supporting cells: columnar cell surrounding and supporting olfactory sensory neurons; bulk of epithelium
stem cells: located near basal surface of epithelium, form new sensory neurons
filaments of olfactory nerve penetrate cribriform foramina and synapse in olfactory bulbs
taste buds contain specific receptors for sense of taste
most taste buds are located in papillae on the dorsal surface of tongue and some are found on soft palate, epiglottis, pharynx, and inner surface of cheek
taste buds located in side walls of large vallate papillae (v-shape in posterior tongue surface), side wall of foliate papillae and fungiform scattered everywhere
each taste bud consists of
gustatory epithelial cells: taste receptors; have long microvilli called gustatory hairs that project through taste pore
basal epithelial cells: precursor cells that divide to replace gustatory epithelial cells
when gustatory hairs contact food molecules dissolved in saliva, gustatory epithelial cells depolarize. afferent neurons innervating taste buds are
facial nerve (7): anterior 2/3
glossopharyngeal (9): posterior 1/3
vagus (10): few fibers from pharyngeal region
sweet receptors: sugars, saccharine, some lead salts, some amino acids
sour: hydrogen ions
salty: influx of Na ions
umami: a savory taste that is produced by the amino acid glutamate
bitter: alkaloids
nasal
A) glomeruli
B) olfactory stem cell
C) olfactory sensory neuron
D) supporting cell
E) olfactory epithelium
F) supporting cell
G) olfactory sensory neuron
H) olfactory cilia
supporting cells: surround and support olfactory sensory neurons, forming a bulk of the olfactory epithelium
olfactory adaption: how smells are less noticeable after some time spent smelling it