Essay about The Human Body Example For Students

Essay about The Human Body Human BodyIn the BeginningWithin a month of conception, the cluster of cells that will, in the course oftime, become a human being begins throbbing, signaling the development ofa primitive heart. Scarcely four weeks more pass before an intricate networkof veins and arteries the size of a pea forms and subdivides into a tiny replicaof the four chambers that will one day make up the adult heart. As the fetusgrows, so does its vitally important circulatory system. Although most of thefunctions of the heart remain dependent upon the mother throughout theentire pregnancy, in the latter stages the organ becomes strong enough to beaton its own. Even so, until birth the baby is cared for and nourished throughthe mothers placenta. An umbilical cord provides a supply line that furnishesfood and oxygen for the baby, and also removes waste. When at last thebirthing moment arrives, the baby emerges a separate individual; almost assoon as its first cries are sounded, its pulmonary and circulatory systemsundergo a change that renders them self-sufficient. How it Works Technically speaking, the circulatory system is a masterpiece of organicactivity. Composed of a network of 60,000 miles of blood vessels and apintsized, powerhouse pump known as the heart, it services more than 2,000gallons of blood per day, feeding and replenishing other organs and makinglife possible. In an adult, the heart is normally an 11 ounce, fistsized organ that literallypushes blood through arteries, veins and capillaries. It does this by means ofmuscular contractions sparked by electrical impulses from the heartspacemaker (sinoatrial node). All of the cells within each of the chambersmagically work on cue. First, the right side sends blood to the lungs. There carbon dioxide is removed and oxygen is added, turning the blood abright red color. Then the blood is pumped to the left side of the heart andsent via the aorta to the rest of the body. To survive, each of the bodys approximately 1 billion cells must benourished. This is the job of the blood, with the heart and vessels acting asfacilitators. After depositing the necessary nutrients with each of the cells, theblood returns to the heart, carrying with it waste products it has picked upalong the way. These are eliminated through a filtering process in the lungsand kidneys. By now the supply of oxygen within the blood i s nearly exhausted, and it istime to restock its supplies and begin the journey again. Incredibly, the wholeprocess has taken just 20 seconds. During the course of an average life, the heart pumps tens of millions ofgallons of blood. It is estimated that the amount would easily fill a24-foot-wide cylinder to a height greater than the Empire StateBuilding. Perhaps more impressively, the circulatory system has the computer-likeability to direct greater and lesser amounts of blood to various areas of thebody according to their immediate needs. This explains why athletes oftenforego eating just prior to a match. During the process of digestion, thegastric organs require more blood to complete their work. As if that werentenough, the heart is also wired through the nervous system to respond to alarge variety of physical and emotional stimuli. Witness the quickening of theheart at the touch of a loved one. What Can Go Wrong Most circulatory problems are caused by a blockage in an artery, which isknown as atherosclerosis or hardening of the arteries. No one knows for surewhy this happens, but the prevailing theory states that something causes theprotective inner lining of an artery wall to be injured. Once impaired, thecollagen in the lining is exposed. That, in turn, attracts platelets and toxicsubstances from the bloodstream, which enter the artery wall. Eventually, theprocess leads to a buildup of debris, narrowing of the artery and finally,blockage. Interestingly enough, although the heart has a continual flow of bloodstreaming in and out of its chambers, it is unable to take the nourishment itneeds from this source. Rather, it must rely on its own miniature circulatorysystem, which branches off from the aorta or main channel. Here tiny butextremely important vessels called coronary arteries provide the means tofeed the heart. Like other arteries, they are also subject to blockage. Andherein lies a potential and fairly common tragedy, because when coronaryarteries cease to function as they should, the heart is deprived of the oxygenand nutrients it needs. Starved, it becomes damaged and, at worst, dies. There are several factors that contribute to circulatory problems, includinghigh blood pressure (hypertension), high levels of cholesterol in thebloodstream, smoking, obesity, heredity, lack of exercise and emotionalstress. Blood pressure refers to the force at which blood courses through arteries andveins as it journeys to the various parts of the body. It is determined by thetotal amount of blood in the body (which may vary from individual toindividual and even time to time), the intensity at which the heart has towork, and the resistance to flow offered by the artery walls. When bloodpressure is elevated above a safe level, it can speed up the process ofdamaging the blood vessels. It can also lead to personality changes and mayaffect the heart, brain and kidneys. Cholesterol Management Cholesterol is a type of animal fat that is either manufactured by the liver orabsorbed through the diet. Although most often it is described in villainousterms, it is actually necessary in some forms for good health. Cholesterolhelps the body metabolize carbohydrates and manufacture its own vitamin D. It also is a prime supplier of certain essential hormones. However, problemsoccur when cholesterol and other fats start lining the insides of arteries,narrowing them and making them susceptible to deposits of plaque. Thishampers the flow of blood, and consequently, the supply of life-givingnutrients and oxygen. Do you know what your cholesterol level is? When was the last time you hadit checked? Or have you ever had it checked? How are you doing with yourcholesterol management? And do you need to be concerned about it? Lets look at some statistics The average American eats 165 pounds of meat, 276 