Lungs, heart, trachea, a bronchital tree, and connecting blood vessels all contribute to the ingenious breathing system that brings oxygen to the blood and removes carbon dioxide. Depleted blood converges on the heart from all parts of the body. Passing through the heart's right side, the blood flows into each lung through the pulmonary artery. From there it flows into the smaller pulmonary arterioles, then into capilliaries that surround each of the hundreds of millions of spongy air sacks, or alveoli, inside our lungs.
The alveoli conduct the real business of gas exchange, or respiration. Constructed of fibrous strands of connective tissue and surrounded by the fine network of blood capilliaries with walls a cell thick, the alveoli's moist inner surfaces absorb oxygen molecules from inhaled air. The molecules then diffuse into the surrounding capillaries, carbon dioxide simultaneously passes from the capilliaries into the alveoli and is exhaled.
The blood now rich in oxygen, flows through the pulmonary venules into the pulmonary veins, then through the heart's left side and back out through the aorta into the body's tissues.
The backview of a new-born's lungs reveals the asymmetrical structure of each organ;the three-lobed right lung weighs a few ounces more than the two-lobed left. Adult lungs, whose convulted surfaces could cover a racquetball court, weigh less than two pounds. A substance lining the walls keeps the lungs from collapsing, lowers surface tension, and reduces the muscular effort required for breathing.
"] Text[2]=["Heart","A map of the heart and a sequence of diagrams help locate the different parts and explain the pumping cycle. Four hollow chambers fortified with blood vessels make up this muscular organ. Two thin-walled ante-rooms, the left atrium and the right atrium, serve as holding tanks for blood entering the heart;thick walled ventricles, one under each atrium, perform the serious labor of pumping blood. An impermeable wall divides the right and left sides of the heart.
The heart fills and empties in a second long rhythmic cycle of contraction and relaxation, a heartbeat. Dark oxygen-spent blood(blue) from the body converges into two great veins, the superior and inferior venae cavae, en route to the right atrium, while bright red oxygenated blood moves towards the left atrium from the lungs via the pulmonary veins. As ventricles relax, a phase called diastole, the atria fill with blood and force open two valves through which the blood drains into the left and right ventricles. In the pumping, or systole, phase, the ventricle contract, closing off the two lower valves. The right ventricle forces the oxygen spent blood into the pulmonary artery;the left ventricle pumps oxygenated blood into the aorta and on into the body's tissues.
The digestive system physically and chemically converts the food we eat into substances our bodies need. The system includes the alimentary canal, a continuous tube made up of mouth, pharynx, esophagus, stomach, small intestine, and large intestine. as food enters the tract, the teeth cut and grind it into morsels that can be swallowed.
Once the food has been swallowed, muscles lining the ailmentary canal mix and propel it by mechanical action. Enzymes in the stomach and small intestine chemically break down the complex food molecules. Other organs - the salivary glands, pancreas, liver, and gall bladder - also contribute enzymes and other digestive substances. Food then is reduced to simple chemical forms that are processed in the liver, enter the bloodstream, and are carried to the cells.
Grapelike clusters in the pancreas, acinar cells produce enzymes that travel through a duct to the small intestine. There the enzymes breakdown carbohydrates, fats, and protiens for absorption into the body by shattering the chemical bonds that link the molecules.
Scattered among the acinar cells, other clusters called islets of Langerhans secrete their hormones directly into the bloodstream. Within one of the islets appears a weblike backdrop of connective tissue and spherical cells dotted with secretions-possibly insulin droplets.
The hills and valleys of the stomachs inner lining will flatten out as the organ fills with food. Food in the stomach will trigger the release of the hormone gastrin. The gastrin then stimulates production of gastric juice.
Such hormones produce their effects by binding tightly to the receptors of a target cell in the stomach. In response, glands in the stomach lining spew forth a mixture of other digestive substances such as hydrochloric acid, and the enzyme pepsin.
To sheild the stomach from the effects of its on corrosive juices, the cells and glands located in the stomach wall secrete a layer of protective mucus. The mucus erupts from a gastric pit; within the pit floats a single red blood cell.
The stress that a child experiences is indescribable. The pressures to excel, daily challenges of youth, the physical changes and loss of innocence that comes with growing in a society that is far from forgiving, creates a potent mixture of insecurity and rebellion. Most children emerge stronger from this experience, some are affected for life. Added to these emotional challenges are the growing number of communicable diseases. Modern medicine is in catch up mode, and will run out of steam one day, unable to cope with the rising resistance to conventional drugs.
