Chapter 9: Gas Exchange

Question 1

What are the main adaptations and functions of the gas exchange system?

Answer 1

1. Clean and warm the air that enters
2. Maximise the surface area
3. Maintain the diffusion distance
4. Maintain the diffusion gradient

Question 2

Why do multicellular organisms need gas exchange surfaces?

Answer 2

The MCO’s have a large diffusion distance, so they need efficient gas exchange surfaces

Question 3

What is the significance of alveoli?

Answer 3

The small alveoli in humans collectively make up a very large surface area.

Question 4

Why in the human body are the lungs?

Answer 4

In the thorax

Question 5

What is the membrane surrounding the lungs?

Answer 5

Pleural membranes

Question 6

What is the function of pleural membranes?

Answer 6

Reduce friction between the the lungs and the diaphragm and ribs

Question 7

What is the pleural membrane?

Answer 7

It is a membrane which surrounds a fluid region around the lungs

Question 8

What is the trachea?

Answer 8

It is a cartilaginous tube that connects the larynx to the bronchi, allowing the passage of air

Question 9

What is the intercostal muscle?

Answer 9

They are a group of muscles that run between the ribs and help form and move the chest walls.

Question 10

What is the function of the intercostal muscles?

Answer 10

They are involved in the mechanical aspect of breathing by helping expand and shrink the chest cavity.

Question 11

What is the diaphragm?

Answer 11

It is a thin skeletal muscle that sits at the bas of the chest and separates the abdomen from the chest.

Question 12

What is the function of the cartilage of the trachea and the bronchi?

Answer 12

They help keep them open and prevent the collapse of the trachea and the bronchi.

Question 13

What is the function of the terminal bronchiole?

Answer 13

It is the most distal segment of the conducting zone.

It branches off the lesser bronchioles. This branches off into the respiratory bronchioles.

Question 14

What is respiratory bronchioles?

Answer 14

They are the final division of the bronchiole.

Question 15

Describe the passage of air from the trachea to the alveoli.

Answer 15

Trachea -> Bronchi -> Bronchioles -> Terminal Bronchioles -> Alveoli

Question 16

Where do we find cartilage in the respiratory system?

Answer 16

Trachea and Bronchus

Question 17

Where do we find Goblet cells in the respiratory system?

Answer 17

In the trachea and Bronchus

Question 18

Where do we find smooth muscle in the respiratory system?

Answer 18

In the Trachea, Bronchus, and Terminal Bronchioles

Question 19

Where dow e find Cilia in the in the respiratory system?

Answer 19

In the Trachea, Bronchus, Terminal Bronchiole and a few in the respiratory bronchiole.

Question 20

What are the gas exchange surface of the respiratory system?

Answer 20

The alveolar duct and the alveoli

Question 21

Why do bronchioles have smooth muscle?

Answer 21

So that they can contract and relax based on the demand of oxygen.

Question 22

How is the air entering the airway moistened?

Answer 22

From the evaporation of the mucus

Question 23

Why is the air entering the air way moistened?

Answer 23

To prevent the lungs from drying out

Question 24

What do mucous hairs do?

Answer 24

They trap larger particles

Question 25

What is Mucin?

Answer 25

It is the highly glycosylated protein made by the epithelial cells

Question 26

What is the function of the Goblet Cell?

Answer 26

To secrete Mucus

Question 27

What is the function of the cilia?

Answer 27

They sweep the mucus upto the larynx where it can get digested

Question 28

What are macrophages?

Answer 28

They are Phagocytic cells found in tissues throughout the body; they act as antigen presenting cells (APCs)

Question 29

Why makes alveoli elastic in nature?

Answer 29

They have elastic fibres in them

Question 30

Why do alveoli have to be elastic in nature?

Answer 30

So that they can stretch and recoil and have an adaptive expansion

Question 31

What is the function of the alveoli?

Answer 31

To increase the surface area of the lungs - this is seen when they are fully expanded

Question 32

Why can O2 and CO2 diffuse easily in and out of the alveoli?

Answer 32

Alveoli have thin squamous cell wall and tightly coiled blood vessels.

Question 33

What are the 3 main threatening chemicals in smoke?

Answer 33

1. Tar 2. Nicotine 3. Carbon Monoxide

Question 34

What is tar? Why are they dangerous?

Answer 34

It is a mixture of compounds that settle on the lungs and cause lung disease and lung cancer.

Question 35

Why are carcinogens dangerous?

Answer 35

They can cause cancer by mutations

Question 36

Why does smoking cause lung diseases?

Answer 36

Harmful gases and particles settle and they are not swept away due to their small size. Tend to settle because of the slow movement of air through the lungs.

Question 37

What is Chronic Obstructive Pulmonary disease?

Answer 37

COPD is a disease of the lungs characterised by bronchitis and emphysema.

Question 38

What is bronchitis?

Answer 38

It is a disease in which the airways in the lungs become inflamed and congested with mucus; chronic bronchitis is often associated with smoking.

Question 39

How does tar affect the respiratory system?

Answer 39

it stimulates the release of excess mucus which clogs the air way and also kills off the ciliated epithelial cells.

Question 40

Name an infection likely to occur due to chronic bronchitis.

Answer 40

Pneumonia

Question 41

What is emphysema?

Answer 41

It is caused when the alveoli burst as they have lost the ability to stretch and recoil

Question 42

How do alveoli lose the ability to stretch and recoil in emphysema?

Answer 42

The elastin of the alveoli is broken down as phagocytes release elactase to reach the site of inflammation

Question 43

Why do patients with emphysema have higher breathing rates?

Answer 43

Due to the decreased ventilation and build up of gases

Question 44

Why doe emphysema patients have a lower quality of life?

Answer 44

Due to the wheezing and breathlessness.

Question 45

Why does smoking cause lung cancer?

Answer 45

Tumours can form due to the mutations that occur due to carcinogens that is contained in tobacco smoke.

Question 46

Why might lung cancer be dangerous and difficult to treat?

Answer 46

The tumour can spread through the bronchial epithelium and then through the lymphatic tissue, causing secondary tumors

Question 47

Where do cancers start in lung cancer patients?

Answer 47

In the trachea because this is where the tar will deposit. However it will eventually spread into the bronchus.

Question 48

What are the 3 main ways of identifying lung cancers?

Answer 48

1. Bronchoscopy 2. Chest X - Ray 3. CT - scan

Question 49

What are the methods taken to help patient whose lung cancers are going under Metastasis?

Answer 49

Chemotherapy and Anticancer drugs

Question 50

How can cancers be treated?

Answer 50

1. Chemotherapy 2. Surgery 3. Radiotherapy

Question 51

What the components of cigarettes smoke that damage the cardiovascular system?

Answer 51

1. Nicotine | 2. Carbon Monoxide

Question 52

What are the effects of consuming nicotine

Answer 52

1. Stimulates the nervous system to constrict arteries 2. Heart rate and the blood pressure increases 3. Increases the risk of blood clots

Question 53

Why is nicotine addictive?

Answer 53

It is a pleasurable compound that stimulates the release of Dopamine.

Question 54

What is the effect of carbon monoxide to the circulatory system?

Answer 54

It moves into haemoglobin and forms the stable compound of carboxyhemoglobin This means that the oxygen saturation decreases It may damage the lining of the arteries

Question 55

What are the long term effects of CO on the cardiovascular system?

Answer 55

Long term deterioration can lead to CHD or stroke due to fat build up.