreciation
1. Localization of pain 2. Discrimination of type of pain.
3. Modulation of pain by emotional and behavioral factors.
21. Arousal reaction to pain signals
The non specific thalamic nuclei (intra-laminar
nuclei) and reticular formation have a strong
arousal effect on the brain which prevents sleep
during pain.
22. Deep pain C. Fibres
Diffuse, Dull aching and Depressor effects.
Causes: - inflammation, ischaemia or muscle spasm.
- Bone fractures; due to stimulation of periosteal pain
receptors.
Characters of deep pain
1. Dull aching or rhythmic cramps.
2. Diffuse (poorly localized).
Depressor autonomic changes: decreased heart rate,
decreased arterial blood pressure ,nausea & vomiting.
23. DEEP PAIN
• Arises from Periosteum & Ligaments
• Continuous Contraction of Muscles
• Poorly Localized
• Associated with Sweating & Changes in Blood
Pressure
• Often Nauseating
• Transmitted via Antero Lateral System
24.
25. Ischaemic pain
Type of deep pain felt in muscles when their blood
supply is decreased.
The Patients complains of severe pain in the muscles
upon walking or running due to accumulation of pain
producing substances as lactic acid.
Examples
1. Cardiac muscle: angina pectoris.
2. Skeletal muscle: intermittent claudication.
26. Visceral pain C Fibres
Most of viscera contain only pain receptors.
Pain from viscera is carried a long; C fibres.
Pain from peritoneum, pleura or pericardium:Adelta.
It differs from cutaneous pain
. Sharp cut in the viscera does not cause pain (why).
. Diffuse stimulation of pain nerve ending ® severe pain.
27. Causes Of Visceral Pain
1. Ischaemia: increased acidic metabolites, bradykinin &
proteolytic enzymes.
2. Inflammation of peritoneal covering of viscera.
3. Irritation (chemical irritation by HCI in peptic ulcer).
4. Overdistension of a hollow viscus e.g urinary bladder.
5. Spasm of a hollow viscus e.g gut, gall bladder or
ureter.
Both 4 & 5: Obliteration of blood vesssels ® Ischaemic
pain.
28. Characters of visceral pain
1. Dull aching or rhythmic cramps.
2. Diffuse (poorly localized).
3. Depressor autonomic changes: decreased heart rate, decreased
arterial blood pressure ,nausea & vomiting.
4. Rigidity of the overlying muscles.
Limitation of the spread of infection.
Decrease the mobility of the diseased viscus for relief of pain.
5. Referred to the surface area i.e referred pain.
29. VISCERAL PAIN
• Arises from Visceral Organs
• Receptors
– Free Nerve Endings of A Delta & C Fibers
– Sparsely Distributed
• Stimulus: Spasm, Distension, Ischemia, Chemical
• Ischemia
– Release Acid Metabolites
– Tissue Degeneration Products Produce Bradykinin &
Proteolytic Enzymes
• Chemicals
– Release of Proteolytic Acid Gastric Juice
30. VISCERAL PAIN
• Input to CNS via Autonomic Nerves
• Cell Bodies of Ist Order Neuron
– DRG & Homologous Cranial Nerve Ganglia of VII,
IX , X & Trigeminal Nerve
• Afferent also Enters via Sympathetic Ganglia for
Reflex Control of Visceral Functions
31. VISCERAL PAIN
• In CNS Fibers Follow Same Route as that of Other
Pain Fibers
– Poorly Localized, Unpleasant
– Associated with Autonomic Changes & Nausea
– Usually Referred to Superficial Parts of Body
• REFERRED PAIN
– Visceral Pain Usually Referred
– Deep Pain May Also be Referred
32.
33. Referred pain
Definition
Pain originating from viscera but felt in somatic
structures which supplied by the same spinal dorsal
root ( the same dermatome) of the diseased viscus.
34. Referred pain
• Examples
• 1. Cardiac pain: is felt in left shoulder.
• 2. Gall bladder pain: is felt in tip of right shoulder.
• 3. Appendicular pain: is felt around the umbilicus.
• 4. Gastric pain: is felt between the umbilicus & xiphoid
process.
• 5. Renal pain: is felt in the back, inguinal region &
testicles.
• 6. Teeth pain: referred to other teeth.
35.
