Week 3 - Respiratory System Flashcards
How does density affect diffusion rates?
More dense = slower
What is Fick’s law
m/t = (D x A x (P1-P2) )/x
le /x c’est le thickness
Define ventilation
The moving of the respiratory medium over the respiratory surface
How do bony fish ventilate
Water flows inside the mouth, jaw muscles push it out through the pharynx
Operculum muscles (flap covering gills) also help
Why are alveoli wet? What are the risks?
Coated by water to protect outer plasma membrane
Risk: cells can collapse when exhaling. Think of trying to separate wet paper
What prevents the lungs from collapsing?
Specialized Alveoli cells secrete surfactant, which prevents hydrogen bonds from forming
Describe positive pressure breathing
Push air into the lungs.
Drop the bucal cavity. Volume increases, so pressure drops. Bulk flow draws air in.
Then close nostril and raise floor of mouth. Reduce volume, increase pressure and push air into lungs where pressure is lower
AMPHIBS DO THIS
Describe negative pressure breathing
Pulls air in
Inhalation: diaphragm goes down. increase volume, decrease pressure. Warmed air also expands lungs.
Ribs and diaphragm relax, volume decreases, air is forced out
MAMMALS DO THIS
What is hemoglobin
Respiratory pigment and protein comprised of four polypeptides. Each has a heme group with iron.
Do RBCs have a nucleus?
No- to be able to carry more hemoglobin
Name another respiratory pigment
Hemocyanin. Same as hemoglobin but iron is replaced by copper
Why are mullusks a great source of dietary copper?
They have hemocyanin, not hemoglobin
What is the Bohr shift?
Drop in PH of blood causes hemoglobin to be able to carry way less O2
What does carbonic acid dissociate into?
A bicarbonate ion and proton (hemoglobin picks up proton to prevent drop in PH)
What does cholesterol do?
Helps maintain normal blood fluidity
