Get help now
  • Pages 12
  • Words 2773
  • Views 511
  • Download


    Verified writer
    • rating star
    • rating star
    • rating star
    • rating star
    • rating star
    • 4.7/5
    Delivery result 5 hours
    Customers reviews 624
    Hire Writer
    +123 relevant experts are online

    The Development of the Circulatory System

    Academic anxiety?

    Get original paper in 3 hours and nail the task

    Get help now

    124 experts online

    In 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 mother’s 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 heart’spacemaker (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 body’s 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 is 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 weren’tenough, 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? Let’s 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 iscontributing 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). All cholesterol is not responsible for heart disease. HDL and LDL mainlycarry cholesterol and play opposite roles in the body.

    HDL’s are the heaviestand have the greatest amount of protein. As they move through the body, theyare able to collect cholesterol and transport it to the liver. There, thecholesterol is processed and then removed. Since it tends to clean up excesscholesterol, HDL has been called a scavenger. LDLs, on the other hand, takecholesterol from the liver to cells, where it is used for hormone synthesis.

    LDL is also a constituent of cell membranes, or arterial plaque deposits. HighLDL levels can contribute to atherosclerosis. A ratio of at least one LDL to three HDL is desirable for circulatory systemhealth. Obesity and a sedentary lifestyle are chiefly responsible for areduction of HDL levels.

    HDL levels can be raised through reducing dietaryfats and cholesterol, increasing aerobic exercise, not smoking andmaintaining ideal body weight. The American Heart Association reports thatideal cholesterol ranges are 130-190 mg / dl. Clinical studies have identifiedthat cholesterol levels higher than 200 mg / dl are related to rapid increases inthe incidence of cardiovascular disease. It has been estimated that one-half ofAmerican males exceed the limit. People with blood cholesterol levels higherthan 265 mg / dl have four times the risk of developing heart disease thanthose with levels below 190 mg / dl. Cholesterol management is the BigThree risk factor most related to nutritional factors.

    The FDA Consumerreported, The consensus of medical opinion is that high blood cholesterol isrelated to the development of coronary artery disease, and that changes in dietcould help reduce this risk factor. Cutting back your intake of animal foods will cut back your intake ofdietary cholesterol. Plants contain no dietary cholesterol. In addition, fat-modified diets can lower blood cholesterol by 30 percent ormore. Reducing dietary fat is centered around reducing saturated fat intake. A surprising source of saturated fat may be the nondairy creamer used incoffee.

    A study by University of Nebraska Medical Center professors foundthat 22 out of 25 non-dairy creamers contained coconut oil. Coconut oil ismore saturated than cream, butter, lard or beef fat. Be aware of otherprepared foods containing coconut oil. Another important consideration is increasing the ratio of polyunsaturatedfats to saturated fats.

    Polyunsaturated fats lower cholesterol by increasinglipoprotein breakdown and removal, and lowering the synthesis oflipoproteins in the liver. Also, the essential fatty acid content, such as linoleicacid, is beneficial. It decreases platelet aggregation and serum cholesterol. Linoleic acid can’t be manufactured in the body; safflower oil has a goodcontent of linoleic acid. Hydrogenated vegetable oils have fewer polyunsaturated fats than do meatsand dairy products. They actually have more saturated fats than butter, wholemilk and meat, while offering few or no vitamins.

    Monounsaturated fats are also receiving more attention. Once thought to beneutral in heart health, they are now considered beneficial. Olive oil andalmond oil are high in monounsaturated fats. An important part of cholesterolmanagement is eating a diet high in complex carbohydrates. Certain fibers incomplex carbohydrates are able to carry cholesterol out of cells and tissues,including arteries, then to the liver where it is excreted. Carrots, cabbage andbroccoli contain calcium pectate, a type of pectin with cholesterol- loweringeffects.

    Eat two carrots a day-that’s what one study reports if you areconcerned about high cholesterol rates. Oat bran has also been shown tolower LDL and blood cholesterol levels. In addition, the saponins insoybeans, chickpeas, peanuts and alfalfa have been shown to reduce bloodcholesterol. An intake of 37 grams of fiber a day is adequate.

    Too much fibermay bind up trace minerals and irritate the intestinal lining. A word about exercise: Regular exercise can lower blood pressure, canraise the HDL cholesterol levels, and can help control weight. TheAmerican Heart Association recommends at least 20 minutes of aerobicexercise three times per week. Smoking robs the heart of oxygen. That’s why heart disease rates for smokersare 70 percent higher than those for nonsmokers. Heavier smokers are in aneven more precarious situation.

    But the good news is that smokers who quitcan reduce their risk for heart disease by about one-half. Recent studiesindicate that the body begins to recover from the effects of smoking soonafter quitting- within months or even days! Even better, in time anex-smoker’s risk for coronary heart disease will approach that of someonewho has never smoked at all. Obesity both directly and indirectly affects a number of other factors thatrelate to circulatory problems. Overweight individuals tend to exercise lessthan those who aren’t overweight, and exercise is important for circulatoryhealth. They also tend to consume more fats, which increase the levels of fatsin the bloodstream, and sugars, which encourage glucose intolerance andeven diabetes.

    One of the many complications of diabetes is damage to bloodvessels, and damaged vessels are prone to hardening and subsequentnarrowing. For some reason, certain people are genetically predisposed to circulatoryproblems. Some unknown factor they inherited from their parents makes theirbodies less able to cope with the things that contribute to heart and bloodvessel difficulties. They may be troubled by elevated levels of cholesterol ortheir blood pressure may rise to dangerous levels, or there may be otherweaknesses.

    The trick is to be aware of any hereditary problems and to worktowards strengthening weaknesses. Despite the boom in fitness spas’s, 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. There’s 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 God’s or Nature’s 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.

    What’s 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 synergistic 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. It’s white like milk and is made from tofu, which means it’s easier todigest than soy milk and doesn’t 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. It’sgood, 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, won’t 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-doesn’t come with a manufacturer’s 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 don’t 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

    This essay was written by a fellow student. You may use it as a guide or sample for writing your own paper, but remember to cite it correctly. Don’t submit it as your own as it will be considered plagiarism.

    Need custom essay sample written special for your assignment?

    Choose skilled expert on your subject and get original paper with free plagiarism report

    Order custom paper Without paying upfront

    The Development of the Circulatory System. (2019, Jan 17). Retrieved from

    We use cookies to give you the best experience possible. By continuing we’ll assume you’re on board with our cookie policy

    Hi, my name is Amy 👋

    In case you can't find a relevant example, our professional writers are ready to help you write a unique paper. Just talk to our smart assistant Amy and she'll connect you with the best match.

    Get help with your paper