Respiratory physiology 5

Question 1

Calculate the patient’s arterial oxygen content from the data set:
Hgb 9 g/dL
HR: 100 bpm
Stroke volume: 70 mL
SaO2: 90%
PaO2: 60 mmHg
a. 10.641 mL O2/dL
b. 11.034 mL O2/dL
c. 11.894 mL O2/dL
d. 12.002 mL O2/dL

Answer 1

b. 11.034 mL O2/dL
CaO2= (1.34 x Hgb x SaO2) + (PaO2 x 0.003)

Question 2

Oxygen content is a measure of how much

Answer 2

oxygen is present in 1 deciliter (100 mL) of blood

Question 3

What is the oxygen content equation?

Answer 3

CaO2= (1.34 x Hgb x SaO2) + (PaO2 x 0.003)

Question 4

Oxygen delivery tells us

Answer 4

how fast a quantity of O2 is delivered to the tissues

Question 5

What is the oxygen delivery equation?

Answer 5

DO2= CaO2 x cardiac output x 10

Question 6

Oxygen consumption is the

Answer 6

difference between the amount of O2 that leaves the lungs and the amount of O2 that returns to the luns

Question 7

What is the oxygen consumption equation?

Answer 7

VO2= cardiac output x (CaO2-CvO2) x 10

Question 8

After oxygen diffuses through the alveolar capillary membrane, it is transported by the blood in 2 ways:

Answer 8

1. reversibly binds with hemoglobin (97%)
2. dissolves in the plasma (3%)

Question 9

Each gram of hemoglobin molecule can carry a theoretical maximum of

Answer 9

1.39 mL of molecular oxygen

Question 10

VO2 equals

Answer 10

3.5 mL/kg/min

Question 11

Vo2 is about ___________ in a 70 kg male

Answer 11

250 mL/min.

Question 12

P50 is reduced by: (select 3) a. hgb f
b. hyperthermia
c. hypocarbia
d. increased 2,3 DPG
e. acidosis
f. carboxyhemoglobin

Answer 12

a. hgb F
c. hypocarbia
f. carboxyhemoglobin

Question 13

P50 is the

Answer 13

PaO2 where hemoglobin is 50% saturated with oxygen

Question 14

The oxyhemoglobin dissociation curve tells us the

Answer 14

tendency of hemoglobin to bind oxygen

Question 15

A right-shifted oxyhemoglobin curve means

Answer 15

right= release
hemoglobin has a lower affinity for oxygen

Question 16

A left-sided oxyhemoglobin curve means

Answer 16

left= love
hemoglobin has a higher affinity for oxygen

Question 17

A lower P50 reflects

Answer 17

a left shift (left= love)

Question 18

A higher P50 reflects a

Answer 18

right shift (right= release)

Question 19

A left shift (decreased P50) is caused by

Answer 19

alkalosis, decreased temperature
decreased 2,3-DPG

Question 20

A right shift (increased P50) is caused by

Answer 20

acidosis
increased temperature
increased 2,3-DPG

Question 21

What hemoglobin species can cause a left shift?

Answer 21

fetal hemoglobin
methemoglobin
carboxyhemoglobin

Question 22

The Bohr effect says that an increased partial pressure of Co2 and decreased pH cause

Answer 22

hemoglobin to release O2

Question 23

Above a PaO2 of 100 mmHg,

Answer 23

hemoglobin is fully saturated with oxygen; increasing the FiO2 further will increase the amount of O2 dissolved in the blood

Question 24

Increased hydrogen leads to

Answer 24

left shift of the oxyhemoglobin curve

Question 25

2,3 DPG is produced during

Answer 25

RBC glycolysis (Rapoport-Leubering pathway)

Question 26

___________ increases 2,3 DPG production

Answer 26

hypoxia; this increases O2 offloading

Question 27

2,3 DPG is an important compensation mechanism during

Answer 27

chronic anemia

Question 28

In banked blood, the concentration of 2,3 DPG

Answer 28

falls- shifts the oxyhemoglobin dissociation curve to the left

Question 29

Identify the statement that BEST describes aerobic metabolism. a. NADH is the final electron acceptor during electron transport b. 1 molecule of glucose converts to 38 molecules ATP c. Pyruvic acid is converted to lactate d. Electron transport occurs in the cytoplasm

Answer 29

b. 1 molecule of glucose converts to 38 molecules ATP

Question 30

_____________ is the energy currency in the body

Answer 30

Adenosine triphosphate (ATP)

Question 31

________ is the primary substrate used for ATP synthesis.

Answer 31

Glucose

Question 32

What are the 3 key processes involved in aerobic metabolism:

Answer 32

1. glycolysis= net gain of 2 ATP 2. Krebs cycle= net gain of 2 ATP 3. oxidative phosphorylation= net gain of 34 ATP

Question 33

The body's enzymes tend not to function properly in

Answer 33

an acidic environment

Question 34

In the absence of oxygen (anaerobic metabolism), pyruvate is converted to

Answer 34

lactic acid- this causes lactic acidosis

Question 35

ATP cannot be

Answer 35

stored so the supply must continuously be replenished

Question 36

Energy sources include

Answer 36

proteins, carbohydrates and fats

Question 37

Energy usage is from

Answer 37

active transport synthetic function muscle contraction cell division and growth

Question 38

The more glucose molecules that go through glycolysis, the more ___________ is produced

Answer 38

2,3 DPG b/c the Rapoport-Luebering pathway occurs halfway through glycolysis

Question 39

The Krebs cycle takes place in the

Answer 39

matrix of the mitochondria

Question 40

The primary goal of the Krebs cycle is to

Answer 40

produce a large quantity of H+ ions in the form of NADH- these are used in electron transport

Question 41

What is the primary goal of electron transport?

Answer 41

to produce a lot of ATP (energy)

Question 42

What is the primary goal of glycolysis?

Answer 42

to convert 1 glucose to 2 pyruvic acid molecules

Question 43

Importation of which ion maintains electroneutrality during the Hamburger shift?

Answer 43

Chloride

Question 44

The primary by-product of aerobic metabolism is

Answer 44

carbon dioxide

Question 45

The 3 primary ways that CO2 is transported (buffered) in the blood:

Answer 45

1. as bicarbonate (70%) 2. bound to hemoglobin (23%) 3. dissolved in the plasma (7%)

Question 46

Carbonic anhydrase is an enzyme that facilitates the formation of

Answer 46

carbonic acid (H2CO3) from H2O & CO2

Question 47

To maintain electroneutrality, for every molecule of HCO3- that leaves the erythrocyte, one ________________ is transported in

Answer 47

Cl- ion- this is known as the chloride or Hamburger shift

Question 48

A more acidic environment enhances O2 ______________ & ________________ CO2 loading into the blood

Answer 48

enhance O2 offloading from hemoglobin (Bohr effect) & increases CO2 loading into the blood (Haldane effect)

Question 49

What is the carbonic anhydrase equation?

Answer 49

H2O+ CO2 <--> H2CO3 <--> H+ + HCO3-

Question 50

In the lungs, the chloride shift operates

Answer 50

in reverse as CO2 is excreted from the body

Question 51

Dissolved CO2 has a solubility coefficient of

Answer 51

0.067 mL/dL/mmHg

Question 52

Solubility is a function of

Answer 52

Henry's law