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Flashcards in 6.4 Deck (11)
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1
Q

In what direction does CO2 and 02 diffuse in gas exchange?

A

CO2 diffuses from plasma to alveolus

O2 diffuses from the alveolus to red blood cells

2
Q

What is ventilation?

A

Physical process of breathing in and out

3
Q

What is gas exchange?

A

Gas diffusion in alveoli

4
Q

What is respiration?

A

The release of energy inside cells

5
Q

How is a concentration gradient maintained in gas exchange?

A

Air in the alveolus has a higher concentration of O2 and a lower concentration of CO2 than the blood in the capillary.

6
Q

What are the properties of type 1 pneumocytes?

A

They have a thin lining for efficient gas exchange and 0.15um of cytoplasm

7
Q

What are the properties of type 2 pneumocytes?

A

They are thick and spherical, secretes fluid ( surfactant)to moisten alveoli, speeding up diffusion and prevents walls sticking together. They make up 5% of surface.

8
Q

What are the stages of inspiration?

A

Pressure decreases. Volume increase. Rib cage moves up and out. External intercostal muscles contract and internal intercostal muscles relax. Diaphragm contracts and flattens and abdominal muscles relax.

9
Q

What are the stages of expiration?

A

Pressure increases. Volume decreases. Rib cage moves in and down. External intercostal muscles relax and internal intercostal muscles contract. Diaphragm relaxes and domes up. Abdominal muscles contract.

10
Q

What are the symptoms of lung cancer?

A

Difficulties with breathing, persisten coughing and coughing up blood. Chest pain. Loss of appetite, weight loss, general fatigue.

11
Q

What happens in emphysema?

A

Thin walled alveoli is replaced by a small number of larger air sacs with thicker walls. The surface area for gas exchange is reduced- lungs become less elastic and ventilation is difficult. Phagocytes inside alveoli normally prevent lung infections by engulfing bacteria and producing elastase to kill them inside vesicles.