Gas Exchanges

Question 1

what type of movement is diffusion?

Answer 1

passive movement, that moves down the concentration gradient

Question 2

Rate of gas movement between the alveolus and blood is determined by:

Answer 2

• Physical property of the gas
• Surface area available for diffusion
• Driving partial pressure gradient between the alveolus and the capillary

Question 3

what are factors influencing ventilation/breathing?

Answer 3

1. air resistance
2. alveolar surface tension surfactant
3. Lung compliance

Question 4

are the chemical bonds between O2 and hemoglobin stable or unstable?

Answer 4

unstable

Question 5

About _____ of the O2 remains bound to hemoglobin in the venous

Answer 5

75%

Question 6

Oxygen capacity

Answer 6

maximum quantity of oxygen that will combine chemically with the hemoglobin in a unit volume of blood

Question 7

Oxygen content

Answer 7

amount of oxygen is in the blood

Question 8

Oxygen saturation

Answer 8

percentage of all the available heme binding sites saturated with oxygen

Question 9

each hemoglobin molecule can bind to how many O2 molecules?

Answer 9

4

Question 10

Cyanosis

Answer 10

• the hemoglobin is depleted of oxygen, and its color change from a bright red to a bluish red
• Can result from deficient oxygen uptake in the lungs or reduced blood flow to the peripheral tissues

Question 11

factors affecting oxygen dissociation

Answer 11

1. blood temperature:
   Increased blood temperature reduces hemoglobin affinity for O2
2. Blood pH
   Lowering of blood pH (acidic)
   Caused by presence of H+ ions from lactic acid or carbonic acid reduces affinity of Hb for O2
3. Carbon dioxide concentration
   Higher CO2 concentration in tissue less the affinity of Hb for O2

Question 12

CO2 transported to the lungs in 3 forms:

Answer 12

1. CO2 dissolved in plasma
2. Part of the compound with hemoglobin
3. Part of the bicarbonate ion (mostly)

Question 13

how does HCO3- make exchange?

Answer 13

Cl- shift

Question 14

factors affecting breathing?

Answer 14

• Partial pressure of oxygen
• Partial pressure of CO2
• Degree of stretch of lung tissue
• Emotional state
• Level of physical activity

Question 15

what receptors are involved in breathing?

Answer 15

mechanoreceptor and central/peripheral chemoreceptors

Question 16

Respiratory areas include:

Answer 16

• Respiratory center of the medulla
• Respiratory group of the pons

Question 17

Chemoreceptors

Answer 17

• Sensitive to Pco2, pH, or Po2 of the blood or cerebrospinal fluid
• Increased Pco2 = increased breathing

Question 18

Baroreceptors

Answer 18

In the aortic or carotid sinuses sensitive to changes in blood pressures

Question 19

Stretch receptors

Answer 19

Respond to changes in volume of the lungs

Question 20

Carotid bodies

Answer 20

• innervated by the cranial nerve IX (glossopharyngeal)
• Respond primarily to Pco2 and secondary to pH or Pco2

Question 21

Aortic bodies

Answer 21

• innervated by the vagus nerve (cranial nerve X)
• Have chemoreceptors similar to carotid bodies

Question 22

local control of O2 delivery is made by?

Answer 22

• arterioles
• Local arterioles will dilate, to due relaxation of vasomotor tone

Question 23

Carbon dioxide is converted into carbonic acid in the cytoplasm or red blood cells by the enzyme_____.

Hemoglobin
Carbonic anhydrase
Oxyhemoglobin
Carbon monoxide

Answer 23

Carbonic anhydrase

Question 24

The majority of carbon dioxide is transported in the blood is _______.

Attached to the hemoglobin
Bound to oxygen
Dissolved in the plasma
Carbon monoxide in the red blood cells
Bicarbonate ions in the red blood cells

Answer 24

Bicarbonate ions in the red blood cells

Question 25

The expansion of the lung and initiation of air in part the result for: Muscles of the lungs relax, allowing the lungs to get larger Decreased pressure of the intrapleural fluid Contraction of the muscles of the diaphragm A and B are correct

Answer 25

Contraction of the muscles of the diaphragm

Question 26

Which of the following statements are true? Increased Pco2 drives increased breathing A decrease in pH increases respiratory rate In high altitude, breathing and heart rate increases Most of the CO2 diffuses unto the RBC All the above

Answer 26

all the above

Question 27

Respiratory areas are located in ______. Pons Medulla Both a and b Carotid and aortic bodies

Answer 27

both A and B

Question 28

During the Mount Kaala hike trail which is the tallest peak, and sits 4,010 feet above sea level, will your blood pH be more acidic? True False

Answer 28

false