Chapter 23: The Respiratory System

Question 1

What is the major function of the respiratory system?

Answer 1

to supply the body with O2 and get rid of CO2

Question 2

What are the 2 division of the respiratory system?

Answer 2

1. The conducting portion -include everything from the nostrils to bronchioles (it is the pathway that conducts air)
2. The respiratory portion - include alveoli for gas exchange

Question 3

How many lobes are in each lung?

Answer 3

Right lung - 3 lobes

Left lung - 2 lobes

(Right lung bigger since it is closer to the heart)

Question 4

What makes up the respiratory zone?

Answer 4

• Bronchioles
• Alveolar ducts
• Alveolar sacs
• Alveoli

Question 5

What makes up the respiratory membrane? What makes this membrane significant?

Answer 5

• type 1 alveolar cells
• basement membrane
• endothelial cells of pulmonary capillaries

The respiratory membrane is the site of gas exchange

Question 6

What is the difference between type 1 and type 2 alveolar cells?

Answer 6

Type 1 - line the alveoli

Type 2 - secrete fluid to keep the surface of the alveoli moist. It also contains surfactant which helps decrease friction while lungs expand

Question 7

What is respiratory distress syndrome?

Answer 7

A breathing disorder of premature newborns in which the alveoli do not remain open due to lack of surfactant.

Question 8

What is chronic obstructive pulmonary disease?

Answer 8

A respiratory disorder involving a chronic obstruction of airflow

Question 9

What is emphysema?

Answer 9

The destruction of the walls in the alveoli, causing abnormally large air spaces that remain filled with air during exhalation.

Causes less surface area for gas exchange

Question 10

What is chronic bronchitis?

Answer 10

Excessive secretion of bronchial mucus, along with a bad cough.

Many mucus- making goblet cells may obstruct the airflow passage, and the thick mucus narrows the airway

Question 11

What is asthma?

Answer 11

Chronic airway inflammation

Symptoms include coughing, wheezing, and general difficulty breathing

Question 12

What are the 3 respiratory pressures?

Answer 12

1. Atmospheric - pressure exerted by air on the surface of the body (≈760mmHg)
2. Intrapleural - pressure within the pleural cavity (≈756mmHg)
3. Alveolar - pressure within the alveoli

Question 13

What is Boyle’s gas law?

Answer 13

States that: under constant temperature, the pressure exerted by a gas varies inversely with volume.

i.e. if volume increases pressure decreases (inhale), is volume decreases pressure increases (exhale)

Question 14

What gases is air made of?

Answer 14

• Nitrogen (78.6%)
• Oxygen (20.9%)
• Carbon dioxide (0.04%)

Rest is other gases and water vapour

Question 15

Define pulmonary ventilation

Answer 15

Gas exchange between atmospheric air and the alveoli of the lungs

Question 16

Define external respiration

Answer 16

The gas exchange between alveoli and the blood of pulmonary capillaries

i.e. O2 moves from alveoli to blood, CO2 moves from blood to alveoli

Question 17

Internal respiration

Answer 17

Involves gas exchange between the blood of capillaries and tissue cells

i.e. O2 moves from capillary to tissue, CO2 moves from tissue to capillary

Question 18

Why is carbon monoxide (CO) so dangerous?

Answer 18

CO binds to hemoglobin just like O2 does, except the bind is 200x stronger than O2 so it is hard to unload it.

This reduces the oxygen carry capacity of hemoglobin and very little oxygen can be transported to tissues

Question 19

How is oxygen transported in the body?

Answer 19

98% of oxygen is transported by binding to hemoglobin (heme portion)

2% is transported by dissolving in plasma

Question 20

How is carbon dioxide transported in the body?

Answer 20

70% of CO2 is transported as bicarbonate ions

23% is transported by hemoglobin (globin portion)

7% is transported by dissolving in plasma

Question 21

How can we sustain life 4-5 minutes after you stop breathing?

Answer 21

This is because hemoglobin only unloads about 25% of the O2 that it carries at a time, and is still saturated with 75% of the O2

Question 22

What are the 2 respiratory centers in the brain?

Answer 22

1. Medulla oblongata
   a) dorsal respiratory group (DRG)
   b) ventral respiratory group (VRG)
2. Pons

Question 23

What is the dorsal respiratory group (DRG) responsible for?

Answer 23

The DRG is responsible for maintaining a basic breathing rhythm.

DRG will send impulses to stimulate the diaphragm to contract for inhalation, then the DRG will be inactive for exhalation

Question 24

What is the ventral respiratory group (VRG) responsible for?

Answer 24

Forced breathing