Podcast
Questions and Answers
What is the adaptive advantage of hemoglobin in oxygen absorption?
What is the adaptive advantage of hemoglobin in oxygen absorption?
The fetus receives its oxygen directly from the air around it.
The fetus receives its oxygen directly from the air around it.
False
What happens to hemoglobin's shape when an oxygen molecule binds to it?
What happens to hemoglobin's shape when an oxygen molecule binds to it?
It changes shape, making it easier for more oxygen molecules to bind.
A fetus is more efficient at extracting oxygen from the mother's blood when her blood is lower in __________.
A fetus is more efficient at extracting oxygen from the mother's blood when her blood is lower in __________.
Signup and view all the answers
Match the following terms to their definitions:
Match the following terms to their definitions:
Signup and view all the answers
What percentage of CO2 is carried in the blood as bicarbonate ions?
What percentage of CO2 is carried in the blood as bicarbonate ions?
Signup and view all the answers
CO2 is only transported in the blood as dissolved gas.
CO2 is only transported in the blood as dissolved gas.
Signup and view all the answers
What happens to CO2 and H2O in the blood in terms of carbonic acid formation?
What happens to CO2 and H2O in the blood in terms of carbonic acid formation?
Signup and view all the answers
At high altitudes, the partial pressure of _____ decreases, leading to a reduction in the rate of diffusion.
At high altitudes, the partial pressure of _____ decreases, leading to a reduction in the rate of diffusion.
Signup and view all the answers
Match the percentage of CO2 transport in blood to its corresponding form:
Match the percentage of CO2 transport in blood to its corresponding form:
Signup and view all the answers
What is a common symptom of altitude sickness?
What is a common symptom of altitude sickness?
Signup and view all the answers
The oxygen concentration in the air remains constant regardless of altitude elevation.
The oxygen concentration in the air remains constant regardless of altitude elevation.
Signup and view all the answers
What is the primary gas carried by red blood cells in the human body?
What is the primary gas carried by red blood cells in the human body?
Signup and view all the answers
Calculate the partial pressure of oxygen at 500 mmHg atmospheric pressure.
Calculate the partial pressure of oxygen at 500 mmHg atmospheric pressure.
Signup and view all the answers
The density of atmospheric air increases as altitude increases.
The density of atmospheric air increases as altitude increases.
Signup and view all the answers
What percentage of oxygen is typically found in atmospheric air?
What percentage of oxygen is typically found in atmospheric air?
Signup and view all the answers
Each hemoglobin molecule can carry ___ O2 molecules.
Each hemoglobin molecule can carry ___ O2 molecules.
Signup and view all the answers
Match the following gases with their descriptions:
Match the following gases with their descriptions:
Signup and view all the answers
At sea level, what is the atmospheric pressure measured in kPa?
At sea level, what is the atmospheric pressure measured in kPa?
Signup and view all the answers
Carbon monoxide is colorless and odorless, making it unnoticeable.
Carbon monoxide is colorless and odorless, making it unnoticeable.
Signup and view all the answers
What happens to oxygen when blood encounters oxygen-depleted tissue?
What happens to oxygen when blood encounters oxygen-depleted tissue?
Signup and view all the answers
Study Notes
Transport & Diffusion of Gases
- Gases transport and diffuse to support life functions.
- Diffusion is the net movement of molecules from an area of high concentration to an area of low concentration.
The Atmosphere
- Earth is surrounded by an atmosphere, most dense near sea level and less dense at higher altitudes.
- Atmospheric pressure is measured in pascals (Pa) or kilopascals (kPa).
- At sea level, pressure is 101.3 kPa or 760 mmHg; and at Mount Everest it's 31 kPa or 250 mmHg.
Composition of Atmosphere
- Inhaled and Exhaled air composition in a typical subject
- Inhaled air: nitrogen (78%), oxygen (21%), carbon dioxide (0.04%), water vapor (0.96%), and other gases (<1%).
- Exhaled air: nitrogen (78%), oxygen (15%), carbon dioxide (4%), water vapor (3%), and other gases (<1%).
Gas Exchange
- Oxygen and carbon dioxide diffuse across the gas exchange surface of the lungs.
- The efficiency of this process depends on the maximization of surface area and the difference in gas concentrations.
Concentration of Gases
- Oxygen diffusion from alveoli to blood increases when the oxygen concentration gradient increases.
- A large gradient between alveoli and blood leads to faster oxygen movement.
- Partial pressure (P) is used to measure the driving force of gas movement.
- The partial pressure of oxygen (P02) increases diffusion rate.
Transport of Gases in the Blood (Oxygen)
- The partial pressure of oxygen (P02) in inhaled air (13.3 kPa) is higher than in incoming blood (5.33 kPa).
- Oxygen diffuses into the bloodstream
- In body tissues (oxygen-depleted tissues), the oxygen partial pressure in the cells is only 5.33kPa. -Blood's oxygen diffuses to cells.
Transport of Gases in Blood (Oxygen) - How Oxygen is Carried
- Blood contains red blood cells (RBCs) and plasma
- Most oxygen (98.5%) is carried by RBCs as oxyhemoglobin
- Hemoglobin (Hb) in RBCs contains four heme groups.
- Each heme group carries one oxygen molecule
- Each RBC contains ~270 million Hb molecules
Transport of Gases in Blood (Oxygen): Release
- When blood encounters oxygen-depleted tissue, the PO2 in the blood is higher than in cells.
- Oxygen dissociates from the iron atoms in haemoglobin.
- The lower pH (acidity) near cells also causes oxygen release.
- Oxygen diffuses out of the blood into the tissue cells via interstitial fluid to enter mitochondria.
Transport of Gases in Blood (Carbon Monoxide (CO))
- CO is a dangerous air pollutant because hemoglobin prefers CO over oxygen
- Prevents oxygen from reaching body tissues
- Is odourless and colourless; being inhaled unnoticed.
- Lethal concentrations cause unconsciousness and death.
Transport of Gases in Blood (Carbon Dioxide (CO2))
- PCO2 in interstitial tissue (5.60 kPa) is higher than in blood.
Transport of Gases in Blood (Carbon Dioxide (CO2)) - How it is Carried
-
Some CO2 is dissolved in plasma
-
20% is carried by hemoglobin as carbaminohemoglobin.
-
73% is carried as bicarbonate ions in the blood plasma (a reaction involving carbonic acid).
-
A reaction occurring during transport releases H+ that must be removed from blood for homeostasis. HCO3- and H+ form Carbonic Acid.
Effect of Altitude on Respiration
- The concentration of oxygen does not change at high altitudes.
- However, density and pressure are lower.
- The lower pressure gradient makes oxygen diffusion slower.
Effects of Altitude Sickness
- Shortness of breath
- Headache
- Dizziness
- Nausea
- Tiredness
Oxygen Dissociation Curve (Graph interpretation)
- Illustrates how effectively blood carries oxygen.
- Shows the relationship between partial pressure and percent oxygen saturation.
Oxygen Dissociation Curve (Sample Questions)
- At a given altitude (e.g., halfway up Mount Everest), oxygen partial pressure. -Determine oxygen saturation % from the dissociation curve
How Low is Too Low?
- Blood oxygen level guidance for health concerns/problems and when to seek medical attention.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
This quiz explores the transport and diffusion of gases essential for life functions. It covers the composition of the atmosphere, measurements of atmospheric pressure, and the gas exchange process in lungs. Test your understanding of how gases behave and support vital processes.
