This document discusses several theories of hearing:
1. Helmholtz's resonance theory proposes that cochlear structures act as resonators tuned to specific frequencies.
2. Place theory suggests every tone is assigned to a specific place on the basilar membrane.
3. Traveling wave theory describes how vibrations travel along the basilar membrane from base to apex.
4. Resonance-volley theory combines aspects of place and volley theories to explain high and low frequency perception.
The document also outlines hypotheses for hair cell transduction and how frequency analysis occurs in the cochlea, with low frequencies detected at the apical end and high frequencies at the basal end.
Audiometry for Undergraduate and postgraduate ENT students Dr Krishna Koirala
Audiometry is one of the essential topic in MBBS.
This presentation helps students to learn about basic audiometry for MBBS level and shall equally be useful for postgraduate ENT students, too.
Audiometry for Undergraduate and postgraduate ENT students Dr Krishna Koirala
Audiometry is one of the essential topic in MBBS.
This presentation helps students to learn about basic audiometry for MBBS level and shall equally be useful for postgraduate ENT students, too.
ECochG is a variant of brainstem audio evoked response (ABR) where the recording electrode is placed as close as practical to the cochlea. We will use the abbreviation ECOG and ECochG interchangeably below. ECOG is preferable to us as it is shorter.
ECOG is intended to diagnose Meniere's disease, and particular, hydrops (swelling of the inner ear). ECOG may also be abnormal in perilymph fistula, and in superior canal dehiscence. The common feature connecting these illnesses is an imbalance in pressure between the endolymphatic and perilymphatic compartment of the inner ear.
ECOG can also be used to show that the cochlea is normal, in persons who are deaf. The cochlear microphonic of ECOG may be normal in auditory neuropathy (Santarelli and Arslan 2002) as well as other disorders in which the cochlea is preserved but the auditory nerve is damaged (Yokoyama, Nishida et al. 1999).
Finally, ECOG's have also been used to as a indicator of the temporary threshold shift that may follow noise injury (Nam et al, 2004).
ECochG is a variant of brainstem audio evoked response (ABR) where the recording electrode is placed as close as practical to the cochlea. We will use the abbreviation ECOG and ECochG interchangeably below. ECOG is preferable to us as it is shorter.
ECOG is intended to diagnose Meniere's disease, and particular, hydrops (swelling of the inner ear). ECOG may also be abnormal in perilymph fistula, and in superior canal dehiscence. The common feature connecting these illnesses is an imbalance in pressure between the endolymphatic and perilymphatic compartment of the inner ear.
ECOG can also be used to show that the cochlea is normal, in persons who are deaf. The cochlear microphonic of ECOG may be normal in auditory neuropathy (Santarelli and Arslan 2002) as well as other disorders in which the cochlea is preserved but the auditory nerve is damaged (Yokoyama, Nishida et al. 1999).
Finally, ECOG's have also been used to as a indicator of the temporary threshold shift that may follow noise injury (Nam et al, 2004).
Auditory brainstem responses are generated by the
activity in structures of the ascending auditory
pathways that occurs during the first 8–10 ms
after a transient sound such as a click sound has
been applied to the ear.
Physiology of ear.
Basic definition related to sound -hearing,sound,sound wave.
mechanism of hearing
mechanical conduction of sound
transfer action of middle ear
impedence
areal ratio/ hydraulic lever
lever ratio of ossicles
catenary lever
transduction of mechanical energy
travelling wave theory of Bekesy
sound propagation in cochlea
electrical conduction of sound
central auditory pathway
acoustic reflex
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
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
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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!
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
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
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.
