4/22/14 Flashcards
What are the three factors that will affect diffusion?
temperature
nature of the bilogical molecule and nature of medium
ectotherms are diffusion limited and is this worse in water or air?
water
WHat was the evolutionary force for going out of the water?
free oxygen
Water is very dense and very viscous and takes a lot more time to diffuse stuff through.
true
What is the difference between a a gill and a lung?
How it is formed:
if it is invagination=lung
if it is evagination=gill
How is the efficiency of the respiratory system determined? What is this also called?
ratio: (initial O2-final O2)/initial
percent utilization
What is the human percent utilization?
5-7%
less oxygen in water than air?
yes
How does oxygen move?
from a low concentration to high concentration in the same medium. In different mediums oxygen moves in a way we dont know.
Membranes in the lung are extremely thin. how does this compare to the skin of amphibians?
amphibian skin must be a happy medium they have thinner skin to allow oxygen diffusing but a little rugged for protection but they have a lung too.
Amphibians are bi motile breathers why?
they have two most of respiration the skin surface and heart
Where is convection found in human membranes?
on both sides of the membrane-ventilation and circulation
What does convection in both directions allow?
greatly enhances the uptake of oxygen
What does the water form around thing?
a boundary layer
What is the ventilation perfusion ratio?
It is extremely wasteful to send more O2 across the membrane than can be picked up by the blood likewise equally wasteful to send more blood than oxygen can pick up
All animals match ventilation to perfusion?
yes
WHat influences perfusion rate?
respiratory medium
temperature
if and what type of respiratory pigment
what determines the Vq ratio?
respiratory medium
temperature if ectotherm
if and what type of respiratory pigment
What is the Vq ratio in humans? fish?
1: 1
1: 35
fish have a higher what to what?
fish have higher perfusion
what is the simpliest system in regards to oxygen respiration?
cutaneous skin in amphbians
What is the mpst efficient respiration system?
fish gills
Whay are fish gills very efficient?
They use counter current flow There is a continuous gradient
Mammal lungs have enormous what?
surface area
