Resp 4

Question 1

Gases, just like ions and water, move

according to the principles of

Answer 1

diffusion

Question 2

he partial pressures of the gases

ONLY include the gases that are

Answer 2

dissolved in the plasma

Question 3

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

Answer 3

increases

increases

Question 4

Tissue PO2 is a function of: (2)

Answer 4

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

Question 5

Increased blood flow and/or
increased metabolism will
result in

Answer 5

more O2 delivery to

the tissues.

Question 6

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

Answer 6

83.3

Question 7

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

Answer 7

2

Question 8

–% of O2 reversibly binds to

hemoglobin inside of the RBC

Answer 8

98

Question 9

98% of O2 reversibly binds to
hemoglobin inside of the RBC
-does not contribute to

Answer 9

partial

pressure

Question 10

Hemoglobin A (α2b2):

Answer 10

4 subunits
each of which each binds 1 O2
molecule.

Question 11

Iron must be in — state

to bind O2

Answer 11

ferrous (Fe2+)

Question 12

The amount of oxygen
bound to Hb
depends on: (2)

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

CaO2 =

Answer 13

ml of O2 carried by oxyhemoglobin plus ml of O2

carried dissolved in plasma

Question 14

skipped
equation
CaO2 =

Answer 14

SaO2 (Hb x 1.34) + 0.003 (PaO2)

Question 15

SaO2 is the

Answer 15

% saturation of hemoglobin

– Average 97%

Question 16

Hb represents

Answer 16

g of hemoglobin/100 ml blood

– Average is 15 g Hb/100 ml blood

Question 17

PaO2 is the

Answer 17

partial pressure of oxygen in arterial blood

– Average is 95 mmHg

Question 18

Average CaO2 is ~

Answer 18

19.782 ml O2/ 100 ml blood

Question 19

Reduction in the 
amount of hemoglobin 
in the blood 
significantly reduces 
the

Answer 19

blood oxygen

content.

Question 20

2,3-BPG binds to

Answer 20

Beta 
subunits of deoxy HB 
and decreases its O2 
affinity. It causes more 
oxygen unloading. 
Normal Venous PvO2 Normal Arterial PaO2

Question 21

At a high PO2,
hemoglobin’s
affinity for O2 is

Answer 21

highest.

Question 22

At a high PO2,
hemoglobin’s
affinity for O2 is
highest.

Answer 22

POSITIVE COOPERATIVITY.

Question 23

The lower the
PO2, the more
likely

Answer 23

O2 will
dissociate from
hemoglobin

Question 24

Oxyhemoglobin Dissociation Curve

Shifts to the RIGHT is called the

Answer 24

bohr effect

Question 25

Oxyhemoglobin Dissociation Curve Shifts to the RIGHT indicates:

Answer 25

DECREASED affinity between hemoglobin and oxygen

Question 26

Oxyhemoglobin Dissociation Curve Shifts to the RIGHT in this instance,

Answer 26

oxygen is MORE likely to dissociate from Hemoglobin.

Question 27

RBCs contain 2,3-bisphosphoglycerate – a metabolic intermediate. Levels of 2,3-BPG increase with (4)

Answer 27

exercise, hypoxia from high altitude, pregnancy and chronic lung disease.

Question 28

Oxyhemoglobin Dissociation Curve Shifts to the RIGHT Helps match

Answer 28

O2 delivery to O2 demand, advantageous since O2 can be released at selective tissues.

Question 29

Oxyhemoglobin Dissociation Curve Shifts to the LEFT indicates

Answer 29

an INCREASED affinity between oxygen and | hemoglobin

Question 30

Oxyhemoglobin Dissociation Curve Shifts to the LEFT In this instance,

Answer 30

oxygen is LESS likely to dissociate | from hemoglobin.

Question 31

Oxyhemoglobin Dissociation Curve Shifts to the LEFT caused by (4)

Answer 31

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

Question 32

Carbon Monoxide has a ---x greater affinity for | Hemoglobin than Oxygen.

