The Circulatory System

1. The Circulatory System

2. What does the Circulatory System do? • The Circulatory System is made of blood vessels, arteries, veins and capillaries that inall one sync that contributes to fueling your body with rich oxygen. Without the circulatory your body would not be able to survive. If the circulatory system fails your vital will not be pumped blood which means they will not receive oxygen to function properly, in which they will shut down and stop working.

3. Blood and It’s Components • Blood is a mixture of cells (White Blood Cells and Red Blood Cells) and a watery liquid called plasma which lets the cells travel through the body with ease. Blood also contains nutrients (sugars), hormones, clotting agents, and waste products that will be flushed out of the body. • There are three types of cells in the blood stream: red blood cells, white blood cells and platelets. Red blood cells carry oxygen from the lungs to the entire body, white blood cells fight infection and platelets help in clotting. Red blood cells (also known as erythrocytes) are what make up most of the bloodstream(40-45%) and these are what give blood is characteristic color. Red blood cells are like little tiny doughnuts with a tiny indentation in the middle instead of a hole. They contain a special molecule called hemoglobin which is what carries the oxygen through the body.

4. Blood Types • Karl Landsteiner first identified the major human blood groups -- namely O, A, B, and AB -- in a series of experiments in 1901 that earned him the Nobel Prize. (At the time, Landsteiner identified only groups A, B, and O; further analysis, two years later, revealed AB.) • The ABO blood groups are defined by specific inherited molecules, or antigens, that are present on the surface of red blood cells. • Thus, one inherits either A or B antigens (group A or B), both A and B antigens (group AB), or neither antigen (group O). • Conversely, a person develops a natural immunity, or antibody, in their plasma to the ABO antigens that are absent on their own red cells. • Thus, a group A person has anti-B antibodies, and group O person has both anti-A and anti-B antibodies.

5. Blood Types • There are many other antigens on the red cell surface. The most important is the Rh factor. • A person is defined as either Rh positive or Rh negative depending on the presence of the primary Rh antigen on the red cell. • In contrast to ABO antigens, however, a person only develops anti-Rh after exposure to Rh-positive red cells through transfusion or pregnancy. • Modern blood-banking technology uses highly sensitive tests to properly identify and match blood between donor and recipient. • The most common blood types in the U.S. are A+ and O+ -- about 72 percent of the population has one or the other. AB- is the rarest blood type (1 percent of the population).

6. The Heart • The heart believe it or not is one of the most important organs in the body. The heart beats around 72 times a minute throughout our lives. It is no more the a pump made of almost all muscle used to pump oxygen rich blood to parts of the body in need of it. This pump also removes the ending waste product the body does not need. • Example: The Brain requires oxygen and glucose, which not received non-stop will cause it to lose consciousness. • The heart is just a little larger then a fist. Even so, it works just like any other muscle in the body by contracting and expanding. The heart unlike the skeletal muscles works on an All-or-Nothing Law; this means that each time the heart contracts it uses its full force. • The pumping of the heart is called Cardiac Cycle. This means that the cycle lasts about eight-tenths of a second. During the cycle the entire heart gets about four-tenths of a second to rest. • The walls of the heart are made up of three layers while the cavity is divided into four parts. The two upper parts of the heart are called the left and right atria and the two lower parts are the left and right ventricles. The Right Atrium receives blood from the body through the superior vena cava and the inferior vena cava as well as the heart muscle itself tothe coronary sinus. The right atrium opens into the right ventricle through the rightatrioventicular valve(tricuspid).

7. The Heart Continued • The Right Ventricle pumps blood to the lungs to be reoxygenated. The left atrium receives blood from the lungs via the four pulmonary veins. The valve between the left atrium and left ventricle the left atrioventicular (bicuspid) is smaller then the tricuspid. The left ventricle pumps blood throughout the entire body; it is called the Aorta, which is the largest artery in the body and begins from the left ventricle. • It is the Atria that draw blood from the lungs to the body, and the ventricles are the ones that pump blood to the lungs and body.

8. Blood Vessels • The blood moves through the body through the blood vessels -- essentially, flexible tubes that branch out and subdivide. There are different types of blood vessels: the arteries, capillaries, and veins.

9. Arteries • Arteries carry the oxygen-rich blood that the heart pumps to the rest of the body. The heart pumps the blood out through one main artery, the dorsal aorta. • This branches out into smaller arteries, which branch out in turn. The smallest arteries are called arterioles, and connect to capillaries.

10. Arteries • Because the arteries carry large quantities of blood that is under high pressure from the beating of the heart, they are wide and thick. • The walls of an artery consist of three layers: a tough outer layer, a middle layer of muscle, and a smooth inner layer through which the blood can flow easily. • The muscles in the middle layer help the heart pump the blood, squeezing down to move the blood along. • You can feel the pulsing of the arteries, that’s your pulse.

11. Vena Cava • The inferior vena cava (or IVC) is the large vein that carries de-oxygenated blood from the lower half of the body into the heart.

