The nervous system/reaction times

Question 1

What does the nervous system enable humans to do?

Answer 1

To react to surroundings and coordinate their behaviour

Question 2

What is the CNS made up of?

Answer 2

Brain and spinal cord

Question 3

What does the CNS do?

Answer 3

Coordinates response of effectors

Question 4

What do the effectors do?

Answer 4

Contract muscles or glands secrete hormones

Question 5

What are reflex actions?

Answer 5

Automatic and rapid. Don’t involve the conscious part of the brain

Question 6

What is each step, in order, of how the nervous system operates?

Answer 6

1. The pain stimulus is detected by receptors.
2. Electrical impulses from the receptor are passed along the sensory neurone to the CNS.
3. An impulse then passes through a relay neurone - this allows the sensory and motor neurone to communicate.
4. The motor neurone carries the impulse to the effector.
5. The effector responds, with muscle contraction or glands secreting hormones.

Question 7

What connects neurones together and how?

Answer 7

Synapses. A chemical is released that diffuses across the synapse. This causes electrical impulse to be generated in second neurone.

Question 8

How can reaction time be investigated?

Answer 8

Seeing how quickly a dropped ruler can be caught between finger and thumb.

Question 9

What are the three variables? (control, independent, dependent.)

Answer 9

Independent - whether the person has taken caffeine or not.
Dependent - the distance the ruler travels.
Control - age of subjects

Question 10

What are the hazards and risks?

Answer 10

May drop ruler on someone, be careful where dropping ruler.

Question 11

Give the 5 steps of the method

Answer 11

1. One person holds a metre ruler from the end, from a certain distance vertically.
2. Another person has their finger and thumb a small distance apart, either side of the ruler, on the 50cm line.
3. The person holding the ruler from the top, drops the ruler and the other person has to trap it between their finger and thumb.
4. The distance the ruler travelled from the 50cm line is noted.
5. The experiment is repeated on subjects who have had caffeine and those who haven’t. It is repeated on each subject to find an average.

Question 12

What are some considerations and mistakes to be made?

Answer 12

Difficult to control variables, and to obtain reliable results, large numbers of subjects need to be tested and averages taken - therefore time consuming.