The ear can be divided into three main sections:
1. The outer ear collects sound waves and directs them to the eardrum.
2. The middle ear contains three small bones that amplify vibrations and transmit them to the inner ear. It also contains two muscles and two nerves.
3. The inner ear contains the cochlea for hearing and semicircular canals for balance. Within the cochlea is the organ of Corti which contains hair cells that transduce sound vibrations into nerve signals.
Anatomy 1-The anatomy and physiology of human earFatima Aftab
how human ear enables us to produce sound waves and how we actually interpret them.I got a grade hope students will be clarifying their basic concepts related to anatomy of the human ear.
Provides a detailed description of the gross anatomy of the ear for undergraduate medical students; i.e. parts of the ear, structures found, their blood supply, their innervation, developmental origins & their functions. It also includes examples of common disorders associated with those parts.
Anatomy 1-The anatomy and physiology of human earFatima Aftab
how human ear enables us to produce sound waves and how we actually interpret them.I got a grade hope students will be clarifying their basic concepts related to anatomy of the human ear.
Provides a detailed description of the gross anatomy of the ear for undergraduate medical students; i.e. parts of the ear, structures found, their blood supply, their innervation, developmental origins & their functions. It also includes examples of common disorders associated with those parts.
Anatomy of ear and mastoid is a must know topic for undergraduate and postgraduate ENT students. In this lecture, Dr Krishna Koirala will be explaining about the anatomy of ear and mastoid in a clear and simplified way.
Anatomy of ear for undergraduate students ( MBBS ) .
Basic anatomy of ear with its clinical importance
nerve supply of ear
blood supply of ear
middle ear ossicles
malleus incus stapes
muscles of middle ear
mastoid air cells
pinna tympanic membrane
lymphatics of ear
walls of middle ear
organ of corti
middle ear cleft
facial recess
sinus tympani
chorda tympani
embryology of ear
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
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
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
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 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
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
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 simplified slides by Dr. Sidra Arshad present an overview of the non-respiratory functions of the respiratory tract.
Learning objectives:
1. Enlist the non-respiratory functions of the respiratory tract
2. Briefly explain how these functions are carried out
3. Discuss the significance of dead space
4. Differentiate between minute ventilation and alveolar ventilation
5. Describe the cough and sneeze reflexes
Study Resources:
1. Chapter 39, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 34, Ganong’s Review of Medical Physiology, 26th edition
3. Chapter 17, Human Physiology by Lauralee Sherwood, 9th edition
4. Non-respiratory functions of the lungs https://academic.oup.com/bjaed/article/13/3/98/278874
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.
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
4. OUTER EAR
Its functions
Collects sound
Localization
Resonator
Protection
Sensitive (earlobe)
• It has Three main parts:
Pinna (auricle), External
Auditory Meatus and eardrum
(tympanic membrane)
5. Pinna(auricle)
The visible portion that is commonly referred to
as "the ear" ,It consists of cartilage and skin
Helps localize sound sources and directs them
towards the external auditory meatus and on to
the tympanic membrane
• Lymphatics; drain into parotid group, upper
deep cervical and mastoid lymph nodes
• Veins; drain into external jugular, common facial
vein
• Arteries; posterior auricular branch of external
carotid artery, anterior auricular branch of
superficial temporal and a branch of occipital
6. Auriculotemporal nerve (CN V3): It is a
branch of mandibular division of trigeminal
nerve and supplies anterosuperior part of lateral
surface of pinna including tragusand crus of
helix.
CN VII (facial nerve): It innervates the skin of
lateral concha and antihelix, lobule and
mastoid.
CN X (vagus nerve): Its auricular branch
(Arnold’s nerve) supplies to concha and post
auricular skin.
Greater auricular nerve (C2,3): This nerve of
cervical plexus supplies most of the medial
surface of auricle and posterior part of lateral
surface and the postauricular region.
Lesser occipital nerve (C2): This nerve of
cervical plexus supplies upper part of medial
surface of auricle and postauricular region.
