Biopsychology Flashcards
What is the human nervous system made up of
Function of the brain
Main job is to ensure that life is maintained
There are many parts of the brain
Some connected with vital functioning and others which are involved in processes such as problem solving and higher order thinking
What is the spinal cord
Facilities the transferral of messages to and from the brain to the PNS
Also involved in reflex action
What is the peripheral nervous system
The PNS transmits messages via millions of neurons (nerve cells), to and from the central nervous system
PNS is further sub-divided into:
The somatic nervous system (SNS)
The autonomic nervous system (ANS)
What does the central nervous system include
Brain and spinal cord
What is the somatic nervous system
The part of the PNS that is responsible for carrying sensory and motor information to and from the spinal cord
Controls conscious activities
What is the autonomic nervous system
The governs vital functions in the body such as breathing, heart rate, digestion, sexual arousal and stress responses (fight or flight)
Controls unconscious activities
Difference between sympathetic and parasympathetic nervous system
Sympathetic: fight or flight to prepare the body to expend energy
Parasympathetic: rest and digest to maintain body energy and functions
These are antagonistic and work oppositely
Functions of sympathetic vs parasympathetic systems
What is a gland
An organ in the body that synthesises and secretes substances such as hormones
What is a hormone
Chemical substances that circulate in the bloodstream, their effects on behaviour can be very powerful
What is homeostasis
The maintenance of a constant internal environment within the body
What does the pineal gland in the endocrine system
Produces and secretes he hormone melatonin which regulates biological rhythms such as sleep and wake cycle
Found in the brain
What does the pituitary gland do in the endocrine system
The master gland as it controls the release of hormones from all the other endocrine glands in the body
Found in the brain
Controlled by the hypothalamus
Made up of anterior (front) and posterior (back) pituitary gland
What does the thyroid gland do in the endocrine system
Produces hormones that regulate the body’s metabolic rate, as well as heart and digestive function, muscles control, brain development and mood
Found in the throat
What do the adrenal glands do in the endocrine system
Release adrenaline directly into the bloodstream from adrenal medulla which prepares the body for fight or flight by constricting blood vessels to the stomach
This inhibits digestion and increases the heart rate
Found above the kidneys
Made up of adrenal cortex (outer) and adrenal medulla (inner)
What do the testes do in the endocrine system
This facilitates the release of the male hormones - testosterone
What do the ovaries do in the endocrine system
This facilitates the release of the female hormones - oestrogen and progesterone
What is the endocrine system
One of the body’s major information systems that instructs glands to release hormones directly into the bloodstream
The hormones are released slowly and help to control slower processes such as cell growth
Provides a system of chemical communication through the bloodstream
What cells do hormones affect
Target cells
Negative evaluation of the endocrine system: gender bias
There are gender differences in how males and females respond to stress:
Taylor found that men usually react to stress with a ‘fight or flight” response but women may show a ‘tend and befriend’ response
Oxytocin (a hormone secreted in both men and women) as a response to stress has been shown to make people les anxious and more sociable
However, male hormones reduce the effects of oxytocin but female hormones oestrogen amplifies it
Therefore, men are more vulnerable to the adverse health effects of stress and more likely to develop stress related disorders (hypertension and CHD)
In contrast, women are more likely to ‘tend and befriend’ and this may protect women against stress and this may explain why women live on average 7 1/2 years longer than men
Negative evaluation of the endocrine system: reductionist
The physiological approach is reductionist
A person’s response depends on a number of different factors
These include the type of stressor involved and the way the person interprets (cognitively) the threat
This suggests that this approach may present an oversimplified explanation
Sensory neurone
Unipolar neurons - only transmit messages
Carries messages from the PNS to the brain and spinal cord
Long dendrites and short axons
Relay neurone
Multipolar neurons - send and receive messages
Transfers messages from sensory neurons to other interconnecting neurons or motor neurons
Short dendrites and short or long axons
Motor neurone
Multipolar neurons - send and receive messages
Carries messages from the CNS to effectors such as muscles and glands
Short dendrites and long axons
Process of synaptic transmission
Nerve impulse travels down an axon
Nerve impulse reaches synaptic terminal
This triggers the release of neurotransmitters
Neurotransmitters are fired into synaptic gap
Neurotransmitter binds with receptors on the dendrite of the adjacent neuron
If successfully transmitted the neurotransmitter is taken up by the post-synaptic neuron
The message will continue to be passed in this way via electrical impulses
Labelled motor neurone
What happens in a reflex arc
In a reflex arc (like the knee jerk reflex) a stimulus (e.g a hammer hitting the knee) is detected by sense organs in peripheral nervous system
These convey a message along a sensory neuron
The message reaches the nervous system where it connects with a relay neuron
This then transfers the message to a motor neuron
Message is carried to an effector such as a muscle, which cause the muscle to contract and, hence, the knee to move
When does an action potential occur
An action potential occurs when a neuron sends information down an axon, away from the cell body
This action potential is an explosion activity - means that some event (a stimulus) causes the resting potential to move forward
What does a reflex arc help to happen
Reflex arcs occur automatically
They bypass the conscious brain and allows the action to happen rapidly to avoid damage
Label the diagram
What is a synapse
The gap between the end of one neuron and the dendrites of the next neuron
What are neurotransmitters
Chemicals that are released from a synaptic vesicle into the synapse by neuron
They affect the transfer of an impulse to another nerve or muscle
They can either be excitatory or inhibitory
Where are neurotransmitters taken back up into
They are taken back up into the terminal buttons of neurons through the process of reuptake
Can also be broken down by an enzyme
What are some neurotransmitters that are excitatory only
Acetylcholine (ACH)
Adrenaline
What are some neurotransmitters that are inhibitory only
Serotonin
GABA
Differences between excitatory or inhibitory synaptic connections
Excitatory: make it more likely the next neuron will fire (such as acetylcholine
Inhibitory: they make it less likely the next neuron will fire (such as GABA)
