Chapter 12 - Homeostasis In Action Flashcards
Which part of the brain controls core body temperature? [1]
Thermoregulatory centre [1]
Give 2 ways that the body cools down [2]
Vasodilation (more blood through capillaries) [1]
Sweating [1]
Give 2 ways that the body keeps warm [2]
Rapid contractions of muscles (Shivering) [1]
Vasoconstriction (Less blood through capillaries) and more sweating. [1]
Explain how shivering keeps the body warm [3]
Muscles contract and relax rapidly, using respiration for energy [1]
This exothermic reaction gives heat to surroundings [1]
which warms the person up [1]
Name 2 waste products and how they are removed from the body [4]
Urea [1] from urine [1]
CO2 [1] from exhalation [1]
What is the function of the kidneys? [2]
Maintain balance of water in the body [1] and filter out toxic substances [1]
How do the kidneys work to remove toxic substances such as urea? [4]
Substances carried by blood enter the kidney [1]
The kidney has a mesh which can filter out the toxic substances [1]
These substances are sent to the bladder to be excreted [1]
The useful substances, such as protein, goes back into the blood [1]
What hormone is used to control water concentration in the body? [1]
ADH [1]
Describe how ADH functions in the body [6]
If water levels are too high, less ADH is released [1]
Less water is reabsorbed by the kidney [1]
Urine is more dilute [1]
If water levels are too low, more ADH is released [1]
More water is reabsorbed by the kidney [1]
Urine is more concentrated [1]
What is dialysis? [1]
Use of a machine to carry out the kidney’s functions [1]
Evaluate the advantages and disadvantages of the use of dialysis [4]
Advantages:
Readily available to use [1]
Very reliable and safe to use [1]
Disadvantages:
Patient cannot lead an active life [1]
Needs to be cleared 3-4 times per week [1]
Why do kidney transplants fail? [1]
Rejection of kidney through the immune system because of different antigens being rejected.[1]
Give 2 advantages and disadvantages of kidney transplants [4]
Advantages:
Person can live a normal life [1]
Relatives can donate kidneys to reduce rejection [1]
Disadvantages:
Is only temporary; needs to be replaced [1]
Immunosuppressant drugs can leave person vulnerable to infection. [1]
Explain how vasodilation and vasoconstriction works [6]
Vasodilation widens the blood vessels near the skin [1] letting more blood flow near the skin [1], therefore more heat is given off from the blood and mroe sweating. [1]
Vasoconstriction constricts the blood vessels near the skin [1], letting less blood flow to the skin [1], therefore less heat is loss from the blood and less sweating.
