BIOM2015 Lecture Notes - Lecture 9: Depolarization, Osmoreceptor, Baroreceptor
Monday, 7 May, 2018
Sensory Nervous System
Why do we need consciousness
-our brain needs to simulate to prepare for action
There are 4 types of sensory stimulus (pain, thermal, touch, light)
Stimulus mechanism
when sensation reach non-specific cation channel open and na+goes in while K+ goes
out, if there are more non-specific channels being opened graded potential can be
generated to open voltage gated ion channels Ca2+ rush in and rapid depolarisation
occurs
1 cell and 2 cells sensation stimulus
2 cells stimulus are the same with non-specific cation channels but 2 cells has
neurotransmitters and synaptic cleft which is being secreted from vesicles when Ca2+
released; neurotransmitters binds to membrane and release to synaptic cleft acting on
nerotransmitters receptors on another neurone to open up channels to continue with the
depolarisation
*modality (how we perceive stimulus) is nerve specific not receptors specific
Sensory Receptors
Thermal-receptor for heat
Photoreceptor for light
Osmoreceptor for [blood]
Mechanalreceptor for (hearing pressure and vibration)
Nocireceptor for pain (free nerve endings)
Baroreceptor for blood pH
modality is how we perceive after stimulus
The brain can tell/ convey
Modality (what type of stimulus)
Location (Where is the stimulation)
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