The retina develops from the optic cup during gestation. By 6 weeks, the retinal pigment epithelium and neurosensory retina have formed from the outer and inner layers of the optic cup. Between 4-12 weeks, the neurosensory retina differentiates into its layers. By birth, the retina has formed its layers - photoreceptor layer, plexiform layers, nuclear layers, ganglion cell layer and nerve fiber layer. The fovea develops later between 5-8 months. The retina has distinct topography with the optic disc, macula and peripheral regions having different thicknesses and cell densities to perform specialized functions like high acuity vision.
The tear film constitutes Three layers :- An outermost lipid (oily) layer An aqueous (watery) layer that makes up 90% of the tear film volume; and A mucin layer that coats the corneal surface.
3. To form smooth optical surface on cornea. To keep the surface of cornea & conjunctiva moist It serve as lubricant It transfer oxygen Provide antibacterial action Wash debris out It provides a pathway for WBC in case of injury
4. Functions of lipid layer Retards evaporation of tear film Prevents the overflow of tears
5. Function of Aqueous Layer Flushes, buffers and lubricates the corneal surface Delivers oxygen and other nutrients to the corneal surface Wash out debris Delivers antibacterial enzymes and antibodies such as lysozyme.
6. Functions of Mucin Layer Spreads tears over corneal surface. Protects the cornea against foreign substances . Makes corneal surface smooth by filling in surface irregularities
The tear film constitutes Three layers :- An outermost lipid (oily) layer An aqueous (watery) layer that makes up 90% of the tear film volume; and A mucin layer that coats the corneal surface.
3. To form smooth optical surface on cornea. To keep the surface of cornea & conjunctiva moist It serve as lubricant It transfer oxygen Provide antibacterial action Wash debris out It provides a pathway for WBC in case of injury
4. Functions of lipid layer Retards evaporation of tear film Prevents the overflow of tears
5. Function of Aqueous Layer Flushes, buffers and lubricates the corneal surface Delivers oxygen and other nutrients to the corneal surface Wash out debris Delivers antibacterial enzymes and antibodies such as lysozyme.
6. Functions of Mucin Layer Spreads tears over corneal surface. Protects the cornea against foreign substances . Makes corneal surface smooth by filling in surface irregularities
Retina : an overview
Seminar Presentation include Anatomy, Physiology, Pathology, Medical management and surgical management of retinal diseases and also latest updates. The Seminar was written and posted by famous ophthalmologist--
Dr Niraj Kumar Yadav
MBBS, MS Ophthalmology
FICM, FID, NDEP Liverpool UK
The retina is the sensory membrane that lines the inner surface of the back of the eyeball. It's composed of several layers, including one that contains specialized cells called photoreceptors.
Photoreceptor cells take light focused by the cornea and lens and convert it into chemical and nervous signals which are transported to visual centers in the brain by way of the optic nerve.
In the visual cortex of the brain (which, ironically, is located in the back of the brain), these signals are converted into images and visual perceptions.
The retina is a thin layer of tissue that lines the back of the eye on the inside. It is located near the optic nerve. The purpose of the retina is to receive light that the lens has focused, convert the light into neural signals, and send these signals on to the brain for visual recognition.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
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.
Anti ulcer drugs and their Advance pharmacology ||
Anti-ulcer drugs are medications used to prevent and treat ulcers in the stomach and upper part of the small intestine (duodenal ulcers). These ulcers are often caused by an imbalance between stomach acid and the mucosal lining, which protects the stomach lining.
||Scope: Overview of various classes of anti-ulcer drugs, their mechanisms of action, indications, side effects, and clinical considerations.
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
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
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
HOT NEW PRODUCT! BIG SALES FAST SHIPPING NOW FROM CHINA!! EU KU DB BK substit...GL Anaacs
Contact us if you are interested:
Email / Skype : kefaya1771@gmail.com
Threema: PXHY5PDH
New BATCH Ku !!! MUCH IN DEMAND FAST SALE EVERY BATCH HAPPY GOOD EFFECT BIG BATCH !