36. REFERRED PAIN
• Superficial Pain Never Referred
• Visceral Pain - Local & Referred
– May also Radiate to Distant Site
– Cardiac Pain
• Inner Aspect of Left Arm, Right Arm, even to Neck &
Abdomen
– Distension of Ureter
• Pain in Testicles
– Irritation of Parietal Plura & Peritoneum
• Pain Referred to Overlying Surface of Body
– Of Diaphragm
• Tip of Shoulder
38. REFERRED PAIN
• Mechanism
– Dermatome Rule
• Parts Develop from Same Embryonic Segment or
Dermatome
• Diaphragm Migrate from Neck
• Heart & Arm have Same Segmental Origin
• Convergence
– Somatic and Visceral Pain Afferents Converge on
Same Second Order Neuron
– Brain Unable to Differentiate Site of Origin
• Hence Pain Felt at Somatic Sites
39. Mechanism of referred pain
a. Convergence – projection theory
Afferent pain fibers from the skin and viscous
converge on the same cells of SGR or thalamus
and will finally activate the same cortical
neurons. Whatever the source of pain, the
cortex will project it to the skin being
the commnest source of pain.
40.
41. b. Facilitation theory
Afferents of diseased viscera, give
facilitation to cutaneous
pain cells in Substantia Gelatinosa of
Rolandi (SGR),
Which leads to facilitation of their
stimulation.
42.
43. REFERRED PAIN
• Facilitation Effect:
– ↑ Activity in Visceral Pain Afferents Collaterals Fibers
→ EPSP in Spinal Neurons Receiving Somatic Inputs
→ ↑ Activity in Somatic Neurons → Continuous Pain
44. PAIN
• Intensity of Pain is Proportional to Degree of
Tissue Damage
• Ischemic Pain → Lactic Acid → Nerve Ending
Stimulation
• Muscle Spasm Mechanoreceptor Stimulation
Ischemia
• Transmission of Pain
– A – Delta Fibers: 6 to 30 M/Sec
– C – Fibers: 0.5 to 2 M/Sec
45. PAIN
• Mixed Spinal Nerve
• Dorsal Root Ganglia Dorsal Root Dorsal
Horn
• A – Delta Fibers
– Terminate in Lamina I of Dorsal Horn Gray Matter (Fast
Pain)Give Local Collateral Branch for Spinal Reflexes
• Second Order Neuron
– Cross to Opposite Side
– Form Anterior Spino-Thalamic Tract (Neospinothalamic
Tract)
• Joins Medial Laminiscus → Few Collaterals to R.F.
46. PAIN
• Second Order Neuron Thalamus
Post Central Gyrus
• Localization is Good
• Neurotransmitter is Glutamate
• Few Fibers Ascends in Dorsal Column
• Slow pain: C –Fibers Ist Order Neuron
Lamina II and III
47. PAIN
• Substantia Gelatinosa of Rolando
• Interneuron Lamina V Second Order
Neuron Cross → Lateral Spinothalamic Tract
• (Paliospinothalamic Tract → Brain Stem Joins →
Medial Leminiscus → Thalamus → Cortex
48. Pain
• Brain Stem: Collaterals Given to:
– Reticular Formation at All Levels of Brain Stem
– Hypothalamus
– Peri Ventricular Gray Matter
– Peri Aqueduct Gray Matter
– Most Fibers End in Intralaminar and Reticular Nuclei
of Thalamus
– Non Specific Thalamo Cortical Projections to All Part
of Cerebral Cortex
– To Somato Sensory Cortex SI and SII
49. PAIN
• While Entering Spinal Cord
– Fibers Ascends or Descends Few Segments → Enters
Spinal Cord
• Through Many Inter-Neurons
– Information Relayed to Anterior Horn Cells of Same &
Opposite Side for Local & Segmental Reflexes of
Spinal Cord
50. PAIN
• Pain & Other Crude Sensations
– Perceived Even in Absence of Cerebral Cortex
• Cortex is Concerned With
– Discriminative, Exact & Meaningful Interpretation of Pain
– Emotional Components of Pain
• Post Injury Pain
– Irritation of Nerve Endings
• Allodynia
– Minor Touch Causes Pain
• Neuropathic Pain
– Occur at Sites Even after Healing of Injury
– Often Resistant to Analgesics
51. PAIN
• Mechanism
– Release of Sensitizing Substance
– ↑ Transmission at Synaptic Junctions
– At Finer Level
• ↑ Activity of Pre-Synaptic NMDA Receptors of Primary
Nerve Ending → ↑ Release of Substance P
– Gene Switch
• Sub Population of A-Beta Fibers from Mechanoreceptors
Inputs Start Producing Substance P
• NMDA(N-methyl-D-aspartate)
– Ion Channels Allow Entry of Ca++
52. Pain Control Mechanisms
• Peripheral
• Gating Theory
– Involves Inhibitory Inter-
Neuron in Cord
impacting Nociceptive
Projection Neurons
• Inhibited by C Fibers
• Stimulated by AAlpha &
Beta Fibers
• TENS
• Central
• Direct Electrical + to
brain → Analgesia
• Nociceptive control
Pathways Descend to
Cord
• Endogenous Opioids
53. Pain Modulation
• Examples
– Stress Analgesia
– War Situation When Person Emotionally Charged
– Pain Relieved by
• Acupressure & Acupuncture and Electrical Vibrator
• Gate Control Mechanism
– Proposed by Malzek & Wall
54.
