(B2) Ventilation and Gas Exchange in the Lungs

Question 1

What system are the lungs a part of?

Answer 1

The respiratory system

Question 2

Where do most living organisms gain their energy from?

Answer 2

Aerobic respiration

Question 3

What does aerobic respiration produce?

Answer 3

ATP

Question 4

Equation of Respiration

Answer 4

Oxygen + Glucose –> Carbon Dioxide + Water + Energy (ATP)

Question 5

Where does respiration take place?

Answer 5

Mitochondria

Question 6

What is ventilation?

Answer 6

Breathing

Question 7

What is inhalation?

Answer 7

Drawing air in

Question 8

What is exhalation?

Answer 8

Pushing air out

Question 9

What is the difference between breathing and respiration?

Answer 9

Breathing is the process of inhaling and exhaling air whilst respiration is a chemical process that takes place in the cell which breaks down glucose to create energy

Question 10

Parts of the Lungs

Answer 10

• Nose
• Mouth
• Larynx and Pharynx
• Lungs
• Diaphragm
• Trachea
• Right and Left Bronchus
• Bronchiole
• Alveoli

Question 11

Role of the Nose

Answer 11

The nose is where the respiratory system starts, and it helps breathing using the hairs and mucus to stop large air impurities from entering the respiratory system

Question 12

Role of the Mouth

Answer 12

A secondary inhaler and exhaler

Question 13

Role of the Pharynx

Answer 13

Connects the nose and mouth to the larynx, separating the pathway from the digestive system from the lungs

Question 14

Functions of the Larynx

Answer 14

1) A passageway for air
2) As a valve to close off the air passageway from the digestive system
3) As a voice box

Question 15

Role of the Trachea

Answer 15

A tube which allows to pass beyond the larynx to the left and right bronchus

Question 16

What is the chest (thoracic) cavity?

Answer 16

The space in your chest that contains the lungs, heart and trachea

Question 17

What is the diaphragm?

Answer 17

a large, dome-shaped muscle which is the main muscle of respiration that contracts

Question 18

Function of the diaphragm

Answer 18

To help expand and contract the lungs, forcing air in and out

Question 19

Function of the Lungs

Answer 19

To exchange carbon dioxide for oxygen and each lung is enclosed off separately within two membranes like a ballon inside a bag which is inside another bag

Question 20

Left Bronchi

Answer 20

A passageway for air to reach the lungs, the left bronchus has a sharper bend than the right bronchus due to the presence of the heart and major blood vessel below it

Question 21

Right Bronchi

Answer 21

A passageway for air to reach the lungs

Question 22

Bronchioles

Answer 22

Each bronchus subdivides and then subdivides again into smaller and smaller branches to make the bronchioles
*like tree branches

Question 23

Role of the bronchioles

Answer 23

To deliver air that has been warmed to body temperature, moistured and filtered to the alveoli

Question 24

What is alveoli?

Answer 24

Tiny air sacs which are the “leaves” of the respiratory system, they are at the end of the bronchioles

Question 25

Role of the alveoli

Answer 25

Where gas exchange occurs (fresh oxygen, O2 is exchanged for carbon dioxide, CO2)

Question 26

What are the alveoli surrounded by?

Answer 26

Capillaries

Question 27

Why are the alveoli surrounded by capillaries?

Answer 27

For faster diffusion

Question 28

What are intercostal muscles?

Answer 28

Muscles on the ribcage that contract and relax to push air in and out of the lungs

Question 29

What happens to the diaphragm during inspiration?

Answer 29

Contracts, flattens and moves down

Question 30

What happens to the diaphragm during expiration?

Answer 30

Relaxes, forms a dome (pushed by the organs beneath)

Question 31

What happens to the intercostal muscles during inspiration?

Answer 31

Contracts, pulling the ribcage upwards and outwards

Question 32

What happens to the intercostal muscles during expiration?

Answer 32

Relaxes to let the ribcage fall downwards and inwards

Question 33

What happens to the volume of the chest cavity during inspiration?

Answer 33

Increases

Question 34

What happens to the volume of the chest cavity during expiration?

Answer 34

Decreases

Question 35

What happens to the pressure of the chest cavity during inspiration?

Answer 35

Decreases below atmospheric/air pressure

Question 36

What happens to the pressure of the chest cavity during expiration?

Answer 36

Increases above atmospheric/air pressure

Question 37

What is the end result of inspiration?

Answer 37

Air moves into the lungs, down the pressure gradient

Question 38

What is the end result of expiration?

Answer 38

Air moves out of the lungs, down the pressure gradient

Question 39

Structure of the trachea and bronchus (left and right)

Answer 39

* Lined with ciliated (hairy) epithelium * Supported by c shaped rings of cartilage * Interspersed with goblet cells to secrete mucus

Question 40

Structure of the bronchioles

Answer 40

* Smooth muscles tissues to contract and restrict the airways * Elastic fibres

Question 41

How is diffusion in the alveoli maximised?

Answer 41

* Large surface areas * The wall of alveoli is 1 cell thick to minimize distance * Moist alveoli walls to maximize dissolved gases * Capillaries are close and surround the alveoli, blood is constantly flowing there so to maintain the concentration gradient between the alveoli and the capillary

Question 42

What is diffusion (concentration) gradient?

Answer 42

A concentration gradient exists when there is a region of high concentration leading to a region of low concentration. In the alveoli a gradient is maintained between the concentration of oxygen in the alveoli and the concentration of oxygen in the lung capillaries

Question 43

What is the pleural membrane?

Answer 43

Two layers of serous membrane which enclose and protect the lungs

Question 44

Role of the Plural Membrane

Answer 44

Provides protection and a smooth, lubricating elastic surface for the lungs to move during breathing

Question 45

What is a spirometer?

Answer 45

An apparatus that measures the breathing rate

Question 46

How does a spirometer work?

Answer 46

When someone breathes out into the tank the mobile upper half which is full of oxygen will rise and when someone breathes in from the tank the static lower half which is full of water will fall. A trace marker is attached to the mobile upper half

Question 47

What is the tidal volume?

Answer 47

The amount of air moving in and out of the lungs during the resting breathing rate

Question 48

What is the inspiratory reserve volume?

Answer 48

How much extra air that can be breathed in during forced inspiration

Question 49

What is the expiratory reserve volume?

Answer 49

How much extra air that can be breathed out during forced expiration

Question 50

What is residual volume?

Answer 50

The volume of air that remains in the lungs even after maximum respiration

Question 51

What is vital capacity?

Answer 51

The largest possible volume change in the lungs (from maximum inspiration to maximum expiration

Question 52

What is the total lung capacity?

Answer 52

Residual volume + vital capacity, the maximum capacity of the lungs

Question 53

Why does the rate of oxygen consumption increase during excercise?

Answer 53

There is a need for more energy so there is more respiration in the mitochondria. There is also a need to get rid of lactic acid.