Maciej Nervous system Maciej

Question 1

Define Homeostasis

Answer 1

The regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in response to internal and external changes

Question 2

What three conditions does the body need to maintain at a constant level ?

Answer 2

Water levels, blood-glucose concentration, temperature

Question 3

In the bodies response system, what are the receptors ?

Answer 3

Receptors are parts of the body that detect changes in the environment (a stimulus)

Question 4

In the bodies response system what are the co-ordination centres ?

Answer 4

Parts of the body which process the information from the receptors e.g. (brain, spinal cord, pancreas)

Question 5

In the bodies response system, what is the effector ?

Answer 5

The part of the body that initiates a response based on the change

Question 6

Describe the pathway of a nervous system response

Answer 6

• A stimulus is detected by a receptor
• An electrical impulse is sent via the sensory neurone to the central nervous system (brain or spinal cord)
• The central nervous system sends an electrical impulse via the motor neurone to the effector
• The effector issues a response

Question 7

Why is there a gap between neurones and what is it called ?

Answer 7

• The tiny gap is called a synapse

- The synapse makes sure that the electrical impulse travels in only one direction

Question 8

What are reflex actions ?

Answer 8

Reflex actions are fast automatic responses, they do not initially involve the brain but rather the spinal cord

Question 9

What is the pathway of an electrical impulse during a reflex action called ?

Answer 9

Reflex arc

Question 10

Describe the pathway if a reflex arc

Answer 10

• Stimulus is detected by receptor and sends an impulse
• The impulse travels via the sensory neurone to the central nervous system (Spinal Cord)
• Electrical impulse sent over Relay neurone then to the motor neurone which travels to the effector which issues a response