Circulatory System SBI 3U Ms. Raper

Open circulatory system Found in many insects Blood returns to the heart via the movement of the animal’s body. inefficient http://fajerpc.magnet.fsu.edu/Education/2010/2010_INDEX.HTM

Closed Circulatory System Found in some invertebrates such as worms and in fish, reptiles, birds and mammals Blood never leaves a system of tubes Heart pumps blood around the body

William Harvey 1568 -1657 Was a physician trained in Italy. Was the first to accurately describe the action of the heart pumping blood around the body. He confirmed the presence of valves in the veins to prevent the backflow of blood. He confirmed his theories by carrying out dissections. http://www.bbc.co.uk/history/historic_figures/harvey_william.shtml

Blood Vessels Arteries – carry blood AWAY from the heart. Veins – carry blood back to the heart – blood returns VIA the veins. Capillaries – CONNECT arteries and veins, it is here that substances are loaded and unloaded into the blood by diffusion.

http://www. owensboro. kctcs http://www.owensboro.kctcs.edu/gcaplan/anat2/notes/Notes5%20Circulatory%20Anatomy.htm

Arteries Thick elastic muscular walls Small lumen Carry oxygenated blood (except pulmonary artery) Carry blood away from the heart. http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookcircSYS.html

Veins Have thin walls Large lumen Carry deoxygenated blood (except pulmonary vein) Have valves to prevent backflow of blood Carry blood back to the heart

Circulatory System

Blood vessels

Arteries Have a smaller lumen than veins Have thick Muscular walls. Carry oxygenated blood (except the Pulmonary artery) Have a pulse Carry blood away from the heart Have blood under high pressure Blood is BRIGHT red A cut artery spurts with the heart beat. Main artery is the AORTA Cross section through an artery.

Capillaries Connect arteries and veins. Are found in organs. Are where substances are dropped off or picked up from the cells Are only one cell thick. Red Blood Cells must travel through in single file. Low pressure Cut capillaries ooze Cross section of a capillary

Veins have thinner muscular walls than arteries, Have a large lumen, Have valves to prevent backflow of blood Carry blood back to the heart Carry deoxygenated blood (except the pulmonary vein) Have blood that is DARK red. Low pressure A cut Vein will gushes. Main vein is the VENA CAVA

Blood Vessels.

http://iws.ccccd.edu/mweis/Images/Histology/2402%20histology/Circulatory%20Histo/labeled%20circ%20histo/circ_vessels_av_compare_heading.png

Exchange in Capillaries

Coronary Arteries http://www.patient.co.uk/showdoc/Pilsinl/112.gif

Peripheral Arteries http://www.patient.co.uk/showdoc/Pilsinl/101.gif

3 parts to the Circulatory System Cardiac - blood supply to and through the heart. Pulmonary – blood flow through the lungs. Systemic – blood flow through the body other than the lungs and heart. Because blood flows through the heart twice for every complete circuit, it is referred to as a DOUBLE circulation.