biopsychology 1 Flashcards
the CNS & its role
made up of the brain and the spinal cord
↳ it controls behaviour and regulates the body’s physiological processes
what does the PNS do?
transmits messages, via neurons, to and from the CNS
what are the subdivisions of the PNS?
-the ANS (autonomic nervous system)
-the SNS (somatic nervous system)
autonomic nervous system (ANS)
controls vital functions e.g. breathing, heart rate
somatic nervous system (SNS)
controls muscle movement and receives information from sensory receptors
(talks to the outside world)
what does the autonomic nervous system split into?
-the SANS (sympathetic autonomic nervous system)
-the PANS (parasympathetic autonomic nervous system)
what two things do humans (like animals) have?
two major physiological systems that regulate behaviour in response to the
environment
(the nervous system and the endocrine system)
what is the endocrine system?
a system of glands that release hormones into the blood stream where they are carried to target organs
what is the nervous system?
-the primary internal communication system
-based on electrical and chemical signals
-neurons are the building blocks of the nervous system
what are the two main functions of the nervous system?
1) collect, process and respond to information from the environment
2) to coordinate the internal environment
(subdivided into the CNS and PNS)
what is the brain?
-the centre of all conscious awareness
-the brain is divided in two hemispheres
what does the brain do?
it receives information from sensory receptors and sends messages to muscle
glands in the body
what is the spinal cord?
an extension of the brain
what does the spinal cord do?
it carries messages between the brain and the nerves that run throughout the body
what does the PNS consist of?
consists of all other nerves which are not part of the CNS, reaching out to the other parts of the body
what does the SNS consist of?
-it includes both sensory receptors and motor pathways
-the sensory neurons carry sensory information to the CNS
-the motor pathways take information from the CNS out, for example to muscles
what does the ANS consist of?
it uses only motor pathways
how is the ANS subdivided?
into two sections…
-sympathetic nervous system (SANS)
-parasympathetic nervous System (PANS)
what does the sympathetic autonomic nervous system do?
gets us ready for emergencies and is involved in the fight or flight response
what does the parasympathetic autonomic nervous system do?
restores natural order, relaxing us after an emergency
(sometimes called ‘rest and digest’)
how is the nervous system working?
(the bell rings, and the students start packing up their bags)
1) the sound of the bell ringing is picked up by the students’ ears and transmitted via the peripheral nervous system (the SNS) to the brain (a sensory message)
2) the brain recognises the sound as a bell and interprets it as a signal that the lesson is ended
3) to fulfil the goal of packing up and going elsewhere, the brain sends out a large number of messages, via the somatic nervous system
4) these motor messages are carried by the spinal cord to the skeletal muscles, where they result in movements that allow the students to pick up their belongings
things that happen due to a fight or flight reaction:
-increased breathing rate
-increased heart rate
-sweating
-churning tummy
-pupils dilate
-dry mouth
why do fight or flight responses occur?
the brain sends messages to the sympathetic nervous system to make changes to prepare the body
for sudden high levels of activity
the opposing actions of the sympathetic and the parasympathetic nervous system:
GUT
slows digestion (SANS) v increases digestion (PANS)
SALIVARY GLANDS
inhibits saliva production (SANS) v increases saliva production (PANS)
LIVER
stimulates glucose production (SANS) vs
stimulates bile production (PANS)
BLADDER
relaxes the bladder & stimulates urination (SANS) v
inhibits urination (PANS)
You are walking home alone late one night and you hear footsteps behind you. You look around to see who / what it is.
It is someone who is looking quite threatening and they are
picking up pace and getting closer.
What parts of the nervous system help you to do these activities?
-sensory nerves via the somatic nervous system send messages to the central nervous system that there is a noise behind you
-the brain identifies the sound as footsteps and via the somatic nervous system sends messages to the muscles and eyes to look around
how does the parasympathetic nervous system control our internal environment?
-mundane activity
-most of our energy is directed towards
digestion
how does the sympathetic nervous system control our internal environment?
-it’s most active when we are going to exert high levels of energy
-energy, blood flow etc diverted away
from the stomach and digestion and
directed towards the muscles
For each of the scenarios in the
table to the right, say whether the
sympathetic or parasympathetic
nervous system is responsible and
what this branch of the nervous
system is doing.
