Biopsychology Flashcards
What is the definition of the nervous system?
The nervous system is a specialised network of cells that enables communication within the body.
What two things do the CNS compose off?
The brain and the spinal cord
What is the job of the brain?
The brain is the centre of all conscious awareness, controlling thought, perception and voluntary movements.
What is the job of the spinal cord?
The spinal cord relays information between the brain and the rest of the body and is responsible for reflex actions
What is the job of the peripheral nervous system?
The peripheral nervous system transmits messages to and from the central nervous system (CNS) to the rest of the body through nerves
What is the peripheral nervous system (PNS) divided into?
The somatic and autonomic nervous systems
What is the job of the somatic nervous system?
The somatic nervous system governs voluntary movements and transmits sensory information from the body/sense receptors to the CNS and from this to effectors to produce voluntary movements.
Which nervous system integrates the brain with the outside world?
Somatic Nervous System
What is the job of the autonomic nervous system (ANS)?
The ANS manages involuntary processes (heart rate and digestion). It is responsible for transmitting information to and from internal bodily organs
Which nervous system works alongside the endocrine system?
The autonomic nervous system
What is the autonomic nervous system divided into?
- Sympathetic Nervous System
- Parasympathetic Nervous System
What is the job of the sympathetic nervous system?
Activates the ‘fight or flight’ response in the body
What is the job of the parasympathetic nervous system?
Promotes the ‘rest and digest’ response in the body
What are the ten structures within the neuron?
- Cell Body (Soma)
- Nucleus
- Cell Membrane
- Dendrites
- Axon Hillock
- Axon
- Myelin Sheath
- Schwann Cells
- Nodes of Ranvier
- Axon Terminal
What is the function of the cell body (soma)?
This contains the nucleus
What is the function of the nucleus?
The nucleus controls the neuron’s activities and provides energy
What is the function of the cell membrane?
Regulates substance movement
What is the function of the dendrites?
The dendrites are branch-like structures that receive electrical signals from other neurons
What is the function of the axon hillock?
Controls the initiation of the electrical signal in the neuron
What is the function of the axon?
The axon is a long fibre that transmits electrical signals (action potentials) away from the cell body
What is the function of the myelin sheath?
The myelin sheath is a fatty layer that insulates the axon, increasing the speed of signal transmission
What do Schwann Cells?
The Schwann cells create the myelin sheath
What is the function of the nodes of ranvier?
The nodes of ranvier are gaps in the myelin sheath where the action potential ‘jumps’ from node to node, increasing the speed of transmission
What is the function of the axon terminal?
This is the endpoint of he neuron where signals are transmitted to the next cell via synaptic transmission
What three types of neurons make up the reflex arc?
- Sensory
- Relay
- Motor
What is the function of a sensory neuron?
Sensory neurons carry information from sensory organs to the CNS.
What is the length of the sensory neurons axons and dendrites?
- Long dendrites
- Short axons
Which type of neuron allows us to feel heat and pressure?
Sensory Neurons
What is the function of the relay neurons (interneurons)?
They connect sensory and motor neurons to keep communication with the CNS.
Which type of neuron is only found in the CNS?
Relay Neurons (Interneurons)
What is the length of the dendrites and axons in relay neurons?
- Short Dendrites
- Short Axon
Which type of neuron normally lacks a myelin sheath and why?
Relay Neurons often lack a myelin sheath as speed is less critical for short-distance transmission
What is the function of a motor neuron?
Motor neurons transmit signals from the CNS to effectors such as muscles and glands. This enables responses like movement of the secretion of hormones (adrenaline from the adrenal glands in fight-or-flight).
What is the length of the dendrites and axons in motor neurons?
- Short dendrites
- Long axons
Which type of neuron has cell bodies located in the CNS, with its axons forming the PNS?
Motor Neurons
What is the definition of synaptic transmission?
Synaptic transmission is the process by which one neuron communicates with another
Describe the process of synaptic transmission (5 steps)
- Action Potential reaches axon terminal
- This triggers vesicles to release their neurotransmitters across the synapse via diffusion (makes signal chemical)
- Chemical then locks into special receptor sites which are only found on the membrane of the post synaptic neuron (back to electrical signal)
- Stimulation of the postsynaptic reception by neurotransmitters results in either excitation (depolarisation) or inhibition (hyper polarisation) of the postsynaptic membrane via summation
- Vesicles are replenished with new and reused neurotransmitters
What is meant by inhibition (hyper polarisation)?
If the total/net effect on the post synaptic neuron is inhibitory, then the neuron is less likely to fire
What is meant by excitation (depolarisation)?
