Special Senses 1

Question 1

Tongue Papillae:

Firiform (FL)

Answer 1

Conical shape, no taste buds (other 3 types have them)

Question 2

Tongue Papillae

Fungiform (FG)

Answer 2

Blunt

Question 3

Tongue Papillae

Foliate

Answer 3

“Slit like” on the margin of the tongue

Question 4

Tongue Papillae

Circumvallate

Answer 4

Large and dome shaped. 6-12 in two lines forming a “V” about 2/3 back on the tongue

Question 5

Tongue Papillae: Types

FL = Filiform

FG = Fungiform

CV = Circumvallate

Answer 5

Question 6

Taste BudsTaste (gustation)

Answer 6

Caried out by around 3000 multicellular chemoreceptive units (taste buds). Extend full thickness of epithelium and contain about 50 specialized cells in a barrel shaped structure. Apical pore (AP) at surface of structure.

Question 7

Taste Buds

How do they work?

Answer 7

When appropriate chemical enters apical pore and binds receptor it causes depolarizaton of the cell and release of a neurotransmitter, stimulating sensory nerve endings within the bud. 5 tastes but not segregated into areas of the tongue

Question 8

Olfactory Epithelium

About

Answer 8

Relatively small area in humans. Epithelium is pseudostratified columnar like respiratory, but is talled and has no goblet cells. 4Stains more darkly than respiratory

Question 9

Olfactory Epithelium Cell Types

Olfactory receptor cells

Answer 9

Nuclei typically in the middle of the epithelial layer

Question 10

Olfactory Epithelium Cell Types

Sustentacular (supporting) cells

Answer 10

Nuclei typically in upper portion of epithelium

Question 11

Olfactory Epithelium Cell Types

Basal cells

Answer 11

Nuclei in basal part of epithelium. Act as stem cells

Question 12

Olfactory Knob

What does it do?

Answer 12

Extends above epithelium and has non-motile cilia with receptors on them. 10,000 odorants that they can detect,, producing action potentials.

Question 13

Olfactory Mucosa

Referred to as

Answer 13

The neuroepithelium because receptor cells are neurons.

Question 14

Olfactory Epithelium

Sustentacular (support cells)

Answer 14

Numerous apical villi, also have enzymes which may play a role in deactivating odorants

Question 15

Olfactory Epithelium

Basal Cells

Answer 15

Olfactory receptors are only neurons directly exposed to external environment - replaced every 1-2 months. Only neurons able to extend axons into the CNS.

Question 16

Olfactory Epithelium

Lamina proporia contents

Answer 16

Blood vessels for warming the airBowmans glands and tubuloalveolar glands to produce a serous secretion released at surface for dissolving odorantsBundles of axons from receptor cells

Question 17

What is this?

Answer 17

Olfactory knobs

Question 18

Anatomy of Hearing

Answer 18

Question 19

External Ear

Skin of pinna of ear and external auditory meatus

Answer 19

Covered by epidermis. Ear canal has hairy skin with sebaceous glands and modified apocrine sweat glands (ceruminous glands) which produce cerumin (waxy substance)

Question 20

External Ear

Tympanic Membrane (eardrum)

Answer 20

3 layers. Outer layer of thin epidermis, middle layer of collagenous connective tissue and an inner layer of simple cuboidal.

Question 21

Schematic View of Chochlea

Answer 21

Question 22

Cochlea

Answer 22

Question 23

CochleaM

Answer 23

Central core: Modiolus

Question 24

CochleaS

Answer 24

Ganglion of bipolar nerve cell bodies. The spiral ganglion.

Question 25

CochleaSV, ST, CD

Answer 25

Three compartments. Scala Vestibuli, and Scalatypani with the Cochlear Duct between them.

Question 26

CochleaSV and ST

Answer 26

Communicate with one another at the very tip of the cochlea, the Helicotrema (H)

Question 27

CochleaOC

Answer 27

The Organ of Corti where sounds are transduced by hair cells.

Question 28

Section through Cochlea

Answer 28

Question 29

Turn of Cochlea

Answer 29

Question 30

Organ of Corti

About

Answer 30

Sits on basal membrane (BM), which gets longer and thicker as you move towards the tip of the cochlea.This lengthening means that the OoC near the tip of the cochlea responds to lower frequencies and near the base responds to higher.

Question 31

Organ of Corti

Hair cells

Answer 31

Two sets of hair cells - triple row of outer hair (OH) cells and a single row of inner hair (IH) cells. Each with support/phalangeal cells (OPh & IPh). Vibrations make the hair cells move against the tectorial membrane (TM). Deformation of stereocilia opens ion channels which depolarize hair cell - neurotransmitters released causing action potentials in terminals of spiral ganglion neurons. Main receptors are inner hair cells.

Question 32

Vestibular Apparatus

Answer 32

Question 33

Vestibular System

Answer 33

Question 34

Semicircular Ducts

Vestibular System Depends on

Answer 34

Hair cells - like the auditory system does

Question 35

Semicircular Ducts

Swelling in semicircular duct

Answer 35

Called ampulla, within which is a sensory organ called the crista amupllaris

Question 36

Semicircular Ducts

Crista ampullaris

Answer 36

Consists of a core of connective tissue bulging into the lumen with a covering of epithelium containing cells with stereocilia, which are embedded in a dome of gelatinous material called the cupola

Question 37

Semicircular Ducts

How movement effects stereocilia

Answer 37

Movement of fluid bows the cupola, which bends the stereocilia. This causes a change in the amount of transmitter being released with more being released in one direction, and less in the other

Question 38

Utricle and Saccule

What are they?

Answer 38

Two swellings in the vestibule. Fluid filled spaces lined by simple cuboidal epithelium but have small patch of sensory epithelium called the macula.

Question 39

Utricle and Saccule

Otoliths

Answer 39

Stereocilia of hair cells are embedded in a gelatinous layer which in turn has crystals of calcium carbonate called otoliths embedded in its surface.