Circulatory System Essay Example

physiological equilibrium of the human organism and interaction with other systems such as digestive, lymphatic, respiratory (lungs), etc: •Transports oxygen from the lungs and gills to the tissues, and transports carbon dioxide from the tissues to the lungs or gills. Distributes nutrients from the digestive system to all body cells. •Transports waste products and toxic substances to the liver, where many of them are detoxified, and to the kidneys for excretion. •Distributes hormones from the glands and organs that produce them to the tissues on which they act.

•Helps to regulate body temperature by adjustments in blood flow. •Helps to heal wounds and prevent bleeding by creating blood clots (Audesirk, Audesirk, Byers, 2010).Blood is not the only fluid transported in this system. Lymph (which contains white cells) is another fluid in the circulatory system which is why we can say the cardiovascular and lymphatic systems make up the circulatory system and work closely with it. The circulatory system has three parts: the heart, the blood, and the blood vessels.

The heart: which consist most of cardiac muscle.Each of these cells is small, divided and filled with an arranged selection of protein strands that give it a stripe appearance. As explained above, pumps oxygenated blood to the body and cells and deoxygenated blood to the lungs. It encloses two types of circulation/pumps, systemic and pulmonary and for each of these, there is one atrium and one ventricle leaving a total of four chambers.

An Atrium collects the blood before passing it to a ventricle that propels it into the body.In one pump we find the right atrium and ventricle they deal with deoxygenated blood. The right

atrium receives blood (oxygen-depleted blood) from the body through the two largest veins, superior and inferior vena cava. Then, once filled with blood, this atrium shrinks pushing blood into the right ventricle which also shrinks/contracts and then sends blood to the lungs through the pulmonary arteries (vessels that take blood away from the heart).

The other pump formed of the left atrium and ventricle, deals with oxygenated blood from the lungs that enters the left atrium through pulmonary veins (vessels carrying blood to the heart as opposed to the arteries) and then forced into the left ventricle, the heart’s most muscular chamber, sends the oxygenated blood coursing out through a major artery, the aorta, to the rest of the body (Audesirk, Audesirk, Byers, 2010). The Atrioventricular valves let the blood flow from the atrium into the ventricle, but not the opposite, serving as passing through canals.Now, the Semilunar valves are the ones that let blood go into the pulmonary and aorta arteries when the ventricles shrink/contract and they avoid blood from coming back as the ventricles ease up. The heart is the most important organ of the human body and the main organ in the circulatory system. If there was no heart, how would blood be transported back and forth through our whole body cells? How would the blood get oxygenated and pumped through the arteries and pick up waste cells? Without a heart, there would be no circulatory or cardiovascular system.

The Blood: contains plasma, red and white cells, and platelets (cell-based components of blood) that are suspended in the plasma. •Plasma composition is mainly water, about 90%, and is about 55% of blood volume, which

has over 100 different types of molecules such as proteins and drives hormones, nutrients, and cellular wastes, like carbon dioxide. Albumin, fibrinogen and globulins are three frequent plasma proteins. Some of the important functions they perform are: - help maintain the blood’s osmotic strength, and so avoids too much fluid from diffusing out of the plasma through capillary walls (albumin). Serve as antibodies that fight infection; bind and transport some hormones, ions, and other molecules (Globulins). – Fibrinogen gives rise to fibrin, which promotes clotting (Audesirk, Audesirk, Byers, 2010).

•Cell-based components (red cells, white cells, and platelets). oBeing white cells the only complete and functional cells. These are also very important as they protect the body from disease which plays a very important role in our immune system as they protect and clean our system by destroying bacteria and dead cells throughout our organism.We find 5 types of white cells (leukocytes) and these are: neutrophils, eosinophils, basophils, lymphocytes, and monocytes. oRed cells (also called erythrocytes) are in charge of the molecular oxygen distribution.

Because they do not contain a nucleus or nucleus was lost through development, their shape looks like a ball of clay squeezed between a thumb and forefinger and provides a larger surface area than would a spherical cell at the same volume, increasing the erythrocyte’s ability to absorb and release oxygen through its plasma membrane (Audesirk, Audesirk, Byers, 2010).They gain their red color thanks to the great amount of iron-containing protein hemoglobin, which serves as an oxygen transporter from the lungs to the cells. The lack of hemoglobin or red cells could cause anemia which is a blood deficiency and this comes

from a poor nutritional diet, genetic defect, lack of iron, leukemia and more. o Platelets, also called megakaryocytes, are very small fragments of large cells.They play an extremely important job in blood clotting.

Blood clotting protects us from losing excessive amount of loss for example. This is not just when injuries such as cuts where platelets help cease bleeding occur by forming a platelet plug but also from internal bleeding such as when a blood vessel breaks. oBlood Vessels (arteries, capillaries and veins) are elastic muscle conducts that distribute and pick up blood from every inch of the body.Arteries are those blood vessels that drive blood away from the heart and runs through arteries to arterioles to capillaries, then into venules, and finally, to veins and returned to the heart.

As earlier mentioned the circulatory system allows individual blood cells to exchange nutrients and wastes and capillaries are the only blood vessels on which this exchange can occur. The circulatory system interacts with many other systems such as: lymphatic system – lymph is a clear fluid formed by plasma and white cells.It returns excess extracellular fluid to the bloodstream. It also transports fats from the small intestine to the bloodstream. Filters aged blood cells and other debris from the blood and defends the body by exposing bacteria and viruses to white blood cells. To mention another one, it interacts with the digestive system when it distributes nutrients from the digestive system to all body cells and transports waste products and toxic substances to the liver, where many of them are detoxified, and to the kidneys for excretion.

As mentioned earlier when explaining red blood cells’ functions,

we find that Anemia is a blood disorder/disease. Anemia is found when the level or red blood cells/hemoglobin is below normal range. Anemia affects the circulatory system and human health because of the fact that hemoglobin helps red blood cells carry oxygen from our lungs to all parts of our body (Women’s Health Zone, 2004). So, if these are missing, how is oxygen distributed?The causes are many from eating disorders to missing Iron in our system and more. Within the forms of anemia, we find many, such as: iron deficiency anemia, hemolytic anemia (destruction of RBCs), vitamin B-12 deficiency anemia, folic acid deficiency anemia, anemias caused by inherited abnormalities of RBCs (for example, sickle cell anemia and thalassemia) and anemia caused by chronic (ongoing) disease.

Reference Texas Heart Institute (July 2010). Hear information center: The Circulatory System. Retrieved December 5, 2010 from http://www. texasheartinstitute.

org/HIC/Anatomy/anatomy2. cfm Audesirk, T. , Audesirk, G. , & Byers, B. (2010).

Biology: Life on Earth with Physiology (9th ed. ). San Francisco, CA: Benjamin Cummings Women’s Health Zone (2004). Circulatory System: Anemia. Retrieved on December 5, 2010 from http://www. womenshealthzone.

net/circulatory-system/anemia/