10-1 Flashcards
Chemical senses
- Olfaction
- Vomeronasal
- Gustatory
- Trigeminal Chemosensory
Olfaction
Smell
Vomeronasal
Pheromone
Gustatory
Taste
Trigeminal Chemosensory
Noxious molecules
All 4 chemical senses can detect _____
Noxious molecules/irritants
Stimuli of olfaction
Odorants
How does olfaction help us identify food vs. noxious substances
Foods infected with bacteria have a smell
Olfaction influences:
Reproduction, social interaction defensive responses, and feeding
Vomeronasal is closely associated with ____
Olfaction
What does the vomeronasal system detect
Airborne odors produced by predators, prey, and potential mates
What animals have a vomeronasal system
Most mammals (not humans)
What detects food taste
Receptors in the tongue
Stimuli of gustatory system
Tastants
Most foods are soluble in ___ or___
Water or fat
What does the trigeminal chemosensory system detect
Noxious molecules that can cause AP in all senses
Odorant
Chemical with a smell
Concentration of water soluble needed to smell
High concentration
Concentration of fat soluble needed to smell
Low concentration
How are odors grouped
By whether they are water or fat soluble
Why can you smell lipid soluble smells at a lower concentration
Mucus is a fatty lipid-based solution that mixes with lipids in the nose. Smell sticks to the mucus and stays there
Discrimination
Being able to differentiate between different odors
Ansomia
Loss of olfactory sensitivity
What is the first sense we lose
Smell
What is loss of smell used to diagnose
Alzheimers, Parkinsons and MS
____ is associated with anosmia
Aging
Olfactory test
Close eyes and smell 7 scents. Normal people will get 90% correct, and anosmic people will get 50% correct
Reasons for anosmia in aging people
- Destruction of neurons in the nose
2. Part of the brain that processes smell may not work
Parts of the brain that process olfactory info
Orbitofrontal and media cerebral cortex
Why is olfactory activity lower in the aging brain
- Not much info coming from the nose
2. Neurons lost in this part of the brain
Nair
Where air enters the nose
Center bone of the nose
Nasal septum
Olfactory turbinates
Bones of the nose on both sides of the septum
Parts of the turbinates
- Superior
- Middle
- Inferior
Epithelium found in front where air is entering the nose
Respiratory epithelium
Where is epithelium in those nose
Smeared on top of the turbinates
What is thinner: respiratory or olfactory epithelium
Respiratory
Where are olfactory receptors located
In the olfactory neuron of the olfactory epithelium
Brain is separated from the turbinate by a bone called _____
Cribriform plate
What bone is the cribriform plate part of
Ethamoid bone
How do olfactory neurons get through the cribriform plate and go to the olfactory bulb
It is perforated (has holes)
What does the short axon of the bipolar olfactory neuron end in
Olfactory knob
Where does the long axon of the bipolar olfactory neuron go
Through the cribriform plate
Where on the olfactory neuron are the receptors
Olfactory cilia
How is the olfactory nerve I formed
Long axons bundle and go up to the olfactory bulb
Bowman’s gland
Produces mucus
Another name for mature olfactory receptor neurons
Sensory neurons
Why are mature olfactory receptor neurons considered OMP+
They produce the olfactory marker protein
Another name for supporting cells
Sustentacular cells
Why dont immature developing olfactory receptor neurons produce OMP
OMP is only made when the axon connects to the olfactory bulb
What is OMP a marker for
MATURE olfactory neurons
What cells divide to make the immature neuron
Basal cells
Why are there olfactory cilia
Increase surface area (can hold more receptors)
How long do olfactory receptor neurons live
30-60 days
Function of supporting cells
Protect olfactory receptor neurons from chemicals (deactivate chemicals, kill virus/bacteria), maintain homeostasis, and clean environment
Why is the sense of smell reduced when the nose is dry
Not much mucus to bind odorants
What is used to kill olfactory neurons in experiments
Zinc sulfate
Zinc sulfate does not kill ___
Basal cells
How long does it take to regenerate olfactory receptor neurons
21 days
How many genes make odorant receptors
1,000
How are genes for odorants made
Switching out amino acids
What happens when odorants are put on the cell body
Nothing. This proves that the receptors are on the cilia
What happens when odorants are put on the cilia
Depolrization –> taken to olfactory bulb
How many transmembrane domains of the odorant receptor
7
What type of receptor is the odorant receptor
G-protein coupled receptor
Where is adenylyl cyclase found
Knob
How many odorant receptor types per neuron
Some have one, some have many