Sue is so nervous before her driving test that she can’t eat a thing for breakfast.
sympathetic → inhibits digestion
Les is not a happy man. He’s just arrived at the pub to find his girlfriend entwined with another man. Breathing heavily, Les decides to confront the pair.
sympathetic → causes increased breathing rate
Lenny absolutely loves the roller coaster ride. When he gets off, his mum notices how big his pupils look.
sympathetic → dilates pupils
Amadeep is about to get the results of an important blood test. She feels really dry mouthed in the doctor’s surgery.
sympathetic → inhibits saliva production
After the shock of thinking there was an intruder in the house, the police sit Mary down and reassure her; she can hear her pounding heart getting slower.
parasympathetic → returns heart rate to normal
After starring in a play for the local amateur dramatics group, Jerry finds he’s very hungry after the performance.
parasympathetic → stimulates digestion
the difference between the SNS and ANS:
SNS
-has motor and sensory neurons and actions
-the SNS controls skeletal muscle, movement etc
ANS
-only has motor neurons and
actions
-the ANS controls internal organs and glands of the body
Explain two differences in the organisation and/or function of the somatic nervous system and autonomic nervous system.
(4 marks)
-the SNS has sensory and motor pathways, whereas the ANS is purely motor
-the ANS controls internal organs and glands of the body whereas the SNS
controls skeletal muscle, movement
-ANS has two subsections (SANS and PANS) whereas the SNS has no subdivisions
what are the parts of a neuron?
cell body, nucleus, dendrites, axon,
myelin sheath, nodes of ranvier,
terminal buttons
the function of a nucleus:
-the control centre of a cell
-contains the cell’s chromosomal DNA
the function of a dendrite:
receives nerve impulses from other neurons or sensory receptor cells
the function of an axon:
carries the nerve impulse away from the cell body towards the terminal buttons
the function of a myelin sheath:
insulates the axon so that the electrical impulses travel faster along the axon
the function of the nodes or ranvier:
these speed up the transmission of the impulse by forcing it to ‘jump’
the function of the terminal buttons:
connects the neuron to other neurons (or directly to organs/muscles), using a process called synaptic transmission
what do sensory neurones do?
-detect changes in the external and internal environment
-send messages from sense organs (receptors) to the central nervous system
where are sensory neurones found?
in sense organs:
skin, tongue, eyes
sensory neurone: structure
-long dendrites and short axons / the cell body is in the middle
- sometimes have an axon that branches into two extensions
(one connected to dendrites that receive
sensory information)
(another that transmits this information to the spinal cord)
where are relay neurones found?
-the brain is made up of relay neurons
-they are also found in spinal cord
-they lie between sensory and motor neurons
what do relay neurones do?
-allow sensory and motor neurons to communicate
-store, process and interpret information in order to pass the message on to the correct neuron
where are motor neurons found?
in the central nervous system
(they project their axons out into the peripheral nervous system)
what do motor neurons do?
-send messages from CNS to effectors (glands and muscles)
-control muscle movements
motor neurones & neurotransmitters:
when motor neurons are stimulated they release neurotransmitters that bind to the receptors on muscles to trigger a response, which lead to movement
motor neuron structure:
-multiple dendrites
-have short dendrites and long axons
-have a cell body on one end, an axon in the middle and dendrites on the other end
(THE ONES FROM GCSE)
why do some sensory neurons stop at the spinal cord?
to allow for quick reflex actions
jeremy is digging in the garden. He feels the spade hit a rock and stops digging.
explain how sensory, relay and motor neurons would function
in this situation.
sensory neurons send information from the senses to the brain
↳ here, receptors in jeremy’s hand would sense the spade hitting the rock and send that information via the PNS to his CNS
relay neurons connect with other neurons, mostly found in the brain/CNS
↳ here they would be involved in analysis of the sensation from jeremy’s
hand, processing what it means, deciding about how to respond to it (by moving his hand) & acting between the sensory and motor neurons
motor neurons send messages via long axons from the brain to the effectors
↳ here the message from the brain instructs Jeremy’s arm muscles to stop working and stop the digging action
what is synaptic transmission?
the process of transmitting messages from one neuron to another neuron
what is each neuron separated from another by?
a tiny gap called the synapse
which two types of signals do neurons have?
