Olfaction And Taste Flashcards
Sensation of odors that results from the detection of odorous substances aerosolized in the environment
Olfaction
Sensation evoked by stimulation of taste receptors located in the oropharyngeal cavity
Taste
Contributes to the experience of flavor by detecting irritating components in smells like ammonia or the “hot” in spicy food like peppers
Somatosensory system
What is responsible for thermal and textural perceptions in food
Somatosensory system
Appetite
Orexia
Lack of appetite
Anorexia
Lack of smell
Anosmia
What is smell most important in humans for
Learning and smelling poison
Plays a role in pleasures associated with eating and with the many scents that make up our world
Olfactory system
What ar the taste sensations
Sweet, salty, sour, bitter, and more recently umami (amino acids)
_____ which originates from receptors in the oropharyngeal cavity, is important to determine the acceptance or rejection of foods. This info is relayed by neural pathways that underlie various ingestive and digestive functions
Taste
What is the sensation of taste though smell
Retrosnasal smell, from food
What part of the nervous system is the olfactory bulb
CNS
Where does the olfactory bulb lie
Cribiform plate
What bone is the cribiform plate on
Ethmoid bone
Olfactory bulb in relation to the frontal lobe
Inferior to the medial aspect of the frontal lobe
Where do the olfactory fibers pass through
Cribiform plate
Receptors responsible for transduction of odor molecules are found in the
Olfactory mucosa
Where is the olfactory nasal mucosa
Roof of the nasal cavity on the inferior surface of the cribiform plate and along the nasal septum and medial wall of the superior turbinate
How is the olfactory mucosa different than the respiratory epithelium
The olfactory mucosa is yellowish in color and has greater thickness
What does the olfactory epithelium contain
- olfactory receptor neurons
- supporting cells
- basal cells
- ducts of small glands (Bowmans) that secrete mucous
Where are the olfactory receptors found
Bodies of bipolar olfactory receptor neurons are found in the basal two thirds of the epithelium
Makeup of olfactory receptor
-each has a single thin apical dendrite and a nasally located unmyelinated axon
The apical dendrite of the olfactory receptor
Extends to the surface of epithelium where it terminates in a knob like olfactory vesicles from which 10 to 30 nonmotile cilia arise
The unmyelinated axons of an olfactory receptor neuron pass through the lamina proprioceptive and group together into bundles called _______, whihc collectively make up the olfactory nerve (CN1)
Olfactory fila
Where do the olfactory film pass through
The cribiform plate and terminate in the olfactory bulb
Where is the olfactory bulb
Located on the ventral surface of the frontal lobe in the olfactory sulcus and is attached to the rest of the brain by the olfactory tract
Where do the olfactory fila synapse?
Olfactory bulb
What type of odorants are more likely to cross the mucus
Hydrophobic such as musk
How do hydrophobic molecules cross the mucus in olfactory transduction
By interacting with small proteins called odorant binding proteins
After crossing the mucus, what do hydrophobic odorants do
Bind to odorants receptors on the cilia of the olfactory receptor neurons, which causes depolarization of the dendrite of the olfactory receptor neuron
What do the axons of the olfactory receptor neuron do
Communicate with the second order neurons in the olfactory tract (in bulb) called mitral cells, which emerge from the caudal portion of he olfactor bulb to form the lateral olfactory tract
What is the only system to bypass the thalamus
Olfactory
How do the axons of the olfactory tract course
Caudally to terminate in areas on the ventral surface of the frontal lobe, which are broadly defined as the olfactory cortex
What are the principal areas making up the olfactory cortex
- anterior olfactory nucleus
- olfactory tubercle
- piriform cortex
- periamygdaloid cortex
- entorhinal cortex
What is unique about the olfactory system
The bulb projects directly to the cortex
Where does the olfactory cortex send projections
To the orbitofrtonal cortex and insula (also receive taste input)
In addition to neocortical projections, the olfactory cortex also sends fibers directly to the
Lateral hypothalamus and hipposcampus