U2 Key Area 7- Absorption Of Materials

Question 1

What must be absorbed for respiration

Answer 1

Oxygen and nutrients from food must be absorbed into the bloodstream to be delivered to cells for respiration

Question 2

Waste materials, such as carbon dioxide, must be…

Answer 2

Removed from cells into the bloodstream

Question 3

What do tissues contain

Answer 3

Tissues contain capillary networks to allow the exchange of materials at cellular level

Question 4

What certain feature do surfaces involved in absorption of materials have in common to increase the efficiently of absorption (3)

Answer 4

• Larger surface area
• Thin walls
• Extensive blood supply

Question 5

What are lungs

Answer 5

Lungs are gas exchange organs

Question 6

How does the air get to its position in the lungs (4)

Answer 6

1. Air enters the body through the nose or mouth
2. The trachea (windpipe) allows inhaled air to enter the lungs through tubular branches, bronchi
3. The bronchi then divides into smaller and smaller branches becoming microscopic.
4. The bronchioles eventually end in clusters of microscopic air sacs called alveoli.

Question 7

How are oxygen and carbon dioxide exchanged

Answer 7

Oxygen on CO2 are exchanged through the alveolar walls

Question 8

What does high O2 concentration in alveoli to low O2 concentration in blood mean

Answer 8

Oxygen in the inhales air in the alveoli diffuses into the bloodstream

Question 9

What does from high CO2 concentration in the blood to low CO2 concentration in alveoli mean

Answer 9

Carbon dioxide diffuses from the bloodstream into alveoli.

Question 10

What do alveoli have which helps make more efficient diffusion of gases (3)

Answer 10

• large surface area
• thin walls
• good blood supply

Question 11

Why is a large surface areas important for gas exchange

Answer 11

This increases the area over which gases can diffuse

Question 12

Why is a rich blood supply important for gas exchange

Answer 12

Alveoli have a large capillary network so that large volumes of gas can be dissolved

Question 13

Why is thin walls important for gas exchange

Answer 13

The alveolar walls are thin so that gases can quickly diffuse through them

Question 14

What is digestion

Answer 14

Digestion is the breakdown of food into small soluble particles that can be absorbed by blood

Question 15

When dies food enter small intestine

Answer 15

When it leaves the stomach

Question 16

What is the surface of the small intestine

Answer 16

Has finger-like structures with thin walls called villi.

Question 17

What does villi do

Answer 17

Nutrients from food are absorbed into the villi in the small intestine

Question 18

What does each villus contain

Answer 18

A network of capillaries to absorb glucose and amino acids and a lacteal to absorb fatty acids and glycerol

Question 19

There are three main nutrients that need to be broken down during digestion

Answer 19

• carbohydrates
• protein
• fat

Question 20

What are carbohydrates composed of

Answer 20

Glucose molecules

Question 21

What happens to carbohydrates during digestion (2)

Answer 21

• carobydrates are broken down into glucose
• glucose can diffuse into the bloodstream (into the capillaries in the villi.

Question 22

What are proteins composed of

Answer 22

Amino acids

Question 23

What happens to proteins during digestion (2)

Answer 23

• proteins are broken down into amino acids
• amino acids can be absorbed by diffusion into he capillaries in the villi.

Question 24

What are fats composed of

Answer 24

Fatty acids and glycerol

Question 25

What happens to fats during digestion (2)

Answer 25

• fats are broken down into fatty acids and glycerol
• theses do not enter the bloodstream. Instead, they are absorbed into the lacteal in the villi.

Question 26

How do villi aid digestion (3)

Answer 26

• the intestine contains numerous villi. This increases the surface area over which absorption can occur.
• villi have thin walls
• villi contain numerous capillaries (rich blood supply)