This document provides an overview of the anatomy of the ear and mastoid. It is divided into three main sections - external ear, middle ear, and inner ear. The external ear includes the pinna and external auditory canal. The middle ear contains the tympanic membrane, ossicles, and mastoid air cells. The inner ear is made up of the bony and membranous labyrinth housing the cochlea and vestibular system. Key structures like the Eustachian tube, oval window, and organ of Corti are also described along with their functions in hearing and balance.
Slides were prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Deviated nasal septum and other septal conditionskrishnakoirala4
Slides prepared by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate MBBS students in the field of otorhinolaryngology. A clear and concise explanation of the basic concepts in the subject matter concerned.
Slides were prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Deviated nasal septum and other septal conditionskrishnakoirala4
Slides prepared by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate MBBS students in the field of otorhinolaryngology. A clear and concise explanation of the basic concepts in the subject matter concerned.
Allergic rhinitis is a very much prevalent condition in the community. This presentation hopes to spread a ray of hope in treating allergic and intrinsic rhinitis.
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.
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Spaces of middle ear and their surgical importanceDr Soumya Singh
one of the imp topics in ENT that should be understood very thoroughly if u want to pursue as an otologist.I tried to simplify the topic with simple diagrams and models for better understanding .
Infratemporal fossa a systematic approachAugustine raj
infratemporal fossa is a irregular space with numerous neurovascular structures. an attempt has been made by me to decode all the boundaries and structures in a systematic way. sincere thanks to Dr. Viren Karia for his awesome video.
Keratosis obturans is a very painful condition of the ear. It is caused due to excessive accumulation of the keratin debris in the bony external canal probably due to faulty migration of the epithelium.
This presentation aims to explain the definition, etiology, clinical features and treatment of keratosis obturans.
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
Allergic rhinitis is a very much prevalent condition in the community. This presentation hopes to spread a ray of hope in treating allergic and intrinsic rhinitis.
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.
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Spaces of middle ear and their surgical importanceDr Soumya Singh
one of the imp topics in ENT that should be understood very thoroughly if u want to pursue as an otologist.I tried to simplify the topic with simple diagrams and models for better understanding .
Infratemporal fossa a systematic approachAugustine raj
infratemporal fossa is a irregular space with numerous neurovascular structures. an attempt has been made by me to decode all the boundaries and structures in a systematic way. sincere thanks to Dr. Viren Karia for his awesome video.
Keratosis obturans is a very painful condition of the ear. It is caused due to excessive accumulation of the keratin debris in the bony external canal probably due to faulty migration of the epithelium.
This presentation aims to explain the definition, etiology, clinical features and treatment of keratosis obturans.
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
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.
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal, for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Acute suppurative otitis media and and cortical mastoidectomykrishnakoirala4
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal, for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal, for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal, for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal, for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students.
This presentation gives a lucid idea about different neoplasms of nose like inverted papilloma, ca maxilla, ethmoid and so on.
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students.
Epistaxis is one of the commonly encountered problem in day to day life by the otolaryngologists. Most of the times, it is mild , but sometimes, it is very difficult to manage and there may be mortality, too.
This presentation gives a lucid idea of causes of epistaxis, emergency treatment options and operative treatment of epistaxis, too.
Deviated nasal septum and other septal conditionskrishnakoirala4
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Clinical features and diagnosis of rhinosinusitiskrishnakoirala4
Slides prepared and compiled by highly experienced ENT teacher, Dr. Krishna Koirala from Nepal , for teaching undergraduate and postgraduate ENT students in the field of otorhinolaryngology.
A clear and concise explanation of the basic concepts in the subject matter concerned.
He is the Head of department with a sound knowledge in the field of ENT to teach both undergraduate and postgraduate ENT students
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
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
Basavarajeeyam is a Sreshta Sangraha grantha (Compiled book ), written by Neelkanta kotturu Basavaraja Virachita. It contains 25 Prakaranas, First 24 Chapters related to Rogas& 25th to Rasadravyas.
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Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
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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.
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
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.
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
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journey
1. anatomy of ear and mastoid
1. Anatomy of ear and
mastoid
Dr. Krishna Koirala
2018/07/03
2. • Paired sensory organs comprising of
– Auditory system involved in the detection of sound
– Vestibular system involved in maintaining body
balance and equilibrium
• Divided anatomically and functionally into
– External ear
– Middle ear
– Inner ear
• All three regions are involved in hearing
• Inner ear is involved in body balance and equilibrium
5. Pinna
• Framework formed by yellow elastic cartilage except
in the lobule and incissura terminalis
• Functions
– Collect and direct sound waves through the ear
canal to the tympanic membrane
– Protect the tympanic membrane
• Importance : Graft material for middle ear & other
reconstructive surgeries
6. Helix: Slightly curved rim of the auricle
Antihelix: Broader curved eminence anterior to helix
Concha : Deep cavity in front of the helix
Cymba conchae : Depression between the antitragus
and ascending crus of the helix (surface landmark of
mastoid antrum)
Tragus
Lobule : Structure made up of areolar tissue & fat
without cartilage
7.
