15.1 Olfaction and Gustation

A&P final

Generator Potential

Depolarization which occurs when dissolved odorants bind to olfactory receptors.

Olfactory Bulb

Superior to the cribiform plate; first synapse occurs here

Olfactory Tract

After leaving the bulb, axons travel here to reach hypothalamus, limbic system, etc

Lamina Propria

Second layer of olfactory organs

Basal cells

Regenerative stem cells in olfactory epithelium

lingual papillae

epithelial projections on the tounge

Vallate papillae

large round, surrounded by fold, each one may contain up to 100 taste buds

Foliate Papillae

Found on lateral margins / posterior tounge

Fungiform papillae

small buttons; around 5 taste buds on each

Filiform papillae

Provide friction to move objects, but do not contain taste buds

Gustatory receptor cell

extends slender microvillae (taste hairs) intor surrounding fluids via taste pore

Na+ leak channels

Diffuse ions for salt and sour taste

Gustducins

G proteins that link to sweet, bitter and unami taste

Gustatory pathway

Links the gustatory receptor cells to the cerebral cortex

Facial nerve (VII)

Innervates on anterior taste buds

Glossopharangeal Nerve (IX)

Inervates on posterior papillae

Vagus Nerve (X)

Innervates taste buds scattered on epiglottis surface

Gustatory Cortex

After a synapse in the thalamus, info is projected to this area of the insula

Medial Leminiscus

Axons of postsynaptic neurons enter this area of the medulla oblongatata

Solitary Nucleus

Sensory afferents carried by the three cranial nerves synapse in this portion of the medulla oblongata