Neuroscience Short Answers Flashcards
What were the Invasive Techniques of Neuroscience in the Past?
Activating areas of the brain through electricity, chemicals, heat, cold - behaviour observed.
How does MRI Work?
Magnetic field over head, H molecule reverberations picked up by scanner, examined for differences, 3D picture created.
How does EEG Work?
Detects electrical currents generated by neurons on brain surface by affixing metal electrodes to scalp.
What is N400?
Linked with language processing - elicited in sentences where last word is surprising but linguistically legal.
How does FMRI Work?
Changes in magnetic fields detected in blood to show fast changing aspects of brain physiology.
How does TMS Work?
Creates temporary brain dysfunction - magnetic pulses on scalp causes disruption below area.
What does Development of Nervous System Look like after 3 Weeks?
Thickening on top of embryo, neural tube formed.
What does Development of Nervous System Look like after 1 Month?
3 thickenings develop into hindbrain, forebrain, midbrain.
What does the Central Nervous System Include?
Brain and spinal cord.
What does the Peripheral Nervous System Include?
Somatic and autonomic systems.
What is the Function of Afferent Nerves?
Transmit information from sense organs to brain and spinal cord.
What is the Function of Efferent Nerves?
Transmit information from CNS to effectors.
What are the 3 Functions of the Cranial Nerves?
Control movements of sensations from head and neck, regulate glandular secretions in head, control visceral functions.
How many Neurons are in the Brain?
10 to 100 billion.
What are the Different Sides of the Brain Used for?
Right = Spatial awareness Left = Language
How does the Cortex Affect Behaviour?
Large cortex = flexibility of behaviour.
What is the Function of the Basal Ganglia?
Regulation and smoothing of movement, beside thalamus.
What is the Function of Primary Areas of the Cortex?
Basic sensory input and motor output.
What is the Function of Association Areas of the Cortex?
Elaboration or “higher functions”.
How is Cortical Space Allocated in the Primary Motor Area?
Based on preciseness of movement.
How is Cortical Space Allocated in the Primary Sensory Areas?
Most sensitive parts of body receive more cortical space.
How is Hemiplegia Caused?
Damage to contralateral motor cortex.
What is Important to Remember about Higher Functions of the Brain?
They require multiple areas of the brain to be at work.
How is Visual Agnosia Caused?
Damage to occipital cortex, parts of temporal and parietal lobes.
How does Visual Agnosia Affect Drawing Ability?
Copying individual parts ok, but can’t integrate into whole picture.
What Happens as a Result of Damage to the Prefrontal Cortex?
Decrease in response inhibition, can’t plan, appear uninvolved, psychopathic.`
When did Lobotomy of Frontal Lobes Stop?
1950s.
What Happens as a Result of Apraxia?
No initiation/organisation of actions, can’t perform well known actions - fragmented and disorganised.
What is Broca’s Area Responsible for?
Speech production.
What is Wernicke’s Area Responsible for?
Speech comprehension.
What is the Arcuate Fasciculus Responsible for?
Connects Wernicke’s and Broca’s areas.
What is the Angular Gyrus Responsible for?
Reading.
What is the Result of Neglect Syndrome?
Damaged right side = neglect left sides of space.
Why is Neglect Asymmetrical?
Right side controls attention to both sides of space, left side controls attention to right side only.
What is the Purpose of Split Brain Surgery?
Relieves intractable, multifocal epilepsy - prevents seizures spreading through the brain by separating hemispheres.
What is an Example of the Split Brain?
Ball in right hemisphere, speech in left, can’t name ball but can easily name banana in left hemisphere.
What does Having a ‘Split Brain’ Mean?
Right brain can understand, but can’t speak.
What Happens as a Result of Callosal Agenesis?
Inter-hemispheric transmission takes 20-30ms instead of 4-6ms.
What is the Function of Dendrites?
Receive nerve impulses from other neurons.
What is the Function of Axons?
Transmit nerve impulses.
What is the Function of Axon Terminals?
Secrete neurotransmitters in synapse.
What Path do Motor Neurons Follow?
CNS, spinal cord, muscle fibre.
What Path do Sensory Neurons Follow?
Sense organ, brain (spinal cord).
What Path do Interneurons Follow?
Between other neurons (computation).
What do Glial Cells Become?
Scaffolding for mature neurons, repair when tissue is damaged.
What is the Resting Potential of Axons?
-70mV.
What Causes an Action Potential?
Pulse applied that exceeds excitation threshold (-55mV), inside swings positive relative to outside.
What does Resting Potential Depend on?
Na+ outside the cell membrane.
What Happens After a Pulse?
Ion channels open, Na+ pours into cell, reversing voltage difference, Na+ chambers then close, K+ leaves cell to restore original voltage difference.
What is the Lock and Key Model?
Neurotransmitter molecules only affect the postsynaptic membrane if the molecule shape fits into certain synaptic receptors.
How do Neurotransmitters Work in the Synapse?
Inactivated by “cleanup” enzymes, reused in synaptic re-uptake.
How do Drugs Work in the Synapse?
Stimulate/inhibit neurotransmitter release, stimulate/block postsynaptic receptor molecules, inhibit uptake.
What is an Example of an Agonist?
Black widow venom - acetylcholine forced to keep releasing until exhaustion.
What is an Example of a Drug Stimulator?
Nicotine stimulates acetylcholine receptors - mimics acetylcholine.
What is an Example of a Drug Blocker?
Curare - blocks acetylcholine receptors on muscle fibres - suffocation.
What is an Example of a Drug Preventing Re-uptake?
Cocaine - affects arousal.
What are some Examples of Agonists?
Prozac, Valium, Heroin.
