Inner ear & balance

Question 1

how do you keep your balance?

Answer 1

• vestibular branch
• visual and sensory systems

Question 2

Auricle (pinna)

Answer 2

• Gathers sound waves
• Aids in localization
• Amplifies sound

Question 3

External auditory canal

Answer 3

• Allows air to warm before before reaching tympanic membrane (™)
• Isolates ™ from physical change
• Cerumen glands moisten/soften skin
• Presence of some cerumen is normal

Question 4

bony labyrinth

Answer 4

• is a system of caverns and tunnels through the petrous temporal bone of the skull
• Contains the receptor organs for both hearing (cochlea) and equilibrium (semicircular canals, utricle and saccule)

Question 5

what part of the ear is responsible for hearing/

Answer 5

cochlea

Question 6

functions of the vestibular branch

Answer 6

Determines the position and motion of the head in space

Question 7

vestibular apparatus: semicircular canals

Answer 7

Since the world is 3 dimensional the vestibular system contains 3 semicircular canals

Question 8

endolymph

Answer 8

“flows” within the membranous labyrinth

Unique ionic composition, higher concentration of K+ ions; extracellular fluids

Question 9

perilymph

Answer 9

“flows” between the bony labyrinth and the membranous labyrinth

Ionic composition is similar to that of blood plasma and cerebrospinal fluid (CSF)

Major cation Na+

Question 10

Crista ampullaris

Answer 10

sense organ in the semicircular canal

In each ampulla, there is a crest of hair cells whose cilia project into a gelatinous mass called capula

Question 11

semicircular canal function

Answer 11

Rotation in one direction occurs, bending of the cilia causes the hair cells to depolarize and impulses reach the brain at a faster rate

opposite side, capula is bent the opposite direction

Question 12

utricle responds to….

Answer 12

horizontal acceleration

Question 13

saccule responds to…

Answer 13

vertical acceleration

Question 14

Vestibular-ocular reflex (VOR)

Answer 14

When rotation starts, eye move slowly in the direction opposite the rotation, maintaining visual fixation

Limit is reach; the eyes snap back to a new fixation potin, then move slowly in the other direction

Question 15

eye is controlled by 3 pair of muscles

Answer 15

1. Medial and lateral rectus
2. Superior and inferior rectus
3. Inferior and superior oblique

Question 16

Which of the following statements are true?

a.Semicircular canals detect linear acceleration, whereas utricle and saccule detect angular acceleration

b. Semicircular canals detect angular acceleration, whereas utricle and saccule detect linear acceleration

Answer 16

b, semicircular canals detect angular acceleration, whereas utricle and saccule detect linear acceleration

Question 17

Which of the following statements are correct?

a. The utricle responds to horizontal acceleration, and the saccule responds to vertical acceleration

b. The saccule responds to horizontal acceleration, and the utricle responds to vertical acceleration

Answer 17

a. the utricle responds to horizontal acceleration, and the saccule responds to vertical acceleration

Question 18

Which of the following statements is true?

a. Endolymph flows within the membranous labyrinth whereas perilymph flows between the bony labyrinth and the membranous labyrinth

b. Perilymph flows within the membranous labyrinth whereas endolymph flows between the bony labyrinth and the membranous labyrinth

Answer 18

a. Endolymph flows within the membranous labyrinth whereas perilymph flows between the bony labyrinth and the membranous labyrinth

Question 19

review parts of the ear!

Answer 19

review parts of the ear!