8. Sensory Nerve supply of pinna
• Lateral surface
– Upper 2/3 : Auriculotemporal nerve (cranial nerve V)
– Lower 1/3 : Greater auricular nerve (C2,3)
• Medial Surface
– Upper 1/3: Lesser occipital nerve (C2)
– Lower 2/3 : Greater auricular nerve (C2, 3)
• Posterior concha and antihelix : Auricular b/o Vagus
• Facial : Small region at the root of concha
10. • Extends from bottom of concha to the tympanic
Membrane
• 24 mm long in adults
– Lateral 1/3 (8 mm) : Cartilaginous, directed
upwards, backward and medially
– Medial 2/3 (16 mm) : Bony, directed downwards,
forward and medially
• Pinna to be pulled upwards, backwards and laterally
to straighten the external auditory canal in adults
11. Only cartilaginous skin has hair follicles,
ceruminous and pilosebaceous glands (wax)
Cartilaginous fissure of Santorini and bony
foramen of Huschke present in anterior wall
infection / metastasis to and from the parotid
gland
16. Tympanic Membrane
• Partition between the external and middle ear
• Obliquely set with 550 to floor
• Dimension: 10 mm x 8 mm x 0.1 mm
• Parts
– Pars Tensa
– Pars Flaccida (Shrapnel's membrane)
18. • Landmarks of TM
– Lateral process of malleus
– Anterior and posterior
malleal folds
– Handle of malleus
– Umbo
– Cone of light
– Annulus tympanicus
19. • Layers of tympanic membrane
1) Outer layer of squamous epithelium continuous
with that of the meatus
2) Middle layer of fibrous tissue that has radial and
circular fibres
3) Inner layer of mucous membrane continuous with
the lining of the tympanic cavity
• Fibrous layer disorganized in pars flaccida
• Annulus deficient superiorly as notch of Rivinus
21. Borders of middle ear cavity
• Roof : Tegmen tympani
• Floor : Separates tympanic cavity from jugular bulb
• Medial wall
− Promontory : Bulge formed by basal turn of cochlea
− Oval window : Communicates between middle ear and the
vestibule of the inner ear, closed by footplate of stapes
− Round window : Communicates between scala tympani and
tympanic cavity, covered by secondary tympanic membrane
22.
23.
24. • Lateral wall
− Largely by TM
− Scutum (outer attic wall)
− Bone inferior to TM
• Anterior wall
− Thin plate of bone
− Openings of canal for tensor tympani and
Eustachian tube
• Posterior wall
− Separates middle ear cavity from mastoid bone
− Contains aditus ,pyramid
25. The mastoid antrum and air cell system
Mastoid antrum : Largest and most consistent air cell of
mastoid air cell system, well developed at birth
Relations
Roof : Part of floor of MCF
Floor : Digastric muscle, sigmoid sinus
Posterior : Bony covering of sigmoid sinus
Lateral : Squamous temporal bone (corresponds to
suprameatal or Macewan’s triangle and Cymba conchae)
26. Mac Ewan’s Triangle (Suprameatal triangle)
• Boundaries
− Superior : Posterior prolongation of upper border of root of
zygoma ( Supramastoid crest)
− Anterioroinferior : Posterosuperior margin of bony external
meatus
− Posteroinferior : Vertical tangent drawn through the
posterior margin of bony external meatus to the first line
• Contains spine of Henle
• Surgical landmark for mastoid antrum (Mastoid antrum lies 12-
15 mm deep to triangle)
27.
28. Mastoid air cell system
Extensive system of interconnecting air filled cavities arising
from walls of mastoid antrum that extend throughout the
mastoid
Lined with flattened non ciliated squamous epithelium
Types
− Cellular ( pneumatized) : Honeycomb appearance on
plain X-Ray mastoid
− Diploic : Air cells interspersed with marrow containing
spaces
− Acellular (sclerotic)
32. Lies in the petrous temporal bone
Divisions
Bony labyrinth
Membranous labyrinth
33. Bony labyrinth ( Vestibule, Semicircular canals ,
Bony cochlea)
Vestibule
Central portion of bony labyrinth, ovoid in shape
Oval window at the lateral wall, utricle and saccule
in the medial
Openings of SCC (5) - lie on posterior, superior and
inferior walls of bony vestibule
34.
35. Semicircular canals (3)
Lie in planes at right angles to each other
Ampullated and non ampullated ends
Ampullated ends contain vestibular sensory
epithelium and independently open into the
vestibule
36. Bony cochlea
Coiled tube like the shell of a snail, contains
2 ½ to 2 ¾ turns
Height around 5mm,base around 9 mm in
diameter
Coils turn around the modiolus - extends along
the entire length of cochlea except for
helicotrema ( small channel at the apex)
37. Three compartments
Scala vestibuli
Scala tympani
Scala media (membranous cochlea)
Within the modiolus lie spiral ganglion
Cochlear nerve lies within the bony modiolus
throughout the entire length
38. Membranous labyrinth
Membranous cochlea
− Triangular in cross section
− Bordered by Reissner's membrane, Basilar
membrane and stria vascularis
Utricle and saccule
Semicircular ducts
Endolymphatic ducts and sac
39.
40. Organ of Corti
Sense organ of hearing
Situated on the basilar membrane
Components
− Tunnel of Corti
− Hair cells ( outer and inner)
− Supporting cells (Deiter's,
− Hansen's)
− Tectorial membrane
41.
42. Differences between inner and outer hair cells
Inner Hair Cells Outer Hair Cells
3500 12,000
Single row Three or four rows
Flask-shaped Cylindrical
Primarily afferent Primarily efferent
Transmit auditory stimuli Modulate inner hair cell
Resistant to damage Vulnerable to damage