Chapter 8: Excretion in Humans ( part 1)

Question 1

What is excretion?

Answer 1

The process of removing metabolic waste products, toxic substances and excess substances from the body.

Question 2

Why is excretion necessary?

Answer 2

Chemical/metabolic activites occur often in our body, with produces harmful or toxic substances ( known as metabolic waste products or excretory products), so they need to be removed as accumulation is harmful.

Question 3

What does metabolic waste products consist of?

Answer 3

• Carbon dioxide
• Urea
• Mineral salts or ions
• water

Question 4

Where does the carbon dioxide in metabolic waste come from?

Answer 4

It is one of the products formed from aerobic respiration.

Question 5

What can happen if we have too much carbon dioxide in our blood?

Answer 5

• Headaches
• Confusion
• Rapid breathing (to take in more o2)

Question 6

Where does the urea in metabolic waste come from?

Answer 6

From the digestive system, proteins-amino acids- used by body/excess deaminated in the liver forming urea

Question 7

What happens if we have too much urea in our blood?

Answer 7

• Nausea
• Vomiting

Question 8

Where does the excess mineral salts or ions in metabolic waste products come from?

Answer 8

Some are used by the body, which the excess mineral salts are removed by the kidneys and excreted in the urine.

Question 9

What will happen if we have too much mineral salts or ions in our blood?

Answer 9

It will lower the blood potential of blood plasma, which causes water to exit the tissue cells into the blood ( via osmosis), causing cells to be dehydrated

Question 10

Where does the water in metabolic waste products come from?

Answer 10

Aerobic respiration

Question 11

What happens if we have too much water in our blood?

Answer 11

It will increase the water potential of the blood plasma, water from the blood enters the tissue cells via osmosis, causing the cells to swell and burst

Question 12

What happens if we have too much water in our blood? ( kidney in relation)

Answer 12

Excess water is removed by the kidney, excreted in urine

Question 13

What does the human urinary system consist of?

Answer 13

A pair of kidneys, a pair of urethers, urinary bladder and urethra

Question 14

What is the difference between female and male urinary system?

Answer 14

The male system consists of the prostate and male genital

Question 15

What is the function of the kidneys?

Answer 15

It excretes urea and excess salt and water as urine

Question 16

What is the function of the urethra?

Answer 16

It is the duct trough which urine passes from the bladder to outside the body

Question 17

What is the function of the bladder?

Answer 17

it is an elastic muscular bag that stores urine

Question 18

What is the function of the ureters?

Answer 18

It connects the kidney to the bladder for urine to pass through

Question 19

What is they pathway taken by urine?

Answer 19

Kidney - Ureter - Bladder - Urethra

Question 20

What are the blood vessels associated with the kidneys?

Answer 20

There is renal arteries which transports oxygenated blood from the heart to the kidneys. The renal veins carry deoxygenated blood from kidneys to the heart.