biopsychology Flashcards
What is the nervous system (1)
A network of cells in the human body, the body’s internal communication system
What is the function of the nervous system (2)
To collect, process and respond to information from the environment (1) and to control organs and cells in the body (1)
The nervous system is broken down into
Central nervous system and the peripheral nervous system
What is the function of the peripheral nervous system
Sends messages to and from the central nervous system via neurons
What is the central nervous system split into
Brain and spinal cord
What is the peripheral nervous system spilt into
Autonomic nervous system and somatic nervous system
What is the autonomic nervous system broken down into
The sympathetic branch and the parasympathetic branch
What is the function of the sympathetic branch
Flight or fight response
What is the function of the parasympathetic branch
Converse and restore body energy when relaxed
What is the role of the brain (6)
Receives and processes information from the senses e.g. visual cortex processes visual info.
The centre of conscious awareness
Responsible for higher mental functions
Generates emotion and thoughts
Initiates responses
Stores memories
What is the role of the spinal cord
Conducts signals (sends messages) to and from the brain
Connects nerves to the PNS
Controls reflex actions e.g.
removing a hand when it touches a hot plate
What is the role or the Autonomic nervous system
Responsible for involuntary responses for vital functions e.g. breathing, digestion and the stress response, heart rate
Controls smooth and cardiac muscles and glands
ANS control centres are in the brain stem.
What is the role of the somatic nervous system
Responsible for voluntary movements such as walking
Transmits information from the brain or the skeletal muscles
SNS carries commands from (controlled by) the motor cortex
Connects the CNS and the senses and integrates the brain with the outside world
Describe two differences between the autonomic nervous system and the somatic nervous system
Responsible for involuntary responses for vital functions e.g. breathing, digestion and the stress response, heart rate
Where as
Responsible for voluntary movement such as walking
Controls smooth and cardiac muscles and glands
Where as
Transmits information from the brain to control skeletal muscles
ANS control centres are in the brain stem.
Where as
SNS carries commands from (controlled by) the motor cortex
What is the structure of a neuron
- Terminal button (pre-synaptic membrane)
- Dendrites (Post synaptic membrane)
- Cell body
- Axon
- Myelin sheath
- Nodes of ranvier (the gap)
What is the terminal button (pre-synaptic membrane)
The end of the neuron and they send the information through to the next neuron, through the release of neurotransmitters.
What are dendrites (post-synaptic membrane)
These are where the neurotransmitter receptors are found. Once the receptor and neurotransmitter bind, this causes a new electrical impulse to occur.
What is the cell body
Includes the nucleus which contains the genetic material of the cell
What is the axon
Sends a nerve impulse (action potential) through the neuron to transmit a message to the
next neuron
What is the myelin sheath
Protect the axon and helps to speed up transmission of the message
What is the node of ranvier
Speeds up the transmission of the impulse by forcing it to ‘jump’ across the gaps along the axon
Where is the location of a sensory neuron
The PNS in clusters known as ganglia
What is the function of the sensory neuron
These send information from the senses (PNS) towards the brain (CNS).
Receptors found in eyes, ears, tongue, skin.
What is the structure of the sensory neuron
They have long dendrites and short axons.
What is the location of a relay neuron
In the brain and the visual system
What is the function of a relay neuron
Relay neurons are found in the CNS (brain/visual system/spinal cord).
They carry nerve impulses between neurons allowing sensory and motor neurons to communicate.
They are involved in analysing the sensations from these neurons and deciding how to respond.
What is the structure of a relay neuron
They have short dendrites and short axons, and no myelin sheath.
What is the location of a motor neuron
Cell bodies are found in the CNS but the long axons form part of the PNS
What is the function of a motor neuron
These send information via long axons from the brain/spinal cord (CNS) through to effectors such as muscles or glands.
What is the structure of a motor neuron
They have short dendrites and long axons
Describe the process of synaptic transmission
- The process of synaptic transmission begins in the presynaptic neuron, action potentials (electrical nerve impulses) are sent down the axon until they reach the presynaptic terminal
- This causes the neurotransmitters (chemicals), which are stored in vesicles and are ONLY located in the presynaptic neuron, to be released into the synaptic cleft (the gap between each neuron)
- These neurotransmitters diffuse across the synapse (from high to low concentration) and then bind with their specific receptor sites that are ONLY present on the postsynaptic neuron (like a key into a lock)
- Once enough neurotransmitters have attached to the receptor sites on the post synaptic neuron, there are two possible outcomes:
The next neuron is ready to fire an impulse, depending on whether the neurotransmitter has an excitatory or inhibitory effect.