Contact me on Threema or skype to start big business!!
Hot-sale products:
NEW HOT EUTYLONE WHITE CRYSTAL!!
5cl-adba precursor (semi finished )
5cl-adba raw materials
ADBB precursor (semi finished )
ADBB raw materials
APVP powder
5fadb/4f-adb
Jwh018 / Jwh210
Eutylone crystal
Protonitazene (hydrochloride) CAS: 119276-01-6
Flubrotizolam CAS: 57801-95-3
Metonitazene CAS: 14680-51-4
Payment terms: Western Union,MoneyGram,Bitcoin or USDT.
Deliver Time: Usually 7-15days
Shipping method: FedEx, TNT, DHL,UPS etc.Our deliveries are 100% safe, fast, reliable and discreet.
Samples will be sent for your evaluation!If you are interested in, please contact me, let's talk details.
We specializes in exporting high quality Research chemical, medical intermediate, Pharmaceutical chemicals and so on. Products are exported to USA, Canada, France, Korea, Japan,Russia, Southeast Asia and other countries.
5. RPE:
Origin: cells of outer wall of optic cup
Start: around 6th wk of gestation
specific: posterior part forms RPE
comprises: initially mitotically active pseudostratified col
ciliated epith---melanogenesis starts---cilia disappears
this mitotic activity ceases by birth
final modelling: finally growth of the eye & RPE itself
accommodated by hypertrophy of existing cells
shape: hexagonal
size: homogenous
6. Neurosensory retina:
origin:inner wall of optic cup—single layered epithelium
epithelium-- with an internal & external basement membrane.
Gestational clock:
4th-5th week: the primitive retina arranged in 2 zones
outer primitive zone –filled with 8-9 rows of nuclei
inner marginal zone– devoid of nuclei
6th- 7th week : neuroepithelial cells divide by mitosis
Inner neuroblastic:--ganglion cells, muller’s cells,amacrine cells
Outer neuroblastic:--rods & cones,bipolar cells,horizontal cells.
(This is separated by transient fibre layer of
CHIEVITZ)
7. At 10.5 wks: Zone where the process of cells from the inner
neuroblastic layer intermingle(Inner plexiform layer).
Outer nuclear layer: this is formed by the remaining components
of outer neuroblastic layer.
External limiting membrane:It is identifiable in the early stages
as rows of tight junctions.
DIFFERENTIATION STARTS BY 6th WK.
Recognizable by 5.5 months
macula: delayed upo to 8 months of gestation.
9. TOPOGRAPHY :-
• Retina proper is- thin
-delicate layer of nervous tissue
-- surface area of 266 mm2
LANDMARKS: 1. optic disc
2.area centralis
3.the peripheral retina : (equator+ora serrata)
4. retinal blood vessel
Retina is thickest near the optic disc (0.56 mm )
thinner towards periphery
equator—0.18 mm, ora serrata– 0.1mm
10. The OPTIC DISC:-
SHAPE: circular to oval
SIZE: 1.5 mm in diameter
CENTRALLY: a depression k/as
physiological cup
Size depends on:
--course of OPTIC NERVE
--glial & connective tissue
--anatomical arrangement of retinal &
choroidal vessels.
11. AREA CENTRALIS
• FOVEA :
PARAFOVEAL(0.5mm)
PERIFOVEAL(1.5mm)
• FOVEOLA
• LOCATION: post.fundus temporal to
Optic disc
• SHAPE:elliptical horizontally
• SIZE:5.5 mm & corresponds to 15’ of
visual field
• Function: adapted for diurnal variation
& colour discrimination.
12. THE FOVEA
• Approx the center of the area centralis
• 4 mm temporal to the O.D
• 1.85 mm in diameter & corresponds to
5’ visual field
• 0.25mm in thickness
• At the center the layers thinned out –
central concave indentation—
foveola—downward sloping border
which meets the floor of foveal pit
k/as clivus.
