B6:Brain and Mind Flashcards
DEFINE: Stimulus
A stimulus is the change in environment of an organism
Name the two organs that make up the CNS
The brain& spinal cord
What are sensory neurons job?
They are neurones that carrys impulses from receptors to the CNS
Where do motor neurons send messages to and from?
Between the CNS and effectors
DEFINE:Receptor and give an example
Receptors are cells that detect stimuli. Examples are taste, sound & pain.
DEFINE: Effector and give an example
Effectors respond to nervous system impulses and bring about a change. Examples are muscles and hormone secreting cells (glands)
What is the role of the CNS?
The CNS is a processing centre, it recieves information from the receptors and then co-ordinates a response
Describe the pathways between a stimulus and response
Stimulus, Receptor, Sensory neuron, CNS, Motor neuron, Effector & Response
How do neurons transmit information?
They transmit information as electrical impulses
What is an axon?
Axons are made from the nerve cells cytoplasm strected out into a long fibre and surronded by a cell membrane.
What is the function of the fatty sheath?
The fatty sheath acts as a electrical insulator, it shields the neuron from neighbouring cells and speeds up the electrical impulse.
DEFINE: Synapse
A synapse is the tiny gap between neurons.
Describe how impulses are transmitted across a synapse.
When an electrical impulsse reaches the end of a neurone it triggers the release of transmitter chemicals into the synapse. The transmitter chemicals diffuse across the gap and bind to receptor molecules on the membrane of the next neurone.
Describe one way ecstasy increases sertonin concentration in the brian
It blocks the sites where the serotonin (transmitter chemical) is reabsorbed. Because it cnat be reabsorbed it builds up inside the brain
DEFINE: Reflex
Reflexes are rapid, automatic responses to certain stimuli. They are involuntary respones.
Give two ways simple reflexes increase chance of survival
For finding food and sheltering form predators
Give three examples of simple reflexes in humans.
Bright light - pupil contracts allowing less light in Hot object - reflex to drop it Knee jerk reflex Suckle reflex Grasp reflex
How are reflexes modified?
The response can be overidden by a nuerone between the brain and the motor neurone of the reflex arc.
Give an example of when it would be an advantage to modifing an reflex.
Dropping a hot plate on the floor, if it was your dinner. Or dropping it on a pet/baby/someone else on the floor.
Breifly describe Pavlov’s experiment.
He noticed dogs salivate when they smell food. He experimented by ringing a bell just before the dogs were given food. After a while he found the dogs salivated when the bell was rung when when they couldnt smell food. The dogs responded to a secondary stimulus. This is a conditioned reflex.
Give another example of a conditioned reflex.
Insects with bright colours are often posionous, their colour as a warning to predators. Predators can develop a conditioned reflex. IF they eat a bright couloured caterpillar it notices it doesnt taste good and makes them ill. It associates the bad taste and illness with the colour. So next time it avoids it.
How can new experiences increase the number of connections in the brain of a child?
Their brain is only partly developed, when they experience new things connections form - neurones are stimulated and they branch out connecting cells that were previously unconnected.
What happend to pathways as activites as repeated?
When experiences are repeated over and over again the pathways that the nerve impulses travel down become strengthened. Strengthened oathways are more likely to transmit impulses than others.
Why is it harder for older people to learn new things?
After the age of 1, pathways that arent used as often start to die off, this is why it is harder for them to learn new things.
DEFINE: MEMORY
Memory is the storage and retrieval of information
Give three methods used by scientistds to study the brain,
Studying brain damaged patients, Electrically stimulating the brain & MRI (magnetic resonance imaging)
Name two things the cerebral cortex is important for
Language, memory, intelligence and consciousness.
Describe the multi-store memory model
Information that you’ve paid attention to is temporarily stored in short-term memory. If its repeated enough its tranferred to the long-term memory and stored there. Memories that are neber transferred from teh short term memory to long term are forgotten. But information can be retrieved from the long term memory and remembered.
