The Kidneys / Plant Transport

Question 1

Function of the liver

Answer 1

Produces urea ; excess amino acids are broken down into ammonium ions - excess ammonium ions are converted into urea

Question 2

Function of the diaphragm

Answer 2

Increases abdominal pressure which helps to push out unwanted fluids such as urine

Question 3

Function of the Aorta/Renal Artery

Answer 3

The aorta brings oxygenated blood containing urea and other substances in solution from the heart - the renal artery branches off of the aorta to deliver these substances to the kidney

Question 4

Function of the Vena Cava/Renal Vein

Answer 4

The Renal Vein carries deoxygenated blood away from the kidney after urea and other substances have been removed - The Renal Vein connects back to the Vena Cava, which carries this blood back to the heart

Question 5

Function of the ureter

Answer 5

A tube to transport urine from the kidney into the bladder

Question 6

Function of the sphincter muscles

Answer 6

Controls the opening and closing of the bladder to allow/inhibit the release of urine out of the body

Question 7

Function of the urethra

Answer 7

A tube to transport urine from the bladder to the outside of the body

Question 8

Basic function of the kidneys

Answer 8

To filter blood and create urine as a waste by-product

Question 9

True or false: a person can survive on only one kidney

Answer 9

True

Question 10

How often does a person have to use a kidney machine if both kidneys have become damaged or diseased?

Answer 10

Approximately for 5 hours 2-3 times per week

Question 11

What is used to prevent a donor kidney from being rejected by the body?

Answer 11

• near relatives have a similar “tissue-type” to the patient; so if a relative donates a kidney the body may respond better
• the bone marrow is treated with radiation to prevent white blood cell production; suppresses patients immune system
• use of drugs; suppress patients immune system

Question 12

Describe how a kidney machine works

Answer 12

• blood carrying waste passes to the machine from a vein
• a thin, partially permeable, membrane (the dialysis membrane) separates blood from the dialysis fluid
• urea diffuses out of the blood, across the dialysis membrane and into the dialysis fluid (useful substances - salt and sugar - stay in the blood because the dialysis fluid already contains them)
• the dialysis fluid containing urea passes out of the machine and the filtered blood passes back into the body via a vein

Question 13

Define homeostasis and give an example

Answer 13

Keeping the conditions of the internal environment of the body relatively constant
E.g humans gain/loose the same volume of water every day to keep the total content of the body approximately the same

Question 14

What are the main 6 solutes in urine and their amounts per dm cubed?

Answer 14

Urea - 23.3 g/dm3

Ammonia - 0.4 g/dm3

Sodium chloride (salt) - 10.0 g/dm3

Potassium - 1.3 g/dm3

Phosphate - 2.3 g/dm3

Other nitrogenous waste (things other than ammonia and urea that contain nitrogen) - 1.6 g/dm3

Question 15

Define excretion

Answer 15

The process by which waste products are removed from the body

Question 16

Why do animals have to excrete nitrogenous waste?

Answer 16

Nitrogen is found in proteins (not carbohydrates and fats). Carbohydrates/fats can be stored in the body when they are in excess, but proteins cannot. The amino acids are broken down in the liver and converted into carbohydrate and urea. The carbohydrate can be stored as glycogen, and the urea passes through the kidney and is filtered out of the body.