Exam 3: The Special Senses Flashcards
General Senses
- Include:
- Somatic sensations (tactile, thermal, pain, and proprioceptive)
- visceral sensations
- Scattered throughout the body
- simple structures
Special Senses
- Include
- smell
- taste
- vision
- hearing
- equilibrium
- concentrated in specific locations in head
- anatomically distinct structures
- complex neural pathway
How many receptors does Olfactory epithelium contain?
10-100 million receptors
Olfactory epithelium is made up of 3 types of cells:
- Olfactory receptor cells
- Supporting Cells
- Basal Cells
Olfactory Receptor Cells
- a bipolar neuron with cilia called olfactory hairs
- respond to chemical stimulation of an odorant molecule
Supporting Cells
Provide support and nourishment
Basal Cells
Replace olfactory receptors
How many different odors can be detected by Olfaction?
10,000
What are the 11 steps of Olfaction?
- Odorant molecule binds to the receptor of an olfactory hair
- Receptor linked to G protein; Odorant binding causes G-protein activation
- G-Protein activates adenylate cyclase
- Adenylate cyclase produces cAMP
- cAMP causes the opening of ligand gated Na+ channels
- Open Na+ channels allow the inflow of Na+
- Inflow of Na+ causes generator potential
- Generator potential turns into nerve impulses along olfacroty nerves
- nerve impulse travels to the olfactory bulbs
- Nerve impulse travels to the olfactory tract
- Nerve impulse travels to the primary olfactory area of the cerebral cortex
From the olfactory tract sensory information reaches:
- Cerebral cortex- allowing for consious smell
- Hypothalamus- controlling visceral reactions
- Amygdala- odor recognition and emotional association
What is another name for taste?
Gustation
The taste bud is made up of three types of epithelial cells:
- Supporting Cells
- Gustatory Receptor Cells
- Basal Cells
About per taste bud
50 Gustatory cells
Where are taste buds found?
Papillae
Three types of papillae with taste buds:
Vallate (circumvallate)
Fungiform
Foliate
Which type of taste bud doesnt have taste buds, but only mechanical function?
Filliform
What are the 5 basic taste sensations?
- Sweet
- Salt
- Sour
- Bitter
- Umami
Sweet
produced by organic compouds; e.g sugar or artificial sweeteners
Salt
produced by metal ions; e.g Na+ and K+
Sour
Associated with acids: e.g vinegar
Bitter
Produced by alkaloids; e.g unsweetened chocolate
Umami
taste related to amino acids to produce meaty flavor