Bøker av James Kennedy

PREVIEW Bone marrow is soft, gelatinous tissue that fills the medullary cavities, or the centers of bones. The two types of bone marrow are red bone marrow, known as myeloid tissue, and yellow bone marrow, known as fatty tissue.Both types of bone marrow are enriched with blood vessels and capillaries.Bone marrow makes more than 220 billion new blood cells every day. Most blood cells in the body develop from cells in the bone marrow.Bone marrow stem cellsBone marrow contains two types of stem cells: mesenchymal and hematopoietic.Red bone marrow consists of a delicate, highly vascular fibrous tissue containing hematopoietic stem cells. These are blood-forming stem cells.Yellow bone marrow contains mesenchymal stem cells, or marrow stromal cells. These produce fat, cartilage, and bone.Stem cells are immature cells that can turn into a number of different types of cells.Hematopoietic stem cells in the bone marrow give rise to two main types of cells: myeloid and lymphoid lineages. These include monocytes, macrophages, neutrophils, basophils, eosinophils, erythrocytes, dendritic cells, and megakaryocytic, or platelets, as well as T cells, B cells, and natural killer (NK) cells.The different types of hematopoietic stem cells vary in their regenerative capacity and potency. They can be multipotent, oligopotent, or unipotent, depending on how many types of cells they can create.Pluripotent hematopoietic stem cells have renewal and differentiation properties. They can reproduce another cell identical to themselves, and they can generate one or more subsets of more mature cells.The process of developing different blood cells from these pluripotent stem cells is known as hematopoiesis. It is these stem cells that are needed in bone marrow transplants.Stem cells constantly divide and produce new cells. Some new cells remain as stem cells, while others go through a series of maturing stages, as precursor or blast cells, before becoming formed, or mature, blood cells. Stem cells rapidly multiply to make millions of blood cells each day.Blood cells have a limited life span. This is around 120 days for red blood cells. The body is constantly replacing them. The production of healthy stem cells is vital.The blood vessels act as a barrier to prevent immature blood cells from leaving bone marrow.Only mature blood cells contain the membrane proteins required to attach to and pass through the blood vessel endothelium. Hematopoietic stem cells can cross the bone marrow barrier, however. Healthcare professionals may harvest these from peripheral, or circulating, blood. Order a copy now!

PREVIEWA hiatal hernia is when your stomach bulges up into your chest through an opening in your diaphragm, the muscle that separates the two areas. The opening is called the hiatus, so this condition is also called a hiatus hernia.There are two main types of hiatal hernias: sliding and paraesophageal.Ordinarily, your esophagus (food pipe) goes through the hiatus and attaches to your stomach. In a sliding hiatal hernia, your stomach and the lower part of your esophagus slide up into your chest through the diaphragm. Most people with hiatal hernias have this type.A paraesophageal hernia is more dangerous. Your esophagus and stomach stay where they should be, but part of your stomach squeezes through the hiatus to sit next to your esophagus. Your stomach can become squeezed and lose its blood supply. Your doctor might call this a strangulated hernia. Order a copy now

PREVIEWAlzheimer's disease is a progressive neurologic disorder that causes the brain to shrink (atrophy) and brain cells to die. Alzheimer's disease is the most common cause of dementia - a continuous decline in thinking, behavioral and social skills that affects a person's ability to function independently.Approximately 5.8 million people in the United States age 65 and older live with Alzheimer's disease. Of those, 80% are 75 years old and older. Out of the approximately 50 million people worldwide with dementia, between 60% and 70% are estimated to have Alzheimer's disease.The early signs of the disease include forgetting recent events or conversations. As the disease progresses, a person with Alzheimer's disease will develop severe memory impairment and lose the ability to carry out everyday tasks.Medications may temporarily improve or slow progression of symptoms. These treatments can sometimes help people with Alzheimer's disease maximize function and maintain independence for a time. Different programs and services can help support people with Alzheimer's disease and their caregivers.There is no treatment that cures Alzheimer's disease or alters the disease process in the brain. In advanced stages of the disease, complications from severe loss of brain function - such as dehydration, malnutrition or infection - result in death. Order a copy now

