Exchange Surfaces And Breathing

Question 0

What effects the exchange of substances?

Answer 0

The organisms surface area to volume ratio.

Question 1

Why do cells need to take in oxygen?

Answer 1

For aerobic respiration and nutrients.

Question 2

Which animals have a higher surface : volume ratios?

Answer 2

Smaller animals

Question 3

What does an organism need it supply it’s cells with?

Answer 3

Glucose and oxygen, it also needs to remove waste products to avoid damaging itself.

Question 4

What’s happens in single felled organisms?

Answer 4

The substances can diffuse directly into or out of the cell across the sell surface membrane.

Question 5

Why is the diffusion rate quick In single called organisms?

Answer 5

They only have to travel small distances, it is one cell thick.

Question 6

Why is diffusion rates slow In multicellular organisms?

Answer 6

The cells can be deep within the body, there is abut distance between them and the outside environment. Larger animals have a low surface area to volume ratio, it’s difficult to exchange enough substances to supply a large volume of animal through a relatively small outer surface.

Question 7

Multicellular animals need specialised exchange substances like lungs, how do the lungs work?

Answer 7

As you breath in air enters the trachea which splits into two bronchi. There is one bronchus leading to each lung. Each bronchus then branches off into smaller tubes called bronchioles. The bronchioles end In small air sacs called alveoli. This is where gases are exchanged.

Question 8

What body parts work together to move air in and and out?

Answer 8

Ribcage, intercostal muscles and diaphragm.

Question 9

Where does gas exchange actually occur?

Answer 9

Alveoli, the lungs contain millions. They are the gas exchange surface.

Question 10

What are the alveoli made from?

Answer 10

A single layer of thin, flat cells called alveolar epithelium.

Question 11

Where are the alveoli?

Answer 11

They are arranged in bunches at the end of bronchioles. They are surrounded by a network of capillaries.

Question 12

What happens in the alveoli?

Answer 12

O2 diffuses out of them, passes the capillaries and enter the haemoglobin in the blood. CO2 diffuses into the alveoli from the blood.

Question 13

What characteristics do gas exchange substances have?

Answer 13

Large surface area, in the lungs the alveoli provide a large surface area.
They are thin to give it a short diffusion pathway.

Question 14

What do goblet cells do?

Answer 14

They secrete mucus, the mucus traps micro organisms and dust particles In the inhaled air, stopping them from reaching the alveoli.

Question 15

What do cilia do?

Answer 15

They are on the surface of cells and they beat the mucus moving it upwards away from the alveoli towards the throat. Here it is swallowed.

Question 16

Where are elastic fibres found?

Answer 16

On the walls of the trachea, bronchi, bronchioles and alveoli.

Question 17

What do elastic fibres do?

Answer 17

Help the process of breathing out. When breathing in the lungs inflate and the elastic fibres are stretched, they then recoil to help push the air out.

Question 18

Where is smooth muscle found?

Answer 18

Walls of the trachea, bronchi and bronchioles.

Question 19

What’s does the smooth muscle do?

Answer 19

It allows the diameter to be controlled, during exercise they relax so the tubes get wider.

Question 20

Where are rings of cartilage found?

Answer 20

On the walls of the trachea and bronchi.

Question 21

What’s the role of the rings of cartilage?

Answer 21

They provide support, they are strong and flexible.

Question 22

Which parts of the lung have ciliated epithelium?

Answer 22

Trachea, bronchi, large and small bronchioles. The smallest bronchioles and alveoli have no cilia.

Question 23

What is ventilation?

Answer 23

Breathing in and out. It consists of inspiration and expiration. ( breathing in and breathing out).

Question 24

What is ventilation controlled by?

Answer 24

It’s controlled by movements of the diaphragm, intercostal muscles and Ribcage.

Question 25

How does inspiration happen?

Answer 25

The intercostal and diaphragm muscles contract. This causes the Ribcage to move upwards and out wards and the diaphragm to flatten increasing the volume of the thorax. As the volume if the thorax increases the lung pressure decreases. Is causes air to flow into the lungs.

Question 26

What type of a process is inspiration?

Answer 26

An active process, it requires energy.

Question 27

How does expiration happen?

Answer 27

The intercostal and diaphragm muscles relax. The Ribcage moves downwards and inwards and the diaphragm becomes curved again. The thorax volume decreases, causing the air pressure to increase. Air is forced out of the lungs.

Question 28

What type of a process is expiration?

Answer 28

It is a passive process, it’s doesn’t require energy.

Question 29

What is tidal volume?

Answer 29

The volume of air in each breath, usually about 0.4dm3

Question 30

Define vital capacity?

Answer 30

The maximum volume of air that can be breathed in or out.

Question 31

What’s the breathing rate?

Answer 31

How many breaths are taken in a time period.

Question 32

What’s is oxygen uptake?

Answer 32

The rate at which a person uses up oxygen.

Question 33

What are spirometers?

Answer 33

It is a machine that can give readings on tidal volume, vital capacity, breathing rate and oxygen uptake.

Question 34

How does a spirometer work?

Answer 34

It has a oxygen filled chamber with a movable lid, the person breaths through a tube connected to the oxygen chamber. As the person breaths in and out the lid moves up and down. These movement are recorded by a pen which writes on a rotating drum creating a trace. The person breaths out into a tube with soda lime which absorbs the carbon dioxide.

Question 35

Why does the total volume of air In a spirometer decrease over time?

Answer 35

The air that breathed out in a mixture of oxygen and carbon dioxide, the carbon dioxide is absorbed by the soda lime so there’s only oxygen left for he person to breath in