THE FOVEOLA
• 0.35 mm in diameter
• 0.13mm in thickness
• Area of highest VA
• Appears deep red in colour than
the adjacent retina because of rich
choroidal circulation
• Colour appears cherry red spot.
13. THE MACULA LUTEA
• SHAPE& COLOUR-- oval zone of
yellow colouration within the
central retina
• The yellow colour is derived from
the presence of the carotenoid
pigment,xanthophyll in the
ganglion & bipolar cells.
14.
15. Peripheral retina:Increases the field of vision
• Near periphery: 1.5 mm around the
area centralis.
• Mid periphery:3 mm around the
near periphery.
• Far periphery:in the horizontal
meridian this region xtends 9-10
mm on the temporal side 16 mm on
the nasal side from the O.D.
• ORA SERRATA:- most anterior region of
the retina,consist of dentate fringe,which
denotes the termination of retina.
• 2.1 mm wide temporally
• 0.7-0.8 mm wide nasally
• From the limbus:6.0 mm nasally
7.0 mm temporally
17. RPE: RETINAL PIGMENT EPITHELIUM
It is to be a continuous brown sheet from optic nerve to the ora serrata.
Grossly more pigmented in the macular region than ora serrata.
Structure: single layer of approx. 5 million cells firmly attached to its basal
lamina.
Size & shape: 4-8 sides & give the appearance of cobblestones,hexagonal
total no from 4.2 to 6.1 million.
Area centralis:12-18µm width & 10-14 µm height.
RPE is attached firmly to bruch’s membrane &loosely attached to layer of
rods & cones.
18. FUNCTIONS OF RPE….
• Important role in photoreceptor
renewal & recycling of vit A.
• It transport nutrients &
metabolites trough the blood
retinal barrier.
• RPE have a phagocytic action.
• These cells provides mechanical
support.
• They manufacture pigment which
presumably has an optical
function.
• Rods shed disc at dawn
• Cones shed at dusk
• Melanin granules: spindle shaped
1 µm in diameter & 2-3 µm long
are abundant at the apex of RPE
• Dihydroxyphenylalanine---
melanin (tyrosinase)
19. BRUCH MEMBRANE:
The basal portion of RPE is attached
to it
which has 4-5 layers
inner to outer:
--BM of the RPE(0.3µ)
--Inner collagenous layer(1.5µ)
--middle layer of elastic fibres(0.8µ)
--outer collagenous layer(0.7µ)
--BM of the endothelium of the
choriocapillaries(0.1µ)
20. LAYER OF “RODS & CONES”(PHOTORECEPTORS): These are the end organs
of vision which transform light energy into visual impulse.
Rods :betw 77.9& 107.3 million
Avg 92 million
Rod free area at the fovea is
0.35mm which is 1.25’ VF
Nasal retina has 20-25%
visual pigments give scotopic
vision.
Cones :betw 4.08 to 5.29 million
Avg 4.6 million
Its density is max. at fovea 199000
mm2
Nasal retin ahas 40-45%
Visual pigments give photopic
vision & colour vision.
21. Structure of photoreceptors:
• Rod: 40-60 µm long
• Outer segment:cylindrical,disc stacked one on other
n.o of disc varies 600-1000/ rod,22.5-24.5nm in thkn
• Inner segment:thicker than the outer segment
Ellipsoid:is adjacent to its OS & contains abundant
n.o of mitochondria
Myoid: contains glycogen
• outer rod fibre: arises from inner end of rod,which
passes through ELM--swells into nucleus –rod
granule(ONL)—terminates as inner rod fibre(OML)
22. Structure of photoreceptors:
• Cones:40-80µm long largest at fovea nd
shortest at periphery
• Outer segment : conical, iodopsin,discs are
narrower 1000-1200discs/cone
• Inner sgment : it is the same as rods only the
ellipsoid is more plump nd contains more
mitochondria.
