Special Senses Flashcards
1
Q
Describe the olfactory epithelium
A
- Olfactory receptor cells (350 diff types)
- Basal cells (produce new OSRs)
- Supporting cells
2
Q
Where are OSR found
A
- Cilia of olfactory cells
- embedded in mucus layer
3
Q
Where do olfactory nerves synapse?
A
- mitral cells (2nd order olfactory neurones)
- within glomeruli
4
Q
Type of odour detected depends on…
A
- Type of receptor protein expressed on cillia.
- Each type of OSR projects to a different glomeruli
- Each odour has a different firing pattern from each type of cell
5
Q
Where are taste buds located?
A
Within papillae (50-150 on each)
6
Q
How do we detect taste?
A
- Chemicals dissolved in saliva enter taste pore
2. Microvilli of taste cells extend into pores
7
Q
And 1/3?
A
Vagus
8
Q
Sensory pathway of taste
A
- Facial nerve 8,9, and 10
- Brain stem: nucleus of solitary tract in medulla oblongata
- VPN of Thalamus
- Gustatory cortex (in insula)
9
Q
What is sound
A
A transverse wave of compressed air
10
Q
Describe the outer ear
A
- Pinna: captures sound efficiently
- Auditory canal ends in
- Tympanic membrane
11
Q
Parts of middle and inner ear
A
Middle: ossicles
Inner: cochlea
12
Q
Pathway of sounds transduction
A
Sound-> tympanic membrane-> ossicles-> oval window-> cochlea
13
Q
Describe how the cochlea works
A
- Stapes hits oval window
- Wave travels length of Basilar membrane (hair cells)
- Through Helicotrema (end hole) and then hits round window
14
Q
Which end of basilar detects which frequency’s
A
Basal end: narrow and stiff (high frequency’s)
Apical end: wide and flexible (low frequencies)
15
Q
Describe the organ of corti
A
- Contains inner (tuning) and outer hair cell receptors which act as auditory receptors
- Their displacement causes AP
- Partially covered by tectorial membrane
