2.1 Effect Of CF On The Lungs

Question 0

Where is mucus found?

Answer 0

Thin coatings of mucus along airways

Question 1

The order of the gas exchange

Answer 1

Trachea
Bronchi
Bronchioles
Alveoli - gas exchange

Question 2

What produces mucus?

Answer 2

Goblet cells - in the walls of airways

Question 3

Function of the Ciliated epithelial cells

What happens if someone has CF?

Answer 3

Brushes the mucus up and away from lungs. It can then be either swallowed or coughed out.
Mucus can trap pathogens, reducing chance of infection

CF - sticky mucus is hard for the cilia to move. Mucus production remains consistent but builds up layers of thickened mucus is airways. Low levels of oxygen in mucus allowing harmful bacteria to thrive in anaerobic conditions

Question 4

What are the two major effects on health due to sticky mucus?

Answer 4

Increases the chance of lung infection

Gas exchange is less efficient

Question 5

Function of mucus

Answer 5

To trap microorganisms, pathogens and dust that enters the airways

Question 6

What type of epithelium tissue covers the wall surface of the alveoli and capillaries?

Answer 6

Squamous epithelium - thin flat cells, short diffusion path so air can diffuse through easily

Question 7

Where can columnar epithelium be located?

Answer 7

In small intestine - epithelial cells extend out from basement membrane

Question 8

What cells line the trachea?

Answer 8

Goblet and Ciliated epithelial cells

trachea is strong and supported to ensure air can continually go to the lungs

Question 9

What happens when mucus leads to infections?

Answer 9

White blood cells break down the infected mucus into DNA which thickens the mucus making it sticker.
Repeated infections can result in damage to the gas exchange system structures as the ability for destroying pathogens weaken

Question 10

The effect of diffusion depends on..

Answer 10

The surface area to volume ratio

Question 11

How do unicellular organisms exchange gases?

Answer 11

Their whole surface membrane is the exchange surface, in comparison to multicellular organisms.

Question 12

Why is maintaining good a concentration gradient important?

Answer 12

To allow substances to continually diffuse in and out of the cell, at a fast rate of diffusion

Question 13

Three adaptions the alveoli has to increase gas exchange…

Answer 13

• Circular shape, large surface area so greater rate of diffusion due to more space. Rate of diffusion is directly proportional
• Blood capillaries surround the alveoli, to maintain a strong conc. gradient so gas exchange is faster. Rate of diffusion is directly proportional
• Short diffusion path, thin walls of the alveoli and capillaries - squamous epithelium, increase rate of diffusion which is inversely proportional

Question 14

How is rate of diffusion calculated?

Answer 14

By Fick’s Law

(S.A x difference in conc)/thickness of gas exchange surface

Question 15

How does sticky mucus effect the alveoli?

Answer 15

Thickening mucus layers block narrow airways of bronchioles , preventing ventilation below the blockage.
Reduces no. of alveoli providing surface area for gas exchange

Question 16

Where is there a greater chance of mucus blocking airways? What is the effect on the lungs?

Answer 16

Narrow ends of airways in the bronchioles.
Often allow air in but not to be breathed out
Over inflation of the lungs after blockage
Overtime reduced elasticity of the lungs

Question 17

Why do CF people find exercise difficult and tiring?

Answer 17

As their gas exchange system is not effective enough, not enough oxygen can reach their muscle cells - required for anaerobic respiration.
Short of breath