Ear

Question 1

How sound moves through the ear

Answer 1

1) external ear/pinnae
2) ear drum
3) middle ear bones
4) eustachian tube
5) semicircular canals
6) cochlea

Question 2

External ear/pinnae

Answer 2

Allows sound to come through ear

Question 3

Ear drum

Answer 3

Movement helps project sound

Question 4

Middle ear bones

Answer 4

Help move/enhance sound

Question 5

Eustachian tube

Answer 5

From back of nose by soft palate to middle ear
Ventilated ear/ helps with pressure changes
Can drain fluid from middle ear
Closed unless needed

Question 6

Semicircular canals

Answer 6

Movement results in vestibular changes

Fluid sloshed around with movement and sensed then transmitted to the brain

Question 7

Cochlea

Answer 7

Movement of hair sensed then transmitted to brain

Question 8

Cerumen (ear wax)

Answer 8

Protects ear, helps clean/lubricate

Protect against bacteria/yeast/insects/water

Question 9

Difference between human ear and dog/cat ear

Answer 9

Vertical component makes it hard to drain/accumulate moisture - ear infections more common
Much longer canal/sharp twist
Cats have much better hearing than dogs
Ear movements detect exact location of prey
Shape helps funnel sound into ear

Question 10

Tympanic bulla

Answer 10

Thin walled bone area that holds middle ear and 3 bones

Question 11

Puppies born deaf and don’t hear until 2 weeks old

Answer 11

Ear canals closed until 10 days
Fully open by 3 weeks (start hearing at 14 days)
Hard to assess deafness until 4 weeks