OR
The neurotransmitters are recycled to be stored back in the vesicles in the presynaptic neuron in a process called reuptake.
What are neurotransmitters
There are chemical messengers within the brain
What is the role of a neurotransmitter
Their role is to transmit information from one neuron to another so that a person performs an action e.g. movement or has an emotional response.
Define excitatory neurotransmitter (3)
Give an example
When the excitatory neurotransmitter binds to the post synaptic receptors - post synaptic cell (the next neuron) becomes positively charged (1)
This will make it more likely that the post synaptic cell will fire so an impulse will travel down its axon (2’
This increases the brain activity in the central nervous system (3)
E.g adrenaline
Define inhibitory neurotransmitter (3)
Give an example
When the inhibitory neurotransmitter binds to the post synaptic receptors the post synaptic cell (next neuron) becomes negatively charged (1)
This prevents or reduced the likelihood that the post synaptic cell will fire (2)
This decreases brain activity in the central nervous system (3)
E.g Serotonin
Define summation (3)
Summation occurs when the excitatory and inhibitory influences are added together (1)
If the overall effect is mainly inhibitory (negatively charged) it reduces the likelihood the neuron will fire an impulse down the post synaptic neuron (2)
If it is mainly excitatory (positively charged) the impulse will fire an impulse down the post synaptic neuron (3)
What is the function of the endocrine system
The endocrine system provides a chemical system of communication within the blood stream to regulate the activity of cells and organs in the body
It is slower than the nervous system but its effects are more widespread and powerful.
These chemical messengers are hormones, which are released by the glands within the endocrine system to regulate many bodily functions.
What are hormones
Chemical messengers which are released by the glands within the endocrine system to regulate many bodily functions
such as melatonin and oestrogen
The role of glands in the endocrine system - what is a gland
A gland is an organ that secretes hormones that regulate functions in the body.
Name 4 glands (need 2 in the exam at least )
Pineal gland
Adrenal gland
Pituitary gland
Ovaries
Testes
The role of the pineal gland
Secretes the hormone melatonin, which is involved in regulating the sleep-wake cycle by making the person feel tired and therefore ready to sleep
The role of the adrenal gland
Releases adrenaline which causes physiological changes involved in the fight or flight response such as increased blood flow to transport oxygen to the brain for rapid response planning.
The role of the pituitary gland (master gland)
This secretes many different hormones that control the functions of the other glands.
Give two examples of the pituitary gland
Anterior pituitary gland in the ovaries and the testes
The role of anterior pituitary gland in the ovaries
Anterior Pituitary gland releases LH & FSH which encourages the ovaries to release oestrogen and progesterone which regulate the female menstrual cycle and prepares the body for reproduction.
The role of the anterior pituitary gland in the testes
Anterior Pituitary gland releases LH & FSH which encourages
the Testicles to release testosterone which is involved in
creating male characteristics and the production of sperm.
Explain how the sympathetic branch of the ANS leads to a flight or fight response
Sally
Has
Potentially
Seen
A
Piranha
- A stressor is identified by the hypothalamus and activated the pituitary gland which triggers activity in the sympathetic branch of the autonomic system (ANS)
- Adrenaline is released by the adrenal medulla into the BLOOD STREAM
- The flight or fight response is produced, preparing the body for sudden PHYSICAL ACTION . This produces physiological reactions such as increased heart rate and blood pressure and increased respiration and reducing saliva production and digestion - this is an immediate and autonomic response
- The parasympathetic branch returns the body back to normal once the stressor has been removed.
(Homeostasis E.g heart reset decreased, respiration decreased, digestion increased)
What are the direct effects of adrenaline
Increase heart rate increasing the rate of blood flow and blood pressure.
This increases blood flow to the brain and skeletal muscles
What are the indirect effects of adrenaline
Prepares the body for action such as flight or fight, increases blood supply to skeletal muscles for physical action stops digestion and saliva production.
Increase oxygen to brain for rapid response planning
Define the term localisation of function
Specific areas of the brain are specialised for certain functions (jobs). E.g. the motor cortex is responsible for voluntary movement. Only this area of the brain is responsible for this job.
What are is Broca’s area and Wernick’s area in
Left hemisphere
Which areas of the brain are in both hemispheres
Motor cortex
Somatosensory cortex
Visual cortex
Auditory cortex
Explain the difference between Broca’s area and Wernicke’s area
Broca’s area -
This area of the brain is involved in production of spoken and written language
where as
Wernickes area -
This is the area that is involved in the understanding
of language.