electrical & chemical:
signals within neurons are transmitted electrically, however signals between neurons are transmitted chemically across the synapse
steps of synaptic transmission:
1) action potential arrives at neuron
2) synaptic vesicles containing neurotransmitters move towards the pre-synaptic membrane
3) the vesicles release neurotransmitters into the synaptic gap
4) neurotransmitters diffuse across the synaptic gap
5) neurotransmitters bind with receptors on the post-synaptic membrane
6) once the receptors have been activated, they either produce excitatory or inhibitory effects on the post-synaptic neuron
7) excess neurotransmitter is absorbed back into the cell (reuptake) or excess neurotransmitter is destroyed by enzymes in the synapse
excitatory vs inhibitory response
an action potential is triggered / reduced
in the next neuron
which two effects can neurotransmitters have?
excitatory or inhibitory
what do excitatory neurotransmitters do?
-increase the positive charge inside the post synaptic neuron
-they make the post-synaptic cell more likely to fire (charge is more likely to cross the threshold)
example of how excitatory neurotransmitters work:
-an excitatory neurotransmitter binds to the post-synaptic receptors
-it will cause an electrical charge in the cell membrane which results in an excitatory post-synaptic potential (EPSP)
-this makes the post-synaptic cell more likely to fire
examples of excitatory neurotransmitters:
-dopamine
-acetylcholine (both)
-noradrenaline (both)
what do inhibitory neurotransmitters do?
they increase the negative charge inside the neuron & decrease the chances of the threshold being met so action potential is less likely
example of how inhibitory neurotransmitters work:
-the inhibitory neurotransmitter binds to the post-synaptic receptor
-this results in an inhibitory post-synaptic potential (IPSP)
-this makes the post-synaptic neuron less likely to fire
examples of inhibitory neurotransmitters:
-GABA
-serotonin
what is summation?
-at any one time there are several different types of neurotransmitters binding to the post-synaptic membrane (some excitatory, others inhibitory)
-summation refers to the net effect of neurotransmitters on the post synaptic neuron.
summation results:
-if the net effect is excitatory overall, the postsynaptic neuron is likely to fire (trigger an action potential)
-if the net effect is inhibitory, then an action potential is less likely to be triggered in the post synaptic membrane.
briefly outline how excitation and inhibition are involved in synaptic transmission
-neurotransmitters can be excitatory or inhibitory (most can be both)
-if the neurotransmitter is excitatory then the post synaptic neuron is more likely to fire an impulse.
-if the neurotransmitter is inhibitory then the post synaptic neuron is less likely to fire an impulse
the excitatory and inhibitory influences are summed, if the net effect on the post synaptic neuron is inhibitory, the neuron will be less likely to ‘fire’ and if the net effect is excitatory, the neuron will
be more likely to fire
[SUMMATION MUST BE MENTIONED FOR FULL MARKS]
what is the endocrine system in charge of and what is the nervous system in charge of?
endocrine -
processes that happen slowly, such as cell growth
nervous -
faster processes like breathing and body
movement
nervous system & endocrine system
even though the nervous system
and endocrine system are separate systems, they often work together to help the body function properly
what is the function of the endocrine system?
-to secrete the hormones which are required to regulate many bodily functions
-to provide a chemical system of
communication via the blood stream
what are the parts of the endocrine system?
-hypothalamus
-pituitary gland
-pineal gland
-thyroid gland
-adrenal glands
-ovary
-testes
HYPOTHALAMUS
hormone it releases & effect:
stimulates and controls the release of hormones from the pituitary gland
PINEAL GLAND
hormone it releases & effect:
melatonin
↳ responsible for important biological rhythms (eg: sleep-wake cycle)
THYROID GLAND
hormone it releases & effect:
thyroxine
↳ Responsible for regulating metabolic reactions
ADRENAL GLAND
hormone it releases & effect:
adrenal medulla - adrenaline, noradrenaline
↳ the key hormones in the fight or flight response
adrenal cortex - cortisol
↳ stimulates the release of glucose to provide the body with energy, while suppressing the immune system
OVARIES
hormone it releases & effect:
oestrogen
↳ controls the regulation of the female reproductive system
TESTES
hormone it releases & effect:
testosterone
responsible for the development of male sex characteristics during puberty, while also promoting muscle growth
what happens when we experience a stressful situation?
