Chapter 7.2

Question 1

What controls the air pressure inside the lungs?

Answer 1

The diaphragm and the rib muscles

Question 2

What is the diaphragm?

Answer 2

A dome shaped layer of muscle the separates the region of the lungs from the region of the stomach and liver

Question 3

What is another name for the rib muscles?

Answer 3

The intercostal muscles

Question 4

Where are the rib muscles found?

Answer 4

Between the ribs along the ventral (inside) surface of the ribs and extend down to the diaphragm

Question 5

How does inhalation begin?

Answer 5

The external rib muscles and the diaphragm contract. This expands the rib cage upward and outward and the floor of the chest cavity downward increasing volume

Question 6

What happens when the volume of the thoracic cavity increases?

Answer 6

The same amount of air is contained in a larger space so molecules of gas are farther apart and they exert less outward pressure. As a result air pressure in the thoracic cavity decreases

Question 7

What happens to the lungs as air pressure decreases?

Answer 7

The walls of the lungs are drawn outward and the lungs expand

Question 8

What happens when the lungs expand?

Answer 8

Air pressure within the lungs is lower than air pressure in the external environment. So air moves into the lungs

Question 9

How does exhalation begin?

Answer 9

The diaphragm and the rib muscles relax reducing volume in the thoracic cavity

Question 10

What happens when volume in the thoracic cavity decreases?

Answer 10

The volume of lungs decrease and the air pressure within the lungs increase and air moves from the lund to the lower pressure environment outside the body

Question 11

What is tidal volume?

Answer 11

The volume of air that is inhaled and exhaled in a normal breathing movement when the body is at rest

Question 12

What is inspiratory volume?

Answer 12

The additional volume of air that can be taken into the lungs beyond a regular/tidal inhalation

Question 13

What is expiratory reserve volume?

Answer 13

The additional volume of air that can be forced out of the lungs beyond regular/tidal inhalation

Question 14

What is vital capacity?

Answer 14

AKA total lung volume capacity. The total volume of gas that can be moved into or out of the lungs.

Question 15

How is vital capacity calculated?

Answer 15

Tidal Volume + Inspiratory Reserve + Expiratory Reserve

Question 16

What is residual volume?

Answer 16

The amount of gas that remains in the lungs and the passageways of the respiratory system after a full exhalation

Question 17

Which gas never leaves the respiratory system?

Answer 17

Residual volume gas

Question 18

What would happen if the residual volume gas left the respiratory system?

Answer 18

The lungs and respiratory passage would collapse

Question 19

Why does residual volume have little value for gas exchange?

Answer 19

Because it is not exchanged with air from the external environment

Question 20

What are the 2 separate processes in respiration?

Answer 20

External respiration and internal respiration

Question 21

Where does external respiration take place?

Answer 21

In the lungs

Question 22

What happens between external respiration?

Answer 22

Gasses are exchanged between the alveoli and the blood in the capillaries

Question 23

What is the concentration of oxygen in air that enters the alveoli after inhalation?

Answer 23

It has a higher concentration of oxygen than the blood in the capillaries

Question 24

What happens because of the difference in concentration of oxygen and CO2 in alveoli and capillaries?

Answer 24

Oxygen diffuses out of the alveoli and into the blood of capillaries

Question 25

Since diffusion is not enough to exchange all gasses what happens?

Answer 25

Approx. 30% of oxygen transfer happens by facilitated diffusion

Question 26

What happens during the facilitated diffusion of oxygen from the alveoli to the capillaries?

Answer 26

Protein based molecules in the walls of the alveoli help with diffusion by by carrying oxygen across cell membranes. This doesn't require extra energy because it is still moving with the concentration gradient

Question 27

What is the concentration of CO2 from the capillaries vs the alveoli?

Answer 27

They have a higher concentration of CO2 because it is returning from body tissues

Question 28

What happens after oxygen and carbon dioxide have been exchanged between the capillaries and the alveoli?

Answer 28

The blood in the capillaries begin their journey back to the heart and then to the tissue cells

Question 29

What kind of respiration happens in the tissue cells?

Answer 29

Internal respiration

Question 30

What is 99% of oxygen transported by to reach cells?

Answer 30

An oxygen transporting molecule called hemoglobin

Question 31

Where is hemoglobin found?

Answer 31

Only in red blood cells

Question 32

How carbon dioxide is carried in the blood by hemoglobin?

Answer 32

23%

Question 33

What is most CO2 carried in the blood by?

Answer 33

70% is dissolved and carried in the blood a bicarbonate ion (HCO3-)

Question 34

How does carbonic acid form?

Answer 34

When carbon dioxide molecule reacts with the water molecule to form H2CO3. Then the carbonic acid breaks down into an H+ ion and bicarbonate ion (HCO3-)

Question 35

Where does the reaction of the CO2 and Water occur?

Answer 35

In the red blood cells

Question 36

What happens to the free H+ ion?

Answer 36

It combines with hemoglobin and bicarbonate ions diffuse out of red blood cells into plasma which carries it too the lungs

Question 37

What happens when the plasma reaches the lungs?

Answer 37

The whole bicarbonate ion reaction reversed to reform CO2 and water