Neuroscience Flashcards
two major divisions of the NS
central nervous system, peripheral nervous system
peripheral nervous system includes
sensory nerves, motor nerves, autonomic nervous system, enteric nervous sytem
sensory nerves
input to CNS from sensory organs
motor nerves
output from CNS to muscles
autonomic nervous system
controls many non-voluntary bodily functions (digestion, heart rate, sweating) has 2 branches - sympathetic and parasympathetic
enteric nervous system
controls digestive activity and senses physcial and chemical conditions of the gut
brain and spinal cord are protected by
bone, meninges, blood brain barrier
meninges
flexible sheet made from 3 membranes between bone and nervous tissue - dura mater, arachnoid membrane, pia mater
blood brain barrier
blood vessels supplying blood to CNS have special walls, restricting entry of many chemicals into CNS
the spinal cord
cable of neural fibres with “roots” branching off. interface between brain and peripheral nervous system
the brain
large clump of 100 billion neurons. 2 hemispheres, midline through the centre
the ventricles
cavities inside the brain filled with cerebro-spinal fluid, sewerage system of the CNS
major subdivision of the brain
brainstem, cerebellum, thalamus and hypothalamus, limbic system, basal ganglia, neocortex, corpus callosum
brainstem
at base of brain. controls life-supporting functions
cerebellum
on top of brainstem.. control of precision movements
thalamus
on top of brainstem, right on midline of brain. relays sensory info, except for smell
hypothalamus
on top of brainstem on midline. involved in control of hormones and motivational control. controls feeding and sexual behaviour
limbic system
wraps around thalamus. involved in control of memory and emotion
what parts are involved in the limbic system
cingulate cortex, fornix, hippocampus, amygdala, mammillary bodies, olfactory bulb
basal ganglia
wraps around thalamus. involved in action, thought, movement. affected by parkinsons disease
what parts are included in basal ganglia
right and left caudate, putamen, globus pallidus
neocortex
the wrinkly structure all over brain, made of tissue. has four lobes
four lobes of the neocortex
frontal lobes, parietal lobes, temporal lobes, occipital lobes
corpus callosum
collection of “cables” connecting our 2 brain hemispheres
neurons are made up of
dendrites, soma, axon
what signals do neurons convey to each other
binary (“on/off”) signlas
the action potential
at specific moments, the neuron can open channels that let sodium ions enter and exit. neuron is bipolarised in these brief moments
myelin
fatty substance on neurons produced by another type of cell in the NS. prevents depolaraisation
how do neurons interact
neurons form small junctions called “synapses,” communicate across these
transcranial magnetic stimulation (TMS)
uses brief magnetic pulse next to skull to induce a small electrical current which depolarises neurons and can provoke action potentials
electroencephalography (EEG)
electrode plates against skull can record electrial fields generated by combined/electrical activity of many neurons
positron emission tomography (PET)
measures activity in brain by measuring changes in blood flow
magnetic resonance imaging (MRI)
bombarding head with high frequency radio waves, while measuring orientation of protons
functional magnetic resonance imaging (fMRI)
measures changes in oxygen in blood
magnetoencephalography (MEG)
measures magnetic fields emitted from brain - created by electrical activity in neurons
what keeps us awake
noradrenaline neurons, serotonin neurons, acetylcholine
decerebration
disconnecting the forebrain frm brainstem. causes profound and almost continuous sleep
preoptic area
destruction to this can cause insomnia, stimulation can induce sleep
slow-wave sleep
role of reciprocal connections between thalamus and cortex in orchestrating synchronised neuronal activity
REM sleep
when the brain waves become desynchronised
hunger and satiety determined by
contents of stomach and substances circulating blood
the lateral hypothalamus
regulates feeding by controlling release of insulin, regulating attention, influencing taste
the ventromedial hypothalamus
destruction of this in rats causes them to become overeaters
the paraventricular nucleus of the hypothalamus
satiety is due to a hormone released in this area
right hemisphere of brain
receives sensory input from left, controls motor response on left side of the body
left hemisphere of the brain
receives sensory input from right side, controls motor response on right side of body
hemispheric dominance
one side is dominant for each person
speech areas of the brain
broca’s area, wenicke’s area
broac’s area
lower posterior region of left frontal lobe. damage causes difficulties speaking
wernicke’s area
posterior of left temporal lobe. damage causes problems with comprehension and speech
case of henry molaison
surgeon removed hippocampus on both sides for treatment of epilepsy - worked for epilepsy but resulted in dense amnesia
wernicke-korsakoff’s syndrome
severe vitamin B1 defficiency in chronic alcoholics triggers this - amnesia
alzheimer’s disease
widespread neuro-degeneration in brain, brain shrinks, abnormal neural tissue present