If the total/net effect is excitatory, the neuron will be more likely to fire
What happens to excess neurotransmitters?
Either:
- Enzymes are released to break them down
- Excess neurotransmitters are reabsorbed
What is the definition of the endocrine system?
A network of glands that secrete hormones into the bloodstream to regulate physiological processes
Which works faster between the endocrine and nervous system?
The Nervous System
What are glands?
Glands are specialised organs in the body that secrete substances such as hormones, enzymes or other fluids.
What is the job of the thyroid gland?
To produce thyroxine
What does thyroxine do?
- Affects cells in the heart (heart rate)
- Impacts metabolic rate (which affects growth rate)
What is hypothyroidism and what are the symptoms?
Hypothyroidism is when you do not have enough thyroxine. The symptoms are:
- Depression
- Slow Movement
- Slow Thought
- Weight Gain
- Tiredness
What is hyperthyroidism and what are the symptoms?
Hyperthyroidism is when you have too much thyroxine. The symptoms are:
- Nervousness
- Anxiety
- Hyperactivity
- Weight Loss
- Insomnia
Where is oxytocin produced?
The Pituitary Gland
What does oxytocin do?
Oxytocin is known as the love hormone because it is released when you bond with another person
Why is oxytocin so important in women?
- Causes contraction during child birth
- Helps shrink the uterus after birth
- Released during breastfeeding to stimulate the ‘let down’ of milk
- Involved in the mother-child bonding process
Which hormones produce adrenaline and cortisol?
The adrenal gland
What are hormones?
Hormones are chemical messengers produced by endocrine glands which are released into the bloodstream. They travel to target organs and tissues to influence processes such as growth, metabolism, reproduction and stress responses
What is meant by the fight-or-flight response?
The fight-or-response is an automatic physiological reaction to a perceived threat
What is the role of adrenaline in the fight-or-flight response?
It prepares the body for immediate physical action by triggering physiological changes such as:
- Increasing heart rate
- Dilating airways to improve oxygen intake
- Redirecting blood flow to muscles
Where is the fight-or-flight response triggered and what does this activate?
- Triggered by the amygdala
- This activates the hypothalamus
Which nervous system stimulates the adrenal glands, and what does this make us release?
The sympathetic nervous system stimulates the adrenal glands to release adrenaline and noradrenaline
What are the effects of fight-or-flight on the body?
- Increased heart rate
- Faster breathing
- Increase in glucose release for energy
Which nervous system activates the effects of fight-or-flight?
Sympathetic Nervous System
Which nervous system activates the effects of rest-and-digest?
Parasympathetic Nervous System
What are the effects of rest-and-digest?
- Slows heart rate
- Slows breathing rate
- Stimulates digestion
- Stimulates salivation
- Promotes energy conservation and recovery
What are the four main ways of studying the brain?
- fMRI (Functional Magnetic Resonance Imaging)
- EEG (Electroencephalogram)
- ERP (Event-Related Potentials)
- Post-Mortem Examinations
What does spatial resolution mean?
The smallest measurement the scan can produce
What does temporal resolution mean?
The accuracy of the scan in relation to time
What is the spatial and temporal resolution of an fMRI?
- Spatial: Approximately 1-2mm (Very High)
- Temporal: 1-4 seconds (Poor)
What is the spatial and temporal resolution of an EEG?
- Spatial: 5-9cm (Low)
- Temporal: Milliseconds (High)
What is the spatial and temporal resolution of an ERP?
Same as a EEG
What is the spatial and temporal resolution of a post-mortem examination?
- Spatial: Very High
- Temporal: Only one measurement so it is low
How does an fMRI work?
Functional Magnetic Resonance Imaging works by detecting the changes in both blood oxygenation and blood flow that occur as a result of neural activity in specific parts of the brain
How does an EEG work?
Electroencephalograms work by measuring brain activity within the brain via electrodes that are fixed to an individuals scalp using a skull cap
What are ERPs?
ERPs work the same way as an EEG, but measures certain brainwaves that are a response to a stimulus
What are post mortem examinations?
The physical analysis of the brain after the patient has passed away
What are the strengths of an fMRI?
- They do not rely on radiation
- Used widely in pieces of research
- Can be used to estimate the risk of surgeries
What are the weaknesses of an fMRI?
- Expensive to use
- Not able to get causation at a neural level
- Can’t see the communication between the certain areas of the brain
What are the strengths of an EEG?
- Used in studying sleep and epilepsy
- Non-invasive
- No use of radiation
- Cheaper than an fMRI
What are the weaknesses of an EEG?
- Uncomfortable for the patient
- Low spatial resolution
What are the strengths of an ERP?
