L3. Respiration - Perfusion

Question 1

Describe the changes in thickness and surface area as you move down the respiratory tract.

Answer 1

Tubes get thinner

Surface area increases

Question 2

Do conducting airways take part in gas exchange? What do they form?

Answer 2

No. They form anatomical dead space.

Question 3

What percentage of air do conducting airways hold and when?

Answer 3

Holds 30% of breath after exhalation.

Question 4

What is the anatomical dead space made up of?

Answer 4

Bronchi with cartilage

non respiratory bronchioles

Question 5

What are respiratory airways?

Answer 5

Bronchioles with alveoli where gas exchange occurs.

Question 6

Describe the make up of the various alveoli.

Answer 6

They are made of type 1 and type 2 epithelial cells.

Type 1 : primary gas exchange site which cover 97% of alveoli surface area.

Type 2 : cover 3% and produce primary surfactant, called septal cells.

Question 7

What does surfactant do?

Answer 7

It lowers surface tension.

Question 8

Describe the changes in values of P O2 in a pulmonary capillary between alveolar air and venous blood. :
P O2 = ______ in alveolar air
to
P O2 = ______ in venous blood

Answer 8

100
to
40

Question 9

Describe the changes in values of P CO2 in a pulmonary capillary between venous blood and alveolar air. :
P CO2 = ______ in venous blood
to
P CO2 = ______ in alveolar air

Answer 9

46
to
40

Question 10

Describe the changes in values of P O2 in a systematic capillary between arterial blood and tissues :
P O2 = ______ in arterial blood
to
P O2 = ______ in tissues

Answer 10

100
to
< 40

Question 11

Describe the changes in values of P CO2 in a systematic capillary between tissues and arterial blood:
P CO2 = ______ in tissues
to
P CO2 = ______ in arterial blood

Answer 11

< 46
to
40