Synaptic connections can be excitatory or inhibitory - the difference lies in the action of the neurotransmitter at the postsynaptic receptor
How do the types of neurotransmitters at synaptic maintain brain function
Normal brain functions depends upon a regulated balance between excitatory and inhibitory influences
What happens with an excitatory neurotransmitter
If neurotransmitter is excitatory then the post synaptic neuron is more likely to fire an impulse as the neurotransmitter increases the positive charge (once the positive charge reaches threshold, depolarisation occurs and the post synaptic neuron fires)
What happens with an inhibitory neurotransmitter
If the neurotransmitter is inhibitory then the post synaptic neuron is less likely to fire an impulse as it increases the negative charge (the neurotransmitter needs to keep the charge below threshold so that depolarisation does not occur and thus the post synaptic neuron will not fire)
What happens when both types of neurotransmitters are released from a synaptic vesicle
The excitatory and inhibitory influences are summed, if the net effect on the postsynaptic 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
What is localisation and when was it discovered
Localisation: the theory that specific areas of the brain are associated with particular physical and psychological functions
During the 19th century it was discovered that certain areas of the brain held particular functions
This is known as localisation of brain function
What does Broca’s area do
Broca: this is responsible for converting thought into speech
What does wernicke’s area do
Wernicke: plays an important role in understanding other people’s speech and for producing speech which makes sense
What does damage to Broca’s or Wernicke’s area result in
Damage to either of these areas would result in aphasia - inability (or impaired ability) to understand or produce speech
What is hemispheric lateralisation
Hemispheric lateralisation: the dominance of one hemisphere of the brain for particular physical and psychological functions
How is the brain divided
Divided into left and right hemispheres where each hemisphere is responsible for specific actions
Both sides a largely similar but language areas are only found on the left side
What does the central core do
This regulates out most primitive and involuntary behaviours such as breathing, sleeping or sneezing
Known as the brain stem
Includes structures such as the hypothalamus - in the midbrain
It regulates eating and drinking as well as regulating the endocrine system in order to maintain homeostasis
What is homeostasis
Homeostasis: the process by which the body maintains a constant physiological state
What does the limbic system do
This controls our emotions
Around the central core of the brain, interconnected with hypothalamus, it contain structures such as the hippocampus; key roles in memory
What does the cerebrum do
This regulates our higher intellectual processes
It has an outermost layer known as the cerebral cortex; appears grey because of the location of cell bodies (hence “grey matter”)
Each of our sensory systems sends messages to and from this cerebral cortex
The cerebrum is made up of the left and right hemispheres which are connected by a bundle of fibres called the corpus callosum
Frontal lobe function
Frontal lobe: the location for awareness of what we are doing within our environment (our consciousness)
Temporal lobe function
Temporal lobe: location for the auditory ability and memory acquisition, responsible for analysis of speech based information
Occipital lobe function
Occipital lobe: location for vision
Parietal lobe function
Parietal lobe: location for sensory and motor movements
Somatosensory located in parietal lobe responds to heat, cold, touch, pain and our sense of body movement
What happens during Broca’s aphasia
Responsible for speech production
Damage means that you are able to speak but comes out as nonsense and grammatically incorrect
What happens during Wernicke’s aphasia
Language comprehension
Damage means you can hear what someone is saying but cannot understand
Positive evaluation of localisation of brain function: brain scan evidence
There is a wealth of evidence providing support for the idea that many neurological functions are localised, particularly in relation to language and memory
Petersen used brain scans to demonstrate how Wernicke’s area was active during a listening task and Broca’s area was active during a reading task, suggesting that these areas of the brain have different functions
There now exists a number of highly sophisticated and objective method for measuring activity in the brain which provide sound scientific evidence for localisation of brain function
Tulving suggested semantic memories resided in left prefrontal cortex, episodic memories in right prefrontal cortex, procedural in cerebellum
Positive evaluation of localisation of brain function: neurosurgical evidence
Most extreme treatment as it involves the destruction of healthy brain tissue:
Lobotomy: removal of brain tissue
Leucotomy: cutting the connections to a particular part of the brain
Neurosurgery is still used today for treatment - resistant severe depressives and extreme cases of OCD
The success of these procedures strongly suggests that symptoms and behaviours associated with serious mental disorders are localised
Positive evaluation of localisation of brain function: case study evidence
Phineas gage
Gage suffered blast injury in a mine where an iron pole was pushed through his left cheek and behind the left eye and exited the brain and skull from the top of his head
Survived but changed from efficient foreman with a well balanced mind, and a shrewd business man with a kind and reserved personality to now a boisterous, rude and grossly blasphemous
Damasio said he taught us a lot about the complexity of psychological processes that occur in the human brain
Negative evaluation of localisation of brain function: high cognitive functions are not localised
The work of Karl lashly suggest that the basic motor and sensory functions were localised, but that higher mental functions were not
Rats had 10%-50% of their cortex removed. No area was shown to be more important than any other area of a rats ability to learn a maze
The process of learning appeared to require every part of the cortex, rather than being confined to a particular area
This seems to suggest that learning is too complex to be localised and requires the involvement of the whole brain
What side of the body does each hemisphere control
Each hemisphere generally deals with information from the opposite side of the body
E.g. information in the right visual field (right half of what you see) goes to visual cortex in the left hemisphere and vice versa
Info passes through corpus callosum whichever side of the brain needs to deal with it
What do ERPs do
ERPs record activity in response to a stimulus introduced by the researcher.
All extraneous brain activity from the original EEG recording is filtered out leaving only those responses that relate to the specific stimuli.
