24
THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear.

THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

Embed Size (px)

DESCRIPTION

The Middle Ear: Tympanic Membrane (Ear drum):a membrane that closes off entry into the middle ear; vibrates when sound waves reach it.

Citation preview

Page 1: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

THE EARis a sensory organ responsible for both hearing and maintenance of balancecomposed of three sections: the outer, middle and inner ear.

Page 2: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

The Outer Ear:The Pinna: the outer flap that funnels sound towards the auditory canalAuditory Canal: a tube that carries sound towards the eardrum, it contains wax secreting cells; the wax traps dust etc.

Page 3: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

The Middle Ear:Tympanic Membrane (Ear drum):a membrane that closes off entry into the middle ear; vibrates when sound waves reach it.

Page 4: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

Ossicles: three small bones (Hammer, anvil and stirrup) that amplify the sound vibrations from the ear drum and carry them to the oval window.

Page 5: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

Oval Window: a small membrane that seperates the middle from the inner ear. Transmits vibrations from the ossicles to the inner ear.

Page 6: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

Eustachian Tube: a tube that connects the middle ear with the throat; used to equalize pressure between the atmosphere and the middle ear.

Page 7: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

The Inner Ear:Vestibule: contains two small sacs called the Utricle and Saccule, aid in establishing head position. (Static Equilibrium)

Page 8: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

Semicircular Canals: 3 tubes arranged at different angles, filled with a fluid that helps in establishing body position (Dynamic Equilibrium)

Page 9: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

Cochlea: a snail shaped organ containing a fluid and specialized hair cells that move when vibrations from the oval window occur. The hair cells respond differently to sound waves of different frequencies and intensities.

Page 10: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

Auditory Nerve: transmits information to the brain from the inner ear on balance and sound.

Page 11: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

STEPS INVOLVED IN HEARING

sound is a form of energy that travels in wavesit is the movement of these waves that initiates the hearing process:

Page 12: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

1.When sound waves reach your ear; they push against the tympanic membrane causing it to vibrate.2. The vibrations are transferred to the ossicles; which concentrate and amplify the sound.

Page 13: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

3. The vibrations from the last bone, the stirrup, cause the movement of the Oval Window inwards4. The movement of the window initiates movement of a fluid found within the Cochlea.

Page 14: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

5. This fluid movement stimulates the Basilar Membrane of the Organ of Corti; the technical name given to the hearing apparatus in the Cochlea.

Page 15: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

6. Attached to the basilar membrane are Hair Cells that will bend in response to the stimulation.

Page 16: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

7. The bending hair cells stimulate sensory neurons that transmit the information through the Auditory Nerve to the Temporal Lobe of the Cerebrum.

Page 17: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

Different Hair cells have different threshold levels that will depolarize depending on the frequency or intensity of the sound.

Page 18: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

Maintenance of Balance

two components to balance:

Page 19: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

1. Static Equilibrium:balance involving the position or movement of the head.head position is determined by the two fluid filled sacs (Utricle and Saccule) found in the vestibule.

Page 20: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

in the fluid are suspended particles called OTOLITHS.when the head moves, the otoliths moves; this causes movement of the hair cells that line the interior of the sacs

Page 21: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

the hair cells stimulate sensory neurons that carry information to the brain, through the auditory nerve, regarding head position

Page 22: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

2. Dynamic Equilibrium

balance involving the movement of the bodyinvolves the movement of the fluid found in the SEMICIRCULAR CANALS

Page 23: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

when we move, the fluid moves causing the movement of hair cells that line the canals.

Page 24: THE EAR is a sensory organ responsible for both hearing and maintenance of balance composed of three sections: the outer, middle and inner ear

when the hair cells move, they stimulate sensory neurons which will carry information regarding body position to the brain through the auditory nerve.