55. Pain Control Systems
(I) Analgesic system
a) The neurons of the periaqueductal gray area are stimulated by
B endorphin reaching them from hypothalamus (neurons of
periventricular area) or pituitary (through blood).
b) Fibres of periaqueductal and interneurones of sp.cd. Secrete
(Enkephalin)
c) Fibres of raphe magnus nucleus secrete (Serotonin)
d) Inhibitory interneurones in spinal cord secrete (Enkephalin).
56.
57.
58. PAIN
• DESCENDING PAIN INHIBITING SYSTEM:
• Fibers Arise from: Peri-Aqueductal Gray matter
Peri-Ventricular Gray Matter
Hypothalamus
Medial Forebrain Bundle
Neurons around IIIrd & IV ventricle
Nucleus Reticularis in Medulla
Spinal Cord Nucleus Raphe
Magnus
Encephalins
59. PAIN
• Nucleus Raphe Magnus
• Dorsal Horn of Spinal Cord in Substantia
Gelatinosa
• Pre-Synaptic and Direct Inhibition by Blocking Ca
++ Channels
• Blocking of Pain Signals
Serotonergic
Neurons
60. • Natural Opioids-
Endorphins
•released from their storage
areas in the brain when a
pain impulse reaches the
brain,
• bind to receptors in the
pain pathway to block
transmission and perception
of pain.
65. (II) Brain Opiate System
Opiate receptors in the brain cause pre and postsynaptic
inhibition of the nociceptive pathway.
Sites of opiate receptors
1. Periaqueductal gray area
2. Periventricular aea.
3. Raphe magnus nucleus in medulla.
4. Substantia nigra.
66. Opioid peptides
(1) Enkephalins.
Act as neurotransmitters at the analgesic system.
(2) Endorphins
-In hypothalamus act as neurotransmitters.
-In pituitary act as hormone.
Release during stress leading to stress analgesia.
(3) Dynorphin
Very potent analgesic.
Types of opiate receptors
Delta, Mu, Kappa, Sigma & Epislon.
67. BRAIN OPIOID SYSTEM
• Opium
– Alkaloid
– Morphine Derived from Opium → Analgesia
– Receptors are Opioid Receptors
• Found in Many Areas of Brain
– Limbic System Hypothalamus, Peri-Ventricular Areas, Pituitary &
Spinal Cord
• Endogenous Substances which Mimic Action of
Opium → Opioid Peptides
– Brain’s Own Morphine
– Act like Neurotransmitter on Opioid Receptors
68. BRAIN OPIOID SYSTEM
• Opioid Peptides
– Beta Endorphins
• Derived from Pro-opiomelanocortin
– Met-and Leu-Encephalins
• Derived from-Proencephalins
– Dynorphin
– Derived from Prodynorphin
• Opioid Peptides Cause Pre-synaptic Inhibition
– At Spinal Cord to Block Pain
• Inhibit Release of Substance P
69. BRAIN OPIOID SYSTEM
• Cause Post Synaptic Inhibition
– Produce IPSP
• In Limbic Areas & Hypothalamus
– Pain Modulation
• Act Peripherally at Site of Injury
• Opioid Mediated Endogenous Analgesia System
→ Activated by Administration of Exogenous
Morphine
• Descending Analgesia System
– Under Tonic Inhibitory Control of Mid Brain &
Medulla
– Opiates Inhibit these Inhibitory Inter-Neurons
70.
71. (III) Gate theory
1) Spinal gate:
SGR (substantia gelatinosa of Rolandi) in layers II & III acts as gate. At
this level, there is a group of inhibitory enkephalinergic interneurons
which form the "Pain Inhibitory complex, PIC". When stimulated,
these interneurons block the transmission of pain
sensation by presynaptic inhibition of pain-conducting fibers.
72. This gate can be closed by:
Impulses from
1. A beta fibres: (rubbing of skin inhibits pain).
2. A delta fibres; counter irritant and acupuncture inhibit
pain. They stimulate cutaneous receptors which send
impulses through A delta fibres stimulate the PIC.