12. Pulmonary • The pulmonary arteries carry blood from the heart to the lungs. They are the only arteries (other than umbilical arteries in the fetus) that carry deoxygenated blood.

13. Ulnar Artery • The ulnar artery is the main blood vessel, with oxygenated blood, of the medial aspect of the forearm. It arises from the brachial artery and terminates in the superficial palmar arch, which joins with the superficial branch of the radial artery. It is palpable on the anterior and medial aspect of the wrist.

14. Radial Artery • In human anatomy, the radial artery is the main blood vessel, with oxygenated blood, of the lateral aspect of the forearm.

15. Renal Artery • The renal arteries normally arise off the side of the abdominal aorta, immediately below the superior mesenteric artery, and supply the kidneys with blood. Each is directed across the crus of the diaphragm, so as to form nearly a right angle with the aorta.

16. Brachial Artery • The brachial artery is the major blood vessel of the upper arm.

17. Aorta • The aorta (pronounced "ay-OR-tuh") is the largest artery in the human body, originating from the left ventricle of the heart and bringing oxygenated blood to all parts of the body in the systemic circulation.

18. Subclavian Artery • In human anatomy, the subclavian artery is a major artery of the upper thorax that mainly supplies blood to the head and arms. It is located below the clavicle, hence the name. There is a left subclavian and a right subclavian.

19. External Carotid Artery • In human anatomy, the external carotid artery is a major artery of the head and neck. It arises from the common carotid artery when it bifurcates into an internal and external branch.

20. Internal Carotid Artery • In human anatomy, the internal carotid artery is a major artery of the head and neck that helps supply blood to the brain.

21. Capillaries • Blood passes from the arterioles into the capillaries. Capillaries are very narrow -- only one cell wide. • They have very thin walls made of overlapping flat cells called endothelium; the walls are thin so that oxygen and carbon dioxide can pass through them easily. • Inside the capillaries, the red blood cells release their oxygen, which passes through the capillary walls and into the surrounding tissue. • The tissue releases its waste products, like carbon dioxide, which passes through the capillary walls and into the red blood cells.

22. Sinusoids • Some organs -- the liver, spleen, and bone marrow -- contain blood vessels called sinusoids instead of capillaries. • Like capillaries, sinusoids are composed of endothelium. Sinusoids are a bit larger than capillaries.

23. Veins • From the capillaries/sinusoids, the de-oxygenated, waste-laden blood passes into the veins for its return trip to the heart. • Veins are like arteries in that they have three layers. But since the blood is not under as much pressure, the walls of veins are thinner. • Veins contain one-way valves to keep the blood flowing toward the heart, even against the pull of gravity. Because the blood in veins contains so little oxygen, it appears bluish rather than bright red. • That's why the veins you can see through your skin (for example, in the underside of your wrist) are blue.

24. Saphenous • The great saphenous vein (GSV), also greater saphenous vein, is the large (subcutaneous) superficial vein of the leg and thigh. First described by the Persian physician Avicenna in the 11th century, it derives its name from the term 'Safin' meaning hidden. It travels mostly in its own fascial compartment in the thigh and is hence 'hidden'.

25. External Jugular Vein • The external jugular vein receives the greater part of the blood from the exterior of the cranium and the deep parts of the face, being formed by the junction of the posterior division of the posterior facial with the posterior auricular vein.

26. Internal Jugular Vein • The internal jugular vein collects the blood from the brain, the superficial parts of the face, and the neck.

27. Pulmonary Veins • The four pulmonary veins carry oxygen-rich blood from the lungs to the left atrium of the heart. They are the only veins in the post-fetal human body that carry oxygenated (red) blood.

28. Subclavian veins • In human anatomy, the subclavian veins are two large veins, one on either side of the body. Its diameter is approximately that of a man's small finger. It is divided into right and left subclavian vein.

29. External Iliac Veins • The external iliac veins are large veins that connect the femoral veins to the common iliac veins. Their origin is at the inferior margin of the inguinal ligaments and they terminate when they join the internal iliac veins (to form the common iliac veins).

30. Basilic Vein • In human anatomy, the basilic vein is a large superficial vein of the upper limb that helps drain parts of hand and forearm. It originates on the medial (ulnar) side of the dorsal venous network of the hand, and it travels up the base of the forearm and arm. Most of its course is superficial; it generally travels in the fat and other fasciae that lie superficial to the muscles of the upper extremity. Because of this, it is usually visible through the skin.

31. Superior Vena Cava • The superior vena cava is a large, yet short vein that carries de-oxygenated blood from the upper half of the body to the heart's right atrium.

32. Femoral Vein • In the human body, the femoral vein is a blood vessel that accompanies the femoral artery in the femoral sheath. It begins at the adducto canal (also known as Hunter's canal) and is a continuation of the popliteal vein. It ends at the inferior margin of the inguinal ligament, where it becomes the external iliac vein.

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