This presentation explains the working of the ear... It is best for medical students.. It includes all the key points necessary for an exam too... So this presentation can also be used as a notes for your exams...
I have tried my level best to complete this one. Basics & subjective details as much possible, are included here with understandable diagrams, CT-scans & charts. Clinical associations with possible anatomical structures are also touched . Frequent questions based on the topic discussed, will be there at the middle & end of presentation.
If you find it helpful then please like it & if any query regarding this ppt or upcoming ppts then mail me
drsuraj1997@gmail.com
Development of the middle ear is not covered in this presentation. If you are interested then please mail me. I will try to upload it as a separate one.
Ear is the anatomical unit serving both hearing and equilibrium. Understanding of the developmental of ear and its clinical anatomy is fundamental in the learning of embryology.
I have tried my level best to complete this one. Basics & subjective details as much possible, are included here with understandable diagrams, CT-scans & charts. Clinical associations with possible anatomical structures are also touched . Frequent questions based on the topic discussed, will be there at the middle & end of presentation.
If you find it helpful then please like it & if any query regarding this ppt or upcoming ppts then mail me
drsuraj1997@gmail.com
Development of the middle ear is not covered in this presentation. If you are interested then please mail me. I will try to upload it as a separate one.
Ear is the anatomical unit serving both hearing and equilibrium. Understanding of the developmental of ear and its clinical anatomy is fundamental in the learning of embryology.
Hearing and vestibular system - simple basicsAdamBilski2
Basic physiology of hearing and vestibular system. Good for a short understanding of how it works. EDIT - SLIDE 10 is a repeated slide, shouldn't be there
The Ear:
• It is the organ that detects sound.
• It not only receives sound, but also aids in balance and body position.
• Part of the auditory system.
• Transforms sound waves (air pressure) into electrical impulses in the brain
Outer Ear:
• Includes:
• The pinna or auricle (the fleshy visible outer ear)
• The ear canal
• The outer layer of the tympanic membrane (ear drum)
Middle Ear:
• An air-filled cavity behind the tympanic membrane, includes three bones (ossicles):
• The malleus; or hammer
• Incus; or anvil
• Stapes; or stirrup
• Connects to the throat via the Eustachian tube
Inner Ear:
• Responsible for sound detection and balance
• it consists of the bony labyrinth, a hollow cavity in the skull with a system of passages comprising two main functional parts:
• The cochlea, dedicated to hearing
• The vestibular system, dedicated to balance
o The Cochlea: Auditory portion of the inner ear
o Spiral-shaped coil
o Inside the bony labyrinth
o Filled with a watery liquid
o As the fluid moves, the Organ of Corti moves
o Organ of Corti: the structure that transduces pressure waves to action potentials
o Specific fibers resonate to sound frequencies and cause Hair Cells to move, which send signals through the Cochlear Nerve onto the brain
o Louder Sounds cause more Hair Cells to move
o Our Brains interpret all this raw data
Balance (Vestibular System):
• Balance is controlled through signals to the brain from your eyes, the inner ear, and the sensory systems of the body (such as the skin, muscles, and joints).
• This balance system is also known as the vestibular system.
• In the inner ear, the balance system consists of three canals (semicircular canals)
• Semicircular shape
• contain fluid
• “sensors” that detect rotational movement of the head.
• Each canals lies at a different angle and is situated at a right angle to each other.
• deal with different movement: up-and-down, side-to-side, and tilting from one side to the other.
• All contain sensory hair cells that are activated by movement of inner ear fluid (endolymph).
• As the head moves, hair cells in the semicircular canals send nerve impulses to the brain by way of the acoustic nerve.
• The nerve impulses are processed in the brain to help us know where we are in space or if we are moving.
• Located near the semicircular canals are the utricle and the saccule.
• The ends of the semicircular canals connect with the utricle,
• the utricle connects with the saccule.
• The semicircular canals provide information about movement of the head.
• The sensory hair cells of the utricle and saccule provide information to the brain about head position when it is not moving.
• The utricle is sensitive to change in horizontal motion
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
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.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
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
Factory Supply Best Quality Pmk Oil CAS 28578–16–7 PMK Powder in Stockrebeccabio
Factory Supply Best Quality Pmk Oil CAS 28578–16–7 PMK Powder in Stock
Telegram: bmksupplier
signal: +85264872720
threema: TUD4A6YC
You can contact me on Telegram or Threema
Communicate promptly and reply
Free of customs clearance, Double Clearance 100% pass delivery to USA, Canada, Spain, Germany, Netherland, Poland, Italy, Sweden, UK, Czech Republic, Australia, Mexico, Russia, Ukraine, Kazakhstan.Door to door service
Hot Selling Organic intermediates
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Ve...kevinkariuki227
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
TEST BANK for Operations Management, 14th Edition by William J. Stevenson, Verified Chapters 1 - 19, Complete Newest Version.pdf
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.
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.
2. INTRODUCTION
• The auditory system is comprised of three components; the
outer, middle, and inner ear, all of which work together to
transfer sounds from the environment to the brain.
3. The outer ear includes the
portion of the ear that we
see—the pinna/auricle
and the ear canal.
The middle ear is
composed of the tympanic
membrane and the cavity,
which houses the
ossicular chain.
The inner ear is
composed of the sensory
organ for hearing—the
cochlea, as well as for
balance—the vestibular
system.
5. ORGAN OF CORTI
• Sense organ of hearing
• Situated in the basilar membrane
• Components are:
Tunnel of corti
Hair cells
Supporting cells
Tectorial membrane
6. • Tunnel of corti is formed by inner and
outer rods. Contains a fluid called
CORTILYMPH. exact function is
unknown
• Hair cells are important receptors of
hearing and convert sound energy to
electrical energy. Inner hair cells are
supplied with afferent cochlear fibres.
