The Respiratory System (T2)

Question 1

What are the two types of breathing movements?

Answer 1

• inspiration (inhalation)

- expiration (exhalation)

Question 2

Briefly describe the process of inhalation…

Answer 2

• the diaphragm contracts and moves downwards
• at the same time the intercostal muscles contract and move the rib cage up and out
• the volume inside the chest (thorax) increases
• the increase in volume causes the pressure to drop
• the pressure in the chest is lower than the atmospheric pressure outside
• air is forced down through the trachea into the lungs

Question 3

Briefly explain the process of exhalation…

Answer 3

• the diaphragm relaxes and moves upwards
• at the same time the intercostal muscles relax and the rib cage falls down and inwards
• the volume inside the chest (thorax) decreases
• the decrease in pressure volume causes the pressure to rise
• the pressure in the chest is higher than the atmospheric pressure outside
• air is forced up and out of the mouth

Question 4

Briefly explains the process of air entering the lungs…

Answer 4

• the air enters through the mouth and down the trachea
• it then branches into the left and right bronchi
• each bronchus then divides further into bronchioles
• after about 20 branches you reach the air sacs (the alveoli)
• each alveolus has a thin layer of epithelial cells separating the air from the blood capillaries
• oxygen molecules diffuse from the alveoli into the blood streams
• the carbon dioxide diffuses the other way

Question 5

What is the the network of trachea, bronchi and alveoli sometimes knowns as?

Answer 5

The Bronchial Tree

Question 6

What muscles connect each pair of ribs?

Answer 6

The intercostal muscles

Question 7

Describe the diaphragm and what it does…

Answer 7

• the diaphragm separates the chest from the abdomen
• it is a dome shaped muscle with a fibrous section in the middle forming the roof of the dome, while its muscular edges form the walls

Question 8

How does the construction of the bronchi and the trachea make sure that the airways stay open?

Answer 8

The walls of the trachea and bronchi contain rings of cartilage for support, which keep the airways open

Question 9

What is the ‘thoracic cavity’ ?

Answer 9

The space inside the chest

Question 10

The lungs are enclosed in the thoracic cavity and protected by the ……. and a sheet of …….. called the ……..

Answer 10

The lungs are enclosed in the thoracic cavity and protected by the rib cage and a sheet of muscular tissue called the diaphragm

Question 11

What separates the inside of the chest from the lungs?

Answer 11

Two moist membranes called the pleural membranes

Question 12

What is the purpose of the pleural liquid in the pleural cavity?

Answer 12

It acts as a lubricant, preventing friction and ensuring the surfaces of the lungs do not stick to the inside of the chest wall when we breathe

Question 13

Explain what mucus is, where it come from and what it does…

Answer 13

• the trachea and larger airways are lined with cells whose role it is to keep the airways clean
• some of these cells produce mucus
• mucus traps any particles of dirt or bacteria that may have otherwise been taken into the airways through the breathing process

Question 14

What are the cilia?

Answer 14

• some cells in the trachea and larger airways contain tiny hair-like structures called cilia
• they move back and forth, sweeping the mucus and trapped particles up and out towards the mouth
• these actions prevent dirt and bacteria from entering the lungs

Question 15

In the respiratory system, the absorption of oxygen and removal of carbon dioxide takes place in the…

Answer 15

Alveoli

Question 16

What are 5 attributes the alveoli have to facilitate the absorption of oxygen and removal of carbon dioxide?

Answer 16

• they possess a very large surface area. Two lungs contain about 700,000,000 alveoli with a total surface area of 60m squared.
• they possess an excellent blood supply. Blood comes straight from the heart to the lungs.
• they bring blood and air close together. Only two cell layers separate the blood from the air. The cell layers make up the wall of the alveoli and the capillarity wall.
• they have internal surfactant and moisture, aiding the movement of gases between the air sac and the blood in the capillaries.
• air in the alveoli has a higher oxygen concentration than the blood in the capillary network. Therefore, oxygen diffuses from the alveoli into the blood and carbon dioxide diffuses from the blood into the alveoli.

Question 17

Oxygenated blood is going to be going from ……. to ……..?

Answer 17

Oxygenated blood is going to be going from the alveoli to the heart.

Question 18

Where does the heart pump the oxygenated blood it receives and why?

Answer 18

The heart pumps the oxygenated blood around the body to supply the respiring cells and tissues.