• Inner segment: directly continues with its
nucleus & lies in ONL, --a stout cone fibre
runs from the nucleus at its end provided
with cone foot (OPL)
23. EXTERNAL LIMITING MEMBRANE:
• Appearance : fenestrated membrane from OS to the edge of OD
through this passes the processes of the rods & cones
electron micro: ELM is formed by junction between the cell memb of photoreceptors nd
muller’s cell.
THIS IS NOT A BASEMENT MEMBRANE.
OUTER NUCLEAR LAYER
Primarily formed by the nuclei of rods & cones
Cone nuclei(6-7µm) rod nuclei(5.5µm)---lie in a single layer next to ELM
Rod nuclei forms the bulk xcept in the foveal region
It varies at places
Nasal to disc: 45µm thick ,8-9 layers of nuclei
Temporal to disc: 22 µm thick , 4 rows of nuclei
Foveal region :50 µm , 10 rows of nuclei
24. OUTER PLEXIFORM
LAYER:A.K.A Henle’s layer
Thickest at macula 51µm.
Mainly consist of oblique fibres that
have deviated from fovea
contains;synapses of rod spherules &
cone pedicles
This layer marks the junction of th
end organs of vision & first order
neurons of retina.
25. Inner nuclear layer:
resembles: outer nuclear layer
absent : at fovea
contents: bipolar cells,horizontal cells,amacrine
cells,soma of mullers cells,capillaries of central retinal
vessels.
26. Bipolar cells
• Neurons of first order of vision.
• Consist: entirely nucleus & in the
INL.
• Dendrites arborize with the rod
spherules & cone pedicles in the
OPL their axons arborize with the
dendrites of ganglionin the IPL.
• Nine types of bipolar cells.
Amacrine cells
• Situation: at the innermost part of
INlayer
• Shape:piriform body & a single
process which passes to IPL.
• Forms connection with axons of
bipolar cells & the dendrites &
soma of the cells.
27. Muller’s cell:
location: nucleus & cell bodies in the inner nuclear layer.
Outer ends:extend to ext. limiting memb.
Inner ends: reach up to the int. limiting memb.
Function: structural support & contribute to the metabolism of
the sensory retina.
28. Inner plexiform layer
• Layer consists of synapses between
the axons of bipolar cells (1st order
neurons)
• Mullers cell are present in this
• This layer is absent at the foveola.
Ganglion cell layer
• The cell bodies & the nuclei lie in this
layer(2nd order neuron)
• This layer is composed of a single row of
cells xcept at macular region where it is
multi-layered & on the temporal side it
is 2 layered.
• This layer is absent in foveola.
29. Nerve fibre Layer
• Layer consist of the unmyelinated
axons of the ganglion cells which
converge at ONH.
• Passes through lamina cribrosa&
become ensheathed by myelin
post to lamina.
Internal limiting membrane
• This is true basement membrane.
• The fibrils of vitreous merge with
internal lamellae of this layer.
• It consists of 4 elements:
• Collagen fibrils
• Proteoglycans
• Basement membrane
• Plasma memebrane of the muller
cells& possibly other glial cells
30. BLOOD RETINAL BARRIER
• INNER & OUTER TYPE
• FUNC: TO MAINTAIN RETINAL HOSTATIS
• OUTER BRB: AT RPE FROM CHOROID TO THE SUB RETINAL SPACE
INNER BBB:INNER REINAL MICROVASCULATURE
• THE FREE FLOW OF FLOW OF FLUIDS & SOLUTES ARE PROHIBITED FROM THE
VASCULAR LUMEN INTO THE REINAL INTERSTITIUM.
• THE ENDO. CELLS ARE CLOSELY BOUND TOGETHER ABOUT THE LUMEN BY
INTERCELLULAR JUNCTIONS OF ZONA OCCLUDENS TYPE.