Outer hair cells mainly receive efferent
innervation from olivary complex.
• Supporting cell. Deiter’s cell are situated
between outer hair cells and provide
support. Cells of Hensen lie outside Deiters
cell.
• Tectorial membrane consist of gelatinous
matrix with delicate fibres. Overlies the
organ of corti.
Electron microscopic image of inner ear hair cell
Higher
magnification
of one of
these cells
7.
8. • Hair cells are innervated by
dendrites of bipolar cells of spiral
ganglion which is situated in
Rosenthal’s canal.
• Axons of these cells form cochlear
division of auditory nerve (CN VIII)
• The area of cortex concerned with
hearing is situated in the Superior
Temporal Gyrus (Brodmann’s area
81)
11. INTRODUCTION
• Any vibrating object causes waves of compression and rarefaction and is
capable of producing sound.
• Sound travels faster in liquids and solids than in air (roughly 344 m per
second)
• When sound energy has to pass from air to liquid, most of it is reflected
because of the impedance offered by the liquid
12. Mechanism of hearing can be broadly classified
into :
Mechanical
conduction of
sound
Transduction of
mechanical energy
into electrical
impulses
Conduction of
electrical impulses
to brain
13. • Pressure changes in
the labyrinthine fluids
move the basilar
membrane.
• This stimulates the
hair cells on the Organ
of Corti
14. You might get a doubt right now – if sound is
reflected when transferred from air to water then
how do we hear clearly through the labyrinthine
fluids?
• Nature has compensated for this loss of energy by having the middle ear
in between which converts sound of greater amplitude but lesser force
to that of lesser amplitude and greater force.
• This function of the middle ear is called impedance matching mechanism
or transformer action.
15. TRANSFORMER ACTION
• It is accomplished by:
• Lever action of the ossicles : handle of malleus is 1.3 times longer than long process of
incus.
• Hydraulic action of tympanic membrane: the area of tympanic membrane is much
larger than the area of stapes footplate. The average ratio is 21:1. The effective
vibratory area of tympanic membrane is only 2/3rd , so the effective areal ratio is
reduced to 14:1. This is the mechanical advantage provided by the tympanic
membrane.
• Curved membrane effect: movements of the tympanic membrane are more at the
periphery than at the centre.
19. PERIPHERAL RECEPTORS
• CRISTAE:
• Located in the ampullated ends of
3 semicircular ducts.
• It is a crest like mound of
connective tissue which lies on
sensory epithelial cells.
• Cilia of sensory hair cells project
into the cupula.
• Hair cells are 2 types:
• Type 1 – flask shaped with single
large nerve terminal.
• Type 2 – cylindrical with multiple
nerve terminals
• MACULAE:
• Located in the otolith organs
(utricle and saccule)
• Macula of utricle lies in its floor
in a horizontal plane
• Macula of saccule lies in its
medial wall in a vertical plane.
• Macula consists of 2 parts:
• Sensory neuroepithelium
• Otolithic membrane
20. VESTIBULAR NERVE / SCARPA’S GANGLION
• Located in the lateral part of the internal acoustic meatus
• Contains bipolar cells
• Distal processes of bipolar cells innervate sensory epithelium
• Central processes aggregate to form the vestibular nerve
21. CENTRAL VESTIBULAR CONNECTIONS
• AFFERENTS come from:
Peripheral vestibular receptors
Cerebellum
Reticular formation
Spinal cord
Contralateral vestibular nuclei
• EFFERENTS go ito:
Nuclei of CN III(optic nerve), IV
(trochlear nerve)and VI (abduscent
nerve)
Motor part of spinal cord
Cerebellum
ANS
Vestibular nuclei of opposite side
Cerebral cortex
23. Vestibular system
• The vestibular system, which contributes to balance and to the
sense of spatial orientation, is the sensory system that provides
the leading contribution about movement and sense of balance.
• Together with the cochlea it constitutes the labyrinth of the
inner ear in most mammals, situated in the vestibulum in the
inner ear
• Vestibular system is divided into:
Peripheral - made of membranous labyrinth and vestibular nerve
Central – made of nuclei and fibre tracts in CNS to integrate vestibular
impulses
24. SEMICIRCULAR CANALS
• The semicircular canal system detects rotational movements.
• The vestibular system contains three semicircular canals in each labyrinth.
• They are approximately orthogonal (right angles) to each other, and are
called
the horizontal (or lateral),
the anterior semicircular canal (or superior) and
the posterior (or inferior) semicircular canal.
Anterior and posterior canals may be collectively called vertical semicircular
canals.
25. PUSH – PULL SYSTEM
• The canals are arranged in such a way that each
canal on the left side has an almost parallel
counterpart on the right side.
• Each of these three pairs works in a push-
pull fashion: when one canal is stimulated, its
corresponding partner on the other side is
inhibited, and vice versa.
• This push-pull system makes it possible to sense
all directions of rotation
• Vertical canals are coupled in a crossed fashion,
i.e. stimulations that are excitatory for an
anterior canal are inhibitory for the posterior,
and vice versa.
26. OTOLITHIC ORGANS
• The otolithic organs sense linear accelerations.
• There are two on each side, one called utricle, the other saccule.
• These organs each contain a patch of hair cells and supporting cells called
a macula.
• Each hair cell of a macula has 40-70 stereocilia and one true cilium called
a kinocilium. The tips of these cilia are embedded in a otolithic membrane.
• Any orientation of the head causes a combination of stimulation to the
utricles and saccules of the two ears.
• The brain interprets head orientation by comparing these inputs to each
other and to other input from the eyes and stretch receptors in the neck,
thereby detecting whether the head is tilted or the entire body is tipping.