week 5

Question 1

1. Each lung is surrounded by two layers of serous membrane known as pleurae. These are:

Answer 1

visceral pleura; covers the surface of the lung

parietal pleura; lines the inside of the thoracic wall.

Question 2

The space in between is called the pleural cavity and it is filled with

Answer 2

pleural fluid

Question 3

This pleural fluid assists breathing movements by acting as a

Answer 3

lubricant.

Question 4

On expiration the lungs do not collapse but are held in a semi-expanded state due to the presence of a vacuum in the

Answer 4

pleural space.

Question 5

2. In the bronchial tree air flows from the trachea through the

Answer 5

primary,
secondary, and
tertiary bronchi into smaller bronchiole and
smaller terminal bronchiole before entering
alveoli.

Question 6

The trachea and bronchi contain

Answer 6

cartilage rings

Question 7

cartilage rings keeps

Answer 7

the airways open.

Question 8

3. Bronchiole do not contain

Answer 8

cartilage rings

Question 9

bronchiole do contain

Answer 9

more smooth muscle

This allows for regulation of airflow.

Question 10

4. The pulmonary artery carries blood

Answer 10

which is low in oxygen to the lungs

Question 11

Pulmonary capillaries exchange

Answer 11

gases with the alveoli

Question 12

Blood leaves the lungs in the pulmonary veins,

Answer 12

which carry oxygenated blood back to the heart.

Question 13

5. Name the three types of cells in the alveolus:

Answer 13

Type I alveolar cell;;
simple squamous epithelium

Alveolar macrophages; removes debris and microbes

Type II alveolar cell;
secretes surfactant.
The surfactant reduces the surface tension which prevents the alveoli from collapsing.

Question 14

6. Oxygen is transported in the blood:
   ?% is bound to hemoglobin
   ?% dissolves in plasma

Answer 14

98%

2%

Question 15

7. When oxygen is loaded onto hemoglobin in the lungs, hemoglobin is called

Answer 15

oxyhemoglobin,

Question 16

when oxygen is unloaded from the hemoglobin at the tissues it is called

Answer 16

carboxyhemoglobin.

Question 17

8. 70% of Carbon dioxide is transported in blood as

Answer 17

Bicarbonates in plasma

the rest is bound to haemoglobin and dissolved in plasma.

Question 18

9. The muscles involved in inspiration are

Answer 18

Diapragm,

external intercostals

and Sternoclidomastoid

Question 19

10. The muscles involved in expiration are

Answer 19

Internal intercostals,

Rectus abdominus,

external oblique

and other abdominals

Question 20

11. The respiratory control area in the brain are the

Answer 20

the Pneumotaxic center,

the Apneustic center,

and Medullary center.

Question 21

12. The pneumotaxic area of the brain controls the depth of

Answer 21

inspiration.

Question 22

13. The term “bronchoconstriction” refers to constriction of the lumen in which part of the bronchial tree?

Answer 22

Terminal bronchiole

Question 23

14. What is the effect of histamine, produced during an asthmatic attack, on the bronchioles?

Answer 23

bronchoconstriction

Question 24

15. What is the effect of adrenaline on the bronchioles?

Answer 24

bronchodilatation

Question 25

16. What is the effect of acetylcholine on the bronchioles?

Answer 25

bronchoconstriction

Question 26

17. The amount of air you quietly breath in and out, (about 500 mls), is referred to as

Answer 26

Tidal volume

Question 27

18. Cartilage rings maintains

Answer 27

the patency (openness) of the trachea.

Question 28

19. State the effect of sympathetic stimulation on the bronchioles.

Answer 28

bronchodilatation

Question 29

Which respiratory-associated muscles would contract if you were to blow up a balloon?_

Answer 29

Internal intercostals, Rectus abdominus, external oblique and other abdominals

Question 30

20. A normal adult lung residual capacity is approximately

Answer 30

1200 mls

Question 31

21. The lungs are perfused by two circulations

Answer 31

the pulmonary and the bronchial

Question 32

The pulmonary circulation is for

Answer 32

oxygenation of blood

Question 33

The bronchial circulation supplies blood

Answer 33

to the lung structures (tissue).

Question 34

22. The factors responsible for holding the lungs to the thorax wall are

Answer 34

vacuum/negative pressure in the pleural cavity and capillary/surface tension from pleural fluid.

Question 35

23. Surfactant helps to prevent the alveoli from collapsing by

Answer 35

decreasing the cohesiveness of water molecules, thereby reducing the surface tension of alveolar fluid.

Question 36

24. The most powerful respiratory stimulus for breathing in a healthy person is increase of

Answer 36

pCo2 in blood.

Question 37

25. Intrapulmonary pressure is the pressure within the

Answer 37

alveoli/parenchyma of the lungs.

Question 38

26. The walls of the alveoli are composed of two types of cells, type I and type II. The function of type II is to

Answer 38

produce surfactant.

Question 39

27. Unlike inspiration, expiration is a

Answer 39

Passive act because no muscular contractions are involved

Question 40

Expiration, however, depends on two factors, the recoil of

Answer 40

elastic tissue/in lungs and muscles that were stretched during inspiration and the inward pull of surface tension due to the film of surfactant_.

Question 41

28. Particles such as dust fail to reach the lungs because of the

Answer 41

pseudostratified ciliated epithelium lining the nasal, pharyngeal and tracheal passageway

Question 42

29. A baby is born at 28 weeks' gestation, what major problem will the doctors look for?

Answer 42

Lack of surfactant/Respiratory distress.

Question 43

30. Name the instrument used to measure lung volumes

Answer 43

Spirometer.