Unit 13 - Excretion in humans

Question 1

Excretion

Answer 1

The removal of toxic materials and substances in excess of requirements from organisms

Question 2

Carbon dioxide excretion

Answer 2

Excreted through the lungs when exhaling

Question 3

Urinary system

Answer 3

Excretes waste and excess substances

Question 4

How urine is excreted

Answer 4

• Kidneys excrete urea, excess water and ions as urine
• Mixtures moves to ureters and to bladder to be stored
• When bladder is full, urethra carries urine from the bladder to outside the body

Question 5

Deamination

Answer 5

The breakdown of excess amino acids in the liver by removing nitrogen-group into stored fat and ammonia which becomes urea

Question 6

Kidneys; the cortex

Answer 6

The outer part where blood is filtered and some selective reabsorption happens

Question 7

Kidneys; the medulla

Answer 7

The inner part where some selective reabsorption happens, fluid is collected to form urine

Question 8

Kidneys; the ureter

Answer 8

Carries urine to the bladder

Question 9

Kidneys; the nephron

Answer 9

Filter blood, separates waste and returning substances to the bloodstream

Question 10

Kidneys; the glomerulus

Answer 10

• Network of capillaries
• Blood filtered under pressure
• Water, glucose, urea and ions leave capillaries and enter tubule
• Protein molecules stay in blood stream

Question 11

Substances that enter the tubule but are reabsorbed into the blood

Answer 11

• All of glucose
• Most of water
• Some ions
• Urea is not reabsorbed