Respiratory physiology 2

Question 1

What is ventilation?

Answer 1

Gas exchange between alveoli and atmosphere

Question 2

What is external respiration?

Answer 2

Passive diffusion of O2 and CO2 between alveoli and blood in pulmonary capillaries
Converts deoxygenated blood to oxygenated blood

Question 3

What is gas transport?

Answer 3

O2 and CO2 carried in blood between alveoli and tissues

Question 4

What is cellular respiration?

Answer 4

O2 utilisation and CO2 production by tissues

Question 5

What are conducting airways?

Answer 5

Tidal flow, air moves in and out following muscle contraction

Question 6

How many respiratory branches are there?

Answer 6

23

Question 7

What are the first 16 respiratory branches?

Answer 7

Conducting airways

Question 8

What are the last 7 respiratory branches?

Answer 8

respiratory exchange - passive diffusion driven by partial pressure gradients

Question 9

What is Dalton’s law?

Answer 9

How gases move down their concentration gradient by diffusion

Question 10

What is Henry’s law?

Answer 10

How the solubility of a gas relates to its diffusion
Quantity of gas dissolved in a liquid is directly proportional to partial pressure of a gas
Solubility of a gas
Higher partial pressure and higher solubility of gas means more gas will stay in solution

Question 11

What is partial pressure?

Answer 11

pressure exerted by a gas in a mixture

Question 12

How to calculate partial pressure?

Answer 12

percentage in mixture x ambient pressure

Question 13

What is internal respiration?

Answer 13

Exchange of O2 and CO2 between systemic capillaries and tissues cells
Converts oxygenated blood into deoxygenated blood

Question 14

Hb + O2

Answer 14

Hb-O2

Question 15

Structure of haemoglobin

Answer 15

Globin protein (4 polypeptides, 2 alpha and 2 beta)
4 haem groups

Question 16

Why does the Hb-O2 saturation curve have a specific shape?

Answer 16

Initial binding of oxygen is difficult
After first molecule has bound. binding the next two is easier
As sites get occupied, saturation is harder to reach

Question 17

What is the Bohr effect?

Answer 17

In tissues that need more O2, the curve shifts to the right to aid unloading of O2

Question 18

Equation for Bohr effect

Answer 18

CO2 + H2O -> H2CO3- + H+ + HCO3-

Question 19

What does H+ do to Hb?

Answer 19

Binds and decreases its O2 carrying capacity

Question 20

Why is foetal Hb good?

Answer 20

Higher affinity for oxygen

Question 21

How is most carbon dioxide stored?

Answer 21

HCO3-

Question 22

Haldane effect

Answer 22

In tissues, Hb gives up O2
Affinity for CO2 increases
Greater CO2 carriage

In lungs, Hb gives up CO2
Affinity for CO2 decreases
Hb binds O2

Question 23

What does higher pp of CO2 mean?

Answer 23

Spinal fluid is more acidic - activates chemoreceptors

Question 24

CO2 in RBC

Answer 24

• CO2 enters RNC to form bicarbonate
• To maintain electrical balance, Cl- moves inside cell (chloride shift)
• CO2 is removed and transported as bicarbonate inside RBCs
• CO2 joins amino groups to form carbamino compound
• More CO2 removed
• Both generate H+ that need to be buffered by amine compound in Hb (Bohr effect means it decreases ability of Hb to bind with oxygen )
• Amount of CO2 influenced by saturation of Hb with O2