Gas Transport Flashcards
Explain the two sites where gas exchange occurs in the human body.
in the lungs, where oxygen is picked up and carbon dioxide is released at the respiratory membrane, and at the tissues, where oxygen is released and carbon dioxide is picked up
Which is more soluble in blood, O2 or CO2?
CO2
What is the function of respiration?
to provide oxygen for use by body cells during cellular respiration and to eliminate carbon dioxide, a waste product of cellular respiration, from the body
Use this image to explain why countercurrent flow is more effective than concurrent flow of blood.
At a certain point there is no net difference in concentration, thus no movement of oxygen.
What is external respiration?
External respiration is the exchange of gases with the external environment and occurs in the alveoli of the lungs.
What is internal respiration?
Internal respiration is the exchange of gases with the internal environment and occurs in the tissues.
Does gas exchange occur do to active or passive diffusion? Why?
Passive. no energy is required to move O2 or CO2 across membranes. This simply occurs because of pressure gradients.
List the 3 main variables in the diffusion rate equation.
A = cross sectional area
X = diffusion distance
P = partial pressure gradient
What are some features of alveoli that make them the optimal site for gas exchage?
High cross sectional area, highly vascularized, thin
Where does perfusion occur in mammals?
Capillaries; movement of O2 to capillaries
How does the anatomy of the human lung maximize diffusion?
highly permeable and thin respiratory membrane
thin blood capillary membranes
large SA throughout the lungs.
What are physiological challenges faced by birds in respiration?
lower pressure and concentration at higher altitudes, low temperatures
Explain the composition of vertebrate blood.
Plasma, red blood cells, white blood cells
What do red blood cells do?
Red blood cells carry oxygen from the lungs to the tissues
Explain the shape of a red blood cell and how this is important for its function.
- The mature human red blood cell is small, round, and biconcave; it appears dumbbell-shaped in
profile - The cell is flexible and can pass through extremely small blood vessels
What is a red blood cell’s membrane composed of?
Lipids and proteins.
Do red blood cells have a nucleus?
No.
What is the important protein contained in red blood cells?
Hemoglobin.
Why is respiratory pigment important for gas transport?
It significantly increases the oxygen concentration in blood.
What are respiratory pigemnts?
Respiratory pigments are metalloproteins which circulate in body fluids and undergo
reversible chemical combination with oxygen.
Give two exmaples of respiratory pigments.
- Hemoglobin (in erythrocytes or red blood cells of blood)
- Hemocyanin (in hemolymph)
What is hemoglobin called when bound to oxygen? What colour is it?
Oxyhemoglobin. bright red
What is hemoglobin called when CO2 binds? What colour is it?
Carbaminohemoglobin – burgundy colored
How many heme units does each hemoglobin molecule have? What does this mean for oxygen binding?
4; 4 O2 molecules can bind.
What is contained in heme?
Iron
What is the hemoglobin saturation range in a healthy individual with normal hemoglobin levels?
95%-99%
How does oxygen bind to hemoglobin?
Oxygen molecules reversibly binds with iron