Chemoreception - Smell Flashcards
What are basal cells?
They are precursor for new olfactory receptor cells
What do the axons of the olfactory receptor cells collectively form?
The olfactory nerve
What do cilia portions of olfactory receptor cells have?
Binding sites for odourants
What does the act of sniffing do?
Enhances the binding process of odourants onto cilia of olfactory receptor cells
To be smelled , a substance must be?
- volatile (in the air)
- water soluble
Describe pathway of olfactory receptor cells
- binding of scent signal to a receptor activates a G protein
- this gives rise to cAMP to open sodium channels
- this generates a receptor potential
- thins produces action potentials in e afferent fibres
Where do afferent fibres synapse?
In the olfactory bulb
Describe olfactory receptors and their glomeruli
- cillia picks up scent
- scent sent to olfactory receptors
- glomeruli separate the components of an odour
- the glomeruli synapse with mitral cells that refine smells
- info sent to limbic system and cerebral cortex
What are the two different routes that and olfactory bulb can travel through?
- subcortical route to limbic systems
- thalamus to Cortex
Describe subcortical route
Goes to the limbic system and to the primary olfactory cortex to analyse smell and behavioural reactions
Describe the thalamus to cortex route of scent
This route is important for conscious perception and fine discrimination of smell
What removes odourants away from the olfactory receptors so at the sensation of a smell doesn’t linger?
Odour eating enzymes
What is the vameronasal organ?
Located in the nose next to the vomer bone that detects pheromones
The binding of a pheromone to its receptor will trigger an action potential that travels thru non-olfactory pathways to?
The limbic system - responds to socio sexual behaviour
What cell types are in the olfactory mucosa?
- olfactory receptor cells
- supporting cells
- basal cells
