CIRCULATORY

CIRCULATORY SYSTEM: The bodily system consisting of the heart, blood vessels, and blood that circulates blood throughout the body, delivers nutrients and other essential materials to cells, and removes waste products.

overall importance of circulatory system:

• circulates blood throughout the body
• moves nutrients and minerals through body
• helps fight disease
• helps to maintain homeostasis
• lymphatic system
• Two types of fluids move through system: blood and lymph
• heart, blood vessels, blood
• open and closed circ. system

evolutionary advantages/disadvantages:

the circulatory main function is to pump the nutrients and blood throughout the body. this is an evolutionary advantage because it helps maintain homeostasis and maintain a healthy body function  in the simple organisms such as the worm and crayfish they have something called an open circulatory system, disadvantage to this is that it creates a problem when creating the needed velocity to help move blood along. advantages is that its easier to push things around and move them where its needed, because earthworms and crayfish don't have a heart and capillaries there liquids and blood free float around to do the jobs its supposed to do. In a closed more complex circulatory system like in the frog and white rat its body functions and fact that the blood and fluids are enclosed are the factor of a advantage in evolution.

GAS EXCHANGE:
the process in which two different gasses usually oxygen and carbon dioxide are transferred and changed through a thin surface in the lungs and heart to create the movement in the blood vessels and then be transferred throughout the body to remain functioning. 

differences and commonalities between animals:

EARTHWORM:

• closed circ. system
• dorsal vessels
• heart (aortic arches)
• segments have capillaries

CRAYFISH:

• tail has capillaries
• closed circ. system
• dorsal vessels
• gills

GRASS FROG:

• blood vessels
• 3 chamber heart
• moist skin
• two atria, one single vetrica
• mixture in heart
• open circ. sytem

WHITE RAT

• 4 chamber heart
• gas exchange whithin body
• no blood mixture
• similar to human circ. system