The document provides an extensive overview of the anatomy and physiology of the ear, detailing its structure, functions, and components including the external, middle, and inner ear. It discusses the roles of various parts like ossicles, tympanic membrane, eustachian tube, cochlea, and components responsible for balance and hearing. Additionally, it covers the clinical aspects and pressure regulation in relation to ear sensitivity during altitude changes.

1. ANATOMY AND PHYSIOLOGY OF
EAR
SAGAR MADIVAL
4TH
YEAR BAMS
NKJAMC

2. Karna
• Definition :
• Indriya which is not seen with naked eye along with shashkuli
( hole / coiled ) is called karna.
• Synonym- shotra
• Origin : karn is originated from aakash mahabhuta.
• Karna sharira:
• Charka stated that karnendriya adhishthana exhibits 2 parts
i.e, 2 karnashashkuli ,
2karnaputraka.
• Chakrapani stated that karnashashkuli is karnagata avarta and
karnaputraka is bahyakarna.
• Karnashashkuli is that part which resembles avarta.
• Sushruta included bahya karna in 9 bahirmukha shrotas.

3. Contents
• Asthi :1 asthi.
• 1 taruna asthi.
• Sandhi : 1 sandhi.
• Peshi :2 peshi present in ear
• Sira : 10 siras
• 4 vatavaha sira. 2 pittavaha sira
• 2 kaphavaha sira. 2 raktavaha sira.
• Dhamani : 2 dhamani that convey shabda.
• Marma : 2 marma
• Vidhura marma
• Shringataka marma.

4. INTRODUCTION AND DEFINITION
• Ear is the organ of hearing
• It is mainly divided into 3 parts :
• EXTERNAL EAR
• MIDDLE EAR
• INTERNAL EAR
• It is also concerned with maintaining of
equilibrium of the body

5. ANATOMY OF EXTERNAL EAR
• It contains the following
The auricle or pinna
The external acoustic meatus

6. Auricle
• It is a flap of elastic cartilage
• It is covered by skin
• It is the opening of the external auditory canal

7. External auditory canal
• It is the passage and it extends up to the ear
drum
• It is 2.5 cm in length
• At the anterior end It contains glands and
hairs
• Gland –ceruminous gland which secrete the
ear wax

8. BLOOD SUPPLY OF EXTERNAL EAR

9. Nerve and lymphatic
• NERVE SUPPLY –Auriculotemporal nerve
• LYMPHATICS – PREAURICULAR
• POST AURICULAR
• CERVICAL LYMPH NODES

10. ANATOMY OF MIDDLE EAR
• It is a small air filled cavity in the temporal bone
• It is also lined by the epithelium
• It is separated by the inner ear by the oval
window
• Contains: ossicles
• oval window
• Eustachian tube
• tympanic membrane

11. AUDITORY OSSICLES
• THE MALLEUS
• THE INCUS
• THE STAPES
• Above mentioned bones are the smallest
bones in the body
• These are connected by the synovial joints

12. OSSICLES

13. MALLEUS
• In latin malleus is called as hammer so
because if it the name is given as malleus
• It resembles as the shape of hammer
• It is the largest among the ossicles
• It articulates with the body of the incus

14. Incus
• It looks like the anvil which are used by the
blacksmith
• It also resembles like the molar teeth .
• It has ;
• Body
• Long process
• Short process
• Lentiform process

15. Stapes
• It is shaped as stirrup
• It is the smallest of the ear ossicles
• It contains ;
• Two limbs :anterior and posterior
• Head
• Neck
• Base

17. Oval window
• It is the intersection between the middle ear
and the inner ear
• It is a membrane cover that leads to vestibule
part of inner ear
• When the sounds reach the oval window the
sound that is travelled is amplified by 10times

18. Tympanic membrane
• It is thin translucent partition between the
external and middle ear
• It is oval in shape
• Dimensions =9x10mm
• It is placed obliquely at an angle of 55 degree
with the floor
• It is held inward pull by the muscle tensor
tympani which is further inserted into the
malleus

19. .
• It is covered by the simple cuboidal epithelium

20. Eustachian tube
• It is the air filled cavity
• It consist of bony and hyaline cartilage
• It connects middle ear to the nasopharnyx
• It is normally closed at the pharyngeal end
• It maintains the pressure on each side
• If there is disturbed pressure then it affects
with the hearing

21. Oval window and eustachian tube

22. Blood supply
• Maxillary artery
• Auricular artery
• Meningial artery
• Pharyngeal artery
• Internal carotid artery

23. LYMPHATIC SUPPLY :
PREAURICULAR AND RETROPHARYNGEAL
NERVE SUPPLY :Glossopharyngeal nerve
caroticotympanic nerve

24. Inner ear

25. Inner ear
• It is also called as labyrinth
• It has two mains division
• outer bony labyrinth
• inner membranous labyrinth
REAL IMAGE

