Test #2 Flashcards
What is Fick’s Law of Diffusion?
It describes the diffusion rate for gas exchange. It also illuminates success of adaptations to maximize gas exchange.
Q=DA((P1-P2)/L)
Q=rate of diffusion
D=diffusion coefficient (molecule, medium, temp specific)
A=area over which diffusion occurs
P1=pressure here
P2=pressure there
L=length of path molecule will take
What are the benefits of Fick’s law?
—Increased surface area for gas exchange
—Minimize diffusion path length
—Maximize partial pressure gradients
—Minimize diffusion that takes place in an aqueous medium
How are lungs respiratory adaptations of terrestrial animals?
—They increase surface area for gas exchange (branched design + surfactant + alveoli)
—Minimize diffusion path length (alveoli)
—Maximize partial pressure gradients
—Ventilation + perfusion
—Minimizes diffusion that takes place in an aqueous medium (air)
What are the sites for gas exchange?
Alveoli
What is surfactant?
—Detergent-like substance produced by alveolar cells
—Decreases work needed to inflate lungs
—Prevents alveoli from collapsing
What does surfactant coat?
The alveolus
What is RDS?
—Respiratory distress syndrome
—Baby does not produce surfactant
What is tidal breathing?
Quiet/restful breathing with air coming and going along the same path. The volume of air inhaled or exhaled in a normal breath
Inhalation vs. Exhalation
Inhalation is active and it creates a negative pressure within your chest cavity. Exhalation is passive and created a positive pressure within your chest cavity.
Where is PO2 the greatest?
PO2 in the lungs is less than PO2 in the atmosphere.
What is residual volume?
The amount of air that remains in the lungs after forcefully exhaling.
What is vital capacity?
The maximum capacity for air exchange.
TOTAL-RESIDUAL=VITAL
What is the normal volume of breathing?
400-500mL
What does blood plasma carry?
Respiratory gases
What is hemoglobin?
It is a protein in red blood cells (RBCs)
