Homeostasis + Human Nervous System

Question 1

what is homeostasis?

Answer 1

it is the regulation of internal conditions of a cell or whole organism in response to internal and external changes, to constantly maintain optimum conditions for functioning.

Question 2

give some examples of homeostasis in the human body

Answer 2

the control of:

~ blood glucose concentration
~ body temperature
~ water levels

Question 3

describe the common features of all control systems

Answer 3

~ receptors - detect stimuli
~ coordination centres - receive and process information from receptors eg. brain
~ effectors - produce responses to restore optimum conditions eg. muscles + glands

Question 4

describe how body temperature is controlled when the temperature is too high - (4.5.2.4)

Answer 4

when the body temperature is too high:

~ the blood vessels dilate (vasodilation)
~ sweat produced from the sweat glands

these all cause energy to be transferred from the skin to environment so temperature falls

Question 5

describe how body temperature is controlled when the temperature is too low

Answer 5

when the body temperature is too low:

~ blood vessels constrict (vasoconstriction)
~ sweating stops and skeletal muscles contract (shivering)

Question 6

what controls and monitors the body temperature?

Answer 6

the thermoregulatory centre in the brain, it contains receptors that are sensitive to blood temperature.
the skin also contains skin temperature receptors and sends nervous impulses to the thermoregulatory centre