Broca’s area -
(Damage to this area can produce Broca’s aphasia where a person may show slow speech that lacks fluency or there is a complete absence of speech. They might produce short meaningful speech that requires a great deal of effort)
Where as
Wernicke’s area -
(Damage to this area can cause Wernicke’s aphasia whereby individuals cannot understand spoken language or where a person produces nonsense words as part of their speech. (fluent but meaningless speech)
What is the function of the Broca’s area
This area of the brain is involved in production of spoken and written language.
What can damage to the Broca’s area lead to
Damage to this area can produce Broca’s aphasia where a person may show slow speech that lacks fluency or there is a complete absence of speech.
They might produce short meaningful speech that requires a great deal of effort
What is the function of the Motor cortex
This is involved in the creation of voluntary motor movements.
(Each hemisphere controls the movement of the opposite side of the body.
What can damage to the Motor cortex lead to
Damage can cause loss of control over fine movements
Small movements on the opposite side of the body (e.g. picking up a small objects or paralysis)
What is the function of the Somatosensory cortex
It processes information from the senses. This includes touch, pain and temperature from all areas in the body.
What can damage to the Somatosensory cortex lead to
Damage can produce problems in perceiving touch, failure to recognise object by touch
What is the function of the Visual cortex
This area of the brain receives information
directly from the eyes. RVF – LH, LVF – RH.
What can damage to the Visual cortex lead to
If this becomes damaged it can produce blindness, hallucinations (seeing things which aren’t there) or an inability to see colour or motion
What is the function of Wernicke’s area
This is the area that is involved in the understanding
of language.
What can damage to the Wernicke’s area lead to
Damage to this area can cause Wernicke’s aphasia whereby individuals cannot understand spoken language or where a person produces nonsense words as part of their speech. (fluent but meaningless speech)
What is the function of the auditory cortex
This area is associated with analysing speech based information e.g. hearing, pitch and volume.
What can damage to the Auditory cortex lead to
Damage could produce partial hearing loss through to full hearing loss
What is holistic theory
Before investigations into localisation and lateralisation, scientists believed that ALL parts of the brain worked together when processing information
Vs
Localisation - specific areas of the brain specialised for certain function
Vs
Hemispheric - split into two hemispheres responsible for different mental processes
Define the term hemispheric lateralisation
The brain is split into two symmetrical halves called the left and right hemisphere.
This is the idea that the two different hemispheres are responsible for different mental processes.
E.g. Left hemisphere is responsible for language and the right is responsible for recognition and creativity.
Define contralateral wiring (2)
The right hemisphere receives information from LEFT visual field and controls the LEFT side of the body (1)
The left hemisphere receives information from the RIGHT visual field and controls the RIGHT side of the body (1)
Define what is meant by spilt brain
Split brain patients have had surgery (normally to treat epilepsy) to cut the area that connects the two hemispheres of the brain (corpus callosum).
While the surgery may relieve epilepsy, it has a major side effect: the two hemispheres become functionally separate (they act as two separate, independent brains).
What was the aim of the split brain research
To investigate the effect of severing the connection between the two hemispheres of the brain (corpus callosum) on functioning
What was the method for split brain research
Natural experiment
What was the sample for the split brain research
Studied 11 individuals who had had their
corpus callosum severed due to surgery
What was the procedure for split brain research
- Participants sit in front of a screen, while fixating their gaze on a spot in the middle of a screen
- Participants were presented with visual information to either their right visual field or left eye visual field for 1/10th of a second (this is so there is not enough time for the other visual field to switch focus to the visual image).
What were the results for split brain research
Visual presentation of information
Objects seen in right visual field
- can be named verbally and in writing as -> the image would be processed by the language centres in the left side of the brain
If objects are only seen in the left visual field then -> they can only be identified though pointing but cannot be named by the participant
What was the conclusion for split brain research
The two hemispheres of the brain have different abilities and functions;
but only the left is able to produce language.
The right hemisphere can recall and identify information, but cannot verbalise this
Define the term plasticity
This is the brain’s ability to change and adapt its structures and processes as a consequence of experience and new learning.
Explain what is meant by synaptic pruning
During infancy the brain experiences a rapid growth in the number of synaptic connections it has, peaking at approximately 15,000 at the age of 2-3 years.
This is around twice as many as an adult brain.
As we age, connections that are not used regularly are deleted and ones that are used regularly are strengthened – this is called synaptic pruning.
Research suggests that at any time in life existing neural connections can change, or new neural connections can be formed between neurons as a result of learning and experience.
It used to be believed that these changes only happened in infancy.
