Excretion

Question 1

What two waste gases do plants produce and what processes produce them?

Answer 1

• Oxygen (O2) is produced as a waste product of photosynthesis
• Carbon dioxide (CO2) is produced as a waste product of respiration

Question 2

What is the function of the kidneys?

Answer 2

• To regulate the volume and concentration of urine
• To remove waste and regulate body water content

Question 3

Describe the general structure of a kidney

Answer 3

• Contains a context and medulla
• Renal artery carries blood to the kidney
• Renal vein carries blood away from the kidney
• Each kidney contains many nephrons
• Ureter carries fluid from the kidneys to the bladder

Question 4

Give 3 waste products produced in the body

Answer 4

• Urea
• Carbon dioxide
• Excess salt and water

Question 5

Name 3 excretory organs

Answer 5

• The lungs
• The kidneys
• The skin

Question 6

State the 4 roles of the kidneys

Answer 6

• Filtration
• Selective reabsorption
• Excretion
• Osmoregulation

Question 7

What does the ureter do?

Answer 7

It carries urine from the kidneys to the bladder for excretion

Question 8

State the 5 main parts of a kidney nephron

Answer 8

• Glomerulus
• Proximal convoluted tubule
• Loop of Henle
• Distal convoluted tubule
• Collecting duct

Question 9

Label the digram of the kidney nephron

Answer 9

Question 10

What is the difference between the ureter and the urethra?

Answer 10

• The ureter leads from the kidneys to the bladder
• The urethra leads from the bladder out of the body

Question 11

How does ultrafiltration work in the Bowman’s capsule?

Answer 11

• Blood vessel leading to the glomerulus is wider than the one leading away which increases the pressure of the blood as it travels along
• Small items in the blood are squeezed out under this high pressure (big portions and cells stay in the blood)

Question 12

State 4 components of glomerular filtrate

Answer 12

• Urea
• Salts
• Water
• Glucose

Question 13

What is the purpose of selective reabsorption?

Answer 13

To prevent the excretion of useful substances like glucose

Question 14

What does ADH stand for?

Answer 14

Antidiuretic hormone

Question 15

When is ADH released?

Answer 15

When the body lacks water

Question 16

How does ADH affect the collecting duct?

Answer 16

ADH makes the collecting duct more permeable to water so that more water is reabsorbed from the filtrate

Question 17

Describe the negative feedback loop when dehydration is detected

Answer 17

• Thirst signals activated
• More ADH released (water retained by kidneys)

Question 18

Describe the negative feedback loop when over hydration is detected

Answer 18

• Less ADH is released
• Dilute urine is produced
• Salts are retained

Question 19

Give 3 components of urine

Answer 19

• Water
• Urea
• Ions