Biopsychology - Paper 2 Flashcards
What is the nervous system?
Consists of central nervous system and the peripheral nervous system
Specialised network of cells in the human body and is our primal internal communication system
2 main functions: collect, process and respond the info in the environment
to coordinate the working of different organs and cells in the body
The nervous system diagram - major subdivisions of the human nervous system
What is the central nervous system?
Consists of brain and spinal chord and is origin of all complex commands and decisions
It passes messages to and from the brain and connects nerves to the PNS
What is the brain?
Centre of all conscious awareness Cerebral cortex (outer layer of brain) is highly developed in humans, what distinguishes our higher mental functions from those of animals Divided into 2 hemispheres, each hemisphere has 4 lobes - frontal, parietal, occipital and temporal
What is the spinal chord?
An extension of the brain
Responsible for reflex actions such as pulling your hand away from a hot plate
Passes messages to and from the brain and connects nerves to the PNS
What is the peripheral nervous system?
Sends info to the CNS from the outside world and transmits messages from the CNS to muscles and glands in the body
It does this via millions of neutrons (nerve cells) and is divided into the autonomic nervous system and somatic nervous system
What is the somatic nervous system?
Transmits info from receptor cells in the sense organs to the central nervous system.
Controls muscle movement and receives info from sensory receptors
It receives info from the central nervous system that directs muscles to act- voluntary effect
What is the autonomic nervous system?
Transmits info to and from internal bodily organs
It is autonomic so system operates involuntarily
2 main divisions - sympathetic and parasympathetic nervous systems
Governs vital functions of the body such as breathing, heart rate, digestion, sexual arousal and stress responses - involuntary effect
What is the parasympathetic nervous system?
Division of the autonomic nervous system which controls the relaxed state (rest and digest), conserving resources and promoting digestion and metabolism
Works in opposition to the sympathetic branch, one or other is active at any time
Relaxes internal organs and decreases bodily activities
What is the sympathetic nervous system?
Division of ANS which activates internal organs and increases bodily activities for vigorous activities and emergencies, such as fight or flight response.
Consists of nerves that control, for example, increased heart rate and breathing, and decreased digestive activity
Sympathetic branch works in opposition to parasympathetic branch, one or other is active at any time
What is the endocrine system?
One of the body’s major information systems that instructs glands to release hormones directly into the blood stream
Hormones carried towards target organs in body
Various glands produce hormones
Hormones secreted into bloodstream and affect any cell in body that has a receptor for that particular hormone
What is a gland?
Organ in body that syntheses (makes) substances such as hormones
What is a hormone?
Chemical substances that circulate in the bloodstream and only affect target organs
They’re produced in large quantities but disappear quickly
Have powerful effects
What hormones do pituitary glands release and what is the impact?
Lots of hormones released
Hormones released by pituitary gland control and stimulate release of hormones from other grands in the endocrine system
Located in brain - known as master gland
What hormone does the thyroid gland release and what is the impact?
Thyroxin
Responsible for regulating metabolism
What hormone does the ovaries release and what is the impact?
Oestrogen
Controls regulation of female reproductive system, including menstrual cycle and pregnancy
What hormone do the testes release and what is the impact?
Testosterone
Responsible for development of male sex characteristics during puberty while also promoting muscle growth
What hormone does the adrenal gland release and what is the impact?
Adrenaline
Responsible for fight or flight response - stimulates heart rate, interacts blood vessels and dilates air passages among other impacts
What hormone does the pancreas release and what is the impact?
Insulin
Allows body to use glucose from carbohydrates in food for energy or to store glucose for future use
Helps keep blood sugar levels stable
What is the fight or flight response?
The way an animal responds when stressed
Body becomes physiologically aroused in readiness to fight or flee ( flight )
Reflexive response- occurs without conscious awareness or thought
Shows how endocrine system and autonomic nervous system work together
What are the 8 stages of the fight or flight response?
1- hypothalamus recognises a threat in the environment
2- autonomic nervous system activates the sympathetic nervous system
3- sympathetic nervous system tells pituitary gland to release ATCH hormone
4- sends a message to the adrenal gland
5- adrenal grand responds by releasing adrenaline
6- adrenaline travels via bloodstream and targets organs in body which have adrenaline receptors
7- causes many physical changes to occur (fight or flight response)
8-once threat has passed, parasympathetic nervous system brings body back to normal, resting functions
What is adrenaline?