Outline one study into plasticity
Maguire et al (2000)
The brains of London taxi drivers were studied.
There was a greater volume of grey matter in the posterior hippocampus
(which is responsible for spatial and navigational skills)
in those who had been a taxi driver for a long time in comparison to those who had only been a taxi driver for a short time.
This difference was due to their greater knowledge of the roads which suggests the structure of
their brain has been altered by their experience = plasticity.
What is an example of plasticity
Functional recovery
Define functional recovery
This is a type of plasticity and refers to recovery of abilities and mental processes (such as movement or language) that have been affected as a result of brain damage or disease (1)
The brain is able to reside itself by forming new synaptic connections close to the damaged area of the brain (1)
Secondary neural pathways that would not typically be used to carry our certain functions are activated to enable functioning to continue, often in the same way as before, this process creates a number of structural changes in the brain
What is axonal sprouting
The growth of new nerve endings which connect with other undamaged nerve cells to form new neural pathways
What is the recruitment of homologous (similar) areas
Areas from opposite side of the brain take over the function of the damaged brain
E.g if the Broca’s area was damaged in the LH, the right side equivalent would carry out its function
What affects recovery after trauma
PAGES
Perseverance
Age
Gender
Education
Stress & alcohol
Name four ways of studying the brain
fMRI
EEG
EPG
Post mortem examinations
Describe how fMRI works
Identifying changes in the levels of oxygen in blood - that occurs due to brain activity in specific areas
When a brain area is more active it leads to more xygen being used so -> there is an increase of blood
flow to this active area
fMRI produces a 3D image showing which part of the brain is active, called an activation map.
It has been used to identify which specific parts of the brain are active in particular mental process (showing localisation)
Describe post mortem examination as a way of studying the brain
The brain of a dead patient is examined and dissected to see if there are any physical/structural abnormalities.
The brain can be compared with a brain that does not show this particular behaviour or mental process.
It is mainly used on people who have a rare disorder or defects
One area of research has been the identification of Broca’s area as an important brain areas for speech production
Describe how EEG is used as a way of studying the brain
EEG is a brain scanning technique that works by:
Electrodes being placed on the scalp using a
skull cap
They detect small electrical changes resulting
from the activity of brain cells
The electrical signals are graphed over a
period of time to see a person’s general brain
activity
EEGs are used to detect sleep patterns and
states such as sleep or arousal
It is used as a diagnostic tool to help diagnose
conditions such as brain tumours and epilepsy
Describe how ERPS work as a way of studying the brain
Like with EEG, electrodes are placed on the scalp
Unlike EEG (which shows general activity) ERP
shows specific brain activity as all extraneous brain activity
A stimulus is presented to a individual many times and their brain activity is measured in the same way as an EEG
However, all extraneous brain activity from the original EEG recording is filtered out leaving only those responses that link to the presentation of the stimulus
What remains once the extraneous activity is filtered are the event related potentials ERPS - types of brainwave that are triggered by particular events
Explain the difference between EEG and an ERP
The EEG, the electrical signals graphed over a period of time to see a persons general activity of the brain whereas , the ERP shows specific brain activity from a stimuli presented to the ppt
What is a biological rhythm
Physical, mental, behavioural changes over a period of time.
Biological rhythms have important influence in the way in which body systems behave
All biological rhythms are controlled by…
And
Influence by…
Endogenous pacemakers = internal body clock
Exogenous zeitgebers = external changes in environment
Define the term circadian rhythm
This is the cycle that lasts for 24 hours E.g body temperature, and the sleep wake cycle
Outline the sleep wake cycle (4)
- One example of a circadian rhythm is the sleep wake cycle which is controlled by the master endogenous pacemaker, the suprachiasmatic nucleus (SCN) found in the hypothalamus
- Our eyes notice a change in light as it gets dark and less light is received by the retina
- This sends information to the SCN which stimulates the pineal gland to release melatonin sand promote sleep
- When our eyes detect light (exogenous zeitgeber) the SCN is reset which maintains the sleep wake cycle to around 24 hours so that we can be in synchrony with the outside world.
Explain the difference between endogenous pacemakers and exogenous zeitgebers
Endogenous pace makers see the internal body clock whereas exogenous zeitgebers are external changes in the environment
Define the term infradian rhythms
This is a cycle that lasts longer than 24 hours
E.g the female menstrual cycle which operates approximately on a 28 day cycle.
