The Excretory System

Question 1

What do chemical reactions do?

Answer 1

1. Produce substances which the body needs as well as substances the body must get rid of.

Question 2

What do chemical reactions help the body to do?

Answer 2

1. Makes the body grow.
2. Digests food.
3. Circulates substances around the body.
4. Uses energy for small movements.
5. Feed the nerves and brain.
6. Cause respiration- energy.

Question 3

What are the chemical processes that take place in our bodies?

Answer 3

1. Respiration
2. Breaking Down of Absorbed Food Molecules
3. Making of Human Biological Molecules (from broken down food molecules that were absorbed).
4. Other

Question 4

What is digestion in relation to excretion?

Answer 4

1. A mechanical process in which undigested food removed is not waste from METABOLIC REACTIONS.
2. The undigested food is egested as farces and is not excreted.

Question 5

What are the products you excrete?

Answer 5

1. Excess water
2. Carbon dioxide
3. Excess salts
4. Urea

Question 6

What is excretion?

Answer 6

1. The removal of WASTE SUBSTANCES from the body, of products from the body’s’ normal chemical reactions (metabolism).

Question 7

What are the organs of excretion?

Answer 7

1. SKIN- urea salts
2. LUNGS- CO2
3. KIDNEY- extra water
   - salts
   - urea

Question 8

What are the organs of the urinary system?

Answer 8

1. Kidney
2. Ureter
3. Bladder
4. Urethra
5. Renal vein
6. Renal artery

Question 9

Where do you lose salts and water?

Answer 9

1. SWEAT GLANDS remove 600 ml of water (plus salt) from the body each day.
2. SURFACE OF LUNGS- 400ml water breathed out in water vapor in air.
3. VOMITING results in loss of water and salts= dehydration
4. FAECES- 100ml water excreted per day.
5. KIDNEYS AND BLADDER is where the largest amount of water is lost (1.5 liters per day)

Question 10

What is evaporated from the lungs?

Answer 10

1. Water (vapor) is evaporated from the moist surfaces inside the lungs and breathing passages.
2. The water produced during respiration is not a harmful product, it is passed into the blood and the excess is removed by the kidneys.

Question 11

What is the function of the lungs?

Answer 11

1. To release carbon dioxide from the body.

Question 12

What is the excretory product removed by the lungs?

Answer 12

1. Carbon Dioxide.

Question 13

What is osmosis?

Answer 13

1. a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one.
2. Movement of substances in water.

Question 14

What is Osmoregulation?

Answer 14

1. The maintenance of constant osmotic pressure in the fluids of an organism by the control of water and salt concentrations.

Question 15

Describe the process which kidneys complete.

Answer 15

1. The AORTA carries blood FROM the heart down into the two kidneys
2. The kidneys REMOVE WASTE AND EXCESS WATER from the blood and send CLEAN BLOOD back to the heart, via the VENA CAVA
3. In the kidneys the WASTE AND WATER go down to the BLADDER
4. The more liquid you drink, THE MORE WATER IS REMOVED from your blood by the KIDNEYS.

Question 16

Describe the compositions of the kidneys products.

Answer 16

1. 95% of urine is WATER, other 5% consist of UREA, SALTS and other waste products.
2. The smell of urine is due to the CHEMICALS IN IT, not because it is rotting.
3. Urine from a healthy person is STERILE- it has no living germs in it
4. Majority of the water in urine comes from what you ate or drank, IT IS NOT A WASTE PRODUCT (from respiration)
5. Continuously drinking water helps your kidneys to WASH OUT THE WASTES that they remove from the blood.

Question 17

What is the kidneys’s job?

Answer 17

1. Osmosis.
2. Kidneys can control the amount of WATER that is lost in urine.
3. 1.5 to 2 liters of water excreted every 24hrs.
4. If the body is short on water- RENAL TUBULES will produce less urine to SAVE WATER
5. Too much water=much more urine

Question 18

Does the amount of waste products change according to the amount of water in the blood?

Answer 18

1. The total amount of waste products dissolved in the urine does not change very much.
2. If there is a larger amount, then the urine is concentrated.
3. If there is a smaller amount, then the urine is diluted.

Question 19

What happens when you become dehydrated?

Answer 19

1. Some of your cells CHEMICAL REACTIONS will stop

Question 20

How much water does your body need and why?

Answer 20

1. Your body needs to have 40 liters in it at all times.

2. This is the amount of water in and around the cells.

Question 21

What can your urine tell about you?

Answer 21

If you have:

1. Diabetes
2. Taken illegal sports drugs
3. Dehydration
4. STD
5. No protein waste- kidney failure.

Question 22

What is diabetes?

Answer 22

1. A condition in which a person’s body does not break down SUGARS PROPERLY.

Question 23

What are the symptoms of diabetes?

Answer 23

1. GLUCOSE In the urine.

2. The person will get tired quickly.

Question 24

What is the procedure regarding sportsmen and illegal drugs?

Answer 24

1. Body changing drugs are harmful (used build muscle and reduce the pain of hard effort)
2. Sports officials collect urine samples from the athletes to test for drugs.
3. The athlete has to give the sample in front of a doctor.

Question 25

What is the sports officials ‘back-up’ plan in case there is a dispute?

Answer 25

1. The urine sample is put into two bottles.

Question 26

What are the parts of the urinary system?

Answer 26

1. Bladder
2. Kidneys
3. Urea
4. Ureter
5. Urethra
6. Renal vein
7. Renal artery

Question 27

What is the function of the bladder?

Answer 27

1. The bladder is a storage sac.

Question 28

What is urine and where does it accumulates?

Answer 28

1. Nitrogen waste called urea, together with excess water and salts accumulates in the BLADDER.