Respiratory System

Question 1

Breathing in is known as…

Answer 1

Inspiration

Question 2

Breathing out is known as…

Answer 2

Expiration

Question 3

How does inspiration work?

Answer 3

Diaphragm flattens, intercostal muscle contracts causing rib cages to move up and out, volume increases causing air to fill lungs

Question 4

How does expiration work?

Answer 4

Diaphragm returns to done shale, intercostal muscle relaxes causing rib cages to move down and in, volume decrease causing air to leave lungs

Question 5

What is in the upper respiratory tract?

Answer 5

Nasal cavity, larynx (voice box & glottis), pharynx (throat), trachea

Question 6

What is the lower respiratory tract?

Answer 6

Bronchi & bronchioles

Question 7

What does the bronchioles open up into?

Answer 7

Alveolar ducts surrounded by capillaries

Question 8

What occurs at the alveoli

Answer 8

Gas exchange (oxygen and carbon dioxide)

Question 9

What in the alveoli structure aids gas exchange?

Answer 9

Thin wall, large surface area:volume, fluid lined (allowing gas to diffuse), surrounded by many capillaries

Question 10

Name the 4 stages of respiration

Answer 10

Breathing (entry and exit of air from lungs), external respiration (exchange of gas between blood and air), internal respiration (exchange of gas between blood and tissue), cellular respiration (ATP production)

Question 11

Name a common lung function test?

Answer 11

Spirometry - measures how much air can be expelled in the first second (forced expiratory volume a.k.a FEV1)

Question 12

Name the 4 major volumes of breathing

Answer 12

Tidal volume, vital capacity, residual volume, dead air space

Question 13

What is tidal volume?

Answer 13

When lungs are at rest a small amount of air is moving in and out (~500ml)

Question 14

What is vital capacity?

Answer 14

Maximum amount of air a person can expel after a full inhalation (3-5L)

Question 15

What is residual volume?

Answer 15

The volume of air remaining in the lungs after exhaling (1L)

Question 16

What is dead air space?

Answer 16

The air inhaled that doesn’t reach lungs

Question 17

What air isn’t involved in gaseous exchange with the blood?

Answer 17

Residual volume and dead air space

Question 18

What principle governs gaseous exchange in the blood?

Answer 18

Diffusion

Question 19

Describe external respiration

Answer 19

Alveolar air has a high partial pressure of O2, blood entering pulmonary capillaries are low in O2, O2 diffuses into plasma than RBC to make oxyhaemoglobin.
Blood in capillaries have a higher pCO2 than air so CO2 diffuses out of blood(bonds to haemoglobin to make carboxyhaemoglobin and as bicarbonate (converted by enzyme carbonic anhydrase found in RBCs)

Question 20

What causes altitude sickness?

Answer 20

Air pressure drops as altitude increases. As the external pressure is less, less air fills the lungs during inspiration.

Question 21

What happens when external pressure increases e.g. diving?

Answer 21

As pressure increases the volume of the lungs decreases (Boyles law) less lung capacity= less O2

Question 22

What is the diving reflex?

Answer 22

When cold water hits the forehead, the body holds its breath, decreases heart rate, blood prioritises vital organs (brain & heart)

Question 23

What are the pH and temp conditions in the lungs?

Answer 23

pH 7.4, 37°C

Question 24

What are the pH and temp conditions in body tissue?

Answer 24

pH 7.38, 38°C

Question 25

How does temperature and pH affect breathing?

Answer 25

Higher pH and lower temperature favours uptake of oxygen by haemoglobin in lungs. Lower pH and higher temperature favour the release of oxygen in tissue