A Simple Guide to the Ear and Its Disorders, Diagnosis, Treatment and Related Conditions

A

Simple

Guide

To

The Ear and Its Disorders,

Diagnosis,

Treatment

And

Related Conditions

By

Dr Kenneth Kee

M.B.,B.S. (Singapore)

Ph.D (Healthcare Administration)

Copyright Kenneth Kee 2021 Smashwords Edition

Published by Kenneth Kee at Smashwords.com

Dedication

This book is dedicated

To my wife Dorothy

And my children

Carolyn, Grace

And Kelvin

This book describes The Ear and Its Disorders, Diagnosis and Treatment and Related Diseases which is seen in some of my patients in my Family Clinic.

(What You Need to Treat The Ear and Its Disorders)

This e-Book is licensed for your personal enjoyment only. This eBook may not be re-sold or given away to other people. If you would like to share this book with another person, please purchase an additional copy for each reader.

If you’re reading this book and did not purchase it, or it was not purchased for your use only, then please return to Smashwords.com and purchase your own copy.

Thank you for respecting the hard work of this author.

Introduction

I have been writing medical articles for my blog: http://kennethkee.blogspot.com (A Simple Guide to Medical Disorder) for the benefit of my patients since 2007.

My purpose in writing these simple guides was for the health education of my patients.

Health Education was also my dissertation for my Ph.D (Healthcare Administration).

I then wrote an autobiography account of my journey as a medical student to family doctor on my other blog: http://afamilydoctorstale.blogspot.com.

This autobiography account A Family Doctor’s Tale was combined with my early A Simple Guide to Medical Disorders into a new Wordpress Blog A Family Doctor’s Tale on http://kenkee481.wordpress.com.

From which many free articles from the blog was taken and put together into 800 eBooks.

Some people have complained that the simple guides are too simple.

For their information they are made simple in order to educate the patients.

The later books go into more details of medical disorders.

The first chapter is always from my earlier blogs which unfortunately tends to have typos and spelling mistakes.

Since 2013, I have tried to improve my spelling and writing.

As I tried to bring the patient the latest information about a disorder or illness by reading the latest journals both online and offline, I find that I am learning more and improving on my own medical knowledge in diagnosis and treatment for my patients.

My diagnosis and treatment capability has improved tremendously from my continued education.

Just by writing all these simple guides I find that I have learned a lot from your reviews (good or bad), criticism and advice.

I am sorry for the repetitions in these simple guides as the second chapters onwards have new information as compared to my first chapter taken from my blog.

I also find repetition definitely help me and maybe some readers to remember the facts in the books more easily.

I apologize if these repetitions are irritating to some readers.

Chapter 1

The Ear

The ear is an organ of hearing and balance for the human body.

The ear can be separated into three parts: external, middle and inner.

Each part has its own important function and disorders.

The external ear can be separated functionally and structurally into two parts:

1. The auricle (or pinna), and

2. The external acoustic meatus – which stops at the eardrum or tympanic membrane.

Auricle

The auricle (most visible part of the outer ear) is a paired structure on either side of the head.

It functions to:

1. Protect the inner ear and

2. Capture and channel sound waves towards the external acoustic meatus.

It is made up of a mostly cartilaginous structure, with the lobule (the flesh part) being the only part not strengthened by cartilage.

The cartilaginous part of the auricle shapes an outer curvature, termed the helix.

The antihelix is the second innermost curvature runs parallel to the helix.

The antihelix separates into two cura:

1. The inferoanterior crus, and

2. The superoposterior crus.

In the middle of the auricle is a hollow depression, termed the concha.

It enters the skull as the external acoustic meatus.

The concha functions to channel sound into the external acoustic meatus.

In front of the beginning of the external acoustic meatus is a raised cartilaginous tissue (the tragus).

Directly opposing the tragus is the antitragus.

External Acoustic Meatus

The external acoustic meatus (ear canal) is a curved shaped tube lined with hairs and glands that secrete wax that extends from the deep part of the concha to the tympanic membrane.

The walls of the external third of the ear canal are formed by cartilage while the inner two thirds are formed by the temporal bone.

