Lec 3

Question 1

What is the process of the oxygen cascade + CO2 cascade

Answer 1

1. Suck air into lungs
2. Diffuse O2 from air into blood
3. Circulate blood
4. Diffuse O2 from blood to cells
5. Into TCA cycle in mitochondria
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6. Diffuse CO2 from cells into blood
7. Circulate blood
8. Diffuse into lungs
9. Exhale

Question 2

Why do our cells need O2 + what are the 3 stages of cellular respiration

Answer 2

• efficiently produce ATP, makes CO2 as a by product
  -O2 is supplied by respiratory system, an CO2 removed by respiratory + renal systems

-glycolysis, TCA, + oxidative phosphorylation

Question 3

Define pulmonary ventilation

Answer 3

-mechanical act of moving air in/out of lungs

Question 4

What is external vs internal respiration

Answer 4

-exchange of gas between blood
External = at lungs, between lungs + blood, internal = in tissues, between cells + blood

Question 5

Explain pressure vs gas pressure

Answer 5

-pressure is the force exerted by a substance on substance
-e.g. when drinking from a straw, suction creates negative pressure inside straw, pressure outside greater, so liquid forced up straw

-pressure of a gas is the force that the gas exerts on the wall of it container
-measured in mmHg (760mmHg = 1 atm)
-when u blow air into a balloon, balloon expands because pressure of air molecules inside > outside
-if balloon released, air moves fro high to low pressure = deflate

Question 6

What creates pressure changes that result in ventilation + what are the 3 pressures involved

Answer 6

• muscular breathing movements + recoil of elastic tissues

-atm (pressure of the air outside the body), Ppul (pulmonary pressure, pressure inside the alveoli of the lungs), and Ppl (pleural pressure within the pleural cavity)
-changes in these 3 pressures are responsible for pulmonary ventilation

Question 7

Explain boyles law

Answer 7

• if vol increase, pressure decrease

Question 8

What are the muscles of inspiration/ expiration + what happens

Answer 8

Inspiration: core muscles- external intercostals (contract to elevate ribs) + diaphragm (contracts to expand thoracic cavity) + pul pressure decrease (neg. Pressure, air sucked in), airflow increases, lung volume increases

Expiration: core muscles- internal intercostals (contracts to pull ribs down) + diaphragm (relaxes to reduce thoracic cavity) + pul pressure increase (pos. Pressure, air pushed out), airflow decreases, lung volume decreases

**note: expiratory muscles are passive when normal quiet resting breathing
** note: pressure when inhaling (760mmHg = 1 atm - 3mmHg), pressure when exhaling (760mmHg = 1 atm + 3 mmHg)

Question 9

What muscles are effected by expiratory muscle

Answer 9

-external obliques
-recuts abdominals
-transversus abdominis
-internal obliques