Special Senses (Test 2) Flashcards
(52 cards)
1
Q
What range can we see on the visible light spectrum?
A
- 390-700 nm
2
Q
What is our maximum sensitity to light?
A
- About 100 photons
3
Q
What is the pathway of light?
A
- Cornea –> iris –> anterior chamber –> lens –> posterior chamber –> retina –> fovea
4
Q
Nicotinic receptors cause pupils to?
A
- Constrict (Parasympathetic)
5
Q
Gq receptors cause pupils to?
A
- Dilate (Sympathetic)
6
Q
What is the structure of the Retina?
A
- Photoreceptors
- Interneurons
- Output neurons
7
Q
Inter-neurons are known as?
A
- Bipolar cells
8
Q
Where do bipolar cells receive their signal from?
A
- Receive input from horizontal cells and communicate with dendrites of Ganglion cells not by action potentials but by graded potentials.
9
Q
How many types of cone bipolar cells are there?
A
- 10
10
Q
How many types of rod bipolar cells are there?
A
- 1
11
Q
What are the 3 types of photoreceptor?
A
- Rods
- Cones
- Intrinsically photoreceptive retinal ganglion cells
12
Q
What are Intrinsically photoreceptive retinal ganglion cells?
A
- They detect light at 482 nm via melanopsin and send that info to the SCN and govern circadian rhythms
13
Q
What do horizontal cells do?
A
- Regulate bipolar signals near photoreceptors
14
Q
What do amacrine cells do?
A
- Regulate bipolar signals near ganglion cells
15
Q
How many photons to excite rods?
A
- 1 photon
16
Q
How many photons to excite cones?
A
- 100 photons
17
Q
How many photons to excite cones?
A
- 100 photons
18
Q
What are the 3 types of cones?
A
- Shortwave cones (445 nm)
- Meddlewave cones (535 nm)
- Longwave cones (575 nm)
19
Q
How does light activate photoreceptors?
A
- Light causes the activation of a phosphodiesterase which converts cGMP to GMP to close sodium channels and cause the cell to polarize
- A lack of light causes a buildup of cGMP, thereby sodium channels open
20
Q
How does optogenetics work?
A
- A light sensitive protein from algae (responds to blue light) is taken and inserted into the DNA of specific neurons in the brain
21
Q
How can optogenetics be used in neuroscience?
A
- With the right combo of neurons, you can activate/deactivate (hyperpolarize) an entire brain circuit to control specific behaviors like movement
22
Q
What cells create the optic nerve?
A
- The axons from ganglion cells and are myelinated by oligodendrocytes
23
Q
Where do signals from the optic nerve project to?
A
- The occipital lobe
24
Q
Receptors on the tongue can double as?
A
- Taste receptors
- Temperature receptors
25
Receptors on the tongue can double as?
- Taste receptors
| - Temperature receptors
26
How many genes are involved in odor reception?
- Over 800
27
What was an unexpected finding regarding olfactory receptor cells?
- Every single one expresses only one gene of all the genes that code for olfactory receptor molecules
28
How many odors can the nose detect?
- 1 trillion odors
29
How do genes aid to odor receptor complexity?
- Genes are alternatively spiced to aid in odor molecule detection
30
Where does the olfactory nerve send information?
- The olfactory cortex
| - The limbic system
31
What do channelrhodopsins do?
- Conduct cations and depolarize neurons upon illumination
32
What do halorhodopsins do?
- Conduct chloride ions into the cytoplasm upon yellow light illumination
33
What is the range of human hearing?
- 20 Hz - 20,000 Hz
34
What organ can interpret pressure changes in the ear?
- The cochlea
35
Pressure waves enter the ___ (ear) and concentrate sound onto the ___ (eardrum)?
- Pinna
| - Tympanic membrane
36
What are the 3 smallest bones in the body?
- The malleus
- The incus
- The stapes
37
What do the 3 smallest bones in the body press against to transfer pressure waves?
- The oval window
38
How do pressure waves convert into chemical signals?
- Pressure waves move the cilia of the cochlea to allow mechanically gated potassium channels to open and depolarize the cell
39
Which system provides information about acceleration?
- The vestibular system
40
What are the horizontal semicircular canals?
- Provide info about vertical axis rotation
41
What are the superior semicircular canals?
- Detect movement about the lateral axis
42
What is the posterior semicircular canal?
- Detects movement about the coronal plane
43
How do stimulation of hair cells in the semicircular cells differ from hair cell stimulation in the cochlea?
- They are actually very similar
44
How does alcohol affect interactions between the endolymph and cupula?
- You spin because alcohol diffuses into the endolymph fluid and changes the density of the fluid, thereby causing the cupula to move and tell the brain that you are moving
45
What are the different types of mechanosensory receptors?
- Merkel receptors
- Meissner's corpulscles
- Pacinian's corpuscles
- Ruffini cylinder
46
What are merkel receptors?
- Slow adapting skin receptors that record deep touch
47
What are meissner corpuscles?
- Fast adapting receptors that record light touch
48
What are pacinian corpuscles?
- Fast adapting receptors that record deep touch
49
What are ruffini cylinders?
- Slow adapting receptors that record stretch
50
What do AMPA receptors mostly depolarize?
- OFF bipolar cells
51
What do Metabatropic mGluR6 mostly depolarize?
- ON bipolar cells
52
Does the fovea contain mostly rods or cones?
- Coness
