Collated Notes

Question 1

What is internal respiration?

Answer 1

Intracellular mechanism which consumes 02 and produces CO2

Question 2

What is external respiration?

Answer 2

Events that lead to exchange of O2 and CO2 between the external environment and the cells of the body

Question 3

How many steps in external respiration?

Answer 3

4 steps

Question 4

4 steps of external respiration?

Answer 4

1- Ventilation = Mechanical process of moving gas in and out of the lungs 2- Gas exchange between alveoli and blood = exchange of 02 and CO2 between air in alveoli and blood in pulmonary capillaries 3- Gas transport in the blood= Binding/transporting of O2 and CO2 in blood 4- Gas exchange at tissue level= Exchange of O2 and CO2 between the blood in the systemic capillaries and the body cells

Question 5

Describe ventilation?

Answer 5

Mechanical process of moving gas in and out of the lungs

Question 6

Describe gas exchange between alveoli and blood?

Answer 6

Exchange of CO2 and O2 between air in alveoli and blood in pulmonary capillaries

Question 7

Describe gas transport in the blood?

Answer 7

Binding and transporting of O2 and CO2 in the blood

Question 8

Describe gas exchange at tissue level?

Answer 8

Exchange of O2 and CO2 between blood in systemic capillaries and the body cells

Question 9

What must the pressures be like for air to flow into the lungs during inspiration?

Answer 9

Intra alveolar pressures must be less than atmospheric pressures

Question 10

What is Boyles law?

Answer 10

As volume of gas increases the pressure exerted by the gas decreases

Question 11

Forces holding the thoracic wall and lungs in close opposition?

Answer 11

Intra-plural fluid cohesiveness Negative intra-pleural pressure (sub-atmospheric pressure forces lungs to expand outwards)

Question 12

3 pressures important in ventilation?

Answer 12

Atmospheric Intra-alveolar Intra-pleural

Question 13

What type of process is inspiration? Compare this to normal resting expiration?

Answer 13

Active = inspiration passive = Expiration

Question 14

What muscles are used in normal resting breathing?

Answer 14

Diaphragm - increases thorax vertically by contraction External intercostal muscle- Contraction lifts ribs and moves out sternum

Question 15

How lungs recoil during expiration?

Answer 15

Elastic connective tissue Alveolar surface tension (Most important)

Question 16

Law of laplace?

Answer 16

Smaller alveoli have a higher tendency to collapse (P= 2T/r)

Question 17

What does pulmonary surfactant do?

Answer 17

Lowers the surface tension of smaller alveoli thus preventing their collapse

Question 18

What does pulmonary surfactant consist of?

Answer 18

Lipids and proteins

Question 19

Fact about respiratory distress syndrome?

Answer 19

It is caused by premature babies not producing enough pulmonary surfactant

Question 20

Muscles of active expiration?

Answer 20

Internal intercostal muscles Abdominal muscles

Question 21

Accessory muscles of inspiration?

Answer 21

Sternocleidomastoid Scalenus (runs deep to^)

Question 22

Inspiratory capacity definition?

Answer 22

Max vol. of air that can be inspired at end of normal quiet expiration (IC = IRV + TV)

Question 23

Equation for inspiratory capacity?

Answer 23

IC= IRV + TV

Question 24

What does IRV stand for?

Answer 24

Inspiratory reserve volume

Question 25

Tv stands for?

Answer 25

Tidal volume

Question 26

Look wow

Question 27

What is the vital capacity?

Answer 27

Max vol. of air that can be moved out during single breath following max. inspiration (VC = IRV + TV + ERV)

Question 28

Equation for vital capacity?

Answer 28

VC = IRV + TV + ERV VC= vital capacity IRV= Inspiratory reserve volume TV= Tidal volume ERV= Expiratory reserve volume

Question 29

Equation for total lung capacity?

Answer 29

Vital capacity + residual volume

Question 30

You can measure total lung capacity with spirometry. True or false?

Answer 30

False

Question 31

What disease makes residual volume increase?

Answer 31

Emphysema Elastic recoil of the lungs is lost

Question 32

Lung diseases and spirometry diagram?

Answer 32

Question 33

Equation for flow and pressure and radius?

Answer 33

Flow= Change in pressure/resistence

Question 34

What is compliance of the lungs?

Answer 34

Measure of effort that has to go into stretching or distending the lungs.

Question 35

Diseases which have decreased lung compliance?

Answer 35

Pulmonary fibrosis Oedema Collapse Pneumonia Absence of surfactant

Question 36

Diseases with increased compliance?

Answer 36

Emphysema Lungs are hyper-inflated patients have to work harder to get air out

Question 37

What increases the work of breathing?

Answer 37

Pulmonary compliance is decreased Airway resistence is increased Elastic recoil is decreased Need for increased ventilation

Question 38

Definition of pulmonary ventilation?

Answer 38

Volume of air breathed in and out per minute

Question 39

Equation for pullmonary ventilation?

Answer 39

Tidal volume x resp rate

Question 40

Definition of alveolar ventilation?

Answer 40

Volume of air exchanged between the atmosphere and alveoli per minute

Question 41

Equation for alveolar ventilation?

Answer 41

(Tidal volume - dead space) x resp rate

Question 42

What is ventilation perfusion matching dependant on?

Answer 42

Ventilation (rate gas passes through lungs) and Perfusion (Rate which blood is passing through lungs)

Question 43

What is alveolar dead space?

Answer 43

Ventilated alveoli which are not adequately perfused with blood

Question 44

What is physiological dead space?

Answer 44

Anatomical dead space + alveolar dead space

Question 45

When can alveolar dead space increase?

Answer 45

In disease

Question 46

Local controls which operate to match perfusion and ventilation in the lungs? 1) When ventilation is larger than perfusion 2) When perfusion is larger than ventilation

Answer 46

1) Decreased C02 constriction of airways Increased 02 dilation of blood vessels 2) Increased CO2 dilation of airways Decreased 02 constriction of blood vessels

Question 47

4 factors which affect gas transfer across the alveolar membrane?

Answer 47

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

Question 48

Dalton's law of partila pressure?

Answer 48

Total pressure= Sum of each indiviudal component in a gas mixture

Question 49

PA02?

Answer 49

Partial pressure of O2 in alveolar air

Question 50

PiO2?

Answer 50

Partila pressure of O2 in inspired air

Question 51

Alveolar gas Equation?

Answer 51

PA02= PiO2 - [PaCO2/0.8]

Question 52

What would a big gradient between PAO2 (alveolar) and PiO2 (arterial) suggest?

Answer 52

Indicate problems with gas exchange in the lungs Or A right to left shunt in the heart

Question 53

Diffusion coefficient (solubility of gas in membrane) of CO2 compared to O2?

Answer 53

20 x that of O2

Question 54

Ficks law of diffusion?

Answer 54

The amount of gas that moves across a tissue is proportional to the area of the sheet BUT inversely proportional to its thickness. (so thicker = less exchange)