Hormone produced by the adrenal gland which is part of body’s stress response system
Has strong effect on cells of the cardiovascular system -stimulating heart rate, contracting blood vessels and dilating air passages
What does the sympathetic state with adrenaline present do to: Heart rate Breathing rate Pupils Digestion Saliva production Rectum
Increases Increases Dilates Inhibits Inhibits Contracts
What does the parasympathetic state with adrenaline present do to: Heart rate Breathing rate Pupils Digestin Saliva production Rectum
Decreases Decreases Constricts Stimulates Stimulates Relaxes
Limitation of the fight or flight response- freeze response
Double whopper
some psychologists suggest that humans engage in initial “freeze” response
gray (1988) suggests first response to danger is to avoid confrontation altogether ie-freeze
During freeze response, animals/ humans are hyper-vigilant while they appraise the situation to decide the best course of action for that particular threat
suggests that the fight on flight response is limited as it does not explain all outcomes
Limitation of the fight or flight response - tend and befriend, Taylor et al (2000)
Hamburger
Recent research shows women ‘tend or befriend’ in stressful/dangerous situations
Taylor et al (2000) - women more likely to tend to offspring and befriend other women rather then fight or flee
Therefore typically a male response to danger
(Can’t generalise to population as only covers half the worlds population)
Limitation of fight or flight response - beta bias
Early research typically conducted on males
Researchers assumed findings could be generalised to females - androcentrism
Underestimates the differences in sexes (beta bias), reducing explanatory power of response
Cannot be applied to all individuals in the same way
Limitation of fight or flight response - maladaptive response
Stressors of modern day life can repeatedly activate fight or flight
Stress faced continually activate the sympathetic nervous system, continually increasing their blood pressure which can cause damage to their blood vessels and heart disease
Suggests that response is maladaptive response in modern day life
Limitation of fight or flight response - biologically reductionist
Response is biologically reductionist
Attempts to explain behaviour based on adrenaline and effects of SNS
Doesn’t account for pother elements that could influence a response to a stressful situation - cognitive processes
Too limited an explanation
What are neurons?
Basic building blocks of nervous system
Nerve calls that process and transmit messages through electrical and chemical impulses
What is the sensory neuron?
Carry messages from the PNS to the CNS (nerve impulses from sensory receptors to the spinal chord and brain)
The receptors for sensory neurons are located on or near the body’s surface
Long dendrites and short axons
What is the relay neuron?
Connect sensory neuron to motor and other relay neurons, allow them to communicate with each other - most common type of neuron in CNS
Located in brain, spinal chord and visual system
Short dendrites and short axons
What is the motor neuron?
Carry brain impulses from the spinal chord and brain to effectors such as muscles and glands - from CNS to PNS
Axons directly or indirectly linked to muscles
Short dendrites and long axons
What is the cell body?
Factory of the neuron
Contains nucleus and produces necessary proteins that neuron requires to function
What is the nucleus?
Contains genetic material within the neuron
What are dendrites?
Branch-like features protrude from cell body
Carry nerve impulses from neighbouring neurons towards the cell body
What is an axon?
Carries electrical impulse from the cell body, down the length of neuron
Covered in myelin sheath
What is the myelin sheath?
Fatty layer surrounding axons to protect axons
Helps speed up electrical transmission of impulse
What are the nodes of ranvier?
Gaps between myelin sheath
Speed up transmission of impulses by forcing it to ‘jump’ across the gaps along the axon
What is synaptic transmission?
Process by which neighbouring neurons communicate with each other by sending chemical messages across the synaptic cleft then separates them
What are neurotransmitters?
Brain chemicals released from synaptic vesicles that relay signals across the synapse from one neuron to another
Can be broadly divided into those that perform an inhibitory or an excitatory function\
Several have been identified in the brain, spinal chord and glands
Each neurotransmitter has its own specific molecular structure that fits perfectly into a post-synaptic receptor site, similar to lock and key
What is excitation?
