Thursday, 4-7-Gustatory system development and histology (Cole) Flashcards
This part of the tongue consists of a core mass of skeletal muscle oriented in longitudinal, transverse, and oblique directions
anterior 2/3
this part of the tongue displays aggregations of lymphatic tissue, the lingual tonsils
posterior 1/3
The dorsal surface of the tongue is covered by a ___ epithelium supported by a lamina propria associated with the muscle core of the tongue
non-keratinized stratified squamous
___ glands extend across the lamina propria and the muscle. Their ducts open into the crypts and furrows of the lingual tonsils and circumvallate papilae
serous and mucous
The dorsal surface of the tongue contains numerous mucosal projections called ___ and is formed by a highly vascular connective tissue
lingual papillae
each lingual papilla is formed by a highly vascular connective tissue core and a covering of ___ epithelium
stratified squamous
what are the 4 types of lingual papillae?
- filiform papillae (narrow conical)
- fungiform papillae (mushroom-shaped)
- circumvallate papillae
- foliate papillae (leaf-shaped)
The classic manifestation of this disorder is an area of erythema with atrophy of the filiform papillae of the tongue, surrounded by serpiginous, white, hyperkeratotic border. It is thought to be an oral manifestation of psoriasis
geographic tongue
in a geographic tongue, atropy of the __ of the tongue is observed
filiform papillae
what type of epithelium makes up the fungiform papillae?
nonkeratinized stratified squamous
where are taste buds on fungiform papillae located?
along the apical surface
Serous glands, or Ebner’s glands, in the connective tissue, in contact with the underlying muscle are associated with which papilla(e)?
foliate and cicumvallate
The ducts of Ebner’s glands open into the floor of the circular furrows and secrete ___
lingual lipase and VEGP (Von Ebner’s Gland Protein)
___ undertakes the selective binding of sapid (flavorful) chemical and their transport to taste receptors
VEGP
What type of epithelium makes up the foliate papillae?
stratified squamous
___ are located in the posterior part of the tongue, aligned in front of the sulcus terminalis. They occupy a recess in the mucosa and ,therefore, it is surrounded by a circular furrow or trench
circumvallate papillae
the sides of the circumvallate papilla and the facing wall of furrow contain several __
taste buds
what are the 3 cell components of a taste bud?
- taste receptor
- supporting cells (immature taste cells)
- precursor cells (basal cells)
__ are ovoid chemoreceptors found in papillae and on the soft palate, posterior pharynx, and epiglottis
taste buds
The __ portion of a taste receptor cell makes contact with an afferent nerve terminal derived from neurons in the sensory ganglia of the VII, IX, and X nerves
basal
taste is initiated when soluble chemicals, called __, diffuse through the taste pore and interact with the G-proteins alpha, beta, and gamma subunits called ___ linked to the taste receptors present in the apical microvilli of the taste receptor cells
tastants
gustducin
determination of being a non-taster, normal taster, or a super-taster is based on the density of ___
fungiform papillae
regarding taste perception:
___ stimuli- tip of the tongue (sugars)
___ stimuli- sodium, posterior and lateral to the tip of the tongue
___ stimuli- on anterior 2/3 of dorsum and along the lateral margin
sweet
salty
sour
Individuals with the sensitive form of the hTAS2R38 taste receptor gene rate ___ as being more bitter than people with the less sensitive form of the gene
Kohlrabi–> contains glucosinolates, compounds that inhibit iodine uptake by the thyroid
Umami is linked to a special receptor for ___ and other AAs
L-glutamate
Taste buds on the palate register primarily ___
Posterior pharynx and epiglottis register primarily ___
bitter and sour
all 5 modalities
___ receptor recognizes the texture of fat. It also functions to facilitate the uptake of FA’s. Alterations in this receptor may decrease (in mice) the desire for fatty foods
Fat (CD36)
Sensory innervation to the anterior 2/3 of the tongue is by ___ and a derivative of arch ___
Lingual n. (branch of V)
1st
SVA (innervation to taste buds) to the anterior 2/3 of the tongue is by ___ and a derivative of arch ___
VII
2nd
Sensory innervation to the posterior 1/3 of the tongue is by ___ and a derivative of arch ___
IX
3rd
SVA (innervation of taste buds) to the posterior 1/3 of the tongue is by ___
IX
X near the base of the tongue (4th arch derivative)
Muscles of the tongue develop from the mesoderm of the occipital myotomes that migrate into the developing tongue and are innervated by ___
XII
Most sensory information that is thought of as taste is actually ___
olfactory sensation subserved by the olfactory mucosa
What is the epithelium type of the nasal cavity?
pseudostratified columnar epithelium with goblet cells
__ of the nasal cavity contains both serous and mucous glands to moisten inspired air and trap particulate contaminants
lamina propria
What are some functions of the nasal mucosa?
- air hydration
- secretions of serous and mucous exocrine glands and goblet cells moisten the surface of the nasal cavity
- add water vapor to inspired air
- air filtration
- conchae interrupt air flow and create turbulence
- particulate matter thrown against conchae and adheres to its moist surface
- cilia move mucus/matter into nasopharynx
- temp regulation
- superficial vascular plexus (swell bodies) w/in lamina propria
- can warm or cool inspired air
What is the epithelium type of the olfactory epithelium?
pseudostratified columnar
What are the 3 cell types of the olfactory epithelium?
- olfactory cells
- supporting (sustentacular) cells
- basal cells
__ are bipolar sensory neurons that span the thickness of the epithelium. Their dendrites extend to free surface and dilate to form the olfactory vesicle. They also project (along with cilia) above the epithelial surface.
olfactory cells
The proximal process of olfactory cells extend basally, become a non-myelinated axon, and forms bundles of nerve fibers known as the ___
fila olfactoria
__ cells are columnar with oval nuclei (apical 1/3 of the cell) in which the apical microvilli are submerged in seromucous fluid layer. They contain a light yellow pigment that gives olfactory epithelium its color. They provide physical support, nourishment and electrical insulation for the olfactory cells
support (sustentacular) cells
Regarding olfaction:
cilia contain the __ receptor.
Olfactory __ glands secrete a serous fluid in which odoriferous substances are dissolved
The secretory fluid contains the __ with high binding affinity for a large number of odorant molecules. They carry odorants to receptors on the surface of the modified cilia and removes them after they have been sensed.
The secretory products of the glands of Bowman contain protective substances such as ___
odorant
serous (glands of Bowman)
odorant-binding protein (OBP)
Lysozyme and IgA
Axons from olfactory cells with the same OR terminate in 1-3 glomeruli present in the olfactory bulb. Dendritic endings of predominantly mitral cells extend into the glomeruli and the axons of mitral cells form the ___
olfactory tract
individuals with Kallman syndrome have anosmia due to a defective gene, ___, that codes for ANOSMIN1, a cell adhesion protein that is expressed in the olfactory system and medial walls of primitive cerebral hemispheres
KAL-1