eggs, 17 pounds ofbutter or margarine and 18 pounds of ice cream annually. Daily, the averageAmerican consumes the equivalent of a full stick of butter in fat andcholesterol. This diet contributes to a 1-2% increase in the cholesterolaccumulating in the arteries each year. Remember, high cholesterol levels arenot something you can feel. To determine if your blood cholesterol level iscontribu ting to your risk of heart disease, have it tested by a qualified healthprofessional through laboratory analysis. Cholesterol is manufactured in theliver and is absorbed from the diet. S nce the major lipids or fats are notsoluble in blood, they are carried in the bloodstream by protein carriers calledlipoproteins. These lipoproteins vary in size and are termed highdensitylipoprotein (HDL), low- density lipoprotein (LDL) and a very low-densitylipoprotein (VLDL). In The Shooting An Elephant, George Orwell Describes An Internal EssayDespite the boom in fitness spass, a government survey shows that onlyabout 8 percent of adults get adequate exercise. It seems we are a generationof couch potatoes and over a period of time, our sedentary habits can exact aheavy price. Aerobic exercise such as walking, running or cycling helps tosupply increased amounts of oxygen to the circulatory system. It alsostrengthens heart muscle tone and improves mass. Theres even evidence thatit helps keep cholesterol at a healthy level. Research indicates that emotional stress can cause the body to releasebiochemicals that may contribute to the injury of arterial tissues. This, inturn, invites the formation of plaque. Preventive MaintenanceThe late, eminent heart specialist Paul Dudley White, M.D., once stated thatheart disease before 80 is our own fault, not Gods or Natures will. Of all the factors that contribute to circulatory problems, all but one heredity can be largely controlled by the way we live and the food we eat. Highblood pressure, for example, can be lowered significantly in some people bysimply limiting the intake of sodium. Common table salt, or sodium, causesthe blood to retain fluids. This swells the volume of blood that must bepumped throughout the body and, accordingly, adds to the workload of theheart. Salt also seems to encourage the smooth muscles in the smallestarteries to constrict, which increases the resistance to flow. Unfortunately, salt is a staple of the modern diet, and an ingredient in mostprocessed foods. That means that most of us probably consume way toomuch. Whats more, when sugar is added to salt, as it very often is, the threatis compounded. Researchers have found that symptoms of high bloodpressure are significantly worsened in test animals fed a diet that is high inboth salt and sugar. They concluded that the synergist ic effect of thiscommon dietary duo is disquieting at the very least. So, limit your sodium intake as much as possible. Avoid salty snacks andmake a deliberate change from seemingly convenient, prepackaged and fastfoods to their more natural counterparts. When you come to the frozen andcanned food sections in your local grocery store, put on mental blinders andquicken your pace. Then head straight for the fresh produce . . . and lingerthere. Avoid fats as much as possible, especially those that are highly saturated, likecoconut oil. Better choices are avocado, almond, canola and peanut oils. Thebest choice is high-grade olive oil. Also, cut down on your intake of meatsand other substances that contain animal fats, while you concentrate onincluding more fish, whole grains and beans in your diet. Whole milk, because it contains animal fat, is a potentially heavycontributor of dietary cholesterol. Consider substituting Natures Sunshine delicious-tasting, dairy-free,cholesterol-free and lactose-free . It is also naturally low in calories andsodium. Its white like milk and is made from tofu, which means its easier todigest than soy milk and doesnt have that bean taste. If you need some additional information on the health implications of dairyproducts for reasons other than the circulatory system, read more at the site. Lately, a lot of publicity has surrounded oat bran as a cholesterol fighter. Itsgood, but other findings indicate that rice bran may even be better. Psyllium, too, looks promising. Doctors at the University of Minnesotarecently released the findings of a study in which psyllium was used tosuccessfully lower patients cholesterol levels. Regular aerobic exercise (at least 20 minutes, three times a week) can be areal boon to a healthier circulatory system. In addition to its many physicalbenefits, aerobic exercise helps people deal with the normal stresses ofeveryday living. If you follow these tips consistently, chances are obesity, another contributorto high blood pressure, wont be much of a problem. If it is, we recommendseeking the services of a qualified health practitioner. Finally, remember that the circulatory system like any other system in thehuman machine-doesnt come with a manufacturers warranty. For thatreason, owners should be advised that a certain amount of timely upkeep isnecessary to keep it in tip-top condition. Failure to do so may result in costlyrepairs, a major overhaul or even a trade-in. As in all matters relating to health, preventive maintenance is the key toadding both years to your life, and life to your years. Read a Success Story on Natural Solutions for Circulatory Problems Circulation, cholesterol, most successful choice for high blood pressure Body deodorizer and cleanser, gum disease, chronic anemia, builds bloodfast, soothing and healing to the digestive and intestinal tracts-1200 mg. of Chinese garlic per tablet, coated with chlorophyll to controlodor without altering garlic properties and enteric coated so you dont burp it blood pressure, cholesterol, infections, colds, yeast A yellowish gummy substance derived from India. Used to improve thecirculatory system and improve cholesterol ratios. A combination of hawthorn berries, capsicum and garlic to strengthen theheart and aid in improving the circulatory system. Oral chelation formula designed to remove plaque from arterial walls;circulation; heart tonic; great preventative aid for heart disease Antioxidant, healing, anti-aging, heart disease, skin healerScience Essays