PREVIEWAging is a gradual, continuous process of natural change that begins in early adulthood. During early middle age, many bodily functions begin to gradually decline.People do not become old or elderly at any specific age. Traditionally, age 65 has been designated as the beginning of old age. But the reason was based in history, not biology. Many years ago, age 65 was chosen as the age for retirement in Germany, the first nation to establish a retirement program. In 1965 in the United States, age 65 was designated as the eligibility age for Medicare insurance. This age is close to the actual retirement age of most people in economically advanced societies.When a person becomes old can be answered in different ways: Chronologic age is based solely on the passage of time. It is a person's age in years. Chronologic age has limited significance in terms of health. Nonetheless, the likelihood of developing a health problem increases as people age, and it is health problems, rather than normal aging, that are the primary cause of functional loss during old age. Because chronologic age helps predict many health problems, it has some legal and financial uses.Biologic age refers to changes in the body that commonly occur as people age. Because these changes affect some people sooner than others, some people are biologically old at 65, and others not until a decade or more later. However, most noticeable differences in apparent age among people of similar chronologic age are caused by lifestyle, habit, and subtle effects of disease rather than by differences in actual aging.Psychologic age is based on how people act and feel. For example, an 80-year-old who works, plans, looks forward to future events, and participates in many activities is considered psychologically younger.Most healthy and active people do not need the expertise of a geriatrician (a doctor who specializes in the care of older people) until they are 70, 75, or even 80 years old. However, some people need to see a geriatrician at a younger chronologic age because of their medical conditions. Oder a copy now!

PREVIEWA flexitarian or semi-vegetarian diet (SVD) is one that is primarily vegetarian with the occasional inclusion of meat or fish. Of late, there appears to be an increasing movement toward this practice. There has not been a recent update on these diets from a health perspective. Using the National Centre for Biotechnology Information PubMed database, a search was made for all studies published between 2000 and 2016 that met defined inclusion criteria. A total of 25 studies were located with 12 focusing on body weight and diet quality. There was emerging evidence suggestive of benefits for body weight, improved markers of metabolic health, blood pressure, and reduced risk of type 2 diabetes. SVD may also have a role to play in the treatment of inflammatory bowel diseases, such as Crohn's disease. Given that there is a higher tendency for females to be flexitarian yet males are more likely to overconsume meat, there is a clear need to communicate the potential health benefits of these diets to males. Order a copy now

PREVIEWBronchitis is an inflammation of the lining of your bronchial tubes, which carry air to and from your lungs. People who have bronchitis often cough up thickened mucus, which can be discolored. Bronchitis may be either acute or chronic.Often developing from a cold or other respiratory infection, acute bronchitis is very common. Chronic bronchitis, a more serious condition, is a constant irritation or inflammation of the lining of the bronchial tubes, often due to smoking.Acute bronchitis, also called a chest cold, usually improves within a week to 10 days without lasting effects, although the cough may linger for weeks.However, if you have repeated bouts of bronchitis, you may have chronic bronchitis, which requires medical attention. Chronic bronchitis is one of the conditions included in chronicobstructive pulmonary disease (COPD). Order a copy now!

PREVIEWCrohn's disease is a type of inflammatory bowel disease (IBD). It causes swelling of the tissues (inflammation) in your digestive tract, which can lead to abdominal pain, severe diarrhea, fatigue, weight loss and malnutrition.Inflammation caused by Crohn's disease can involve different areas of the digestive tract in different people, most commonly the small intestine. This inflammation often spreads into the deeper layers of the bowel.Crohn's disease can be both painful and debilitating, and sometimes may lead to life-threatening complications.There's no known cure for Crohn's disease, but therapies can greatly reduce its signs and symptoms and even bring about long-term remission and healing of inflammation. With treatment, many people with Crohn's disease are able to function well. Order a copy now!

PREVIEW There are two types of HSV: herpes simplex virus type 1 (HSV-1) causes oral herpes, which usually affects the mouth and surrounding skin but can also affect the genital region.herpes simplex virus type 2 (HSV-2) typically causes genital herpes, usually sexually transmitted.There is no cure for herpes, but treatment can help manage symptoms and reduce the likelihood of outbreaks recurring and transmission to partners.HSV is a common virus. According to the World Health Organization (WHO) Trusted Source, around 67% of people under age 50 globally have an HSV-1 infection, and 13% under age 50 have an HSV-2 infection.In this article, we describe the symptoms of genital and oral herpes, how to treat them, and how to prevent these infections. Order a copy now

PRЕVIЕWAcute pancreatitis is inflammation of the pancreas that develops quickly. The pancreas is a small organ that plays a crucial role in digestion. Some mild cases of acute pancreatitis resolve without treatment, but severe ones can have potentially fatal complications.Acute pancreatitis means inflammation of the pancreas that develops quickly. The main symptom is tummy (abdominal) pain. It usually settles in a few days but sometimes it becomes severe and very serious. The most common causes of acute pancreatitis are gallstones and drinking a lot of alcohol. Order a copy now

PREVIEW Diverticulosis and diverticulitis are two conditions that occur in your large intestine (colon). Together they are known as diverticular disease. Both share the common feature of diverticula. Diverticula are one or more pockets or bulges that form in the wall of your colon.Diverticula are like expanded areas or bubbles that form when you fill the inner tube of a bike tire with too much air. The increase in pressure from too much air being pumped into the inner tube causes the bubble to form where the rubber is the weakest. Similarly, an increase in pressure inside the colon causes pockets or bulges (diverticula) to form in weakened areas of your colon's walls.Diverticula can range from pea-size to much larger. Although they can form anywhere in the inner lining of your colon, they are most commonly found in your lower left side, in the S-shaped segment of your colon called the sigmoid colon. Order a copy now!

