homeostasis

Question 1

what is homeostasis

Answer 1

-maintaining a relatively constant internal environemnt/body maintains a dynamic equilibrium

• with fluctuations over a narrow range

-despite changes in the internal/external environement

Question 2

role of communication systems and state communication systems in humans

Answer 2

role is to coordinate responses

nervous and endocrine system

Question 3

Describe what is meant by negative feedback

Answer 3

A body’s mechanism that :
- sensory receptors detect change ,effectros work to reverse that change change ,so that the optimum conditions can be restored

Question 4

explain the negative feedback loop

Answer 4

sensory Receptors detect fluctuation away from the optimum point ….e.g. ph/blood glucose/temperature/water potential

-send signals to a co-ordinators where a response is coordinated

-the coordinator sens signals to an effect to produce the desired response,to reverse the change and restore the conditions back to their optimum point

Question 5

describe what is meant by a positive feedback

Answer 5

does not maintain homeostasis
This is where sensory receptors detect a change in the internal environment and effectors are stimulated to reinforce that change and increase the response .

Question 6

how do receptors and effectors communicate

Answer 6

communicate via cell signalling within a communication system

Question 7

what are some features of a good communication system

Answer 7

covers the whole bosy-so all receptors can communicate with effectors

-provides specififc communcation,meaning that all chemicals released bind to specific,complimentary receptors

-communicate rapidly so a response can be produced immediately

Question 8

where is negative feedback used

Answer 8

regulation of temperature
regulation of water potential
regulation of ph
regulation of blood glucose concentration

Question 9

examples of positive feedback systems

Answer 9

• action potential in neurones
• blood clotting
  -childbirth

Question 10

importance of regulating ph

Answer 10

-pH has to be maintained at optimum so proteins dont denature

-maintain at optimum for enzyme enzyme
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Question 11

importance of regulating water potential

Answer 11

-if water potential changes it can cause cell damage

-if too high water enters cell by osmosis,causes cell to burst

• if too low water will leave the cell by osmosis and cell will shrink