Lung mechanics 1

Question 1

Describe the term ventilation

Answer 1

The flow of air in and out of the respiratory system

Delivers air to the alveoli where gas exchange occurs

Question 2

Describe how air moves and what physiological component creates the required conditions?

Answer 2

Air moves from a region of high pressure to a region of low pressure

This pressure difference is created by the respiratory muscles for the lungs

Question 3

Describe what happens to the body to cause inhalation

Answer 3

Diaphragm contracts and flattens, lungs expand, air moves into the lungs

Question 4

Describe what happens to the body to cause exhalation

Answer 4

Diaphragm relaxes, lungs decrease in size , air moves out of the lungs

Question 5

How is lung function measured?

Answer 5

Spirometer

Question 6

What is the tidal volume?

Answer 6

Amount of air moved in and out of lungs during rest

Question 7

What is vital capacity?

Answer 7

Maximum volume of air moved into & out of your lungs in a single respiratory cycle (deep breath)

Question 8

What is the inspiratory reserve volume?

Answer 8

the maximal amount of additional air that can be drawn into the lungs after normal inspiration (at rest)

Question 9

What is the expiratory reserve volume?

Answer 9

the maximal amount of additional air that can be exhaled out of the lungs after normal exhalation (at rest)

Question 10

What is the residual volume?

Answer 10

the volume of air still remaining in the lungs after forced expiration

Question 11

How is forced vital capacity calculated?

Answer 11

Inspiratory reserve capacity + tidal volume + expiratory reserve volume

Question 12

What is respiratory capacity

Answer 12

the total amount of air that can be drawn into the lungs after forced inspiration.
Tital volume + inspiratory reserve volume

Question 13

What is FEVI/FVC? What is a normal value? What can affect this value?

Answer 13

A ratio of Forced Expiratory Volume in 1 sec & Forced Vital Capacity

Normal- 70-80%

What can limit it- Asthma

Question 14

What effect will asthma have on a lung function test?

Answer 14

There will be a reduced flow rate

Question 15

Describe what happens to the diaphragm and muscles during quite and forced inspiration

Answer 15

Quite- Diaphragm and external intercostal muscles contracts.

Forced - Diaphragm, external intercostal muscles & accessory muscles contract

Accessory msucles- (Pectoralis major & minor, & Serratus anterior)

Question 16

Describe the two movements external intercostal muscles conduct during inspiration

Answer 16

Pump-handle movements-anterior end of each rib is elevated

Bucket-handle movements-diameter of chest increases

Question 17

Describe what happens to the diaphragm and muscles during quite and forced Expiration

Answer 17

Quite- Passive because of elastic recoil of the lungs

Forced- active- Involves accessory respiratory muscles

E.g. Anterior abdominal muscles

Question 18

What is alveolar ventilation?

Answer 18

portion of the total ventilation that reaches the alveoli and participates in gas exchange

Question 19

What defines the movement of gasses in the lungs?

Answer 19

Partial pressure gradients

Question 20

What is the anatomical dead space?

Answer 20

Volume of air in the mouth, pharynx, trachea and bronchi up to the terminal bronchioles. Volume of air in the conducting airwaysm does not take part in gas exchange
= 150ml

Question 21

What is Alveolar dead space?

Answer 21

Alveoli that have insufficient blood supply to be properly perfused - act as effective respiratory membranes

Question 22

What is the equation to calculate Alveolar Ventilation

Answer 22

(Tidal volume –dead space) X respiratory rate

Question 23

What is Alveolar Ventilation

Answer 23

Rate at which new air reaches the alveoli