Neurobiology - part 2 Flashcards
types of stretch receptors
muscle spindle - stimulate muscle contraction
golgi tendon organ - inhibit muscle contraction
central pattern generator (CPG)
two processes that sequentially increase and decrease interact resulting in repeat return to starting condition
regulate programmed movements within brain stem/ spinal cord to retain rhythmic activation
e.g. breathing, swallowing, walking, mastication, sleeping
excitatory neurotransmitter
glutamate
inhibitory neurotransmitter
GABA
innocuous stimulation
touch/ pressure
transmitted by A-β fibres
analgesia
analgesia signals (enkephalin) block pain before it is relayed to brain enkephalin controlled by serotonin and noradrenaline
what modulates pain signal
opioids and endogenous ligands (e.g. enkephalin) on opiate receptors on periaqueductal grey (PAG) and raphe nuclei of reticular system
functions of cerebellum
vestibulocerebellum - posture and balance
spinocerebellum - updating ongoing movements
neocerebrum - initiation and planning of movements, motor learning
function of basal ganglia
inhibits movement
proprioceptors
sensory receptors that respond to position and movement
reticular formation
network of interconnected nuclei located in brainstem (midbrain, pons, medulla)
reticular nuclei divided into three columns
median column - regulate mood (serotonin), raphe nucleus
medial column - motor coordination, gigantocellular nuclei
lateral column - regulate breathing, parvocellular nuclei
also modulates pain by serotonin
ascending reticular activating system
dopaminergic
serotonergic
noradrenergic
cholinergic
amygdala
structure in limbic system
emotional learning, memory, fear, fear conditioning , rewards
stimulation causes anxiety, fear
lesion induces mellow, incapable of fear
phototransduction
conversion of light to change in electrical potential across membrane in rods and cones
peripheral vision
rods throughout retina dimlight (scotopic vision, monochromatic) high sensitivity low resolution/ poor spatial acuity motion detection large receptive field
central vision
cones around fovea daylight (phototopic vision, chromatic) low sensitivity high resolution/ spatial acuity narrow angle of coverage low receptive field
trichromacy
three types of cones (red, blue, green)
otilith organs
utricle (horizontal) and saccule (verticle)
calcium carbonate deposit on top of hair cells
control of bite force
detected by periodontal ligament receptors
inhibit CN V by inhibitory interneurons
