Unit 1, AOS 1: The role of the brain Flashcards
what is split brain surgery?
treatment for epilepsy that involves cutting corpus callosum.
what is structural neuroimaging?
techniques that produce images showing brain structure
CT stands for
computerised tomography
what is computerised tomography? what does it involve?
a type of structural neuroimaging. first used early 1970s. patient given iodine contrast to highlight brain blood vessels. shows horizontal cross-section of brain. used to show brain abnormalities and tracking changes caused by parkinson’s and alzheimer’s.
MRI stands for
magnetic resonance imaging
what is magnetic resonance imaging? what does it involve?
a type of structural neuroimaging. first used in 1977, popular in 1980s. uses magnetic fields to vibrate atoms in brain’s neurons to generate computer image. can detect extremely small changes.
what is functional neuroimaging?
provides views of some particular aspects of brain function by showing images of the brain at work.
PET stands for
position emission tomography
what is position emission tomography? what does it involve?
a type of functional neuroimaging used in late 1970s. participant is injected with glucose solution with short-lived radioactive tracer. assumed that areas with increased blood flow have increased neural activity. participant then engages in mental or low-level physical task. less detailed than MRI.
fMRI stands for
functional magnetic resonance imaging
what is functional magnetic resonance imaging? what does it involve?
a type of functional neuroimaging in the 1990s. measures the brain’s oxygen consumption during different tasks. blood is more oxygenated in highly active parts of the brain.
what does the nervous system do?
enables brain to obtain information about happenings inside + outside the body. it:
- receives info
- processes info
- responds to info
CNS stands for
central nervous system
what is the central nervous system? what does it do?
central to all mental processes and behaviours. main function is to process info received through sensory systems + other body parts to activate appropriate actions. made up of the brain and spinal cord.
PNS stands for
peripheral nervous system
what is the peripheral nervous system? what does it do?
made up of entire network of nerves outside the CNS, transmits info to + from the CNS.
- receives info from sense organs, muscles, glands
- sends info from sense organs, muscles, glands
SNS stands for
somatic nervous system
what is the somatic nervous system? what does it do?
network of nervous that carry sensory info to the CNS and motor info from the CNS. involved in voluntary movement.
ANS stands for
autonomic nervous system
what is the autonomic nervous system? what does it do?
network of nerves that carry messages between the CNS and the heart, lungs, other internal organs + glands. involved in automatic/involuntary movement.
what is the sympathetic nervous system? what does it do?
part of the ANS. arouses body when we experience an extreme emotion or feel threatened. (fight/flight)
what is the parasympathetic nervous system? what does it do?
part of the ANS. calms or restores the body to its normal state. (rest/digest)
what is a spinal reflex?
reflex reaction to certain stimuli. these are involuntary and occur automatically without the involvement of the brain.
how does a spinal reflex work?
- nerves send message via sensory neurons on the afferent neural pathway to the CNS (spinal cord)
- CNS (spinal cord) sends motor neuron along efferent neural pathway to the muscle.
- whilst this is happening, a sensory neuron is sent to the CNS (brain) where it becomes aware of the stimulus and pain or another sensation is felt.
what are afferent neurons?
also known as sensory neurons. these neurons are sent from the body to the brain.
what are efferent neurons?
also known as motor neurons. these neurons are sent from brain to body (relevant areas)
what is the dendrite?
thin extension of a neuron that receives info from other neurons and transmits it to the soma.
what is the soma?
also known as the cell body. combines neural info received from the dendrites and sends it to the axon.
what is the axon?
single, tube-like extension that transmits neural info away from the soma to other neurons.
what is the myelin sheath?
fatty substance that helps insulate the axon from the activity of other nearby axons.
what are the nodes of ranvier?
small gaps where myelin is missing. these increase speed of the action.
where are axon collaterals located?
at the end of the axon.
what are axon terminals?
located after the axon collaterals. these hold synaptic buttons that secrete a chemical called a neurotransmitter. these carry info across the synaptic gap to the next neuron’s dendrites in which the process repeats.
what are glial cells?
support the neurons. located in both the CNS and the PNS. they surround the neuron, and without glial cells neurons could not function.
what is the neural transmission process?
dendrite > soma (converted to action potential) > axon > axon terminal > terminal buttons > synaptic gap > receptor site (on dendrite of postsynaptic neuron) > repeat
where is the hindbrain? what structures does it involve?
lower level brain structures including:
- cerebellum
- medulla
- pons
what is the cerebellum?
part of the hindbrain. coordinates fine muscle movements and regulates posture + balance. it organises and adjusts muscle activity. it is involved in learning movements and remembering movements.
—- cerebellum = movement
what is the medulla?
part of the hindbrain. it is a continuation of the spinal cord which connects it to the brain. controls vital bodily functions: swallowing, breathing, heart rate, blood pressure.
