biopsychology Flashcards
(59 cards)
the nervous system
specialised network of cells in body.
our primary internal communication system
based on electrical and chemical signals.
two main functions: process collect and respond to info in environment via senses, co-ordinate the working of different organs n cells.
central nervous system - brain
2 hemispheres (right and left) - contralateral.
4 lobes - frontal, temporal, parietal, occipital.
cerebellum.
outer layer called cerebral cortex.
main dip is central sulcus.
corpus collosum is tissue connecting hemispheres.
central nervous system - spinal cord
31 pairs of spinal nerves.
passed messages to and from the brain and connects nerves to the PND.
also responsible for reflex actions.
peripheral nervous system
transmits messages via millions of neurons, to and from the CNS.
1) somatic nervous system
2) autonomic nervous system
somatic nervous system
detects sensory info in environment and sends it to CNS.
motor info.
(voluntary)
autonomic nervous system
controls vital functions. (involuntary)
function of endocrine system.
works alongside NS to control vital functions in the body.
various glands in the body produce hormones.
These are released into the bloodstream and affect any cell in the body that has a receptor for that hormone.
The key gland is the pituitary gland located in the brain.(master gland)
it controls the release of hormones from all the other endocrine glands such as thyroid and adrenal.
endocrine and autonomic nervous system working together: fight or flight
during a stressful event.
ANS is divided into two branch branches: sympathetic NS and parasympathetic NS
sympathetic NS
prepare body for fight or flight in response to an acute stressor.
pituarity gland instructs adrenal medulla to release adrenaline.
increases heart rate, BP, O2.
decreases digestion, immune system.
parasympathetic NS
after acute stressor has passed, the PNS returns the body to relaxation.
increases thought process, creativity
decreases metabolism, adrenaline.
(opposite to SNS)
neurons
100 billion, 80% in brain
by transmitting signals electrically and chemically, these neurons provide the NS with primary function of communication.
process and transmit messages in NS using electrical and chemical signals
structure of a neuron
soma (cell body) - includes a nucleus containing genetic material of cell.
dendrites - protrude from soma.
axon - carries impulse down length of cell. covered in…
myelin sheath - fatty layer for protection and speeds up transmission. separated by gaps…
nodes of ranvier - speed up, jump across gaps.
axon terminals - communicate with next neuron across synapse.
electrical transmission: firing of a neuron
when neuron in resting state, inside of the cell is negatively charged, outside positive.
when neuron activated by stimulus, inside of cell becomes positively charged for split second, causing an action potential to occur (whole neuron positive).
creates an electrical impulse that travels down axon towards end of neuron (carrying the info)
sensory neuron
carry out sensory info from environment to CNS.
found in peripheral NS.
long dendrites, short axons.
cell body half way down axon
relay neurons
carry msgs from one part of CNS to another.
only found in CNS.
carry info from sensory to motor.
short dendrites and axons.
small congested one.
motor neuron
connect CNS to effectors such as muscles.
sends instructional info.
found in peripheral NS.
short dendrites, long axons.
excitation
when a NT increases the + charge of the postsynaptic neuron, increase in likelihood the neuron will fire n pass on electrical impulse.
inhibition
when a NT increases the - charge of postsynaptic neuron, decrease in likelihood neuron will fire n pass on electrical impulse.
synaptic transmission
The electron impulse from the neuron is transmitted across the gap chemically next to the neuron.
When it reaches the end of the neuron, it triggers release of a NT from vesicles.
Each NT has its own specific structure that fits perfectly into a postsynaptic receptor site.
when they fit, an ion channel in the membrane is opened.
this can cause an action potential in the dendrites. These can be excitatory or inhibitory.
Summation
whether the postsynaptic fires or not, is decided by summation.
excitatory and inhibitory influences are summed.
If total effect on neuron is inhibitory, less likely to fire. (Inside stays negative)
Once NT has diffused across synapse and bound to receptor site, chemical message converts back into an electrical impulse and process of transmission begins again.
This is via reuptake channels.
Motor Centre
Back of the frontal lobe on both sides.
Controls voluntary movement in opposite sides of the body
Motor cortex organised systematically with muscles of body mapped onto cortex, legs at the top, complicated face at the bottom.
Bigger area for most complicated
somatosensory Centre
Sensation of body.
Receive sensory input from receptors in the skin
Front of both parietal lobes.
Similar map of body surface with greater areas for more touch sensitive places
Visual centres
In occipital lobes at the back of the brain.
Process colours and shapes
HI sends info from bright visual field to left visual Centre and vice versa.
Face recognition= right occipital lobe only.
Damage in LH of occipital cortex can cause blindness in RVF of both eyes
auditory centres
both hemispheres, temporal lobes.
recieves info from both ears via two pathways which transmit info about the sound n its location
