Circulation & Gas Exchange Flashcards
Definition of gas Exchange
The uptake of oxygen from the environment, and the discharge of carbon dioxide to the environment
Why does the body need gas exchange & the circulatory system
To provide the oxygen necessary for aerobic cellular respiration and removes the waste product, carbon dioxide.
Do hydra and other cnidarians need a circulatory systme
No, the body wall is only a few cells thick that serves for both digestion and diffusion of substances throughout the body.
What do open and closed circulatory systems have in common
Both have circulatory fluid (blood) a set of tubes (blood vessels) and a muscular pump (the heart)
Function of the heart
Power circulation by elevating the hydrostatic pressure of the blood (blood pressure)
How does the open circulatory system in insects and mollusks work
There is no distinction between blood and interstitial fluid (collectively called hemolymph). One or more hearts pump the hemolymph into interconnected sinuses surrounding the organs, allowing exchange between hemolymph and body cells.
Tracheal system in Insects and Mollusks
Larger insects ventilate their tracheal systems. They have many little holes across their body which connect to trachea and proliferate throughout the organism.
Why do insects need widespread tracheal system
An insect in flight has a very high metabolic rate, consuming to to 200 times more O2 than it does at rest
Closed Circulatory System
Blood is confined to vessels and is distinct from interstitial fluid. One or more hearts pump blood into large vessels that branch into smaller ones cursing through organs. Materials are exchanged by diffusion between the blood and the interstitial fluid bathing the cells.
Worms respiratory system
The entire outer skin is a respiratory organ - just below the moist skin is a dense net of capillaries. The respiratory surface must be moist.
Arteries
Carry blood away from the heart to organs
Arterioles
Small vessels that carry blood to capillaries
Capillary beds
Networks of very thin capillaries with porous walls.
Veins
Return blood to the heart
What type of circulatory system do 2 chambered fish have
Closed circulatory system
What does 2 chambered mean
One atrium one ventricle
How do 2 chambered system in fish works
Blood is pumped from the ventricle to the gills where it picks up oxygen and disposes of carbon dioxide. The gill capillaries converge into a vessel that carries oxygenated blood to capillary beds at the vein and back to the heart.
Metabollic rate of two chambered fish
Is SLOW - blood is depressurized and not repressurized causing blood pressure to substantially drop which therefore LOWERS metabolic rate.
Frogs circulatory system
3 chambered