Respiratory 4

Question 1

Oxygen is carried both physically _____ in the blood and chemically combined to _____

Answer 1

dissolved; hemoglobin1

Question 2

If cells utilize more oxygen than normal, the gradient _____ which _____ flow of oxygen from the blood to the tissues.

Answer 2

increases; increases

Question 3

Tissue ____ is a function of:

1) The rate of O2 transport to the tissues in blood (blood flow
(2) The rate at which the tissues use O2.

Answer 3

PO2

Question 4

Increased blood flow and/or increased metabolism will result in ____ O2 delivery to the tissues.

Answer 4

more

Question 5

Without Hemoglobin, ____ would need to be 83.3 L/min to transport sufficient oxygen to meet the needs of the tissues at rest.

Answer 5

CO

Question 6

______ of total oxygen content is dissolved in plasma (PaO2 = 100 mmHg)

Answer 6

2%

Question 7

____ of O2 reversibly binds to hemoglobin inside of the RBC -does not contribute to partial pressure

Answer 7

98%

Question 8

2,3- BPG binds to which subunit of hemoglobin

Answer 8

Beta

Question 9

Which form of iron is the normal state used in hemoglobin used for O2 binding?

Answer 9

Ferrous (Fe 2+)

Question 10

Which form of iron is the methemoglobin state causing less O2 release to tissues?

Answer 10

Ferric (Fe 3+)

Question 11

4 subunits each of which each binds 1 O2molecule.

Answer 11

Hemoglobin A (α22):

Question 12

The amount of oxygen bound to Hb depends on what 2 things?

Answer 12

1. Plasma PO2
2. Number of binding sites in RBCs – depends on the Hb amount per RBC. (normally each RBC contains ~1 million Hb molecules)

Question 13

Reduction in the amount of hemoglobin in the blood significantly ____ the blood oxygen content.

Answer 13

reduces

Question 14

____ is the % saturation of hemoglobin in the arteries

Answer 14

SaO2

Question 15

What is the average % saturation of hemoglobin in the arteries(SaO2)

Answer 15

97%

Question 16

What is the average Hb (g of hemoglobin/ 100mL of blood?

Answer 16

15 g Hb/100 mL

Question 17

_____ is the partial pressure of oxygen in arterial blood

Answer 17

PaO2

Question 18

what is the average partial pressure of oxygen in arterial blood (PaO2)

Answer 18

95 mmHg

Question 19

_____ binds to Beta subunits of deoxy HB and decreases its O2affinity. It causes more oxygen unloading.

Answer 19

2,3-BPG

Question 20

What is the average saturation of hemoglobin in the veins SvO2?

Answer 20

75%

Question 21

At what PO2 do the peripheral chemoreceptors increase alveolar ventilation?

Answer 21

60 mmHg

Question 22

Increased dissolved O2 leads to _____ hemoglobin bound to oxygen

Answer 22

Increased

Question 23

______ Indicates DECREASED affinity between hemoglobin and oxygen

Answer 23

Bohr effect / right shift in oxyhemoglobin dissociation curve

Question 24

In a ____ shift of the oxyhemoglobin dissociation curve, oxygen is MORE likely to dissociate from Hemoglobin.

Answer 24

Right shift

Question 25

What are the 4 things causing the right shift of the oxyhemoglobin dissociation curve?

Answer 25

Increased H+ ions
Increased CO2
Increased temp
Increased BPG

Question 26

A ____ shift of the oxyhemoglobin dissociation curve Indicates an INCREASED affinity between oxygen and hemoglobin; In this instance, oxygen is LESS likely to dissociate from hemoglobin.

Answer 26

Left shift

Question 27

A left shift of the oxyhemoglobin dissociation curve is caused by:

Answer 27

–Decreased PCO2
–Increased pH (ex. 7.6)
–Decreased temperature
–Decreased 2,3-BPG

Question 28

Does CO or O2 have a higher affinity for hemoglobin?

Answer 28

CO

Question 29

Heme with Fe3+ does not bind O2 as readily (reduced affinity) & also causes any heme groups in the same Hb molecule with heme in the Fe2+ state to have have higher affinity for bound O2; net effect is reduced O2 delivery to the tissues
–Can occur due to G6PDH deficiency or upon exposure to some local anesthetics (prilocaine and benzocaine).

Answer 29

Methemoglobin

Question 30

–α2g2 (no β chains)

–Higher affinity for oxygen than HbA because it doesn’t contain the Beta chain that binds to 2, 3-BPG.

Answer 30

Hemoglobin F (Fetal hemoglobin)

Question 31

–Normal α units, abnormal beta units (due to one amino acid change)
–When deoxygenated, RBCs form sickle shapes, obstructing small vessels
–O2 has lower affinity for HbS than Hb A

Answer 31

Hemoglobin S (sickle cell

Question 32

Does methemoglobin cause a left or a right shift?

Answer 32

Left shift

Question 33

Does methemoglobin reduce or increase O2 release to tissues?

Answer 33

Reduce

Question 34

_____ is low dissolved O2 (PaO2)

Answer 34

Hypoxemia

Question 35

Does hemoglobin bind CO2?

Answer 35

Yes

Question 36

What is the main way CO2 is transported?

Answer 36

Bicarbonate

Question 37

What are the 3 ways CO2 can be transported?

Answer 37

1. Dissolved CO2
2. Carbamino-hemoglobin (CO2Hgb)
3. Bicarbonate (HCO3-)

Question 38

What is the protein that exchanges HCO3 into plasma for Cl?

Answer 38

Band 3 protein

Question 39

CO2 forms a ____, _____ bond with hemoglobin (on terminal amine groups)

Answer 39

loose, reversible

Question 40

CO2 forms a loose, reversible bond with hemoglobin on _____ groups

Answer 40

terminal amine

Question 41

In RBCs, ______ rapidly forms carbonic acid from H2O and CO2, which in turn dissociates to H+ and HCO3-

Answer 41

carbonic anhydrase

Question 42

Deoxygenated Hb promotes _____ binding of CO2 to Hb

Answer 42

increased

Question 43

Oxygenated Hb promotes _____ of CO2 from Hb.

Answer 43

dissociation