B6 - Synapses & the Brain
- Created by: Lilly_B
- Created on: 10-04-15 17:33
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- B6 - Synapses & the Brain
- Synapses & Drug Effects
- There are tiny gaps (synapses) between neurons in the reflex arc
- Nerve impulses must cross these gaps to get them from one neuron to the next - special chemicals pass the impulses across synapses
- This is how the process works:
- 1. A nerve impulse gets to the end of a sensory neuron
- 2. The sensory neuron releases the transmitter chemical into the synapse
- 3. The transmitter chemical diffuses across the synapse
- 4. The transmitter chemical arrives at the receptor molecules on the motor neurons membrane - the molecules are the correct shape to bind the receptor olecules
- 6. The chemical is absorbed back into the sensory neuron to be used again
- 5. A nerve impulse is stimulate in the motor neuron
- Some drugs, including ecstasy, beta blockers, & prozac, make it difficult for impulses to get across the synapse
- Ecstasy (MDMA) blocks the place that removes serotonin - the serotonin concentration increases
- This makes the Ecstasy user happy for a short while but can be seriously harmful
- Ecstasy (MDMA) blocks the place that removes serotonin - the serotonin concentration increases
- Serotonin (a transmitter chemical) is released at some brain synapses - this gives a feeling of pleasure & sensory neurons later remove the serotonin
- Inside the brain
- Different regions of the brain do different jobs
- Neuroscientists map the brain by:
- Studying patients with brain damage
- Electricity stimulating different parts of the brain
- Doing MRI scans
- The cerebral Cortex is the part of the brain most closely linked to intelligence, language, memory, & conciousness (MILC)
- Reflex Responses
- Animals can learn a reflex response to a new stimulus - the new stimulus (secondary stimulus) becomes linked to the primary stimulus - this s called conditioning
- Pavlov taught a dog to salivate when it heard a bell ring:
- 1. The dogs simple reflex was to salivate when it was given food
- 2. Pavlov rang a bell whilst the dog was eating
- 3. After a while, the dog salivated every time it heard the bell, even when there was no food
- In this conditioned reflex, the stimulus (ringing the bell) became linked to food - the final response (salivating) had no direct connection to the stimulus
- Conditioned reflexes are a simple form of learning - They increase an animals chance of survival
- Synapses & Drug Effects
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