Topic 2 The Respiratory System: Gas Exchange in Humans

Question 1

• Active exchange of oxygen in and CO2 out
• CO2 transported as HCO3- (bicarbonate ion) in plasm
• Conversion of CO2 into HCO3- is catalyzed by enzyme carbonic anhydrase via this reaction: CO2 + H2O H2CO3 H+ + HCO3-
• This process occurs in red blood cells
• Some CO2 can mix with plasma as gas rather then HCO3- or can bind with hemoglobin inside red blood cells forming carbaminohemoglobin

Answer 1

Gas Exchange

Question 2

1. Alveoli
2. Nose
3. Pharynx
4. Larynx
5. Trachea
6. Bronchi/Bronchioles
7. Alveoli

Answer 2

Lung Structures and their Contribution to Gas Exchange

Question 3

• gas exchange between circulatory system and lungs
• Coated with surfactant: liquid covering that reduced surface tension preventing H2O from collapsing the alveoli
• 2 types of epithelial cells in alveoli: 1: structural support and 2: produce surfactant

Answer 3

Alveoli

Question 4

• Filters, moistens, warms incoming air

- Mucus secreted by goblet cells traps dust particles

Answer 4

Nose

Question 5

• Throat

- Dust and mucus are swept back here by cilia for disposal via spitting or swallowing

Answer 5

Pharynx

Question 6

• Voice box
• When non-gas enters, cough reflex activates
• After the epiglottis

Answer 6

Larynx

Question 7

• Epiglottis covers this during swallowing

- Contains C-shaped ringed cartilage covered by cilia and mucus cells

Answer 7

Trachea

Question 8

• 2 bronchi

- Enter lungs and branch into bronchioles

Answer 8

Bronchi/Bronchioles

Question 9

• Each bronchiole branch ends in these small sacs: surrounded by blood-carrying capillaries

Answer 9

Alveoli