Lecture 18: Lung Function

Question 1

Non-infectious airway diseases are the 3rd leading cause of death worldwide. Why?

Answer 1

• indoor smoke/fire to cook food

- heavy cigarette marketing in developing countries

Question 2

Cigarette Marketing

Answer 2

• decreasing in the US and other developed nations
• 3% increase of smoking in developing countries due to

1. Companies losing business in US so they heavily market in other countries
2. No laws of selling cigarettes to children, making tobacco companies have life long consumers
3. No trade regulations; allows for favorable environment to promote smoking

Question 3

What is the leading cause of lung cancer?

Answer 3

Smoking

Question 4

Diseases that smoking causes

Answer 4

• Cancer
• Heart disease
• Strokes
• COPD

Question 5

Hippocrates and Galen

Answer 5

• had no microscopes/lenses to properly study lungs
• prohibition of dissecting corpses
• caused misunderstandings about human bodies

Question 6

Misunderstanding of the lungs by Greeks and Romans

Answer 6

1. Blood flowed in only one way
2. Food converted to blood in liver
3. Pulmonary artery supplied fuel to lungs
4. Lungs primarily a cool organ to offset excess heat created by body

Question 7

William Harvey

Answer 7

• became the court physician
• first person to hypothesize that blood didn’t flow one way but pumped around body
• however, still did not know true function of lungs

Question 8

Joseph Priestley

Answer 8

• isolated oxygen

- was closer to finding true meaning of lungs

Question 9

Heinrich Magnus

Answer 9

• measured concentration of gases going into and out of lungs (discovered blood going in had more gases)
• scientist who found true function of lungs (to help oxygen get to red blood cells, which then carry it around the body. Also helps to release CO2 from body

Question 10

How our lungs evolved

Answer 10

• we evolved from creatures with gills

- lungs evolved from digestive pouches of air gulpers (they use these to store oxygen because they don’t have lungs)

Question 11

Fatal flaw of lungs due to evolution

Answer 11

-food goes down the same pipe as air, making it very easy to choke

Question 12

Alveoli

Answer 12

• final branching of the respiratory tree and the primary gas exchange units of the lungs
• basically little air sacks in the lungs
• about 300 million of them

Question 13

Alveoli function

Answer 13

-allows for the exchange of gas (oxygen and CO2)

Question 14

Alveoli damage

Answer 14

• can be damaged because very thin
• damage to alveoli:

1. Invading microbes
2. Inhaled particle matter
3. Immune system response to above

-smoking damages surface area, allows less gas exchange

Question 15

Function of Mucus

Answer 15

• traps dirt particles
• cilia cells push mucus up body out of lungs
• viral infections could produce excess mucus

Question 16

Cystic Fibrosis and Mucus

Answer 16

-makes mucus not right consistency so cilia cannot move up body; goes into stomach instead