Biopsychology Flashcards
How is the nervous system divided
into CNS and peripheral NS
what is the CNS split up into
Brain and spinal chord
What does the brain do in the CNS
centre of conscious awareness. cerebral cortex highly developed and distinguishes our higher mental functions from those of animals.
what does the spine do in the CNS
extension of the brain. responsible for reflex actions. receives and passes messages to and from the brain and connects nerves to the peripheral NS
What is the function of the peripheral NS as a whole and what is it divided into
transmits messages via millions of neurons to and from the CNS. Further subdivided into somatic and autonomic NS.
What does the autonomic NS (ANS) do
divided into sympathetic and parasympathetic. ANS links the CNS to internal organs, controls functions including breathing, stress response and sexual arousal.
can the ANS be controlled voluntarily
no
what does the somatic NS do
transmits info received by receptors (eyes, ears nose etc.) to the CNS and transmits messages from the CNS to the muscles to instruct them to act.
What is the structure of a neuron
nucleus cell body dendrite axon myelin sheath schwanns cells nodes of ranvier axon terminals
what does the nucleus do
holds genetic material of the cell
what does the dendrites do
branch like structures that protrude from the cell body, they carry nerve impulses from neighbouring neurons to the cell body.
what does the axon do
carries the impulses away from the cell body and down the length of the neuron
what does the myelin sheath do
protects the axon and speeds up the electrical transmission of the impulse.
what do the nodes of ranvier do
if the myelin sheath was continuous it would slow down the impulse. the nodes of ranvier are gaps in the sheath that force the impulse to jump across the gaps and along the axon.
what do the axon terminals do
terminal buttons that communicate with the next neuron in the chain, they communicate across the synapse.
describe a neuron in its resting state
inside of the cell is negatively charged compared to the outside
what happens when the neuron is activated by a stimulus
activated by stimulus= inside of the cell becomes positively charged causing an action potential to occur. this creates an electrical impulse that travels down the axon to the end of the neuron.
what are the three types of neurons
sensory, relay and motor
describe sensory neurons and what they do
long dendrites short axons
tells brain about external and internal environment by processing info from the 5 senses. carry messages from PNS to CNS
describe relay neurons and what they do
short dendrites short axons
carry messages from one part of CNS to another.
connect motor and sensory neurons
describe motor neurons and what they do
short dendrites long axons
carry signals from CNS to control effector organs, including glands, muscles and their functions.
where does transmission of an impulse take place
the synapse. the transmission of an impulse between neurons is chemical.
describe synaptic transmission
the impulse reaches the pre synaptic terminal on the pre synaptic neuron, causing the synaptic vesicles to release neurotransmitters into the synapse. they diffuse across the synapse and are taken up by the post synaptic receptor site. the chemical message is then converted back into an electrical impulse and transmission begins again in the post synaptic neuron
why does the shape of the neurotransmitter (ntm) matter
each one has its own specific molecular structure that is complementary to the post synaptic receptor site. fits like a lock and key.
give an example of a neurotransmitter with a specialist function
acetylcholine is found where a motor neuron meets a muscle and upon its release causes the muscle to contract
what is excitation
when a neurotransmitter increases the positive charge of the post synaptic neuron, increasing the likelihood that the neuron will fire and pass on the impulse.
what is inhibition
when a neurotransmitter increases the negative charge of the post synaptic neuron. decreases the likelihood the neuron will fire and pass on the impulse.
what effect does serotonin have as a ntm
causes inhibition in the receiving neuron, more neg charge less likely to fire
what effect does adrenaline have as a ntm
causes excitation of post synaptic neuron more pos charge increase likelihood next neuron will fire
how does the endocrine system vary from the nervouse system
acts much slower but has a widespread effect. ns more localised. uses hormones rather than electrical impulse.
what produces hormones
glands
what do hormones effect
any cell that has the receptor for that particular hormone
what is the major endocrine gland
pituitary gland located in the brain and controls the release of hormones from all other glands in the body
what does the thyroid gland do
produces thyroxin for the regulation of growth and metabolism
what does the adrenal gland do
produces adrenaline responsible for the flight or fight response
ovaries gland function
produce oestrogen and progesterone, responsible for female sexual behaviour
testes as gland function
produce testosterone responsible for male sexual behaviour
what are the effects of sympathetic action
gets fight or flight ready heart rate increases pupils dilate intestine (gut) action slows salivation stops and mouth dries
what is the parasympathetic action
heart rate decreases
pupil constricts
intestine/ gut action restored
salivation restored
how do the parasymp and the symp NS link
symp gets you prepared for a fight or flight response
parasymp restores bodily functions to normal state of rest and digest
describe the fight or flight response
stressor perceived by hypothalamus and ANS changes from resting state to physiologically aroused sympathetic state
hypothalamus recognises threat sends message to adrenal medulla
triggers release of adrenaline into the bloodstream and noradrenaline in the brain results in sympathetic responses.
threat passed parasym ns works in opposition to symp ns - its actions are antagonistic to symp ns reduces the activities of the body increased by symp branch.
what might you feel during the fight or flight response
stress panic excitement sick feeling as blood is diverted away from the digestive system
what is localisation of function in the brain
the principle that specific functions e,g language have specific locations within the brain
also referred to as cortical specialisation
what happened to Phineas Gage
railroad worker Gage suffered an explosive accident that resulted in him having a railroad spike through his left eye and out the back of his head. accident removed most of left frontal lobe.