Nerve supply
7. Is a curved tube about 2.5cm that lies in the temporal bone and leads from the
auricle to the eardrum (tympanic membrane)
Near to the exterior of its opening there is a few hairs and specialized
sebaceous (oil) glands called ceruminous glands that secrete cerumen (earwax)
The combination of hairs and cerumen help prevent dust and foreign objects
from entering the ear and cleaning mechanism of ear
NERVE SUPLY
(i) Anterior wall and roof: auriculotemporal (V3) supplies anterosuperior wall
of external auditory canal
(ii) Posterior wall and floor: auricular branch of vagus nerve (CNX) supplies to
infer posterior external auditory canal.
Posterior wall of the auditory canal also receives sensory fibres of cranial N VII
(facial nerve) through auricular branch of vagus.
External Auditory Meatus
8. Eardrum(tympanic membrane)
It is a thin, semitransparent partition between the external auditory canal and
middle ear.
It has two parts :(a) Pars Tensa:
It forms most of tympanic membrane..
Its periphery is thickened to form a fibro cartilaginous ring called the
annulus tympanicus which fits in the tympanic sulcus.
The central part is tented inwards at the level of the tip of malleus and is
called the umbo.
(b) Pars Flaccida (Shrapnel's Membrane)
• This is situated above the lateral process of malleus between the notch of
Rivinus and the anterior and posterior malleolar folds.
It has three layers:
(i) Outer epithelial layer, which is continuous with the skin lining the
meatus. no hairs and glands
(ii) Middle fibrous layer, which encloses the handle of malleus and has three
types of fibres-the radial, circular and the parabolic.
(iii) Inner mucosal layer, which is continuous with the mucosa of the middle
ear
9. 1. Malleus 2,6
2. Anterior mallear fold
3. Post mallear fold
4. Pars flaccida
5. projection of long process of
incus.
6. Pars tensa
7. Annular ligament.
Tympanic membrane
NERVE SUPPLY
(i) Anterior half of lateral surface:
auriculotemporal(V 3)
(ii) Posterior half of lateral surface: auricular
branch of vagus nerve (CN X) (Arnold’s nerve)
(iii) Medial surface: Tympanic branch of CN
IX glossopharyngeal nerve (Jacobson's nerve).
10. MIDDLE EAR
It has two main parts:
Auditory ossicles
(transmit and amplify sound
from the tympanic membrane
to the oval window)
Auditory (eustachian)
tube (equalizes pressure on
both sides of the tympanic
membrane).
11. MIDDLE EAR
The middle ear together with the Eustachian tube,
aditus, antrum and mastoid air cells is called the
middle ear cleft.
its lined with mucous membrane and filled with
air.
Aditus and Antrum: Aditus is an opening through
which the attic communicates with the antrum.
The Mastoid and its Air Cell System: The
mastoid consists of bone cortex with a
"honeycomb“ of air cells underneath.
Depending on development of air cell, three types
of mastoid have been described: Well-pneumatised
or cellular; Diploetic; Sclerotic or acellular
It is divided into:
I. Mesotympanum (lying opposite to parsa
tensa).
II. Epitmpanum or attic (lying above parsa
tensa but medial to shrapnel's membrane and
the bony lateral attic wall)
III. Hypotympanum (lying below the level of
parca tensa).
13. BOUNDARIES OF MIDDLE EAR
Roof (Tegmental Wall): is formed by a thin plate of bone called tegmen tympani.
Floor (Jugular Wall): is also thin plate of bone which separates tympanic cavity from
the jugular bulb
Anterior (Carotid Wall): has a thin plate of bone which separates the cavity from
internal carotid artery. has following features: Eustachian tube, Canal of tensor
tympani muscle, Canal for chorda tympani nerve, Attachment of anterior malleolar
ligament
Posterior (Mastoid Wall):lies close to the mastoid air cells. Has:
Pyramid, Aditus ad antrum, Facial nerve
Medial (Labyrinthine Wall):is formed by labyrinth (including promontory, Round
window, oval window).
