Chapter 17 Flashcards
Olfaction
Sense of smell
located in epithelium of the nose
total area of 5 cm²
Olfactory epithelium
Occupies the superior part of the nasal cavity, inferior surface of the cribriform plate, and extending along the superior nasal concha
What are the three cells of the olfactory epithelium?
- Olfactory receptor cells
- Supporting cells
- Basal cells
Olfactory receptor cells
First order neurons of the olfactory pathway
bipolar neuron with an expose knob shaped dendrite
axon projecting through the cribriform plate that ends in the olfactory bulb
Olfactory cilia
Extends from the dendride of an olfactory receptor cell and is the site of olfactory transduction
Olfactory receptor
Located in the plasma membranes of the olfactory cilia
proteins that detect inhaled chemicals
Odorants
The chemicals that stimulate the olfactory receptors in the olfactory cilia
Supporting cells
Columnar epithelial cells of the mucus membrane lining the nose
provide physical support, nourishment, and electrical insulation for the old factory receptor cells
detoxify chemicals that come in contact with the olfactory epithelium
Basal cells
Stem cells located between the bases of the supporting cells
continually undergo cell division to produce new old factory receptor cells which live for two months
Olfactory glands or Bowmans glands
Produce mucus that is carried to the surface of the epithelium by ducts
moistening the surface of the olfactory epithelium
dissolves odorants so that transduction can occur
Olfactory transduction
When a receptor potential (depolarization) develops and triggers one or more nerve impulses
Gustation
Taste
What are the five primary taste?
- Salty
- Sour
- Sweet
- Bitter
- Umami
What is the taste salty caused by?
Sodium
What is the taste sour caused by?
Hydrogen ions
What is the taste sweet caused by?
Glucose, fructose, sucrose, aspartame, Saccharin, and sucralose
What is bitter taste caused by?
Wide variety of substances including caffeine, morphine, quinine, and many poisons
What is umami taste caused by?
Meaty or savoury caused by amino acids
What is the shape of a taste bud and what three cells are they consisted of?
Oval body containing supporting cells, gustatory receptor cells, and basal cells
In each taste bud how How many gustatory receptors cells are surrounded by a supporting cell?
50 Gustatory receptor cells
What and where are the gustatory microvilli?
Project from each gustatory receptor cell to the external surface through the taste poor
Taste pore
An opening in the taste bad
Basal cell of taste bud
Stem cells found at the perphery of the Tastebud near the connective tissue layer
produce supporting cells which develop into gustatory receptors cells every 10 days
Papillae of tastebuds
Taste buds are found in elevations on the tongue called papillae
They increase surface area and provide a rough texture to the upper surface of the tongue