nervous/endocrine system, neurons, synaptic transmissions, localisation Flashcards
BIOPSYCH
what is the nervous system?
a specialised network of cells in the human body and is our primary internal communication system
how many main functions does the nervous system have and what are they?
2
to collect, process and respond to information in the environment
to co-ordinate the working of different of different organs and cells in the body
what are the 2 subsystems in the nervous system?
central nervous system
peripheral nervous system
what is the central nervous system made up of?
the brain and the spinal cord
what does the brain do in terms of the central nervous system?
key parts of the brain
it is the centre of all concious awareness
the brains outer layer is the cerebral cortex. it is highly developed in humans and distinguishes our higher mental functions from animals
it is divided into 2 hemispheres
what is the spinal cord in terms of the central nervous system?
what is it responsible for?
it is an extension of the brain
it is responsible for reflex actions
it passes messages to and from the brain and connects nerves to the PNS
what does the peripheral nervous system (PNS) do?
it transmits messages via millions of neurons (nerve cells) to and from the central nervous system
what does the PNS sub-divide into?
the autonomic nervous system (ANS)
the somatic nervous system (SNS)
what does the autonomic nervous system do?
governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses
what does the somatic nervous system do?
controls muscle movement and receives information from sensory receptors
what is the endocrine system?
one of the body’s major information systems that instructs glands to release hormones directly into the bloodstream. these hormones are carried towards target organs in the body
what system does the endocrine system work alongside and to do what?
the central nervous system
to control vital functions in the body
does the endocrine system work faster or slower than the nervous system?
considerably slower
does the endocrine system have widespread and powerful effects?
yes
what are the main endocrine glands in the human body?
hypothalamus, pituitary, thyroid, parathyroid, adrenals, pancreas and ovaries/testes
what is the major endocrine gland and why?
the pituitary gland in the brain
it controls the release of hormones from all the other endocrine glands in the body
what is the fight or flight response?
the way an animal responds when stressed. the body becomes physiologically aroused in readiness to fight an aggressor or, in some cases, flee
what system does the autonomous nervous system work in parallel with in terms of fight or flight?
the endocrine system
how do the endocrine and the ANS work in parallel during a stressful event?
when a stressor is percieved, the hypothalamus triggers activity in the sympathetic branch of the autonomous nervous system. the ANS changes from its normal resting state (the parasympathetic state) to the physiologically aroused, sympathetic state. the stress hormone adrenaline is released from the adrenal medulla into the bloodstream. adrenaline triggers physiological changes in the body, which creates the physiological arousal necessary for the fight or flight response
how fast does the physiological arousal necessary for the fight or flight response happen?
in an instant as soon as a threat is detected
the fight or flight response is an acute response, and what type of reaction?
an automatic reaction
what happens in our body once the perceived threat has passed?
the parasympathetic nervous system returns the body to its resting state
the parasympathetic’s actions are what to the sympathetic system?
antagonistic
what is the ‘rest and digest’ response?
the parasympathetic system acts as a ‘brake’ and reduces the activities of the body that were increased by the actions of the sympathetic branch
what is a gland?
an organ in the body that produces substances such as hormones
what are neurons?
nerve cells that process and transmit messages through electrical and chemical signals
how many neurons are there in the human nervous system?
100 billion
how many of these neurons (percentage) are located in the brain?
80%
what are the 3 types of neurons?
motor neurons
sensory neurons
relay neurons
what are the branch like structures that protrude from the call body of a neuron called?
dendrites
what do dendrites do?
carry nerve impulses from neighbouring neurons towards the cell body
what does the axon do?
carries the impulses away from the cell body down the length of the neuron
what is the fatty layer that covers the axon called and what does it do?
myelin sheath
it protects the axon and speeds up electrical transmissions
if the myelin sheath was continuous, what would happen?
what are the gaps that segment the myelin sheath?
it would have the reverse effect and slow down the electrical impulse
nodes of Ranvier
what do the nodes of Ranvier do?
they speed up the transmission of the impulse by forcing it to ‘jump’ across the gaps along the axon
what is at the end of the axon?
terminal buttons
what do terminal buttons do?
communicate with the next neuron in the chain across a gap known as the synapse
when a neuron is in resting state is the inside of the cell negatively or positively charged?
negatively charged
when a neuron is activated by a stimulus, the inside of the cell becomes positively charged for how long?