26. OUTER BONY LABYRINTH
• It is a series of cavity in the temporal bone
• It is divided into three regions
• Cochlea
• Vestibule
• 3 Semicircular canals
Bony labyrinth is lined by the periosteum and
contains the perilymph which is similar to the CSF

27. Bony labyrinth
cochlea

28. INNER MEMBRANOUS LABYRINTH
• It is a series of sacs and tubes inside the bony
labyrinth
• It is lined by the epithelium
• It contains the endolymph
• Here the pottasium level is high because it will
generate the auditory signals
• It consists of :
• Utricle
• Saccule

29. Membranous labyrinth

30. .
• Blood supply :labyrinthine branch of basilar
artery
• Nerve supply :vestibulocochlear nerve

31. Clinical anatomy
• Acoustic neuroma is the tumor of schwan cells
of 8 th nerve
• Why do we feel the clogged sensation in the
ear when we are in the plane or underwater
or specially if there is altitude change ?

32. Answer
• It happens because the difference between the
pressure on the outside and inside we know
that when we are in the higher or the lower
altitude there will be the pressure difference
• It can be managed by maintaining the pressure
which can be done by stimulating the
eustachian tube
• Keep making the mouth movements by eating
and drinking

33. Physiology of ear
• External ear :collecting and conveying the
sound waves
• To protect against the pathogens by producing
the ear wax
• To filter out the dust and unwanted substance
entering the ear

34. Ear canal
• * Once the sound waves have passed the
pinna, they move two to three
centimeters into the auditory canal
before hitting the eardrum, also known
as tympanic membrane. The function of
ear canal is to transmit sound from pinna
to the eardrum.

35. Ear drum
• ➤ Ear drum is the end point of the external
ear.
• ➤The eardrum is extremely sensitive and
pressure from sound wave makes the ear
drum vibrate.
• ➤The auditory canal is slightly curved in order
to protect the eardrum and also it
automatically amplifies low and less
penetrating sound of human voice.

36. Physiology of middle ear
• Amplifying the sound waves by the bones of
middle ear
• Conveying the sounds energy to the internal
ear through the bones
• Maintaining the pressure on both the sides
via eustachian tube which connects the
middle ear to the pharynx

37. Middle ear
• Ossicles will amplify the sounds
• THE OVAL WINDOW :
• ➤The main function of the oval window is to
amplify the sound before they move to inner ear.
• THE ROUND WINDOW:
• ➤It allows fluid in the cochlea to move
EUSTACHIAN TUBE:
• ➤The function of Eustachian tube is to equalize
the air pressure inside and outside the ear.

38. Inner ear
• To maintain the balance or the posture of the
body it helps in walking dancing and all other
activities
• To convert the sound which is reached to
inner ear by through middle ear into
electrical signals
• To send the electrical signal to the auditory
area in the brain via nerves

39. Inner ear
• COCHLEA: The cochlea resembles a snail which is
filled with fluid. When the fluid moves inside the
cochlea, thousands of microscopic hair fibers comes
in motion. The hair fibers send auditory nerve which
is connected to the auditory center of the brain.
• In cochlea sound waves are transformed into
electrical impulses which are sent to brains The
brain then translates the impulses into sound that
we know and understand

40. Bony labyrinth
cochlea

41. Organ of corti
Scala media
Endolymph

42. Mechanism

43. The pathway of hearing
• Auditory Pathway Flowchart
• Action potential generated in the cochlea
• ↓
• Mid Pons (superior olive)
• ↓
• Pons-midbrain junction (lateral lemniscus)
• ↓
• Caudal midbrain (inferior colliculus)
• ↓
• Rostral midbrain (medial geniculate complex of the
thalamus)
• ↓
• Primary auditory cortex

44. Mechanism of hearing

45. Balance
Semicircular organ
Otholith organ

46. Mechanism
Semicircular canals one for the up down and
one for side ways and other for the right and
left movements
The otolith organ which has the saccule and
utricle are involved in the head positioning
Both the organs have stereo cilia which move
according to the position of head and sends
the signal to the brain

47. Semicircular canals
Nodding the head up and down

48. Side ways movements

49. Left and right movements

50. Utricle and saccule
• Utricle that is sensitive to the horizontal
motion we can see that in the car motion
• Saccule is sensitive to the vertical motion we
can observe it in elevator
• Some actions are dealt by combination of
both the Saccule and utricle

51. THANK YOU