Lung volumes and capacities

Question 1

How can lung volumes be measured?

Answer 1

By a spirometry

Question 2

What can inluence lung volumes?

Answer 2

Age, species, conditions.

Question 3

What is a water spirometer?

Answer 3

A bell jar, containing a volume of 8-10 litres, which moves within a solid container filled with water. Volume value is read on a scale.

Question 4

What is a personal spirometer used for?

Answer 4

human patients with respiration troubles, chronic bronchtitis or bronchial asthma.

Question 5

Static volumes?

Answer 5

TV, ERV, VC, IRV

Question 6

Dynamic volumes?

Answer 6

FEV1, FVC, relaxed resp. output , max. resp output.

Question 7

TV?

Answer 7

Tidal Volume, volume of air entering or leaving the lungs during a single breath.

Question 8

ERV?

Answer 8

Expiratory reserve volume, the extra volume of air that can be actively expired my maximal contractions of the expiratory muscles (after TV is expired)

Question 9

VC?

Answer 9

Vital capacity, the maximum volume change possible in the lungs.

Question 10

IRV?

Answer 10

Inspiratory reserve volume = VC -TD-ERV

Question 11

FVC?

Answer 11

Forced vital capacity

Question 12

FEV1?

Answer 12

Forced expiration volume in the first second –> volume of air expired during the first second of expiration. (Usually 80% of VC)

Question 13

Relaxed respiratory output?

Answer 13

Minute ventilation –> TV x ventilation frequency

Question 14

Maximal respiratory output?

Answer 14

VC x maximal ventilation frequency

Question 15

The expected vital capacity depends on…?

Answer 15

sex, body height, age.

Can be calculated by the Cournand-Beldwin equation

Question 16

RV?

Answer 16

Residual volume –> involves the collapse volume that is released during pulmonary damage and the minimal volume. Can not be measured using spirometry.

Question 17

FRC?

Answer 17

Functional residual capacity –> the residual air volume in the lungs after maximal expiration. FRC = ERV + RV.

Question 18

Total lung capacity?

Answer 18

Consist of the residual volume and vital capacity. RV + TC = RV + (TV + IRV + ERV)

Question 19

Anatomic dead volume?

Answer 19

refers tot he parts of the respiratory system without resp. epithelium (conducting airways) 150 - 200 mL

Question 20

Total dead volume?

Answer 20

the anatomical dead air volume plus the non-functional alveoli.