Gustatory and Olfactory System Histology Flashcards Preview

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Flashcards in Gustatory and Olfactory System Histology Deck (86):
0

What portion of the tongue consists of a core mass of skeletal muscle oriented in three directions

anterior 2/3

1

In what directions is the skeletal muscle of the tongue organized

longitudinal, transverse, and oblique

2

The posterior 1/3 of the tongue displays what

aggregates of lymphatic tissue, the lingual tonsils

3

The tongue is developed from which branchial arches

1-4

4

The anterior 2/3 of the tongue comes from which branchial arches. What are their innervation

1st and 2nd
trigeminal (1) and facial (2)

5

The posterior 1/3 of the tongue comes from what branchial arches? What are their innervation

3rd and 4th
glossopharyngeal
vagus

6

Dorsal surface of the tongue is covered by what kind of epithelium

non keritinized stratified squamous epithelium (supported by a lamina propria, associates with the muscle core of the tongue)

7

what kind of papillae are located in front ot the v shaped sulcus terminalis, what are they associated with

circumvalate papillae, ebners glands

8

What are the four pairs of intrinsic muscles in the tongue

superior longitudinal
inferior longitudinal
transversus linguae
verticalis linguae

9

Serous and mucous glands extend across the ________ and the _____

lamina propria and the muscle

10

What is the purpose of the serous and mucous glands

suspend tastants so they can be taken and delivered to taste buds

11

where do the ducts of serous and mucous glands open

into the crypts and furrows of the lingual tonsils and circumvallate papillae

12

What forms a lingual papilla

a core of CT, and an epithelial layer on top (stratified squamous epithelium)

the CT is highly vascular

13

What are the four types of lingual papillae?

filiform
fungiform
circumvallate
foliate

14

What are the three types of papillae that contain taste buds?

fungiform
circumvallate
foliate

15

Describe the type of lingual papilla that doesn't contain taste buds

filliform - have barbs that grab ahold of food. Dogs and cats have a lot of these

16

Describe geographic tongue

oral manifestation of psoriasis
dermatological condition which causes patches of dry, flaky, itchy skin
classic manifestation= area of erythema, with atrophy of filiform papille of tong, surrounded by serpiginous white, hyperkaratotic border

17

What type of epithelium are found on fungiform papillae? where are their taste buds located?

non keritinized stratified squamous
taste buds along apical surface

18

What types of lingual papillae are the serous glands (Ebner's) associated with

circumvallate and foliate.

19

What layers of the tongue are ebner's glands found in

in the CT, in contact with the underlying muscle

20

What do the ebner's glands secrete (2)

lingual lipase and VEGP

21

What does Von Ebner's Gland Protein (VEGP) do

undertakes selective binding of sapid (flavorful) chemicals and their transport to taste receptors.

22

What type of epithelium are associated with foliate papillae? What structures are associated with them?

Stratified squamous epithelium
Von Ebner's glands (Serous glands)

23

How are foliate papillae arranged? where are their taste buds located

parallel rows
taste buds in lateral walls.

24

What part of the tongue are circumvallate papillae located

posterior part, aligned in front of the sulcus terminalis

25

Describe the circumvallate papillae

circumvallate= wall-like
occupy a recess in the mucosa, and therefore are surrounded by a circular furrow or trench

26

What is the benefit of the trench surrounding a circumvallate papilla

can suspend fluid in it and localized tastant particles in that trench. difficult for them to get out, easier for taste buds to access

27

Where are the taste buds located in circumvallate papillae?

sides of the papillae and the facing wall of the furrow

28

How many cells are there in a taste bud

50- 150, with the narrow, apical end of the taste bud extending into a taste pore

29

What are the three components of each taste bud

taste receptor cells
supporting cells
precursor cells

30

Where are the ovoid chemoreceptors found in the tongue

papillae
soft palate
posterior pharynx
epiglotis

31

life span of taste receptor cells

10-14 days

32

Describe the life cycle of taste receptor cells

precursor cells give rise to supporting cells (immature taste cells) which in turn become mature taste receptor cells.

33

How to taste receptor cells communicate with the cranial nerves

basal portion of taste receptor cell makes contact with an afferent nerve terminal derived from neurons in the sensory ganglia of the facial, glossopharyngeal and vagus nerves

(each taste receptor cell has its own afferent nerve fiber coming out of it)

34

Mechanism of taste

tastant binds taste receptor
GPCR, causes the cell to either depolarize or hyperpolarize
a change in intracellular Ca2+ triggers the release of NTs at the afferent synapse with the afferent nerve terminal
AP goes back to brain through cranial nerves to be analyzed

35

Nerve fibers innervate which cells in taste buds

all three
basal cells, supporting cells, receptor cells

36

What are the 5 taste sensations

sweet, salty, sour, bitter, umami

37

Facial nerve carries what sensations

all 5

38

glossopharyngeal carries what taste sensations

sweet and bitter

39

Nontaster, normal and super taster is based on density of what

fungiform papillae

40

Sweet stimuli is sensed where
what type of compounds

tip of tongue (sugars)

41

Salty stimuli is tasted where
what type of compounds

posterior and lateral to tip of tongue
(sodium)

42

Sour is tasted where
what type of compounds

on anterior 2/3 of dorsum and along the lateral margin
(acidic, H+)

43

Bitter tastants are what kind of compounds

varied compounds with no common molecular structure
caffeine, morphine, nicotine

44

Is there a genetic component to taste?

yes - some people more sensitive to bitter (kohlrabi test)

45

Umami is linked to a specialized receptor for what

L glutamate and other amino acids.

