circulatory systems
reptiles
-2 separate atria - septum partially decides the ventricle
the right atrium
-Receives deoxygenated blood from the body - right ventricle pumps to lungs
no circulatory system
-gastrovascular cavity functions indigestion and distribution of nutrients -highly branched -organisms with gastrovascular cavities tend to be only a few cells thick - sponges, hyrda, and nemotode
the lung atrium
-receives oxygenated blood from lungs - delivers it to left ventricle which pumps blood to the rest of the body
pumping chambers of the heart
1. sinus venous 2. atrium 3. ventricle 4. conus anteriorsus
closed circulatory system
A circulatory system in which blood is confined to vessels and is kept separate from the interstitial fluid. - earthworms and all vertebrates
open circulatory system
A circulatory system that allows the blood to flow out of the blood vessels and into various body cavities so that the cells are in direct contact with the blood - found in mollusks and arthrapods - hemolymph- no distinction between circulating fluid and extracellular fluid - grasshoppers
why you can't hold your breath
as you hold your breath, the increasing levels of carbon dioxide in her blood will lead to stimulation of the respiratory control center in her brain.
vertebrate in which blood flows directly form respiratory organs to body tissues without first returning to the heart
fishes
To adjust blood pressure independently in the capillaries of the gas-exchange surface and in the capillaries of the general body circulation, an organism would need a(n) _____.
four chambered heart
A decrease from pH 7.4 to pH 7.2 causes hemoglobin to _____.
give up more of its oxygen molecules
Why is an open circulatory system less efficient than a closed circulatory system?
it is more difficult to deliver O2 to specific tissues when needed
If the O2-binding curves were plotted for the following molecules at the pH levels indicated, with pO2 on the x-axis and % oxyhemoglobin saturation on the y-axis, which curve would be to the left of all the others?
myoglobin at ph 6
The rate at which a gas diffuses between two locations is _______ the surface area involved
negatively related to
When submerged, frogs receive most of their O2 from capillaries within the skin. Which of the following structures would contain blood with the highest O2 concentration in a submerged frog that is not able to breathe using its lungs?
right atrium