11/8/24 - Respiratory System (Part 3) Lecture Questions

Reading 3

What are the two circuits that make up the Respiration Center?

What do these circuits do?

1. Pulmonary Circuit — where gas exchange occurs in the Lungs; External Respiration

2. Systemic Circuit — where gas exchange occurs in the Tissues; Internal Respiration

What are Partial Pressures?

What is Dalton’s Law of Partial Pressures?

Pressure exerted by an individual gas in a mixture of gases

Dalton’s Law says that the total pressure is the sum of all partial pressures in the gas mixture

What are the two main components of blood?

1. Plasma — fluid medium for carrying materials in the blood; contains CO2 and O2

2. Formed Cellular Elements / Cells — in this case, we focus on RBCs

Does Gas Exchange occur in the heart?

No.

What are Erythrocytes?

Fancy word for RBCs

What are RBCs?

Red Blood Cells; sacs of Hemoglobin

What is the structure of Hemoglobin?

What is contained in each Globin?

What does O2 bind to in Hemoglobin?

How many O2 molecules can a Hemoglobin molecules carry?

Protein comprised of 2 Alpha-subunits and 2 Beta-subunits (which are called Globin / Globular Proteins)

Each Globin contains 1 Heme group, which contains 1 Iron Molecule

O2 binds to the Iron molecule

Hemoglobin can carry 4 O2 molecules

Where is O2 loaded?

Unloaded?

Loaded in the Lungs

Unloaded in the Tissues

What is the name for Hemoglobin that is loaded with O2?

What color is it?

Oxyhemoglobin

Bright red

What is the name for Hemoglobin that is NOT loaded with O2?

What color is it?

Deoxyhemoglobin

Dark Red

How do O2 and CO2 cross membranes?

Simple Diffusion

Is oxygen loaded or unloaded during External Respiration?

Internal Respiration?

External Respiration — O2 is loaded

Internal Respiration — O2 is unloaded

How much O2 falls off of Hemoglobin into the Tissue cells?

What happens to the remaining amount?

25%

Remaining 75% stays bound to the Hemoglobin

Why does oxygen remain bound to Hemoglobin?

Something something so it keeps it’s affinity for O2

What part of the Hemoglobin does O2 bind to?

CO2?

O2 binds to the Heme Group

CO2 binds to the Globin part

What is name for when CO2 binds to Hemoglobin?

Carbaminohemoglobin

What are the three main ways in which CO2 is transported in the blood?

1. CO2 is carried in RBCs, bound to Hemoglobin

2. Turns into Bicarbonate that is dissolved in the Plasma (~80% of CO2 is transported this way)

3. CO2 is dissolved in the plasma itself

What is Bicarbonates role in the blood?

Serves as a buffer to Hydrogen ions

What is the enzyme responsible for turning CO2 and H2O into Carbonic Acid?

Carbonic Anhydrase

What is the “Chloride Shift”?

Why does this occur?

What is the “Reverse Chloride Shift”?

Exchange of a Cl- with a Bicarbonate (Cl- goes in, HCO3- goes out)

Maintains the ionic charge within the RBC due to H+ binding to Hemoglobin (buffered H+)

Reverse of the chloride shift, yeah