—- medulla = vital
what is the pons?
part of the hindbrain. involbed in sleep, dreaming, waking, breathing control and coordination of some muscle movements. connects parts of the brain together by relaying messages,
—- pons = sleep + relay
what is the midbrain?
receives lots of info from ears + eyes and processes to help produce orienting movements (not as complex).
what is the reticular formation?
part of the midbrain. helps screen incoming info so the brain doesn’t overload. alerts higher brain centres to important info.
—- reticular formation = screen + alert
where is the forebrain? what structures does it involve?
collection of upper level structures that regulate complex cognitive processes including
- thalamus
- hypothalamus
- cerebrum.
what is the hypothalamus?
part of the forebrain. maintains body’s internal environment and influences behaviours with basic biological needs such as hunger/thirst/sleep.
—- hypothalamus = biological needs
what is the thalamus?
part of the forebrain. filters info from sense receptor sites (except nose) and passes it to relevant brain areas for further processing.
—- thalamus = sensory filter
what is the cerebrum?
part of the forebrain. main area of the brain that is divided into two cerebral hemispheres.
what is grey matter?
unmyelinated axons in the cerebral cortex. processes info from white matter and sends response back through it.
what is white matter?
myelinated axons in the cerebral cortex. transmits sensory + motor impulses between PNS and grey matter.
what is hemispheric specialisation?
the idea that one hemisphere has dominant functions over the other (left-brained/right-brained)
name examples of some left hemispheric specialisations
- receive and process sensations from right side of body
- control voluntary movements from right side of body
- verbal tasks
- analysis
- logical reasoning
(and more)
name examples of some right hemispheric specialisations
- receive and process sensations from left side of body
- control voluntary movements on left side of body
- spatial and visual thinking
- recognising emotions
- appreciation of art + music
(and more)
what are cortical lobes?
areas of the cerebral cortex associated with different functions.
where is the frontal lobe? what three parts does it contain?
located roughly at the front of the brain. composed of:
- the prefrontal cortex (involved with mental abilities such as reasoning, planning, problem-solving, regulating emotions)
- the premotor cortex (plans appropriate movement)
- the primary motor cortex (initiates + controls voluntary movements)
what and where is the parietal lobe?
located roughly at the top part of the brain. receives + processes somatosensory info. amount of cortex devoted to particular body part corresponds to sensitivity/amount of use of body part, represented by a homunculus.
what and where is the occipital lobe?
located roughly at the back of the brain. almost exclusively devoted to the sense of vision. primary visual cortex located here.
what and where is the temporal lobe?
located roughly at the bottom part of the cerebrum. involved in auditory perception, memory, visual perception, identification + recognition, emotional responses to sensory info and memories.
what is broca’s area?
located in the frontal lobe. involved in the production of articulate speech.
what is wernicke’s area?
located in the temporal lobe. involved with comprehension of speech.
how big is an infant’s brain?
1/4 the size of an adult brain
how big is a 6 month old’s brain size?
1/2 the size of an adult brain
how big is a 2 year old’s brain size?
3/4 the size of of an adult brain
how big is a 6 year old’s brain size
90-95% the size of an adult’s
what is myelination? how does it occur and where does it begin?
production of myelin. allows neurons to be more efficient in sending messages to other neurons. occurs hindbrain > midbrain > forebrain. Begins in sensory/motor areas, then complex/association areas.
what is synaptogenesis?
dendrites growing to create more synapses. occurs quickly in sensory/motor neurons, slower in association areas.
what is synaptic pruning? when does this occur most?
weak/unused connections are pruned. burst in synaptic pruning during adolescence. this burst calms at around age of 30.
what is a brain injury that occurs at once called?
sudden onset brain injury
what happened to phineas gage?
in 1848 he had a metal rod go through top of his skull in an accident and survived.
what were the biological changes of phineas gage?
problems with motor activities and movement
what were the psychological changes of phineas gage?
emotional changes: lacking empathy, lack of concern for past/present, impulsive behaviour.
forgetfulness shown in tasks that require continuous attention
what were the social changes in phineas gage?
- breakdown in personal relationships due to changes
- became aggressive and irresponsible
- increased risk of unemployment and social isolation
what is spatial neglect?
a neurological disorder where individuals are unable to notice anything on the left/right side.
what is brain plasticity?
the ability of the brain to change in response to experience.
what does brain plasticity occur in response to?
- (developmental) ageing and learning associated with maturation
- (adaptive) brain trauma and injury
aspects of developmental plasticity are
- myelination
- synaptogenesis
- synaptic pruning
- frontal lobe development
define neurodegenerative disorder
a disorder that occurs when a negative change to neural functioning occurs, resulting in neurons deteriorating over a person’s lifespan.
aspects of adaptive plasticity are:
- rerouting (undamaged neuron seeks new connection
- sprouting (neuron sprouts more dendrite branches to make new connections)