a split second
when a neuron is activated by a stimulus, the inside of the cell becomes positively charged for a split second, causing what to occur?
an action potential
what does the action potential create?
an electrical impulse that travels down the axon towards the end of the neuron
what are the groups that neurons communicate in with each other called?
neural networks
what is the tiny gap that separates one neuron from the next called?
the synapse
signals within neurons are transmitted how?
electrically
signals between neurons are transmitted how?
chemically
what is the end of the neuron called?
the presynaptic terminal
when the electrical impulse reaches the end of the presynaptic terminal, it triggers the release of what?
where does it release from?
neurotransmitter
tiny sacs called synaptic vesicles
what are neurotransmitters?
chemicals that diffuse across the synapse to the next neuron in the chain
once the neurotransmitter crosses the synapse (gap), what is it taken up by?
postsynaptic receptor site- or the dendrites of the next neuron
what is the ‘lock and key’ analogy?
each neurotransmitter has its own specific molecular structure that fits perfectly into its a post-synaptic receptor site- like a lock and key
do neurotransmitters have specialist functions?
yes
what are the 2 types of effect that neurotransmitters can have on the neighbouring neuron?
excitatory
inhibitory
what is excitation?
when a neurotransmitter increases the positive charge of the postsynaptic neuron. this increases the likeliness that the neuron will fire and pass on the electrical impulse
example of a neurotransmitter that causes excitation
adrenaline
what is inhibition?
when a neurotransmitter increases the negative charge of the postsynaptic neuron. this decreases the likeliness that the neuron will fire and pass on the electrical impulse
example of a neurotransmitter that causes inhibition
serotonin
what is summation?
the process that determines whether or not an action potential will be triggered, based on the combined effects of the excitatory and inhibitory signals of the neurotransmitters
definition of localisation of function
the theory that different areas of the brain are responsible for different behaviors, processes or activities
what are the 4 key areas of the brain according to localisation of function
frontal lobe
parietal lobe
temporal lobe
occipital lobe
what does the motor area do and where is it located?
its involved in regulating movement
its a region in the frontal lobe
what does the somatosensory area do and where is it located?
it processes sensory information such as touch
its an area in the parietal lobe
what does the visual area do and where is it located?
it receives and processes visual information
its a part of the occipital lobe
what does the auditory area do and where is it located?
it analyses speech-based information
located in the temporal lobe
what does Broca’s area do and where is it located?
its responsible for speech production
an area of the frontal lobe, usually in the left hemisphere
what does Wernicke’s area do and where is it located?
its responsible for language comprehension
an area of the temporal lobe, usually in the left hemisphere
what theory of the brain did scientists believe before investigations?
the holistic theory- all parts of the brain were involved in the processing of thoughts and actions
what is the localisation of function sometimes referred to?
cortical specialisation
if a certain area of the brain becomes damaged through illness or injury, what happens?
the function associated with that area will be effected
is activity on the left hand side of the body controlled by the left or the right hemisphere?
right hemisphere
is activity on the right hand side of the body controlled by the left or right hemisphere?
left hemisphere
what is the outer layer of both hemispheres called?
cerebral cortex
why does the cerebral cortex appear grey and what phrase is used to describe it?
due to the location of cell bodies
‘grey matter’
what does damage to Broca’s area cause?
Broca’s aphasia- speech that is slow, laborious and lacking fluency
what does damage to Wernicke’s area cause?
Wernicke’s aphasia- producing nonsense words (neologisms)
is there evidence for localisation?
yes
who found evidence for localisation and what methods did they use (2)?
Peterson et al. used brain scans to show how different areas lit up when doing different tasks
Tulving et al. study of long term memory- semantic and episodic memory lie in different areas of the brain
what is neurosurgery and does it provide evidence for localisation?
the practice of surgically removing or destroying areas of the brain to control aspects of behavior
what is a lobotomy?
when you severe connections in the frontal lobe in an attempt to control aggressive behavior
what part of his brain did Phineas Gage damage and what were the consequences on his personality?
left frontal lobe
he went from being calm and reserved to quick tempered, rude, and ‘no longer Gage’
did Lashley’s research into rats support the localised or holistic theory?
holistic
what did Lashley do in his research on rats?
he removed areas of the cortex in rats (between 10-50%) that were learning a maze and found that no area was more important than others in terms of the rats ability to learn the maze