The external acoustic meatus is not straight and instead travels in an S-shaped curve:

1. In the beginning it travels in a superoanterior direction.

2. It then turns slightly to move superoposteriorly.

3. It finishes by running in an inferoanterior direction.

Tympanic Membrane

The tympanic membrane is present at the distal end of the external acoustic meatus.

It is a connective tissue membrane covered with skin externally and a mucous membrane inside.

The tympanic membrane is connected to the enclosing temporal bone by a fibrocartilaginous ring.

The translucency of the tympanic membrane permits the structures within the middle ear to be seen during otoscopy using an auroscope.

On the inner surface of the membrane, the handle of malleus is attached to the tympanic membrane, at a location termed the umbo of tympanic membrane.

The handle of malleus travels superiorly, and at its highest point, a small projection called the lateral process of the malleus can be observed.

The parts of the tympanic membrane moving away from the lateral process are termed:

1. The anterior malleolar fold and

2. Posterior malleolar fold.

Blood supply

The external ear is provided with blood from the branches of the external carotid artery:

1. Posterior auricular artery

2. Superficial temporal artery

3. Occipital artery

4. Maxillary artery (deep auricular branch) – supplies the deep aspect of the external acoustic meatus and tympanic membrane only.

The venous drainage is through veins that follow the arteries above.

Nerve Supply

The sensory innervation to the skin of the auricle arises from different nerves:

1. Greater auricular nerve (branch of the cervical plexus) innervates the skin of the auricle

2. Lesser occipital nerve (branch of the cervical plexus) innervates the skin of the auricle

3. Auriculotemporal nerve (branch of the mandibular nerve) innervates the skin of the auricle and external auditory meatus.

4. Branches of the facial and vagus nerves innervates the deeper aspect of the auricle and external auditory meatus

Some people may develop an involuntary cough when cleaning their ears.

This is caused by the stimulation of the auricular branch of the vagus nerve (the vagus nerve is also responsible for the cough reflex).

Lymphatic supply

The lymphatic vessels of the external ear drain to the superficial parotid, mastoid, upper deep cervical and superficial cervical nodes.

The middle ear

The middle ear is located within the temporal bone, and extends from the tympanic membrane to the lateral wall of the inner ear.

The main function of the middle ear is to send out vibrations from the tympanic membrane to the inner ear through the auditory ossicles.

The middle ear can be separated into two parts:

1. Tympanic cavity sited medially to the tympanic membrane.

It has three tiny bones termed the auditory ossicles: the malleus, incus and stapes.

They send out sound vibrations through the middle ear.

2. Epitympanic recess (space superior to the tympanic cavity, next to the mastoid air cells.

The malleus and incus partly extend upwards into the epitympanic recess.

Borders

The middle ear can be observed as a rectangular box, with a roof and floor, medial and lateral walls and anterior and posterior walls.

1. Roof formed by a thin bone from the petrous part of the temporal bone.

It divides the middle ear from the middle cranial fossa.

2. Floor – termed the jugular wall, it comprises a thin layer of bone, which separates the middle ear from the internal jugular vein

3. Lateral wall – formed by the tympanic membrane and the lateral wall of the epitympanic recess.

4. Medial wall – formed by the lateral wall of the internal ear

It has a prominent bulge, formed by the facial nerve as it travels nearby.

5. Anterior wall – a thin bony plate with 2 openings; for the auditory tube and the tensor tympani muscle.

It divides the middle ear from the internal carotid artery.

6. Posterior wall (mastoid wall) – it comprises a bony partition between the tympanic cavity and the mastoid air cells.

Superiorly, there is a hole in this partition, permitting the 2 areas to communicate.

This hole is termed the aditus to the mastoid antrum.

Bones

The bones of the middle ear are the auditory ossicles which comprises the malleus, incus and stapes.

They are attached in a chain-like fashion, joining the tympanic membrane to the oval window of the internal ear.

Sound vibrations produce a movement in the tympanic membrane which then transmits movement, or oscillation, in the auditory ossicles.

This oscillation helps to transfer the sound waves from the tympanic membrane of external ear to the oval window of the internal ear.

The malleus is the largest and most lateral of the ear bones, binding to the tympanic membrane, through the handle of malleus.

The head of the malleus is sited in the epitympanic recess, where it moves with the next auditory ossicle, the incus.

The