B6:Brain and Mind

Question 1

DEFINE: Stimulus

Answer 1

A stimulus is the change in environment of an organism

Question 2

Name the two organs that make up the CNS

Answer 2

The brain& spinal cord

Question 3

What are sensory neurons job?

Answer 3

They are neurones that carrys impulses from receptors to the CNS

Question 4

Where do motor neurons send messages to and from?

Answer 4

Between the CNS and effectors

Question 5

DEFINE:Receptor and give an example

Answer 5

Receptors are cells that detect stimuli. Examples are taste, sound & pain.

Question 6

DEFINE: Effector and give an example

Answer 6

Effectors respond to nervous system impulses and bring about a change. Examples are muscles and hormone secreting cells (glands)

Question 7

What is the role of the CNS?

Answer 7

The CNS is a processing centre, it recieves information from the receptors and then co-ordinates a response

Question 8

Describe the pathways between a stimulus and response

Answer 8

Stimulus, Receptor, Sensory neuron, CNS, Motor neuron, Effector & Response

Question 9

How do neurons transmit information?

Answer 9

They transmit information as electrical impulses

Question 10

What is an axon?

Answer 10

Axons are made from the nerve cells cytoplasm strected out into a long fibre and surronded by a cell membrane.

Question 11

What is the function of the fatty sheath?

Answer 11

The fatty sheath acts as a electrical insulator, it shields the neuron from neighbouring cells and speeds up the electrical impulse.

Question 12

DEFINE: Synapse

Answer 12

A synapse is the tiny gap between neurons.

Question 13

Describe how impulses are transmitted across a synapse.

Answer 13

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.

Question 14

Describe one way ecstasy increases sertonin concentration in the brian

Answer 14

It blocks the sites where the serotonin (transmitter chemical) is reabsorbed. Because it cnat be reabsorbed it builds up inside the brain

Question 15

DEFINE: Reflex

Answer 15

Reflexes are rapid, automatic responses to certain stimuli. They are involuntary respones.

Question 16

Give two ways simple reflexes increase chance of survival

Answer 16

For finding food and sheltering form predators

Question 17

Give three examples of simple reflexes in humans.

Answer 17

Bright light - pupil contracts allowing less light in
Hot object - reflex to drop it
Knee jerk reflex
Suckle reflex
Grasp reflex

Question 18

How are reflexes modified?

Answer 18

The response can be overidden by a nuerone between the brain and the motor neurone of the reflex arc.

Question 19

Give an example of when it would be an advantage to modifing an reflex.

Answer 19

Dropping a hot plate on the floor, if it was your dinner. Or dropping it on a pet/baby/someone else on the floor.

Question 20

Breifly describe Pavlov’s experiment.

Answer 20

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.

Question 21

Give another example of a conditioned reflex.

Answer 21

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.

Question 22

How can new experiences increase the number of connections in the brain of a child?

Answer 22

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.

Question 23

What happend to pathways as activites as repeated?

Answer 23

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.

Question 24

Why is it harder for older people to learn new things?

Answer 24

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.

Question 25

DEFINE: MEMORY

Answer 25

Memory is the storage and retrieval of information

Question 26

Give three methods used by scientistds to study the brain,

Answer 26

Studying brain damaged patients, Electrically stimulating the brain & MRI (magnetic resonance imaging)

Question 27

Name two things the cerebral cortex is important for

Answer 27

Language, memory, intelligence and consciousness.

Question 28

Describe the multi-store memory model

Answer 28

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.