46

Umami is associated with

meats, cheeses, some vegies, glutamate signals presence of proteins and causes intake of proteinious foods.

added to processed foods as MSG, which is a flavor enhancer

47

taste buds on the palate register primarily (2)

bitter and sour

48

Posterior pharynx and epiglottis register which modalities

all 5

49

CD36

Protein receptor that specifucally responds to the flavor of fat
functions to facilitate the uptake of fatty acids
may also increase preference for fatty foods.

50

Sensory innervation to the anterior 2/3 of tongue

lingual nerve (trigeminal)

51

innervation of taste buds to anterior 2/3 of tongue (SVA)

facial nerve

52

Origin of ant 2/3 of tongue

median tongue bud, lateral lingual swellings

53

Origin of posterior 1/3 of tongue

hypopharyngeal eminence

54

Sensory innervation to posterior 1/3 of tongue

glossopharyngeal nerve

55

innervation of taste buds (SVA) to posterior 1/3 of tongue

glossopharyngeal
vagus

56

Type of epithelium that lines the nasal cavity

pseudostratified columnar epithelium with goblet cells

57

The lamina propria of the nasal cavity contains both _______ and _______ ______ and their function is to

The lamina propria also contains extensive ______ or _____ for _______

serous and mucous glands
moisten inspired air and trap particulate contaminants
vascular plexus swell/cavernous bodies for temperature control

58

what are the immune cells present in the nasal cavity

mast cells
plasma cells (IgA, IgE, IgG)

59

Three functions of the nasal mucosa

air hydration
air filtration
temperature regulation

60

Air hydration

secretions of serous and mucous glands and goblet cells moisten the surface of the nasal cavity
add water vapor to inspired air

61

Air filtration

chonchae interrupt air flow and create turbulance
particulate matter thrown against chonchae and adheres to its moist surface
cilia move mucus/matter into nasopharynx

62

Temperature regulation

superficial vascular plexus (swell bodies) within lamina propria
can warm or cool inspired air

63

Where is olfactory epithelium found. what type of epithelium is it?

restricted to roof of nasal cavity-upper surface of superior conchae
pseudostratified columnar epithelium with three types of cells.
underlying lamina propria also contains lymphoid cells

64

What are the three types of cells in olfactory epithelium?

olfactory cells
supporting (sustentacular cells)
basal cells

65

Describe olfactory cells

bipolar sensory neurons, span the thickness of the epithelium
dendrite extends to surface and dilates to form olfactory vesicle
projects, along with cilia, above epithelial surface
proximal surface extends basally, becomes a non- myelinated axon and forms bundles of nerve fibers - the fila olfactoria (goes up through cribiform plate)

66

Describe the supporting cells (olfactory)

=sustentacular cells
columnar cells with oval nuclei
apical surface has microvilli submerged in seromucous fluid layer
light yellow pigment
PROIDE PHYSICAL SUPPORT, NOURISHMENT AND ELECTRICAL INSULATION (TIGHT JUNCTIONS AROUND THEM) FOR OLFACTORY CELLS.

67

Describe the basal cells (olfactory)

mitotically avtive stem cells
produce daughter cells that first differentiate into immature olfactory cells and thn mature olfactory cells

68

Do olfactory cells proliferate during adult life

yes

69

what is the lifespan of an olfactory cell

30-60 days

70

Cilia contain the ________. there are ~1000 genes expressing these, but each olfactory cell expresses only one ____ gene

olfactory receptor
OR

71

Olfactory serous glands (aka______) secrete a serous fluid in which_____

glands of BOwman
odoriferous substances are dissolved

72

The secretory fluid of the olfactory serous glands contains_____ with high binding affinity for a large number of odorant molecules . what is its purpose

odorant-binding protein OBP
OBP carries odorants to receptors present on the surface of the modified cilia and remeoves them after they have been sensed

73

The secretory product of the glands of bowman contains protective substances such as

lysozyme and IgA secreted by plasma cells.

74

Olfactory nerve filaments are bundled in groups of 10-100 and penetrate the ______ of the _____bone. reaching the ___________.
Here, the axon terminals connect with synaptic terminals of _____ cells, forming synaptic structures called _______.

cribiform plate
ethmoid bone
olfactory bulb
mitral cells
glomeruli

75

The olfactory signal is sent by _______ cells through the olfactory nerve tract to the __________ of the brain

mitral
corticomedial amygdala portion

76

temporary or permanant eamage to the olfactory epithelium causes

anosmia (loss of sense of smell)

77

axons from olfactory cells with the same odorant receptor terminate in 1-3 ______ present in the olfactory bulb

glomeruli

78

dendritic endings of predominantly mitral cells extend into the _______. Axons of mitral cells form the ________.

glomeruli
olfactory tract

79

lifespan of olfactory receptor cells is ______. can regenerate from _____-

30-60 days
basal cells.

80

Physical characteristics of Kallman syndrome

anosmia, small genitalia and sterile glands

81

What is responsible for the anosmia in Kallman syndrome

lack of neurons in the brain (mitral cells) that receive input from olfactory nerurons (olfactory bulb does not develop)

82

what is responsible for the small genitalia/sterility in Kallman syndrome?

lack of GnRH secreted by hypothalamus
GnRH required of secretion of LH, which is required for development of gonads and genital maturation

83

GnRH secreting neurons originate where

NOT in the hypothalamus
originate in olfactory epithelium (vomeronasal organ) and migrate into the brain

84

What is the mechanism of Kallman syndrome

failure of GnRH secreting neurons and olfactory neuron growth cones to migrate into the brain

(axons of olfactory neurons must contact developing brain to stimulate olfactory bulb development)
If they dont migrate, you dont get GnRH secreting neurons or mitral cells

85

Genetic defect that causes Kallman syndrome

KAL-1 is the defective gene
codes for anosmin 1, a cell adhesion protein that is expressed in the olfactory system and the medial walls of primitive cerebral hemispheres.