Chapter 22: Introduction to Oxygen and Carbon Dioxide Physiology

These flashcards cover key concepts about the physiology of oxygen and carbon dioxide, their properties in gases and solutions, diffusion mechanisms, and the effects of environmental factors on gas transport.

What are the respiratory gases?

Oxygen (O2) and Carbon Dioxide (CO2)

How does oxygen move from environmental water to animal cells?

Through passive transport, as active-transport mechanisms for O2 do not exist.

What happens to the oxygen we inhale?

It is transported to cells for metabolic processes.

Where does the carbon dioxide we exhale come from?

It is a byproduct of cellular metabolism.

What is the partial pressure of a gas?

The pressure exerted by a particular gas within a mixture of gases.

What drives the diffusion of gases?

Partial pressure, not percent concentration.

What is the barometric pressure at sea level?

760 mm Hg.

What is the oxygen percentage in the atmosphere?

20.9%.

What is the calculated partial pressure of oxygen at sea level?

158.8 mm Hg (torr).

What is the barometric pressure at the summit of Mt. Everest?

247 mm Hg.

What is the partial pressure of oxygen at Mt. Everest's summit?

51.6 mm Hg (torr).

What is the importance of the partial pressure of gases dissolved in water?

It affects how gases diffuse and solubility.

How does temperature affect the solubility of gases in aqueous solutions?

Solubility decreases with increasing temperature.

What is the salting-out effect?

The phenomenon where increasing salinity drives gases out of solution.

What is the fundamental law of gas diffusion?

Gases diffuse from areas of high partial pressure to low partial pressure.

What happens to gases under increased hydrostatic pressure?

More gases are forced into solution.

What does rapid ascent during diving cause?

Gases to rapidly come out of solution, forming bubbles in the blood (the bends).

What is unidirectional flow in respiratory physiology?

A flow pattern where gas moves in a single direction.

What is tidal flow in respiratory physiology?

A flow pattern where gas moves in and out, like breathing.

What are the two transport methods for oxygen from atmosphere to mitochondria?

Convection (bulk flow) and diffusion.

What is the Oxygen Cascade?

An analysis of the transport of O2 from the environment to mitochondria.

What are common units for expressing gases?

torr, mmHg, kilopascal, atmosphere.

How does the concentration of O2 in air differ from that in freshwater and seawater?

O2 concentration is higher in air than in freshwater and seawater.

What is the oxygen diffusion coefficient ratio between water and air?

~1:10,000.

What is the carbon dioxide diffusion coefficient ratio between water and air?

~1:10,000.

What is the solubility of carbon dioxide compared to oxygen?

CO2 has a far higher solubility than O2.

How do resident organisms affect local partial pressures of O2 and CO2?

They can cause significant differences compared to neighboring regions.

What is the effect of temperature on oxygen solubility?

Solubility decreases with increasing temperature.

What is the maximum solubility of oxygen in freshwater at STP (0°C)?

10.2 mL O2 at STP/L.

What is the maximum solubility of carbon dioxide in seawater?

930 mL CO2 per liter.

What is the role of ventilation in animals?

To maintain adequate levels of O2 and remove CO2.

What is the composition of gasses in the atmosphere?

Mostly nitrogen (78%) and oxygen (20.9%), with trace amounts of other gases.

What can affect the efficiency of gas exchange in organisms?

Factors like temperature, salinity, and pressure.

What is the relationship between blood flow and gas exchange?

Blood flow enhances the delivery and removal of gases through convection.

What happens to gas exchanges in photosynthetic organisms at night?

They exhale CO2 instead of O2.

At what depth does hydrostatic pressure significantly affect gas transport?

Increased pressure is felt when diving deeper in water.

What physiological adaptation do mammals have to mitigate the bends while diving?

Some dive on expiration to avoid rapid ascent from depths.

What are the partial pressures of oxygen in the Trinity River at various altitudes?

Drops significantly from sea level to high elevations.