B06 Gas Exchange

Question 1

Where are the lungs situated?

Answer 1

In the thorax (chest cavity)

Question 2

Sequence in which air travels down the human gas exchange system

Answer 2

Nasal cavity to Epiglottis to Gullet to Trachea to Bronchus to Bronchiole to Alveolus.

Question 3

The function of the blood capillaries surrounding the alveoli

Answer 3

Site of gas exchange. Oxygen diffuses from the alveoli into the bloodstream. Carbon dioxide diffuses from the bloodstream into the alveoli.

Question 4

Function of Larynx

Answer 4

Manipulates pitch and volume

Question 5

Function of Trachea

Answer 5

Main windpipe that brings gases into the thoracic cavity. Surrounded by C-shaped rings of cartilage.

Question 6

Function of Bronchi

Answer 6

Extension of windpipe that shuttles air to and from the lungs.

Question 7

Function of Aveoli

Answer 7

Sac-like structures with walls only one cell thick. There are thousands of these in the lungs and they serve to increase surface area for gas exchange.

Question 8

Function of Bronchioles

Answer 8

Passageways which air passes through the nose or mouth to the alveoli. Part of conductivity zone of respiratory system.

Question 9

List characteristics of efficient gas exchange surfaces

Answer 9

Have large surface area, be thin (allow diffusion to occur quickly), have mechanisms for maintaining step concentration gradients across themselves (for fast diffusion), be permeable to gases, be moist so that oxygen and carbon dioxide can dissolve and then diffuse across.

Question 10

Differences in composition between inspired and expired air.

Answer 10

Inspired air: more oxygen and less carbon dioxide.
Oxygen in inhaled air diffuses from lungs to the blood stream while carbon dioxide diffuses out of the bloodstream into the lungs to be exhaled.

Question 11

Oxygen concentration in inhaled air

Answer 11

21%

Question 12

Oxygen concentration in exhaled air

Answer 12

16%

Question 13

Carbon dioxide concentration in inhaled air

Answer 13

0.04%

Question 14

Carbon dioxide concentration in exhaled air

Answer 14

4%

Question 15

Define goblet cells

Answer 15

Mucus secreting cells that produce mucus for trapping dust.

Question 16

Define cilia

Answer 16

Small hair like projections from the cells, for moving and sweeping mucus out of the gas exchange system.

Question 17

Effects of tar on gas exchange system

Answer 17

Stick to and damage the cilia of airways

Question 18

Effects of Carbon Monoxide on gas exchange system

Answer 18

Sticks permanently to red blood cells, occupies where the haemoglobin should be carrying oxygen

Question 19

.Effects of smoke particles on gas exchange system

Answer 19

Irritate lungs, damage cilia

Question 20

Effects of nicotine on gas exchange system

Answer 20

Damages wall of blood vessels, makes it easier for them to burst.

Question 21

Define gaseous exchange

Answer 21

When carbon dioxide and oxygen diffuse into and out of the blood at the respiratory surfaces in the lungs.

Question 22

Define ventilation

Answer 22

The muscular movements where air with a relatively high oxygen concentration is taken into the thoracic cavity and air with relatively high carbon dioxide concentration is removed