Neurobiology - part 2

Question 1

types of stretch receptors

Answer 1

muscle spindle - stimulate muscle contraction

golgi tendon organ - inhibit muscle contraction

Question 2

central pattern generator (CPG)

Answer 2

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

Question 3

excitatory neurotransmitter

Answer 3

glutamate

Question 4

inhibitory neurotransmitter

Answer 4

GABA

Question 5

innocuous stimulation

Answer 5

touch/ pressure

transmitted by A-β fibres

Question 6

analgesia

Answer 6

analgesia signals (enkephalin) block pain before it is relayed to brain 
enkephalin controlled by serotonin and noradrenaline

Question 7

what modulates pain signal

Answer 7

opioids and endogenous ligands (e.g. enkephalin) on opiate receptors on periaqueductal grey (PAG) and raphe nuclei of reticular system

Question 8

functions of cerebellum

Answer 8

vestibulocerebellum - posture and balance
spinocerebellum - updating ongoing movements
neocerebrum - initiation and planning of movements, motor learning

Question 9

function of basal ganglia

Answer 9

inhibits movement

Question 10

proprioceptors

Answer 10

sensory receptors that respond to position and movement

Question 11

reticular formation

Answer 11

network of interconnected nuclei located in brainstem (midbrain, pons, medulla)

Question 12

reticular nuclei divided into three columns

Answer 12

median column - regulate mood (serotonin), raphe nucleus
medial column - motor coordination, gigantocellular nuclei
lateral column - regulate breathing, parvocellular nuclei
also modulates pain by serotonin

Question 13

ascending reticular activating system

Answer 13

dopaminergic
serotonergic
noradrenergic
cholinergic

Question 14

amygdala

Answer 14

structure in limbic system
emotional learning, memory, fear, fear conditioning , rewards
stimulation causes anxiety, fear
lesion induces mellow, incapable of fear

Question 15

phototransduction

Answer 15

conversion of light to change in electrical potential across membrane in rods and cones

Question 16

peripheral vision

Answer 16

rods throughout retina 
dimlight (scotopic vision, monochromatic) 
high sensitivity 
low resolution/ poor spatial acuity 
motion detection 
large receptive field

Question 17

central vision

Answer 17

cones around fovea
daylight (phototopic vision, chromatic) 
low sensitivity 
high resolution/ spatial acuity 
narrow angle of coverage 
low receptive field

Question 18

trichromacy

Answer 18

three types of cones (red, blue, green)

Question 19

otilith organs

Answer 19

utricle (horizontal) and saccule (verticle)

calcium carbonate deposit on top of hair cells

Question 20

control of bite force

Answer 20

detected by periodontal ligament receptors

inhibit CN V by inhibitory interneurons