Excretory system

Question 1

What kinds of waste do our bodies produce?

Answer 1

Sweat, carbon dioxide gas, feces, and urine

Question 2

How does sweat leave our bodies?

Answer 2

It is released through pores in the skin

Question 3

How does water vapour leave our bodies?

Answer 3

It is exhaled from the lungs

Question 4

How does carbon dioxide leave our bodies?

Answer 4

It is exhaled from the lungs

Question 5

How do undigested food materials leave our bodies?

Answer 5

They are formed into feces in the colon and excreted from the body as solid waste in bowel movements

Question 6

What is the main function of our excretory system?

Answer 6

To filter blood to remove waste and excess substances such as urea and water. It also eliminates this waste, a process called excretion

Question 7

What is the main function of the kidneys?

Answer 7

To filter blood through millions of nephrons

Question 8

What are nephrons?

Answer 8

Small filtration units

Question 9

Where do the kidneys receive blood from?

Answer 9

From the renal artery, which is connected through capillaries surrounding the nephrons

Question 10

How do the nephrons filter blood?

Answer 10

As blood circulates in the capillaries, the nephrons filter it by removing excess substances through the process of diffusion

Question 11

Does the composition of urine vary?

Answer 11

Yes, from one person to the next and from one time of the day to another

Question 12

What is urine made of?

Answer 12

Mostly water, but it also contains waste products such as: urea, uric acid, potassium, sodium, vitamins, and urochrome

Question 13

What is urochrome?

Answer 13

A pigment that gives urine a yellow colour

Question 14

Where does urochrome come from?

Answer 14

The destruction of hemoglobin present in old red blood cells

Question 15

What in the urine would indicate a health problem like diabetes?

Answer 15

Glucose and proteins

Question 16

What are ureters?

Answer 16

Tubes connecting the kidneys to the bladder and they carry urine to the bladder

Question 17

What is the bladder?

Answer 17

A stretchy bag made of muscles

Question 18

What does the kidney store?

Answer 18

Urine before it is expelled

Question 19

Where is the sphincter?

Answer 19

It is located at the bottom of the baldder

Question 20

What is a sphincter?

Answer 20

A circular muscle

Question 21

What does the sphincter do?

Answer 21

It contracts to stop the flow of urine and relaxes to expel it

Question 22

What is the urethra?

Answer 22

A tube which transports urine from the bladder to outside the body

Question 23

What is homeostasis?

Answer 23

The body’s ability to maintain balance (mineral salts in blood, blood pH, water, temperature)

Question 24

When does the volume of blood increase?

Answer 24

When there is too much water in the blood

Question 25

What happens when the volume of blood increases?

Answer 25

The pituitary gland send a message to the kidneys which will remove water from the blood resulting in more diluted urine (less solute per volume of urine). Therefore the concentration of mineral salts in the blood will return to normal level

Question 26

What happens if we eat too much salty food?

Answer 26

The large intestine will absorb a lot of minerals and the concentration of minerals in the blood will be too high. The pituitary gland sends a signal to the kidneys to hold on to water. Therefore the kidneys remove less water and more mineral salts from the blood, resulting in a more concentrated urine (more solute per volume of urine)