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| The Anatomy and physiology of the ear diseases |
The Anatomy and physiology of the ear diseases
The human anatomy and physiology of the ear are divided into three parts, namely the outer, middle, and inner ear. The Anatomy and physiology of the ear eyes are the same the anatomy of the ear as wide and deep and require deep studies. The outer ear consists of the pinna and the external auditory meatus. The middle ear is made up of the eardrum also called the A tyr-panum, and a chain of three bones connected and called the ossicles. These three ossicles are the malleus, incus, and stapes. They are also called the hammer, anvil, and stirrup. The bones are at a right angle to each other. below are the types of the human ear anatomy
- Tensortympanic Utriculus
- Incus
- Malleus
- Muscule
- Sacculus
- Stapes
- Semicircular Canals
- Ampulla
- Auditory
- nerve
- Hoa
- Pinna
- Cochlea
- Tympanic Eustachian
- Membrane
- Fenestra ovalis
- External
- tubers pharynx (oval window)
- auditory meatus
- Stapedius
- Fenestra rotunda
- muscle (Round window).
The mammalian ear structure
The middle ear is connected to the pharynx by the eustachian tube. Through this connection, the pressure in the middle ear is equalized. The inner ear is made up of two very important structures – three, and a snail shell-shaped canal called the Cochlea. These structures loop canals called the semicircular canal with utriculus and sacculus, are called the membranous labyrinth, and are surrounded by a fluid called perilymph. The semi-circular canals and cochlea have their inside filled with another fluid called the endolymph.
Mechanism of Hearing:
The sound wave is directed into the ear by the pinna. As the vibrating then transmitted to the ossicle. The ossicles act as a lever and magnify the sound hit the tympanic membrane there is further vibration. This is the sound wave at the end of the stapes. The stapes vibrate against the oral window, and thus set up a vibration in the perilymph. This then passes to the cochlea, The vibration is therefore passed to the endolymph and from here to the organ of Corti. From the organ of the Corti, nervous impulses are passed through the auditory nerve to the brain. The brain interprets it and sends it back to the ear and hearing is affected.
The function of the ear
- Hearing as already discussed.
- Balance: The semicircular canals are sensitive to changes in the direction of movement. The sacculus and utriculus are sensitive to changes in the position of the head.
Signs and symptoms of the ear disease
- Earache.
- Vertigo.
- Discharge.
- Deafness.
- Tinnitus.
Causes of earache
There are Otogenic and non-otogenic Causes: Otogenic causes are as follows:
- Wax.
- Otitis Media.
- Boil.
- Eustachian Tube Obstruction.
Non-Otogenl. Causes:
- Sinusitis.
- Tonsilitis.
- Arthritis of Tempora-Mandibular Joint (TMJ)
- Carious Molar Tooth.
- Cancer of the Tongue.
Wax
This is a thick oily fluid in the ear. It may be soft or hard. Soft wax is removed with a probe covered by cotton wool (cotton board). Hard wax is removed using a 10% solution of soap in water.
Foreign body in the ear
Except for organic foreign bodies, all other foreign bodies are removed by syringing, Organic foreign bodies such as peanut swell during syringing making it difficult for them to come out.
Suppurative otitis media
This may be acute or chronic. In this condition, the large air containing space of the ear lined with mucous membrane is inflamed.
CAUSES:-
1. May result from secondary disease of the nasopharynx.
2. Inflamed adenoid.
3. Mucopus from a sinus.
The predisposing factor especially in children is measles. The organisms commonly implicated are staphylococcus, streptococcus, and pneumococcus.
CLINICAL FEATURES
(a) Ear Ache.
(c) Malaria and fever in the early stage.
(b) Suppuration discharge. (d) Deafness when chronic.
INVESTIGATION
Ear swab for microscopy, culture, and sensitivity.
TREATMENT
1. Analgesics.
3. Eardrop
2. Antibiotics based on the laboratory report. 4. Aural toilet.
It fails to resolve, then the patient is referred to the Ear, Nose, and Throat (ENT) department for expert management in the ENT department, further treatment includes myringotomy and Grommet insertion.
COMPLICATIONS
- Failure to resolve.
- Rapid reoccurrence after treatment
- Deafness may be temporary or permanent.
- Spread to other structures such as Mastoid, Facial Nerve, Sinus, and the Cranium
