SECTION 1- CNS Flashcards
(20 cards)
What is the cerebral cortex?
The outer layer of neural tissue of the cerebrum- largest part of the brain.
manages conscious thought
consists of the neo-cortex
what is the neo-cortex?
layers of the cerebral cortex that are associated with higher brain functions
What is a ventricle?
A fluid-filled cavity in the heart or brain
what is a synapse?
A small gap at the end of a neuron that allows a signal to pass from one neuron to the next- where nurons communicate
what is the cerebral self?
the understanding of ourselves as our brains
Vidal C17th- our identity is linked to having a brain (challenges other views of brainhood e.g., spiritualism)
Locke- identity is psych not phys- who we are in our memories
What is Descartes (1662) theory of reflex action?
A hydraulic model of causation and brain function- stimulus causes reflex action activated by animal spirits
influenced the modern account of spinal reflex= stimulus- triggers electrical activity- feel pain
Who discovered the synapse?
Cajal discovered synaptic connections (before this, neurons were continuous structures)
Sherrington (1897) coined the term ‘synapse’
who discovered neurotransmission?
Loewi confirmed chemical neurotransmission and discovered the first known neurotransmitter
what are the 2 ways that neurons communicate?
1) electrochemical conduction= from the dendrites (input) along the axon (output)
2) chemical transmission= across the synaptic gap
what is the first stage of electrical conduction?
Action potential
what is the resting potential of a neuron?
- the resting potential of a neuron is similar to salt water
- contains the chemicals Sodium (Na+), Potassium (K+), Chloride (Cl-), Anion (A-)
- at resting potential sodium ion levels are higher outside the cell and potassium levels higher inside the cell
- the differences in chemical concentartions and electrical charges forces cause neuron to stay at steady resting
- 70 millivolts less positive inside the cell membrane than outside
how does an action potential get triggered in a neuron?
Sodium channels open up in the membrane allowing sodium to flow in to the neuron = membrane potential becomes more positively charged
what is depolarisation?
the process by which the membrane potential becomes less negative, causing an action potential (moves towards zero)
what is overshoot?
when the neurons membrane potential reaches a positive charge
what is repolarization?
when sodium channels shut which changes the membrane potential- potassium channels open back up and they flow in- making it less positive and eventually negatively charged
what are the effects of alcohol in the brain?
Alcohol effects the brain by Increasing inhibitory activity in the brain by:
- Inhibiting responsiveness of neurons by interacting with GABA system (inhibitory neurotransmitters)
- inhibites the glutamate system (a major excitatory system)
- releases dopamine into the brains reward system
- increases seritonin which implicates mood regulation
How do antidepressants work?
By manipulating activity in the neuron
e.g., SSRI- block seritonin reuptake therefore stays in synapse for longer periods
neurotransmission and learning
learning strengthens and activates synaptic connections
what is synaptic plasticity?
the ability of weakening and strengthening of synaptic connections over time
what is synaptic pruning?
a change in neural structure by reducing neurons and connections that are lesser used
can be seen as maturing or developing
represents learning
influenced by enviroment