When a neurotransmitter such as adrenaline increases positive charge of postsynaptic neuron
Increases likelihood that neuron will fire and pass on the electrical impulse
What is inhibition?
When a neurotransmitter, such as serotonin, makes the change of the postsynaptic neuron more negative
This decreases the likelihood that the neuron will fire and pass on an electrical signal
Whether or not a post synaptic neuron is fired is decided by:
ASK ABOUT TO CLARIFY
Summation
Excitatory and inhibitory influence are summed up
If net effect on postsynaptic neuron is inhibitory, the neuron is less likely to fire
If net effect is excitatory, neuron is more likely to fire
Action potentials (nerve impulses) of postsynaptic neuron are only triggered if sum of exciter your and inhibitory signals at any one time reach the threshold
What is the synapse?
Junction between two neurons
Includes the pre-synaptic neuron, synaptic cleft and post-synaptic receptor site
What is the synaptic cleft?
Space between the pre-synaptic and post-synaptic neuron
What are synaptic vesicles?
Small sacs at the end of pre-synaptic neuron that contain neurotransmitters that will be released into the synapse
What is the pre-synaptic neuron?
Transmitting neuron before the synaptic cleft
What is the post-synaptic neuron?
Neuron that is receiving the information from the synapse
What is the post-synaptic receptor site?
Receptor on the post-synaptic neuron
Neurotransmitter locks into a specific receptor on the posts-synaptic neuron
This triggers an electrical impulse in the post-synaptic neuron
Outline the process of synaptic transmission - 9 steps/points
- Electrical impulse travels down pre-synaptic neuron, along axon to terminal buttons of neuron
- When electrical impulse gets to terminal buttons it stimulates the synaptic vesicles - contain neurotransmitters which are chemicals
- Neurotransmitters released from synaptic vesicles and travel across synapse - electrical impulse changed too chemical impulse
- Neurotransmitters cross synapse to get to the dendrites of post-synaptic neuron
- There are receptors on the dendrites of the post-synaptic neuron - receptors are the lock in the lock and key theory
- If neurotransmitters (key) are the correct shape, they can fit into receptors on dendrites of the post-synaptic neuron
- Connection between neurotransmitter and receptor CAN cause electrical impulse created in dendrites on point-synaptic neuron - depends on whether neurotransmitters are excitatory or inhibitory
- If neurotransmitter is excitatory, more likely that electrical impulse will travel down post-synaptic neuron and process will begin all over again
- Neurotransmitter doesn’t always fit receptor, if this is the case there will be no electrical impulse created in the second neuron
What are the two effects drugs can have on synaptic transmission?
- Increase amount of neurotransmitters- block reuptake channel
- Decrease amount of neurotransmitters- block receptors
What is an example of drugs increasing the amount of neurotransmitters?
SSRIs in OCD block reuptake channels so serotonin remains in synapse and can continue to bind with more receptors - too little serotonin is thought to cause OCD
What is an example of drugs decreasing the amount of neurotransmitters?
Antipsychotic drugs used in schizophrenia block the receptors to prevent dopamine binding - too much dopamine is thought to cause schizophrenia
What are fMRIs?
Works by detecting changes in blood oxygenation and blood flow that indicate increased neural activity
People asked to do a task and observed where brain activity is
When brain area is more active it consumes more oxygen and to meet its increased demand, blood flow is directed to the active area - haemodynamic response
Produces 3D images showing which parts of brain are involved in particular mental process - localisation of function
What are EEGs?
Records changes in electrical activity using electrodes attached to the scalp (20 mins to set up)
Scan recording represent brainwave patterns, generated from the action of millions of neurons, provides overall account of brain activity
Used as diagnostic tool as unusual arithmetic patterns may indicate neurological abnormalities (epilepsy)
What are ERPs?
Changes in electrical activity using electrodes attached to scalp but uses specific stimulus (sensory, cognitive or motor) to see where activity is
Uses statistical averaging technique so all extraneous brain activity from the original EEG recording is filtered out leaving only those responses related to the specific task or stimulus
Research revealed many different forms of ERP and how they’re linked to cognitive processes
What are post mortems?
Examine abnormalities in structure of brain to try explain psychological abnormalities that people have before death
Also involves comparison to neurotypical (normal) brain to ascertain extent of difference
