Special Senses 1

Question 1

Name the 4 types of papillae

Answer 1

1. Filiform
2. Fungiform
3. Foliate
4. Circumvallate

Question 2

Which papillae do not contain taste buds

Answer 2

Filiform

Question 3

Roughly how many taste buds exist in the oral cavity

Answer 3

3000

Question 4

What is at the surface of a taste bud

Answer 4

An apical taste pore

Question 5

Name the 3 cell types within a taste bud

Answer 5

1. Sensory cells or taste receptor cells
2. Support cells
3. Basal cells

Question 6

What do the sensory cells contain

Answer 6

Apical microvilli with chemical receptors at the apical pore

Question 7

What is the lifespan of the sensory and support cells

Answer 7

Around 10-14 days

Question 8

What are the 5 principal tastes

Answer 8

1. Sweet
2. Sour
3. Bitter
4. Salty
5. Umami

Question 9

What happens when an appropriate chemical enters the taste pore and binds to a receptor

Answer 9

It releases neurotransmitters from the receptor cell (which are epithelial), that stimulate sensory nerve endings

Question 10

Describe the olfactory epithelium

Answer 10

Pseudostratified columnar (lacks goblet cells)

Question 11

What grows out from the olfactory bulb

Answer 11

Olfactor nerves, which dive down through the cribriform plate

Question 12

Name the 3 cells of the olfactory epithelium

Answer 12

1. Olfactory receptor cells
2. Support cells (or sustentacular cells)
3. Basal cells

Question 13

What extends above the olfactory epithelial layer, coming from the olfactory receptor cells

Answer 13

Olfactory vesicle with 10-20 long non-motile cilia attached

Question 14

What type of epithelium is the olfactory mucosa

Answer 14

Neuroepithelium

Question 15

Roughly how many odorants can our bodies detect

Answer 15

Around 10,000

Question 16

What do the olfactory support cells secrete

Answer 16

Odorant binding proteins

Question 17

What is the lifespan of an olfactory receptor cell

Answer 17

Around a month

Question 18

What do Bowman’s glands help to do in the nasal cavity

Answer 18

Solubilise the odorant, allowing it to interact better with the neuroepithelium

Question 19

What layers does the olfactory mucosa consist of

Answer 19

1. Olfactory epithelium

2. Lamina propria (underneath)

Question 20

What does the lamina propria contain

Answer 20

1. Connective tissue
2. Blood vessels (warm the air)
3. Bowman’s glands
4. Bundles of axons (from receptor cells)

Question 21

What glands exist within the ear canal (external auditory meatus)

Answer 21

1. Sebaceous

2. Ceruminous glands

Question 22

What do the ceruminous glands produce

Answer 22

Cerumin, a yellowish waxy substance

Question 23

How many layers does the tympanic membrane have; and describe them

Answer 23

Three layers

1. Outer layer of thin epidermis
2. Middle layer of collagenous connective tissue
3. Inner layer of simple cuboidal

Question 24

What does the round window allow

Answer 24

Allows for pressure changes to move through the cochlea

Question 25

How many spirals exist in the cochlea

Answer 25

2.5 turns

Question 26

Name the membranes that separate the scala vestibuli and scala tympani

Answer 26

1. Basilar membrane | 2. Vestibular membrane

Question 27

What is the function of the organ of Corti

Answer 27

Changes the vibrations into electrical impulses that are then sent to the brain

Question 28

Name the central core of the cochlea

Answer 28

The modiolus

Question 29

Name the three compartments of the cochlea

Answer 29

1. Scala vestibuli 2. Scala tympani 3. Cochlear duct between them

Question 30

Where do the scala tympani and scala vestibuli communicate with each other

Answer 30

At the very tip of the cochlea, at the Helicotrema

Question 31

What structures detect sound on the organ of Corti

Answer 31

Stereocilia: 1. Inner 2. Outer

Question 32

What row of stereocilia do we hear with

Answer 32

One row of inner stereocilia

Question 33

What do the stereocilia move against to allow us to hear

Answer 33

The tectorial membrane

Question 34

How many semicircular canals are located within each inner ear

Answer 34

Three: 1. Anterior 2. Posterior 3. Lateral

Question 35

What do the hair cells in the utricle and saccule detect

Answer 35

Head position

Question 36

What do the hair cells in the semicircular canals detect

Answer 36

Movement

Question 37

What exists within the ampulla of each semicircular canal

Answer 37

A sensory organ called the crista ampullaris

Question 38

What does the crista ampullaris consist of

Answer 38

A core of connective tissue bulging into the lumen with a covering of epithelium containing hair cells with stereocilia

Question 39

Where are the stereocilia located

Answer 39

Embedded within a dome called the cupola

Question 40

What happens to the cupola when the head turns

Answer 40

The movement of the fluid bows the cupola, and in turns bends the stereocilia

Question 41

What is the small patch of sensory epithelium in the vestibule of the semicircular canals

Answer 41

Macula

Question 42

What do the stereocilia contain on their surface

Answer 42

Crystals of calcium carbonate and protein, called otoconia

Question 43

Why do the otoconia move under gravity

Answer 43

They are denser than the surrounding endolymph fluid; thus under gravity, they will get misplaced