Nervous system: week 3 Flashcards
What is sensory adaptation?
When our receptor cells and sensory neurons get used to a specific stimulus and stop responding to it
What do precisely localized information does?
(fine touch)
Axons reach the top of the spinal cord (medulla)
what does poorly localized information do?
(temperature/pain)
Axons synapse immediately with other neurons
How do sensory neurons from the head send axons directly into the brain?
via cranial nerves (optic nerve)
Transmitted Through several relay stations
Describe the Retina
-Layer of photoreceptors
-Bipolar cells
-ganglion cells
How do photoreceptors work
Photoreceptors get hit by light
they get hit by a photon that causes a cascade of chemical changes inside the receptor.
This triggers activity in the bipolar neuron -> triggers activity in the ganglion cells -> activity of ganglion cells form track into brain.
-> Ends in the middle of the brain (thalamus)
-> connect to thalamic neurones
-> this sends their axons into the back of the brain
(called optic radiation)
-> optic radiation from the thalamus gets sent back to the visual cortex
In terms of visual processing, photoreceptors are…
-at the lowest level
-the first step of visual processing
True/False
Ganglion cells receive information (input) from other parts of the brain
True
What is the brainstem?
Medulla, Pons, Midbrain
What is the thalamus?
Massive structure on top of midbrain, centre of brain
-> main relay station for all incoming sensory signals
-> receives downwards going input from higher areas
-> Modulates relay of sensory signals
What is the hypothalamus?
Small structure in front and below the thalamus
-> directly connected to the pituitary gland (master gland of the ES)
-Brains gateway to the ES.
True/false: Is the amygdala involved in motor control?
False! the Amygdala is a part of the limbic system
What is the Cerebral Cortex?
-> Multi Layered sheet of neurons cell bodies
-> Many send their axons to the opposite hemisphere (do this via the corpus callosum)
What is the corpus callosum?
-> thick bundles of axons connecting the 2 hemispheres
->Main connection
->Almost all signal transfers between hemispheres done by CC
What is the Cerebral Cortex?
It is highly folded.
Gyrus: outward folded
Sulcus: Inward folded
