Respiratory System

Question 1

What do the lungs occupy in the thoracic cavity?

Answer 1

-Virtually all of the thoracic cavity
-sharing it only with the heart and associated vessels, oesophagus,thymus and some nerves

Question 2

Are there any muscles associated with the lungs themselves?

Answer 2

No

Question 3

What type of muscle in walls of the arterioles and bronchioles?

Answer 3

Smooth muscle

Question 4

Answer 4

Question 5

Answer 5

Question 6

Answer 6

Question 7

Answer 7

Question 8

Answer 8

Question 10

Answer 10

Question 11

What changes in lung volume?

Answer 11

Changes in lung volume are achieved by changing the dimensions of the outer chest wall.

Question 12

What does the thorax consist of?

Answer 12

12 pairs of curved ribs joining the sternum to the thoracic vertebrae.

Question 13

What forms the floor of the thoracic cavity?

Answer 13

Diaphragm-curved sheet of skeletal muscle separating the thoracic cavity from the abdominal cavity

Question 14

To cushion the friction that might otherwise occur between the lungs and the thoracic cavity, what are the lungs encased in?

Answer 14

double walled closed sac called the pleural sac.

Question 15

What is the function of the intrapleural fluid?

Answer 15

-inner surfaces of the pleural sac secrete intrapleural fluid
-which lubricates the pleural surfaces.
-this allows the surfaces to slide past one another during respiratory movements.

Question 16

Answer 16

Question 17

Answer 17

Question 18

What is the average lung capacity for males?

Answer 18

5.7 litres

Question 19

What is the average lung capacity for females?

Answer 19

4.2 litres

Question 20

What is the lung volume after complete expiration for females?

Answer 20

1.0 litres

Question 21

What is the lung volume after complete expiration for males?

Answer 21

1.2 litres

Question 22

What is the minimum volume of air in the lungs under resting conditions?

Answer 22

2.2 litres

Question 23

What is the maximum volume of air in the lungs under resting conditions?

Answer 23

2.7 litres

Question 24

How much air do we typically take in and breathe out in each cycle?

Answer 24

500 ml

Question 25

True or False: Normally, lungs are completely inflated or deflated.

Answer 25

False

Question 26

What is a major advantage of not completely emptying the lungs?

Answer 26

The gas content of the blood leaving the lungs remains virtually constant

Question 27

Why does gas exchange compensate in the lungs?

Answer 27

For metabolic activity in the tissues

Question 28

What are the two groups of neurones in the medullary respiratory centre?

Answer 28

Dorsal respiratory group (DRG) and ventral respiratory group

Question 29

What does the dorsal respiratory group (DRG) primarily control?

Answer 29

Inspiration

Question 30

What is the role of the ventral respiratory group during quiet breathing?

Answer 30

Normally inactive

Question 31

What can the ventral respiratory group control during active respiration?

Answer 31

Both inspiration and expiration

Question 32

What controls the activity of the medullary respiration centre?

Answer 32

Carbon dioxide which generates [H+] in the extracellular brain fluid

Question 33

What is the role of the feedback mechanism in the medullary respiratory centre?

Answer 33

maintains the concentration of carbon dioxide in the arterial blood at a more or less constant value.

Question 34

What is the consequence of the medullary respiratory centre's activity on blood pH?

Answer 34

It helps to maintain blood pH at a constant level. (The regulation of carbon dioxide levels directly influences blood pH)