"] Text[7]=["Liver","A landscape of the liver, reveals the hexagonal lobules that make this organ one of the body's most vital and versatile. Blood borne nutrients enter the lobules from branches of the portal vien. Branches of the hepatic artery carry oxygen-rich blood.
Inside the liver, the blood flows through a spongelike warren of specialized capillaries called sinusoids. Kupffer cells embedded in the sinusoid walls and roving white cells clean the blood of impurities. Tiny holes, or fenestrations, in the sinusoids allow nourishment to reach the liver cells(hepatocytes). Here the nutrients, converted to glucose and other chemicals by the liver, reenter the bloodstream via the porous capillaries and the central veins.
Bile secreted by the hepatocytes collects in tiny canals, the bile canaliculi, that feed into the network of bile ducts.
Largest of the body's internal organs, the liver is made up of some 50,000 lobules and processes about a quart of blood a minute. Its multitude of functions include producing blood sugar, storing excess nutrients and building protiens. The liver also secretes bile to aid digestion and helps rid the body of potentially toxic chemicals.
A joint is the place where the ends of two or more bones meet. For example, the bone of the lower leg (called the shin, or tibia) and the thighbone (called the femur) meet at the knee joint. Arthritis, regardless of the cause, typically makes your joints painful, stiff, and swollen. As we age, the tissue that protects these joints become worn, friction results between two joints leading to pain. Swelling is a natural response to pain and when this cycle becomes chronic, the person is said to suffer from arthritis. In many cases the cause of arthritis is due to auto-immune disorders, unrelated to age. This could strike in childhood and the cause could be as simple as an allergic reaction or a lot more complicated
"] Text[9]=["Body","The finger joints of a 75-year old man are thinner and show signs of arthritis-small out growths projecting from some of the bones.
"] Text[10]=["Brain","The human brain distinguishes Homosapeins from all other life-and makes each person unique. The deeply folded cerebral cortex makes up 40% of the brains total weight. The cortex enables us to percieve, communicate, remember, understand and appreciate a melody.
During fetal development the brain generates about 360 million new nerve cells a day. a process that probably halts at birth.
A bundle of nerve fibres called the corpus callosum connects the two cerebral hemispheres, enabling the individual to function as a co-ordinated whole.
Beneath the cortex lie the brains more promitive structures, which govern many basic bodily functions. The medulla helps to maintain life support systems such as breathing heart rate, and blood pressure. The various parts of the limbic system-including hypothalamus, hippocampus, amygdala,fornix and olfactory bulb-cntrol emotions and rule the basic drives for food sex and survival.The thalamus acts a relay station for information related to sensation and movement.
It processes the data and passes them to the cerebral cortex. The cerebellum, at the back of the head and the caudate nucleus part of the basal ganglia help co-ordinate body movements and maintain balance. The pons acts as a communication bridge between the cerebellum and the cerebral cortex.
Cancer cells invade the bronchial tract. Hair like cilia cover the healthy cells. This cancer crowds out normal cells, whose cilia form a carpet of living fibres that normally sweep dust and foriegn particles away from the lungs. A heathy bronchial wall is covered with countless cilia which can be killed or paralysed by cigarette smoke and other pollutants.
"] Text[12]=["Cholesterol","The leading cause of mortality is cardio vascular diseases. Elevated cholesterol is implicated in the increased risk of CVD. Dietary fats, lack of exercise, smoking, environmental pollutants are all aggravating factors leading to a series of high risk issues including the silent killer "hypertension". Conventional therapies such as Statins, are at best a difficult choice, more akin to "between a rock and a hard place". Statins have proven severe side effects that normally would be considered extremely dangerous, Kidney failure, hepatoxicity, glaucoma are just some of the known side effects of statins.
"] Text[13]=["Kidneys","Two hard working kidneys control the amount of water, acids and salts in the body. A child's kidney is lined with creases that disappear with maturity. In adults, these structures weigh about 5 ounces. They process about 425 gallons of blood a day of which all is recycled except a fraction that is converted into urine.
While ridding us of waste products from every cell, the kidneys also produce atleast three hormones, including renin, which helps control blood pressure. A cushioning layer of fat surrounds and helps protect the fragile kidneys.
Women's health care is one of the most challenging areas of medicine. A woman goes through more emotional challenges and physical changes than a man does, yet bears this burden alone for the most part. Women's Health in the third world is at best basic. Archaic social beliefs and economic pressures combine to exclude women from effective preventive health options
"] Text[15]=["Male Health","To take just one step, we first need to know the positions and spatial relationships of the parts of the body. Data are provided by the eyes, and receptors in the skin, muscles, joints, and vestibular organs - the balance mechanisms in the inner ears. The central nervous system processes these messages and sends orders of movement, all while monitoring new feedback.
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