Special Senses- Ear

Question 1

Ear provides input for 2 senses

Answer 1

1. Equilibrium- informs us of position of body in space by monitoring gravity, linear acceleration and rotation
2. Hearing- enables us to detect and interpret sound waves

Question 2

Regions of war

Answer 2

3

Question 3

External ear

Answer 3

Gathers sound

Ear drum out- pinna, external auditory canal, ten panic membrane

Question 4

Middle ear

Answer 4

Produces sound- behind eardrum ( ossicles- malleus, incus, stapes)

Question 5

Inner ear

Answer 5

Interprets sound- within occipital bone

Question 6

Outer

Pinba

Answer 6

MAde of cartlidge and skin and shaped like a funnel

Collects and directs sound into ear canal

Question 7

Outer

External auditory canal

Answer 7

Tunnel that begins at external and extends inward towRd ear drum, lined with hairs

Question 8

Outer

Tempanic membrane

Answer 8

Eardrum

Question 9

Middle - between cochlea and ear drum

Auditory tube - 3 main functions ( runs mid ear down into throat)

Answer 9

1. Equalize pressure between middle ear and nasopharyngeal ( ears popping)
2. Protects middle ear from nasopharyngeal secretion and loud sound
3. Ventilation and drainage of middle eAr

Balances air pressure at both sides of ear drum

Question 10

Middle

Ossicles- conductive portion of hearing

Answer 10

Malleus- attached to tempanic membrane

Incus- trunk, connector function

Stapes- smallest bone in body, footplate inserts in oval window

Intensifies vibration of sound wave by 22 times enforce transmitting to oval window

Amplified of TM to smaller areas enables vibration of cochlear fluid

Vibrations equal energy

Question 11

Oval window

Answer 11

Within vestibule- base of semicircular canals

Between middle and inner, transmits sound vibrations

Question 12

Muscles of middle ear

Stapedius

Answer 12

Smallest skeletal muscle in the human body connected to stapes

Contacts- reduces stapes action( reduce amplification)
Contracts before speaking/chewing
Innervated by facial nerve VII

Question 13

Internal ear

Answer 13

In temporal bone

Question 14

Cochlea

Answer 14

Where hearing happens

3 chambers- vestibular (top), tempanic (bottom) cochlear duct ( middle)

Question 15

Vestibular apparatus

Answer 15

Balance receptors

Question 16

Vestibule

Answer 16

Base for semicircular canals

Organ of Corti electromechanical sensitive hair cells- hearing organ,needs activate to activate brai. Found in cochlea

Question 17

Vestibulocochlear nerve CN 8

Answer 17

Carries impulse to brain which interprets the impulse as sound

Question 18

Cochlear Canals are hollow

Answer 18

Filled with perilymph- excellent at transmitting energy(waves)

Question 19

Hearing pathway

Answer 19

Receptor (organ of corti)— CN 8- vestibulocochlear— brain stem— thalamus— temporal lobe— cerebral cortex—

Question 20

Equilibrium

2 types

Answer 20

Static- standing/sitting/laying- receptors in vestibule. Maintenance of position of body ( mainly head) relative to force of gravity

Saccule and urticle (organs) monitor static equilibrium, located in vestibule and contain macula- sensory organ

Otolithic membrane of saccule and urticle contains crystals (otoliths)— ear stones, and make it top heavy- monitored in internal ear with head movement ( back and forth)

Dynamic- moving. Receptors in semicircular canals. Maintenance of body position I response to sudden movement

Vestibular apparatus maintains the body at equilibrium and stabilizing eyes relative to movement

Canals contain crista ( flexible membrane) made of hair like cell and supporting cell covered by jelly like material (cupola)— movement stimulates hair cells

Question 21

Semicircular canals

Answer 21

Hollow and contain endoliph (fluid) rotate body, fluid moves ( level bubble)

Ballooned out part where all canals meet us the ampulla

Question 22

Neurological pathway (vestibular) equilibrium— most complex- not direct

Answer 22

Receptor ( saccule/ urticle) — vestibulocochlear nerve— brain stem- CN 6,4,3– impulse to vestibular area