Studied by 1 personThe CNS is made up of
Brain and spinal cord
CNS
Central nervous system
The PNS is made up of
Everything else e.g: nerves, motor pathways, sensory pathways
PNS
Peripheral nervous system
Brain receives a constant blood flow from the heart of around
20%
Name 3 key brain structures
Cerebrum, Cerebellum and Brain stem
Contralateral
opposite side
Ipsilateral
Same side
Top of brain
superior or dorsal
Back of brain
Posterior or cadual
Bottom of brain
Inferior or ventral
Front of brain
Anterior or rostral
Towards the middle
Medial
Towards the side
Lateral
Pathway that connects the left and right side of hemisphere is called a
commissure
Fibre bundle that connects the two hemispheres of the brain
Corpus callosum
meninges
3 layers of tissue that protect the brain and spinal cord
cerebrospinal fluid CSF
a clear fluid that fills the subarachnoid space
functions of cerbrospinal fluid
shock absorber, bouyancy
Ventricles
hollow space filled with CSF. Helps with the exchange of materials between blood vessel and brain tissue
Capillaries in the brain have no
gaps
How thick is the cerebral cortex?
3mm
what are the folds in the cerebral cortex called?
gyri
4 lobes in the cerebral cortex
frontal, parietal, temporal and occipital
Grooves in the cerebral cortex
sulci
main functions of frontal lobe
motor and cognition
main functions of the parietal lobe
somatosensory
function of occipital lobe
vision
functions of temporal lobe
hearing, vision, cognition and emotion
the basal ganglia is
a collection of nuclei
the basal ganglia is important for
the control of movement, reward systems
lesions in the basal ganglia can cause disorders such as
parkinson’s and Huntington’s
The limbic system is important for
emotion and learning/memory
the limbic system involves
limbic cortex, hippocamous, amygdala and more
The basal ganglia consists of
the caudate nucleus, putamen and globus pallidus
The limbic system is important for
emotion and learning/memory
Thalamus receives and sends info to
the cortex
Hypothalamus is connected to
pituitary gland
Hypothalamus controls the
autonomic nervous system
forebrain
diencephalon
Midbrain
mescencephalon
Hindbrain
rhombencephalon
Metencephalon is made of
pons and cerebellum
Pons is involved in
sleep and arousal, relaying info to cerebellum
cerebellum is important for
the co ordination of movement
How many neurons do we have
86 billion
Soma
neuron cell body
neuron soma holds
the nucleus
dendrites
receive messages
axon
carries info from soma to terminal buttons
Myelin sheath
wraps around axon
terminal buttons
at the end of axon branches
Supporting cells for neurons such as glia help by
supplying nutrients, chemicals and waste services
All cells have an
electrical charge
Neurons can reverse their
electrical charge
Membrane’s are made of
2 layers of phosholipid molecules
ion channels span
the membrane
cations are
positively charged
Anions are
negatively charged
intercellular fluid contains
potassium ions and anions
extracellular fluid contains
sodium and chloride ions
the membrane potential is the difference
in electrical potential inside and outside the cell
Resting potential of a neuron
-70mV
Resting potential is important to allow
stimulus response
depolarization
decrease from normal resting potential (brings membranes closer to 0)
hyperpolarization
increase relative to resting potential (more negative)
Action potential transmitted down axon via
propagation
neurons send messages via
synaptic transmission
neurotransmitters are released from one neuron and
attached to another neuron
EPSP
Excitary postsynaptic potential
IPSP
Inhibitory postsynaptic potential
Neurotransmitters bind by using
lock and key method
Ionotropic receptor
contains a binding site and an ion channel
metabotropic receptor
contains a binding site, starts a chain reaction, requires energy
Reuptake
transmitter taken back by the presynaptic terminal
enzyme deactivation
transmitter broken down by an enzyme
excitatory
increases the likelihood of neurons firing
inhibitory
decreases the likelihood of neuron firing
integration
summation of PSPs in control of neurons firing
inhibition of inhibitory neurons
more likelihood of behaviour
excitation of inhibitory neurons
less likelihood of behaviour
GABA
Most abundant inhibitory neurotransmitter in CNS (reduces chances of neuronal firing)
Glutamate
most abundant exciting neurotransmitter in CNS. Can bind to a number of receptors
Acetylcholine
found in CNS and PNS at neuromuscular junctions
Dopamine
Motor control, reward, addiction
serotonin
regulation of mood, eating, sleep
Antagonist
A drug that blocks a neurotransmitter e.g: botox
Agonist
A drug that mimics a neurotransmitter and enhances a synapse function
The visual pathway
Retina - lateral geniculate body - visual cortex
3 parts of the retina
photo-receptors, bipolar cells, retinal ganglion cells
Do photoreceptors have more rods or cones?
Rods
Roughly how many rods are in the human retina?
120 million
Rods are sensitive in
low light situations
Rods do not discriminate
colour (wavelength)
Rods have higher density in
periphery
Rods track
high rate changes
Aprox how many cones in human retina?
6 million
number of cones in the human eye
3
The 3 cones in the human eye help differentiate
wavelength
Eye cones are less
sensitive to low light
Note
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