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
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
2. THEORIES OF HEARING
Precise means of hearing remains unknown
Most theories attempt to explain how we perceive pitch
Hearing theories:
Helmholtz's resonance theory
Place theory
Traveling wave theory
Frequency theory
Resonance-volley theory
3. Helmholtz's Resonance Hearing Theory
Cochlear structures consists of many tiny resonators
Each tuned to a specific frequency
The ear performs a Fourier analysis; breaking each complex sound
into its components
Each resonator responded most vigorously to its tuned frequency with
less amplitude to adjacent frequencies
Propose the placement of high frequency fibers at the basal end of
the cochlea and lower frequencies near the apex
4. Place Theory of Hearing
Every tone that could be heard was assigned to its own specific
place in the cochlea (i.e. piano keys)
Assumes that there is neural representation for every place on
the basilar membrane
Good in explaining some phenomenon (i.e. masking & sharp
pitch discrimination)
Explains loudness in terms of amplitude of movement of BM
A loud sound creates greater amplitude than a softer sound
Greater amplitude increases the number of impulses transmitted
by the nerve fibers
Drawbacks: didn’t explain why pitch discrimination is very poor
close to auditory threshold
Unacceptable hearing theory
5. Traveling Wave Theory
Each inward and outward movement of footplate of the stapes,
there is a downward and upward movement of the BM
Produced by the disturbance of endolymph
The wave moves down the cochlear duct from base to apex with
the max. amplitude for HF tones occurring at the basal end and that
for the LFs at the apical end
HFs excite only fibers in the basal turn of the cochlea
LFs excite fibers all along the BM
Frequency determines:
The distance of the motion of traveling wave
The rate of BM vibration (related to frequency & period)
6. Frequency Hearing Theory
Analysis happens in a retrocochelar area
Auditory nerve transmits a pattern that corresponds directly with
the input signal
Explain loudness in terms of the amount of spread along the BM
The greater the amplitude of the input signal, the larger the surface
area of BM stimulated
i.e. 100 Hz tone make the auditory nerve fires 100 times per sec
But the auditory nerve can fire up to about 400 times per sec, the
theory doesn’t explain the perception of tones above this frequency
7. Volley Theory of Hearing
A series of impulses is sent along the auditory nerve
The sum represents a reproduction of the vibrations of the BM
During the refractory (rest) period of one set of neurons,
another set is actively firing
Explains only frequencies up to 4000 Hz
8. Resonance Volley Theory of Hearing
Combines the two following theories:
Place theory suggests spatial representation and explains HF perception
Volley theory suggests temporal dimension and explains LF interpretation
9. HYPOTHESIS FOR HAIR CELL
TRANSDUCTION
Mechanical motion of hair cells (Shearing); converting a sound
source into a form of energy that can be transmitted by the auditory
Nerve
A. Mechanical Hypothesis: the pressure that moves the hair cells
stimulates the nerve endings directly
B. Chemical Hypothesis: the hair cells are deformed, a
neurotransmitter substance is released that stimulates the nerve
endings
C. Electrical Hypothesis: cochlear potential stimulates the nerve
endings
10. FREQUENCY ANALYSIS IN THE
COCHLEA
Lowest frequencies (about 20 Hz) → apical end of cochlea
2000 Hz to 20,000 Hz → from midpoint of BM to the basal end of
cochlea near the OW
Below 2000 Hz → on the other half of the BM
Why human ears have excellent frequency discrimination
capabilities?
Auditory N fibers are sharply tuned to specific frequencies
Characteristic Frequency /Best Frequency: Frequency that can
increase the firing rate of a neuron above its spontaneous firing rate
11. Psychophysical tuning curve (PTC)
Created to study the tuning mechanism of cochlea
Used to measure cochlear frequency resolving abilities
Tuning becomes sharper (narrower bandwidth) as frequency is
increased (traveling wave peaks closer to the basal turn)
Less sharply tuned than the auditory nerve
The slope of tuning curve is much steeper above the stimulating
frequency than below it
When the PTC is widened in damaged ears, this can explain speech
discrimination difficulties those pts. have
12.
13.
14. VESTIBULAR SYSTEM
This system regulates balance.
It is also within the inner ear.
SEMI-CIRCULAR CANALS (Three of them, all in
different planes) determine movement in three
planes.
Within each semi-circular canal is endolymph and
hair cells, which connect to nerves that go to the
cerebellum.
15. When you move in one direction, like sliding
across the room, the fluid slashes like a cup of
coffee, and it makes the hair cells move.