Physiology 3

Question 1

Anatomical dead space?

Answer 1

Inspired air that remains in the airways where it is not available for gas exchange

Question 2

Pulmonary ventilation equation

Answer 2

Pulmonary ventilation (L)= Tidal volume (L/breath) x Respiratory rate (breath/min) under resting conditions

Question 3

Difference between alveolar ventilation and pulmonary ventilation?

Answer 3

Alveolar ventilation is less due to presence of anatomical dead space

Question 4

Alveolar ventilation equation?

Answer 4

Alveolar ventilation (L)- Tidal volume- dead space volume) x Respiratory rate under resting conditions

Question 5

Pulmonary ventilation?

Answer 5

Volume of air breathed in and out per minute

Question 6

Alveolar ventilation?

Answer 6

Volume of air exchanged between atmosphere and alveoli per minute

Question 7

Why is alveolar ventilation more important?

Answer 7

Represents new air available for gas exchange within the blood

Question 8

How to increase pulmonary ventilation?

Answer 8

Depth (TV) and rate of breathing increases

Question 9

Why is dead anatomical space significant?

Answer 9

To increase pulmonary ventilation t is more advantageous to increase the depth of breathing instead of the rate of breathing (Although both increase)

Question 10

What does the transfer of gases around the body depend on?

Answer 10

Ventilation

Perfusion

Question 11

Perfusion

Answer 11

Rate at which blood is passing through the lungs

Question 12

Ventilation

Answer 12

Rate at which gas is passing through the lungs

Question 13

When does differing alveolar and arterial partial pressures being different have a significant effect? and what is it due to?

Answer 13

In disease

Blood flow and ventilation varying from the top to the bottom of the lung

Question 14

What are ventilated alveoli that are nit adequately perfused with blood considered as?

Answer 14

Alveolar dead space

Question 15

Alveolar dead space in

a) Healthy
b) Diseased

Answer 15

a) Very small and of little importance

b) could increase significantly

Question 16

Physiological dead space equals

Answer 16

anatomical + alveolar dead space

Question 17

What leads to accumulation of CO2 in the alveoli?

Answer 17

Increased perfusion

Question 18

What does accumulation of CO2 in the airway cause?

Answer 18

Decreased airway resistance

Increased airflow

Question 19

What causes an increase in alveolar O2 concentration?

Answer 19

Increased Ventilation

Question 20

What does increased concentration of 02 alveolar cause?

Answer 20

Pulmonary vasodilation

Increased blood flow to match larger airflow

Question 21

O2 decreases in the area? (Perfusion is greater than ventilation)

Answer 21

Constriction of local blood vessels

Blood flow decreases

Question 22

CO2 decreases in the area? (Ventilation greater than perfusion)

Answer 22

Constriction of local airways

Airflow decrease

Question 23

Effect of decreased O2 on pulmonary arterioles?

Answer 23

Vasoconstriction

Question 24

Effect of increased O2 on pulmonary arterioles?

Answer 24

Vasodilation

Question 25

Effect of a) Decreased O2 b) Increased O2 on systemic arterioles?

Answer 25

a) Vasodilation | b) Vasoconstriction

Question 26

4 factors that influence the rate of gas exchange across an alveolar membrane?

Answer 26

Partial pressure gradient of O2 and CO2 Diffusion coefficient for O2 and CO2 Surface area of the alveolar membrane Thickness of alveolar membrane

Question 27

Daltons law of partial pressure letter equation?

Answer 27

Ptotal= P1 + P2 +... + Pn

Question 28

Daltons law of partial pressure word equation?

Answer 28

The total pressure exerted by a gaseous mixture = The sum of the partial pressures of each individual component in the gas mixture

Question 29

Partial pressure of Gas definition?

Answer 29

The pressure that one gas in a mixture of gases would exert if it were the only gas present in the whole volume occupied by the mixture at a given temperature

Question 30

Alveolar Gas equation?

Answer 30

PAO2= PiO2- [PaCO2/0.8] PAO2=Partial pressure of 02 in alveolar air PiO2= Partial pressure of O2 in inspired air PaC02=Partial pressure of CO2 in arterial blood 0.8 is the respiratory exchange ratio (RER) (ratio of CO2 produced/ O2 consumed for someone eating a mixed diet

Question 31

What does water vapour pressure contribute to to the total pressure of the lungs?

Answer 31

47mmHg

Question 32

Pressure of inspired air=

Answer 32

Atmospheric pressure - water vapour pressure | 760- 47= 713mmHg at sea level

Question 33

Pi02=

Answer 33

713 x 0.21 v=150mmHg

Question 34

Which is more soluble in membranes Co2 or O2?

Answer 34

CO2 Diffusion coefficient is 20 times that of 02 Partial pressure gradient of CO2 is much smaller than partial pressure gradient of O2

Question 35

Diffusion coefficient for gas?

Answer 35

Solubility of gases in membranes

Question 36

Fick's Law of Diffusion

Answer 36

The amount of gas that moves across a sheet of tissue in unit time is proportional to the area of the sheet but inversely proportional to its thickness

Question 37

How do lungs provide a large SA for gas exchange? | + what is their circulation like

Answer 37

Airways repeatedly divide Small airways divide into alveoli Extensive pulmonary capillary network

Question 38

Fun fact about pulmonary capillary network?

Answer 38

Receives entire cardiac output

Question 39

Alveoli Description Function

Answer 39

Thin walled inflatable sacs | Function in gas exchange

Question 40

Walls of alveoli

Answer 40

Walls consist of single layer of flattened Type 1 alveolar cells

Question 41

What encircles each alveolus

Answer 41

Pulmonary capillaries

Question 42

As partial pressure of CO2/ O2 increases?

Answer 42

Rate of Transfer of gases increases

Question 43

As the diffusion concentration gradient increases?

Answer 43

Rate of gas transfer increases

Question 44

SA of alveolar membrane increases?

Answer 44

Rate of gas transfer increases

Question 45

Thickness of alveolar membrane increases?

Answer 45

Rate of gas transfer decreases

Question 46

Non respiratory functions of respiratory system?

Answer 46

* Route for water loss and heat elimination * Enhances venous return (cardiovascular physiology) * Helps maintain normal acid-base balance (Resp & Renal physiology) * Enables speech, singing and other vocalizations * Defends against inhaled foreign matter * Removes, modified, activates or inactivates various materials passing through the pulmonary circulation * Nose serves as organ of smell