Lateral wall: is formed largely by tympanic membrane.
14. Auditory ossicles
– Malleus
• Attaches to ear drum
• Articulates with incus
– Incus
• Articulates with stapes
– Stapes (stirrup)
• Footplate of stapes fits into oval
window
Ossicles Allows communication
between the external and internal ear
and amplification
15. MIDDLE EAR MUSCLES
There are two middle ear muscles also
called intratympanic muscle (tensor
tympani and the stapedius).
1. Tensor tympani: It runs above the
eustachian tube. Originate from Bony
tunnel above the osseous part of
eustachian tube. inserted Just below the
neck of malleus and is supplied by a
branch of mandibular division of
trigeminal nerve (CN V3)
2. Stapedius: On contraction it reduces
the loud sounds and
prevents noise trauma to the inner ear.
Originate from Conical cavity and canal
within pyramid. it insert to the neck
stapes and supplied by a branch of CN
VII (nerve to stapedius of facial nerve).
16. Auditory (eustachian) tube
• It consists of both of both bone and hyaline cartilage
and connects the middle ear with the nasopharynx.it is
normally closed at its medial (pharyngeal) end; during
swallowing and yawning, it opens then atmospheric
pressure from throat enters or leaves the middle ear
until internal pressure is equal to external pressure.
• When the pressures are balanced, the eardrum vibrates
freely as soundwaves strike it
• It is also a route where pathogens can travel from throat
and nose to the middle ear
17. NERVE SUPPLY:
• tympanic plexus which is formed by 1) tympanic branch of
glossopharyngeal nerve and 2) sympathetic fibers from the plexus round
the internal carotid artery.
• Tympanic plexus supplies innervation to the medial surface of the
tympanic membrane, tympanic cavity, mastoid air cells and the bony
Eustachian tube. It also carries secretomotor fibres for the parotid gland.
• Chorda Tympani Nerve: It is a branch of the facial nerve which enters
the middle ear through posterior canaliculus, and runs on the medial
surface of the tympanic membrane between the handle of malleus and
long process of incus, above the attachment of tendon of tensor tympani. It
carries taste from anterior two-thirds of tongue and supplies secretomotor
fibres to the submaxillary and sublingual salivary glands.
18. Blood supply:
Middle ear is supplied by six arteries, out of which two are the main,
i.e.
(i) Anterior tympanic branch of maxillary artery which supplies
tympanic membrane.
(ii) Stylomastoid branch of posterior auricular artery which supplies
middle ear and mastoid air cells.
venous Drainage
Veins from the middle ear cleft drain into pterygoid venous plexus,
Superior petrosal sinus and sigmoid sinus.
Lymphatic drainage of ear
The lymphatics of middle ear drain into retropharyngeal and parotid
nodes. Eustachian tube lymphatics drain into retropharyngeal group of
lymph nodes. Internal ear does not have any lymphatics.
19. SUMMARY
Middle ear contains:
1. Air
2. Two muscles (Tensor tympani and stapedius)
3. Two nerves (corda tympani and tympanic plexus on the promontory)
4. 3 bone (maleus, incus, stapes)
Mucosa of middle ear is stratified columnar with goblet and seromucinous glands
Its function:
Conduction
– Conduct sound from the outer ear to the inner ear
Protection
– Creates a barrier that protects the middle and inner areas from foreign objects
– Middle ear muscles may provide protection from loud sounds
Transducer
– Converts acoustic energy to mechanical energy
– Converts mechanical energy to hydraulic energy
Amplifier
– Transformer action of the middle ear
– only about 1/1000 of the acoustic energy in air would be transmitted to the inner-ear
fluids (about 30 dB hearing loss)
20. INNER EAR
The internal ear or the labyrinth is an important
organ of hearing and balance. It consists of a
bony and a membranous labyrinth.