Answer 32

250X

Question 33

Only small amounts of CO can be lethal

Answer 33

• CO bound to hemoglobin increases Hb’s affinity for O2 (a left-ward shift in curve)

Question 34

Even though CaO2 may be greatly | reduced,

Answer 34

PaO2 of blood may be normal.

Question 35

Carbon Monoxide-Hemoglobin Curve | Treatment: (2)

Answer 35

* Pure oxygen | * 5% CO2

Question 36

Presentation of CO Poisoning:

Answer 36

“Common in smoke inhalation, enclosed exposure to automobile exhaust, or in the wintertime with home furnaces. Patients present with cherry red skin (classic), flu- like symptoms, headache, and neurologic symptoms.”

Question 37

Variants of Hemoglobin (3)

Answer 37

``` Methemoglobin Hemoglobin F (Fetal Hemoglobin) Hemoglobin S (Sickle Cell) ```

Question 38

Methemoglobin (2)

Answer 38

– 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).

Question 39

Hemoglobin F (Fetal Hemoglobin) (2)

Answer 39

– α2gamma2 (no β chains) – Higher affinity for oxygen than HbA because it doesn’t contain the Beta chain that binds to 2, 3- BPG.

Question 40

Hemoglobin S (Sickle Cell) (3)

Answer 40

– 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

Question 41

About --- mL of carbon dioxide is produced by the tissue metabolism each minute in a resting 70-kg person and must be carried by the --- blood to the lung for removal from the body.

Answer 41

200 to 250 | venous

Question 42

At a cardiac output of 5 L/min, each 100 mL of blood passing through the lungs must therefore unload --- mL of carbon dioxide

Answer 42

4 to 5

Question 43

Carbon Dioxide Transport in the Blood | Transported as: (3)

Answer 43

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

Question 44

Carbon Dioxide Transport in the Blood | Volume of transport is

Answer 44

~4 ml CO2/ 100 ml blood.

Question 45

Carbon Dioxide Transport Mechanisms (3)

Answer 45

1. Dissolved CO2 ~7% 2. Carbaminohemoglobin (& Carbamino Compounds) ~23% 3. Bicarbonate ~70%

Question 46

Dissolved CO2 ~7%

Answer 46

– PCO2 is 40mmHg in arterial blood, 46 mmHg in venous bl

Question 47

Carbaminohemoglobin (& Carbamino Compounds) ~23% (2)

Answer 47

– CO2 forms a loose, reversible bond with hemoglobin (on terminal amine groups) – Slowest of the reactions

Question 48

Bicarbonate ~70% FAST! (2)

Answer 48

– In RBCs, carbonic anhydrase rapidly forms carbonic acid from H2O and CO2, which in turn dissociates to H+ and HCO3- – H+ combines with hemoglobin for buffering and HCO3- moves into plasma in exchange for Cl- (via band 3 protein)

Question 49

Carbon Dioxide Transport Mechanisms: Systemic Capillaries ``` If there were no carbonic anhydrase, PaCO2 would equal ```

Answer 49

80 mmHg (compared to the normal of 45 mmHg).

Question 50

Carbon Dioxide Transport Mechanisms: Systemic Capillaries Haldane Effect:

Answer 50

``` Deoxygenated Hb promotes increased binding of CO2 to Hb. ```

Question 51

Carbon Dioxide Transport Mechanisms: Pulmonary Capillaries ``` Note the reverse direction of the transport by band three protein, which leads to (2) ```

Answer 51

``` an increase in intracellular HCO3- and production of CO2 via carbonic anhydrase. ```

Question 52

Carbon Dioxide Transport Mechanisms: Pulmonary Capillaries Haldane Effect:

Answer 52

Oxygenated Hb promotes dissociation of CO2 from Hb.

Question 53

Carbon Dioxide Transport Mechanisms: Pulmonary Capillaries Movement of CO2 into the alveolus will --- PaCO2

Answer 53

decrease