Chapter 18

Question 1

VO2

Answer 1

The ability to INTAKE,
TRANSPORT and
UTILIZE oxygen

Question 2

VO2

Answer 2

The ability to INTAKE,
TRANSPORT and
UTILIZE oxygen

Question 3

Oxygen is transported in the blood in two ways:

Answer 3

Bound to hemoglobin on RBCs. (Majority)
Dissolved in plasma.

Question 4

At rest

Hemoglobin and plasma

Answer 4

Fully saturated Hemoglobin can carry ~20 mL O2/L blood

Plasma can maximally dissolve ~0.3 mL O2/L blood

Question 5

Ficks Equation

Answer 5

VO2 = Q x A-V O2 difference
Q = HRxSV

Q = Cardiac output: total O2 content of Arterial and Venous

Question 6

Total O2 content in Red Blood cells
PER 100ML OF BLOOD

Answer 6

Amount of Hemoglobin X Amount of O2 Bound to hemoglobin X % Saturation at a given PO2

Amount of Hemoglobin = 15/100

Question 7

Oxyhemoglobin

HbO2

Answer 7

Found in Heme group
Has iron in the centre

1g of Hb transports 1.34ml of O2

Question 8

Saturation of A and V blood

Answer 8

Saturation of Arterial blood is 100%
Saturation of Venous blood is closer to 75%

Question 9

Partial Pressure of O2

Alveoli, Arterial blood, cells, Venous blood

Answer 9

Alveoli - 100 mmHg
Arterial blood - 100 mmHg
cells - ≤40 mmHg
Venous blood - ≤ 40 mmHg

Question 10

Partial Pressures of CO2

Alveoli, Arterial blood, cells, Venous blood

Answer 10

Alveoli - 40 mmHg
Arterial blood - 40 mmHg
cells - ≥46 mmHg
Venous blood - ≥46 mmHg

Question 11

Higher altitude and O2

Answer 11

Decreases pressure of O2

Question 11

Higher altitude and O2

Answer 11

Decreases pressure of O2

Question 12

Hypoxia

Answer 12

too little oxygen

Question 13

Hypercapnia

Answer 13

increased concentrations of carbon dioxide

Question 14

PH of Blood

Answer 14

7.37

Question 15

Effect Gas exchange

Answer 15

Surface area (Emphysema
Diffusion barrier permeability
Diffusion Distance

Question 16

98%

Answer 16

oxygen binding to Hb

Question 17

Effects on O2 binding to Hb

Answer 17

pH. (goes down during exercise)
Temperature.
CO2. (More)
2,3-Diphosphoglycerate (2,3-DPG). (more glycolosis)

Question 18

CO2 Transport (3)

Answer 18

Dissolved in plasma. (7%)
Combined with bicarbonate (HCO3-) ions
Bound to Hb. (23%)

Question 19

CO2 role in Ventilation

Answer 19

Primary stimulus for ventilation changes

O2 and H+ play less of a role

Question 20

Respiratory neurons in the medulla

Answer 20

control inspiratory and expiratory muscles

Question 21

Rhythmic pattern

Answer 21

spontaneously discharging neurons

Question 22

Ventilation is subject to

Answer 22

continuous modulation by chemoreceptor- and mechanoreceptor-linked reflexes and higher brain centers

Question 23

Ventilation is subject to

Answer 23

chemoreceptor- and mechanoreceptor-and higher brain centers

Question 24

How to stimulate peripheral chemoreceptors

Answer 24

PO2 must fall below 60 mmHg

Question 25

How do central Chemoreceptors work in the body?

Answer 25

Central chemoreceptors monitor CO2 in cerebrospinal fluid
- (the sensors are built into the fluid)
- We are trading off H+ and CO2 in this process (this is buffering)
- The central receptors do not directly interact with CO2 (it is a secondary messenger system)