The membranous labyrinth is filled with a clear
fluid called endolymph while the space between
membranous and bony labyrinths is filled with
perilymph.
Bony labyrinth: It consists of
i. the vestibule,
ii. the semi-circular canals and
iii. the cochlea.
Membranous labyrinth: consists of
i. The membranous cochlear duct
ii. The membranous semi-circular canals.
iii. The utricle and saccule (that lie within the
vestibule)
iv. The endolymphatic duct and sac
21. A. Cochlear part
it is fluid filled organ.
it is bony coiled up on axis like
a snail’s shell (central pyramid called
modiolus)
Its basal turn forms the promontory.
It has three compartment
a. Scala vestibule
b. Scala tympani
Above 2 are filled with perilymph and
communicate with each other at apex of cochlea through Helicotrema
c. Scala media(cochlear duct): its blind coiled tube and it appears triangular on cross-
section and its three wall are formed by:
i. basilar membrane which supports the organ of corti (inner, outer hair cells and
tectorial mem)
ii. The Reisner's membrane which separate it from Scala vestibuli,
iii. The stria vasculars which contains vascular epithelium and is concerned with
secretion of endolymph.
22.
23. B) Vestibular part:
- its bony cavity that lodges the utricle and saccule.
- it contains the sensory organs responsible for equilibrium = maculae (responsible for linear
acceleration)
C) Semi-circular canals (SCC):
they are not complete circles, the have one ampullary and one non-ampullary ends.
Oriented as superior, lateral, posterior canals with 90 degree relation to each other.
Sensory organs are crista ampullaris (which is responsible for angular acceleration).
3) the vestibular nerve:
Superior and inferior vestibular nerve arise from the sensory organs of SCC and utricle and
saccule to enter the internal acoustic canal.
24. Membranous labyrinth
Cochlear Duct (Membranous Cochlea or Scala Media) This blind coiled tube,
which appears triangular on cross-section, is connected to the saccule through
ductus reunions
Saccule: The saccule lies anterior to the utricle opposite the stapes footplate in
the bony vestibule. Its sensory epithelium, macula responds to linear acceleration
and
deceleration. The saccule is connected to the cochlea through the thin reunion
duct
Semicircular Ducts: The three semicircular ducts, which open in the utricle,
correspond exactly to the three bony canals
Endolymphatic Duct and Sac: The ducts from utricle and saccule unite and form
utriculosaccular duct, which continues as endolymphatic duct that passes through
the vestibular aqueduct
Endolymphatic sac is thought to regulate pressure of membranous labyrinth.
Endolymphatic sac is decompressed, drained or shunt in Meniere’s disease
25. INNER EAR FLUIDS
Perilymph fills the space between bony and membranous labyrinth while endolymph
fills the entire membranous labyrinth.
Perilymph
It resembles extracellular fluid and is rich in sodium ions.
Originate from Filtrate of blood serum from the capillaries of spiral ligament and CSF
reaching labyrinth via aqueduct of cochlea.
Endolymph
It resembles intracellular fluid and is rich in potassium ions Protein and glucose
contents are less than in perilymph.
„originate from Stria vascularis and Dark cells of utricle and ampullated ends of
semicircular ducts.
26. This sensory organ of the hearing, is situated on the basilar membrane. It is spread like a ribbon
along the entire length of basilar membrane. It consists of: 1. Tunnel of Corti: This tunnel, which
is situated between the inner and outer rods, contains a fluid called cortilymph. The functions of
the rods and cortilymph are yet not clear.
2. Hair Cells: hese important receptor cells of hearing transduce sound energy into electrical
energy. There are two types of hair cells—inner and outer.
ORGAN OF CORTI
27. REFERENCE
1,Harold Ludman and Patrick J Bradley 2007 Ear, Nose and Throat
Fifth Edition
2,Mohan Bansal 2013 Diseases of Ear, Nose and Throat First edition
published by jaypee brothers medical; New Delhi in India
3, Ghada M W F. Ear Anatomy. Glob J Otolaryngol 2017