Outline an example of an infradian rhythm : menstrual cycle
The menstrual cycle is an endogenous system which typically lasts between 28 - 35 days
It begins on the first day of a woman’s period, when the womb lining is shed, to the day before her next period
In the brain the Pituitary gland releases FSH which activates the release of oestrogen from the ovaries and causes an egg to mature.
The increase of oestrogen, increases the levels of LH (released by the pituitary gland) which promote the release of an egg
Oestrogen develops the lining of the womb and progesterone helps it grow thicker, readying the womb for pregnancy
If pregnancy does not occur, the egg is absorbed into the body, the womb lining comes away and leaves the body and the cycle begins again.
Although the menstrual cycle is mainly an endogenous system that maintains the infradian rhythm, it can be affected by exogenous factors such as stress and pheromones (chemical scents given off by females and males)
Define the term ultradian rhythms
This is a cycle that is less than 24 hours e.g. the stages of sleep which last approximately 90 minutes.
Ultradian rhythm introduction
An ultradian rhythm is a biological rhythm that occurs more frequently than once every 24 hours (this cycle
is shorter than 24 hours). (1)
One type of ultradian rhythm are the stages of sleep (1)
This cycle lasts approximately 90 minutes and consists of 5 stages and alternates between REM (Rapid Eye Movement) sleep and NREM (Non Rapid Eye Movement) sleep. (1)
It is known as the sleep escalator/staircase, a person can experience up to 5 cycles per night that repeat in a rhythmic pattern. (1)
What are the 5 stages of sleep
Stage 1 & 2 - (light sleep -NREM)
Stage 3 & 4 (deep sleep - NREM)
Stage 5 - (REM)
Describe brain activity in stage 1 & 2 (light sleep - NREM)
This is light sleep where a person may be easily woken
Stage 1 = experience alpha waves
Stage 2 - alpha waves continue but there are occasional random changes in pattern called sleep spindles (high frequency- protect the brain from awakening)
Describe brain activity in stage 3 & 4 (deep sleep - NREM)
Known as deep sleep or slow wave sleep (SWS)
The brain waves at delta waves with lower frequency and higher amplitude
It is difficult to wake someone at this point
Describe brain activity in stage 5 (REM)
The body is paralysed
Brain activity closely resembles that of the awake brain
The brain produces theta waves and eyes occasionally move around - this is called rapid eye movement (REM)
Dreams are often experienced in this stage but may also occur in deep sleep
What happens when our sleep wake cycle is disrupted?
This can occur for many reasons such as jet lag (especially traveling West to East) and through shift work. It can produce many negative consequences such as:
Difficulty in sleeping (harder to sleep or falling asleep whilst driving)
Decreased attention which can lead to accidents
Digestive problems
Tiredness and poorer reasoning skills
Increased anxiety and irritability
Disruption to biological rhythms - ao2 only
How could we maintain our sleep wake cycle?
Keep to local times for eating
Keep to local times for sleeping e.g. sleeping when it is dark and forcing yourself to get up when it is light.
Stimulate yourself during the day by being social and
active, such as talking and eating.
The effect of endogenous pacemakers and exogenous zeitgebers on the sleep wake cycle intro
Endogenous pacemakers are internal factors which help us to maintain our biological rhythms. It is also thought that are rhythms are entrained (synchronised) by exogenous zeitgebers (external factors) such as light and meal times.
Describe the role of the suprachiasmatic nucleus as an endogenous pacemaker
Endogenous Pacemaker: Internal Body clock (Suprachiasmatic Nucleus)
- The sleep wake cycle is controlled by the master endogenous pacemaker, the suprachiasmatic nucleus (SCN)
- Our eyes notice a change in light as it gets dark and less light is received by the retina
- This sends information to the SC which stimulates the pineal gland to release melatonin and promote sleep.
- When our eyes detect light again (exogenous zeitgeber) the SCN is reset which stimulates the SCN and pineal gland, which inhibits the release of melatonin to promote wakefulness. This suggests the sleep wake cycle is controlled by endogenous factors
Describe how exogenous zeitgebers can influence the SCN as an endogenous pacemaker
However, exogenous zeitgebers are external factors which are in our environment which can influence our sleep/wake cycle through entrainment, such as light, which supresses the release of melatonin from the pineal gland, influencing the sleep/wake cycle, which suggests our sleep/wake cycle is not only influenced by endogenous pacemakers (internal factors).
Social cues such as meal times and social interaction can also influence our sleep/wake cycle, making us less alert once we have finished our evening meal.
Research suggests that adapting to local eating and sleeping times before travelling to a different time zone can prevent jet lag, suggesting that exogenous zeitgebers can influence the sleep-wake cycle.