- More specific measurement of processing changes
- Non-invasive
- Cheaper than an EEG
What are the weaknesses of an ERP?
- Cannot eliminate background noise and other extraneous variables
- Uncomfortable
What are the strengths of a post-mortem examination?
- Vital in the understanding of the brain
- Invasive, but this not an issue due to them being dead
- Can clearly see neurochemical aspects
What are the weaknesses of a post mortem examination?
- Lack of causation
- Ethical issues surrounding consent
What is meant by localisation?
The idea that different functions are localised in specific areas of the brain
What is meant by lateralisation?
The idea that certain activities are controlled/dominated by one hemisphere of the brain rather than the other
Which two scientists discovered the idea of localisation?
Paul Broca and Karl Wernicke
Name the areas of the brain that you need to know
- Temporal Lobe
- Wernicke’s Area
- Frontal Lobe
- Broca’s Area
- Visual Cortex
- Occipital Lobe
- Parietal Lobe
- Auditory Cortex
- Motor Cortex
- Somatosensory Cortex
What is the occipital lobe?
An area of the cerebral cortex that is related to the visual processing of colour and depth perception
What is the somatosensory cortex?
An area of the parietal lobe that processes sensory information from the skin
What is the auditory cortex?
This is located in the temporal lobe and analyses speech based information
What is the parietal lobe?
An area of the cerebral cortex that is vital for sensory perception and integration
What is Broca’s area?
An area of the frontal lobe in the left hemisphere responsible for speech production
What is the motor cortex?
An area of the frontal lobe involved in regulating movement
What is the frontal lobe?
An area of the cortex relating to thinking, decision making and social skills
What is Wernicke’s area?
Located in the temporal lobe of the left hemisphere, this area is responsible for language comprehension
What is the visual cortex?
A part of the occipital lobe that receives and processes visual information
What is the temporal lobe?
An area of the cerebral cortex that is related to auditory processing
What is Wernicke’s Aphasia?
This disorder is caused by damage to Wernicke’s area causing language comprehension deficit
What is Broca’s Aphasia?
This disorder is caused by damage to Broca’s area causing speech production deficits
What was the name of Broca’s patient who helped with the discovery of Broca’s area?
‘Tan’
Which hemisphere of the language centres located in?
For most people, they are located in the left hemisphere
What does it mean that motor is contralateral?
The RH controls the movement on the left side of the body and the LH controls the movement on the right side of the body
Vision is contralateral and what else?
Ipsilateral
What is meant by plasticity?
The sense that the brain has the ability to change throughout life
What is meant by functional recovery?
The idea that after a traumatic event, unaffected areas of the brain are able to adapt and compensate for the damaged areas
What is meant by the term ‘spontaneous recovery’?
The suggestion that function recovery can happen quickly after the traumatic event
What is the definition of axonal sprouting?
The growth of new nerve endings which connect with other undamaged nerve cells to form new neuronal pathways
What is meant by denervation super sensitivity?
This occurs when axons that do a similar job become aroused to a higher level to compensate for the ones that are lost
What is the definition of a biological rhythm?
A change in the body’s processes or behaviour that repeats regularly
What is meant by a circadian rhythm?
Circadian rhythms last for approximately 24 hours
Give an example of a circadian rhythm
The sleep/wake cycle
What is an endogenous pacemaker?
Internal mechanisms that govern biological rhythms
What are exogenous zeitgebers?
External factors in the environment that reset our biological clocks through a process known as entrainment
What is the name of the tiny bundle of nerve cells located in the brain which has an effect on the sleep wake cycle?
The Suprchiasmatic Nucleus (SCN)
Name two exogenous zeitgebers that have an impact of the sleep/wake cycle
- Light
- Social Cues
What is an infradian rhythm?
A biological rhythm that lasts longer than 24 hours
Name two examples of infradian rhythms
- Seasonal Affective Disorder (SAD)
- Menstrual Cycle
Is SAD and endogenous or exogenous system? And why?
Exogenous due to the impacts of light which is an exogenous zeitgeber
What are the four phases of the menstrual cycle in order and how long do they generally last?
- Menstruation (3-7 days)
- Follicular Phase (around 14 days)
- Ovulation (24 hours)
- Luteal Phase (around 14 days)
How long is the menstrual cycle?
It is generally 28 days but can be anything between 24 and 35
What is an ultradian rhythm?
Biological rhythms that last less than 24 hours
What sleep are you in for each stage of a cycle of sleep?
Stage One: N1 Sleep
Stage Two: N2 Sleep
Stage Three: N3 Sleep
Stage Four: REM Sleep
