Chapter 17 - Special Senses
Olfactory & gustatory impulses travel not only to the ________________, but also the _______________
Cerebral cortex; limbic system
Define: Limbic system
A complex system of nerves and networks in the brain that controls the basic emotions and drives
Which is stronger? Olfaction or gustatory?
The olfactory epithelium is located in the ____________.
Superior part of the nasal cavity
(surface of the cribriform plate & extending along the superior nasal concha)
Olfactory epithelium = 3 types of cells
1. Olfactory receptor
2. Supporting columnar epithelial cells
3. Basal cells
Olfactory receptor is a _________ neuron with ___________ (olfactory hairs). These receptors respond to _________ molecules
bipolar; cilia; odorant
Supporting columnar epithelial cells provide _____ and ______
Basal cells are ______ cells that replace olfactory _______ (replaced ________ly)
Stem; receptors; month
Olfactory cascade of events (5 steps)
Odorant binds → G-protein & cAMP produced & released → opening of Na+ channels → Inflow of Na+ → Action potentials
Pathway of olfactory nerve impulses
2 olfactory nerves → olfactory bulbs → olfactory tract → Cortex's PRIMARY OLFACTORY AREA (temporal lobe)
Olfaction is the only sensory system that has _________ cortical projections. Does not go through the ________ (relay station)
Olfactory supporting cells & glands are innervated by the ______ nerve (CN _____)
Parasympathetic motor innervation to _______ glands & the ___________ in the nasal cavity is provided by the CN _______ or ______ nerve.
lacrimal; mucous membrane; VII; facial
The five primary tastes of gustation are:
The taste buds are located on the _________, _________, ___________ & ___________
Tongue; soft palate; pharynx; larynx
Each taste bud consists of about ___ gustatory receptor cells
_______ cells located near the CT base _______ and differentiate, first becoming _____ cells, then ______ _______ cells inside the taste buds.
Basal; multiply; supporting; gustatory receptor
Each gustatory receptor cell has a single, long ______, called a ___________ hair, which projects through the ________.
microvillus; gustatory; taste pre
Each gustatory receptor cell has a lifespan of about _____________
4 different types of papillae:
1. Vallate papillae
2. Fungiform papillae
3. Foliate papillae
4. Filiform papillae
Vallate papillae: amt, size, formation, found where, # taste buds each?
12; Very large; form a row; back of the tongue; 100-300
Fungiform papillae: shape, found where, # taste buds each
Mushroom; all over scattered; 5
Foliate papillae: found where? Last how long?
Small trenches on the lateral margins of the tongue; most degenerate in early childhood
Filiform papillae: Contain ___ but not _____. Fnx?
tactile receptors; no taste buds
Incr friction btw tongue and food (easier to manipulate food)