3. Cortico-fugal fibres: (thinking decrease pain).
All these fibers causes presynaptic inhibition of pain by
activating an interneurone which secrete (GABA).
73. 2)Thalamic gate:
The same "gating" mechanism for pain is found also at the
thalamus where
pain signals could be blocked by corticofugal fibers or
facilitated by
intralaminar thalamic nuclei. In this way,
the thalamus considered as a secondary gate far pain
transmission.
74. Stress analgesia; During stress, Pain is blocked at
two levels :
A) At the thalamus: (the second gate of pain transmission ).
Corticofugal fibers to the thalamus block by presynaptic inhibition the
transmission of pain signals in the thalamus before they reach the cerebral cortex.
B) At the dorsal horn of the spinal cord: (the first gate of pain
transmission).
The hypothalamus, and other parts of the central analgesia system, activate the
spinal PIC which blocks the transmission of pain signals at the dorsal horn.
75.
76.
77.
78. Melzack and Wall (1965, 1988) developed a comprehensive
theory of pain (‘gate-control theory’) which has generally
received wide support
• Fast ‘touch’ fibres and slow ‘pain’ fibres
connect with substantia gelatinosa (SG) and transmission cells (T
cells) in spinal cord
• T cells send pain information to the brain
• SG acts as “gate” to allow or inhibit T cells
81. Activity in fast fibers tends to close the gate (touch but
no pain) and slow fibers open the gate (pain)
A light touch accompanying a noxious stimulus partially closes
gate (reduces pain) — rub skin to alleviate pain
Psychological factors? Modify gate via descending pathway
and/or release of endogenous opiates (e.g. endorphins) in the CNS
producing analgesic effects.
Ignore pain to escape from greater danger (e.g. death!)
82. Headache
• Brain is insensitive to pain.
• Pain sensitive intracranial structure;
• (Arteries, Veins, Nerves and Dura at the base of
the brain)
• Headache is referred pain
• a. Supratenterial is referred along the
ophthalmic n ® frontal Head ache.
• b. Infratentorial is referred along Cervical 2 ®
occipital Headache.
83. Causes of intracranial headache: 5%
1. Meningeal irritation; me nin gitis ; gen eral ize d.
Br ain tum our; loca lize d.
2. Migraine headache; Abn orma l va scul ar phe nom eno
n.
3. Hypertension: He ada che a pu lse Pre ssur e.
4. Low CSF pressure: Rem oval of 20 ml of CS F.
® bra in desc ent ® tra ctio n of th e d ura & h ead ache .
5. Alcoholic headache
al coh ol pr odu ces dir ect meni nge al irrita tio n.
6. Constipation.
Ab sorp tion of tox ins pro duce s di rect me nin geal irri
tati on.
84. Causes of intracranial headache: 5%
• 1. Meningeal irritation; meningitis ; generalized.
• Brain tumour; localized.
• 2. Migraine headache; Abnorma l vascular phenomenon.
• 3. Hypertension: Headache a pulse Pressure.
• 4. Low CSF pressure: Removal of 20 ml of CSF.
• ® brain descent ® traction of the dura & headache .
• 5. Alcoholic headache
• alcohol produces direct meningeal irritation.
• 6. Constipation.
• Absorption of toxins produces direct meningeal irri tation.
85. Causes of extra-cranial headache
95%
• 1. Muscular spasm of scalp and neck
muscles due to emotions .
• 2. Irritation of the nasal sinuses.
• 3. Errors of refraction .
• 4. Otitis media.
• 5. Toothache.
86. Hyperalgia(increased pain
sensation)
• 1. primary hyperalgesia;
• It occurs in the inflammed skin due to
decreased threshold of pain receptors
• by bradykinin, K, Histamine and
prostaglandins.
• So non painful stimuli become painful.
87. Hyperalgia
Secondary hyperalgesia;
It occurs in normal skin due to increased
threshold of pain receptors. So pain receptors
need stronger stimulus, but once pain is elicited ,it is
very severe
It can be explained by (Convergence facilitation
theory).
Impulses from the injured area facilitate a central
neuron. Impulses from the area of
secondary hyperalgesia converge on same central
neuron. The convergence on a central
facilitated neuron explains the exaggerated pain
sensibility.
88. Why the threshold of pain is increased in the area of secondary
hyperalgesia.
The facilitator neuron which arises from the area of primary
hyperalgesia exerts lateral inhibition on the stimulator neuron
which arises from the area of secondary hyperalgesia.