The Circulatory System : The Circulatory System Kimberly Allen fallingpixel.com What it is: : What it is: The circulatory system’s main objective is to oxygenate and pump blood throughout the body. To do so, the heart must work in conjunction with the lungs. Exploringnature.org The Heart… : The Heart… Clearly, the heart is the central organ involved in the circulatory system, acting as a kind of hub for the arteries carrying blood away from the heart and for the veins delivering blood to the heart. Library.thinkquest.org …and how it works : …and how it works Deoxygenated blood is delivered through the inferior and superior vena cava to the right atrium.
The blood is pumped through the tricuspid valve into the right ventricle, where it then moves through the pulmonary artery to be taken to the lungs for oxygenation.
After being oxygenated, the blood returns to the left atrium through the pulmonary vein.
The blood is pumped through the mitral (bicuspid) valve and into the final chamber of the heart: the left ventricle.
From the left ventricle, the blood is pumped through the aorta, where it is sent to various arteries throughout the body. Slide 5: It is important to note the cyclical nature of this system! Exploringnature.org The Tissues : The Tissues There are three main tissues involved in the circulatory system:
Cardiac muscle (myocardium)- responsible for the pumping of the blood from the heart to various arteries; the physical muscle tissue of the heart
Smooth muscle tissue- provide the structure for blood vessels; aid in their contraction and expansion
Endothelium- line the walls of blood vessels Slide 7: Endothelial tissue Cardiac muscle tissue (myocardium) Smooth muscle tissue Exploringnature.org Globalclassroom.org Yale.edu Endothelial Cells : Endothelial Cells -Comprise the endothelium
- The endothelium is the layer of endothelial cells lining all blood vessels in the circulatory system
Line the internal surface of blood vessels
Create an interface between the circulating blood in the lumen and the wall of the blood vessel Nature.com Endothelial Cells (cont’d) : Endothelial Cells (cont’d) The function of endothelial cells include:
Vasoconstriction and vasodilation
Serving as a selectively permeable barrier, controlling the passage of white blood cells in and out of the bloodstream A Summary: : A Summary: An integral part of the circulatory system are the blood vessels, which act as a means of transport for the blood. Lining these blood vessels is the endothelial tissue, comprised of endothelial cells. These cells help reduce the turbulence of blood flow, perform angiogenesis, and aid in vasoconstriction and vasodilation. Bibliography : Bibliography “The Circulatory System”. Nature’s Best: The Human Body. 2 October 2010.
http://library.thinkquest.org/2935/Natures_Best/Nat_Best_High_Level/Title_Net_Page/Title_page_h.html Bibliography (cont’d) : Bibliography (cont’d) “The Circulatory System”. Global Classroom. 2 October 2010.