Chapter 17: Lecture Midterm II Flashcards
On each side of the nose, there are 40 or so bundles of axons of
olfactory sensory neurons from the right and left olfactory (I) nerves
the olfactory nerves pass through the
cribriform foramina of the cribriform plate of the ethmoid bone
where do olfactory nerves extend to?
parts of the brain known as olfactory bulbs, which contain glomeruli
where do the second order neurons synapse with the olfactory nerves
at the glomerulus (second order neurons called; mitral cells)
Each glomerulus of the olfactory pathway recieves input from
only one type of olfactory sensory neuron
the axons of mitral cells form
the olfactory tract
where does conscious awareness of smell occur
olfactory cortex in the temporal lobe of the cerebrum
olfactory sensations are the only sensations that
reach the cerebral cortex without synapsing in the thalamus
where does out emotional responses to odours occur
some axons of the olfactory tract project to the limbic system
what type of sense is smell
chemical
the olfactory epithelium covers the…
inferior surface of the cribriform plate and extends along the superior nasal concha
extending from the dendrite of an olfactory sensory neuron are several nonmotile
olfactory cilia,
olfactory cilia are the site of
olfactory transduction
within the plasma membranes of the olfactory cilia are
olfactory receptor proteins that detect inhaled chemicals
Odorants:
chemicals that bind to and stimulate olfactory sensory neurons in the olfactory cilia
Supporting epithelial cells:
columnar epithelial cells of the mucous membrane lining the nose
- they provide physical support, nourishment and electrical insulation for the olfactory sensory neurons and help detoxify chemicals that they come in contact with
Basal epithelial cells
- stem cells located between the bases of the supporting epithelial cells
- they continue to undergo cell division to product new olfactory sensory neurons, which live for only about 2 months before being replaced
Olfactory glands (Bowman’s glands)
- within the connective tissue that supports the olfactory epithelium
- produce mucus that is carried to the surface of the epithelium by ducts
Olfactory transduction
binding of an odorant molecule to an olfactory receptor protein
Chemical reactions involving cyclic AMP (cAMP) cause
depolariztion
Neural pathway for olfaction
- action potential travels to the primary olfactory area
- impulses travel to the frontal lobe (orbitofrontal area) for odor identification
taste is a
chemical sense
taste buds contain
receptors for the sensation of taste
where are taste buds found
tongue, soft palate, pharynx, epitlottis