our body reacts with the fight or flight response (a result of both the nervous system and the endocrine system working together)
steps of the fight of flight response:
1) person enters a stressful situation
2) the amygdala is activated which sends a distress signal to the hypothalamus
3) the hypothalamus activates the SAM pathway which connects the adrenal medulla and the sympathetic nervous system
4) the sympathetic nervous system stimulates the adrenal medulla
5) the adrenal medulla secretes adrenaline and noradrenaline into the bloodstream
6) adrenaline causes a number of physiological changes to prepare the body for fight or flight
why does heart rate increase during the fight or flight response?
to increase blood flow to organs and increase the movement of adrenaline around the body
why does breathing rate increase during the fight or flight response?
to increase oxygen intake
why do pupils dilate during the fight or flight response?
to increase light entry into the eye and enhance vision (especially in the dark)
why is sweat produced during the fight or flight response?
to regulate temperature
why are non/essential functions reduced during the fight or flight response?
to increase energy for other essential functions
what happens after the fight or flight response?
-the parasympathetic autonomic nervous system (PANS) is activated to return the body back to its ‘normal’ resting state
the PANS slows down our heart rate and breathing rate and reduces our blood pressure
-any functions that were previously slowed down are started again (e.g. digestion)
outline the fight or flight response.
(4 marks)
-the hypothalamus prepares the body for action/emergency response
-it involves the release of adrenaline (from the adrenal gland/medulla)
-it switches from parasympathetic to sympathetic activity
-direct effects of adrenaline (increase heart rate , increases respiration and sweating)
outline the role of adrenaline in the fight or flight response. (4 marks)
-adrenaline is released from the adrenal medulla in response to activation of the
sympathomedullary pathway
direct effects:
-adrenaline has a range of effects on the body (increase heart rate, constricts blood vessels, increases respiration and sweating)
he general effects of adrenaline
general effects:
–prepare the body for action, fight
–increase blood supply/oxygen, to skeletal muscle for physical action
explain how the body responds during fight or flight and why this could be unhelpful in a driving test situation.
(4 marks)
-the fight or flight response causes adrenaline to be released which can cause an increased production of sweat and faster heart and breathing rate which could be off putting and unhelpful during a driving test (e.g. sweaty hands may make
it harder to grip the steering wheel)
-the fight or flight response enables a quick reaction to fight the threat or run away from it but neither of these options
would be helpful in a driving test as if you ran away or attacked the instructor you would fail the test
criticisms of the fight or flight response:
-human behaviour is not limited to just two responses
-the fight or flight explanation doesn’t fully explain the stress response in females
-the fight or flight response can have a
negative effect on health, especially in modern-day life
ao3 / criticism - human behaviour is not limited to just two responses
P - human behaviour is not limited to just two responses
E - Gray (1988) suggests that the first response to danger is to avoid
confrontation altogether, a ‘freeze’
response
↳ during the freeze response, humans are hyper-vigilant while they appraise the situation to decide the best course of
action for that particular threat
L - this suggests that the fight or flight explanation of behaviour is limited and doesn’t fully explain the complex factors that underpin the human response to stress/danger.
ao3 / criticism - the fight or flight explanation doesn’t fully explain the stress response in females
P - the fight or flight explanation doesn’t fully explain the stress response in females
E - taylor et al. (2002) suggest that females adopt a ‘tend and befriend’ response in stressful/dangerous situations
↳ according to taylor et al. (2000), women are more likely to protect their offspring (tending) and form alliances with other women (befriend), rather than fight an adversary or flee
↳ this highlights a beta bias within this area of psychology as psychologists
assumed that females responded in the same way as males
L - therefore, the original fight or flight explanation was limited in its application to females, this has prompted more recent research which has provided an alternate explanation which is applicable to females
ao3 / criticism - the fight or flight response can have a negative effect on health, especially in modern-day life
P - the fight or flight response can have a negative effect on health, especially in modern-day life
E - while the fight or flight response may have been a useful survival mechanism for our ancestors who faced life-threatening situations (e.g. from predators), modern-day life rarely requires such an intense biological response
↳ this matters because the activation of the fight or flight response can increase blood pressure, cause damage blood vessels and contribute to heart disease
L - this suggests that the fight or flight response is a maladaptive response in modern-day life
