Teim-part 2 Flashcards
Diff between sensory afferent and extensor efferent connections and interneuron
Connections between sensory afferents and extensor efferent are excitatory but interneurons activated by afferents are inhibitory
Diff between grey and white Mayer
Grey are nuclei, white are axon tracts
Layout of sensory ganglia
Sensory ganglia lie adjacent to eachother in the spinal cord (dorsal root ganglia) or the brainstem (cranial nerve ganglia), autonomic ganglia in the peripheral nervous system: in sympathetic, they are along the vertebral column and send to peripheral targets, in parassympathetic: ganglia are in organs
7 parts of cns
spinak cord, medulla, pons, midbrain, cerebellum, diencephalon and two cerebral hemis. Medulla pons and midbrain are the stem hemis are the forebrain
Brain stem
Houses nuclei of the cranial nerves that receive input from cranial sensory ganglia or give rise to axons that form motor nerves
Superior and inferior colliculli which control eye movements and auditory processing. Substantial nigra and ventral tegmental area which process reward
Spinal cord
Runs from first to twelfth thoracic vertebra, divided into cervical, thoracic, lumbar, sacral and coccygeal regions, each gives rise to to spinal nerves . sensory info carried by afferent spinal nerves enters the cord via dorsal roots and motor commands leave by ventral roots.
Interior cord is formed by grey matter, surrounded by white matter. Grey matter divided into dorsal, lateral and ventral horns
Savant syndrome
Damage during childbirth, have disordered lives, can’t live independently
Some have special skills (art, maths, music, languages ect.)
Neuroethology
Brain differs across species due to natural selection. Allometry is idea brain size relative to body but in some it is bigger e.g. humans and some smaller blue whale called residual brain size. Residual brain size related to more complex behaviour e.g. howler monkeys has smaller grain as general feeder but spider monkeys has foraging so bigger, in bats bigger brains hunt meat but insects opportunity
Evolution of human brain
Endocranial vol increased over time W body size but at a faster rate. Correlated W increased tool use and more developed, started creating art. Evolution-microsephillie genes mutation have smaller brains and behavioural issues
Brain adaptations
Echolocation so have larger auditory processing, tarsier has huge eyes. Superior colliculus bigger in animals W greater need for vision and inferior bigger in those with greater auditory. In brains of rats, over representation of whiskers, face in humans as well as hands compared to elbow. Birds W bigger brains have bigger hippo as clarks nutcracker stores 2000 pieces of food and eats the ones that decompose , scrub jay has smaller as doesn’t.
Evolution of social intelligence
when we started group behaviour, we need more complex behaviour so we developed an increase in neocortex size (monkeys hide their grooming from the alpha male). Tactical deception index correlates with neocortex vol
Size of face regions and social networks
some regions have great preference for faces in monkeys, animals raised in diff group sizes- found size of face regions increases in larger groups
As brain size increases as does group size in humans as well as monkeys (dunbars model)
Communication in songbirds plus humans
Reed warbler has more complex songs and has higher residual hvc size in brain and the grasshopper warbler has simple sound with smaller brain area
In humans: broca’s area is larger than other areas in animals similar to Broca’s area
Cortical thickness
Correlation between iq and cortical thickness, thicker during development correlated intelligence but thickness becomes the same in adulthood . For violin players, non playing thumb is same as normal but big diff in the little finger. Diff in those who use thumb vs index finger to text and those who don’t have touchscreen in brain activity. Maguire taxi driver study
The frontal lobe
Largest, most common region for brain injury, last to mature, inhibits inappropriate thoughts
