Lecture 4 visual system Flashcards
1
Q
What do sensory systems not process
A
Random information
2
Q
What does the right hemifield activate
A
LEFT BRAIN
3
Q
Where does the ventral pathway terminate
A
inferior temporal
4
Q
Where does the dorsal pathway terminate
A
posterior parietal
5
Q
Where is the outer plexiform layer
A
between PR BP H
6
Q
Where is the inner plexiform layer
A
between G A
7
Q
Amacrine are between
A
ganglion and bipolar
8
Q
Horizontal between
A
bipolar and PR
9
Q
Pathway from front to back of eye
A
optic nerve gang BP Rod/cone nuclei Rod/cone outer segment Pigmented epithelium Choroid Sclera
10
Q
Where is phototransduction
A
Outer segment PR
11
Q
Humans PR response to light
A
hyperpolarise
12
Q
Describe pathway in dark
A
cGMP non-selective channels open
na+ influx dark current
depolarise PR
13
Q
Describe pathway in light
A
Rhodopsin activated Conf change Activate transducin Tranducin GTP alpha activates phosphodiesterase decrease cGMP Closes Na+/cGMP channels hyperpolarised
14
Q
describe what happens to bipolar ON cells when ligh shone
A
Less glutamate from PRs Metabotropic R's = inhibitory Not stimulated so channels open na= influx depolarised
15
Q
describe what happens to bipolar OFF cells when ligh shone
A
Less glutamate from PRs ionotropic glutamate = excitatory Channels not stimulated so closed no influx Na+ hyperpolarised
