17 - Gas exchange

Question 1

What are some of the protective festures of the Respratory system?

Answer 1

• cilia
• mucus
• cartilage
• caughting & sneezing

Question 2

What are the white blood cells in the lungs?

Answer 2

aveolar macrophages

Question 3

Why can you hold your breath longer when you take a big breath of air first?

Answer 3

less CO₂ and higher pH

Question 4

What kind of cells are in the aveoli?

Answer 4

simple squalmous

Question 5

________________ are how the lungs are attached to the thoracic cavity

Answer 5

plura mambrane

Question 6

In order to inhale what three things have to happen?

Answer 6

1. decreas in aveoloar pressure = draws pressure in
2. diaphram contracts
3. intercostals contract

Question 7

what happens when we exhale?

Answer 7

• diaphram relaxes
• intercostals relax
• and elastic recoil of the lungs

Question 8

what is going on with a patient with emphysema?

Answer 8

• decreased surface area of aveoli
• elastic tissue of the lungs have hardened

Therefore

• lower CO₂ exchange
• decreased mobility
• laboured breathing

Question 9

What areas of the brain regulates breathing?

Answer 9

• pons: sensors from aorta
• medulla: intercostals & diaphram

Question 10

How would the following affect respiration rate?

[CO₂] if high would ____ rate. If Low would ___ rate

Answer 10

increase

decrease

Question 11

[H⁺] if high would ___ rate. If low would ___ rate.

Answer 11

increase

decrease

Question 12

how does the concentration of O₂ affect respiration?

Answer 12

not as sensitive - only responds to decreased [] of O₂

Question 13

Why does O₂ move from the lungs into the blood?

Answer 13

concentration gradient

Question 14

Why does O₂ move fromt eh blood into the tissues?

Answer 14

conentration gradient

Question 15

Why is the concentration of O₂ lower in the aveoli than in the atmosphere?

Answer 15

b/c we never fully exhale all of the gasses, so the mingling of the CO₂ that never made it all of the way out lowers the concentration of O₂

Question 16

What is the enzyme in the blood that helps speed up the creation of H⁺ ions and maintains a CO₂ gradient?

Answer 16

carbonic anhydrase

Question 17

What are the three ways that CO₂ are removed from the tissue?

Answer 17

1. disolved in plasma ~ 7%
2. as carbaminohemoglobin (CO₂ x Hgb) ~ 23% O₂ saturation
3. bicarbonate ion ~ 70%

Question 18

What are the factors that affect the affinity of Hgb for O₂?

Answer 18

• low pH
• high Temp
• high CO₂
• low O₂

Question 19

how many oxygen molecules can hemoglobin carry?

Answer 19

4

Question 20

What is the blood ph level held at?

Answer 20

7.35-7.45

Question 21

How does the body help to regulate acid production?

Answer 21

• buffers: proteins, phosphate, bone, carbonic acid (H₂CO₃)
• kidneys: secretion of H⁺ amd saves HCO₃^- or secretes HCO₃^- and save H⁺
• respriatory system can only remove carbonic acids not metabolic acids

Question 22

CO₂ + H₂O <-> H₂CO₃ <-> HCO₃^- + H⁺

Which side of the equation does the blood tend to lie on when we are underbreathing?

Overbreathing?

Answer 22

Underbreathing to the right = decreased pH

Overbreathing to the left = increased pH

Question 23

How does the stomach flu affect pH and respiration?

Answer 23

decreases pH in gut

increases blood pH

decreases respiration

Question 24

Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arteries has a

Select one:
A. Higher PO2
B. Higher PCO2
C. Greater bicarbonate concentration
D. Lower pH
E. Lower osmotic pressure

Answer 24

Higher PO2

Question 25

One feature that bird lungs and human lungs have in common is that
Select one:
A. They both have unidirectional air flow
B. They both use countercurrent mechanisms to maximize oxygen uptake
C. They are both internalized to reduce water loss
D. The both have low blood pressure in the systemic circuit

Answer 25

They are both internalized to reduce water loss

Question 26

The driving force for diffusion of oxygen across the cells of a respiratory organ is

Select one or more:
A. The difference in partial pressure of oxygen between the respiratory surface and the blood
B. The humidity
C. The partial pressure of carbon dioxide in the blood
D. The air temperature
E. All answers apply
F. A function of altitude

Answer 26

The difference in partial pressure of oxygen between the respiratory surface and the blood

Question 27

Carbonic anhydrase is helpful in that it

Select one:
A. Helps carbon dioxide come into equilibrium between the tissues and the blood
B. Promotes the release of oxygen from hemoglobin by stimulating H+ production
C. Increases the PO2 of the arterial blood
D. Increases the pH of the blood

Answer 27

Promotes the release of oxygen from hemoglobin by stimulating H+ production

Question 28

Hypoventilation (low breathing rate) would cause a/an

Select one:
A. Increase in pH
B. Decrease in pH
C. Excess O2 levels in the Hgb
D. Loss of bicarbonate ions
E. Decrease in H+ ions

Answer 28

Decrease in pH

Question 29

When you hold your breath, which of the following blood gas changes first leads to the urge to breathe?

Select one:
A. Rising O2
B. Falling O2
C. Rising CO2
D. Falling CO2
E. Rising CO2 and falling O2

Answer 29

Rising CO2