PREVIEWThe lymphatic system is a network of tissues, vessels and organs that work together to move a colorless, watery fluid called lymph back into your circulatory system (your bloodstream).Some 20 liters of plasma flow through your body's arteries and smaller arteriole blood vessels and capillaries every day. After delivering nutrients to the body's cells and tissues and receiving their waste products, about 17 liters are returned to the circulation by way of veins. The remaining three liters seep through the capillaries and into your body's tissues. The lymphatic system collects this excess fluid, now called lymph, from tissues in your body and moves it along until it's ultimately returned to your bloodstream.Your lymphatic system has many functions. Its key functions include: Maintains fluid levels in your body: As just described, the lymphatic system collects excess fluid that drains from cells and tissue throughout your body and returns it to your bloodstream, which is then recirculated through your body.Absorbs fats from the digestive tract: Lymph includes fluids from your intestines that contain fats and proteins and transports it back to your bloodstream.Protects your body against foreign invaders: The lymphatic system is part of the immune system. It produces and releases lymphocytes (white blood cells) and other immune cells that monitor and then destroy the foreign invaders - such as bacteria, viruses, parasites and fungi - that may enter your body. Order a copy now!

PREVIEWLupus is a disease that occurs when your body's immune system attacks your own tissues and organs (autoimmune disease). Inflammation caused by lupus can affect many different body systems - including your joints, skin, kidneys, blood cells, brain, heart and lungs.Lupus can be difficult to diagnose because its signs and symptoms often mimic those of other ailments. The most distinctive sign of lupus - a facial rash that resembles the wings of a butterfly unfolding across both cheeks - occurs in many but not all cases of lupus.Some people are born with a tendency toward developing lupus, which may be triggered by infections, certain drugs or even sunlight. While there's no cure for lupus, treatments can help control symptoms. Order a copy now!

PREVIEWAcne is a common skin condition where the pores of your skin become blocked by hair, sebum (an oily substance), bacteria and dead skin cells. Those blockages produce blackheads, whiteheads, nodules and other types of pimples. If you have acne, know you're not alone. It's the most common skin condition that people experience. It's estimated that 80% of people ages 11 to 30 will have at least a mild form of acne, and most people are affected by it at some point in their lives. Order a copy now

PREVIEWThe word cerebrovascular is made up of two parts - "cerebro" which refers to the large part of the brain, and "vascular" which means arteries and veins. Together, the word cerebrovascular refers to blood flow in the brain. The term cerebrovascular disease includes all disorders in which an area of the brain is temporarily or permanently affected by ischemia or bleeding and one or more of the cerebral blood vessels are involved in the pathological process. Cerebrovascular disease includes stroke, carotid stenosis, vertebral stenosis and intracranial stenosis, aneurysms, and vascular malformations.Restrictions in blood flow may occur from vessel narrowing (stenosis), clot formation (thrombosis), blockage (embolism) or blood vessel rupture (hemorrhage). Lack of sufficient blood flow (ischemia) affects brain tissue and may cause a stroke. Order a copy now!

PREVIEWBeing constipated means your bowel movements are tough or happen less often than normal. Almost everyone goes through it at some point.Although it's not usually serious, you'll feel much better when your body is back on track.The normal length of time between bowel movements varies widely from person to person. Some people have them three times a day. Others have them just a few times a week.Going longer than 3 or more days without one, though, is usually too long. After 3 days, your stool gets harder and more difficult to pass. Order a copy now!

PREVIEWAutism spectrum disorders (ASD) are a diverse group of conditions. They are characterised by some degree of difficulty with social interaction and communication. Other characteristics are atypical patterns of activities and behaviours, such as difficulty with transition from one activity to another, a focus on details and unusual reactions to sensations.The abilities and needs of autistic people vary and can evolve over time. While some people with autism can live independently, others have severe disabilities and require life-long care and support. Autism often has an impact on education and employment opportunities. In addition, the demands on families providing care and support can be significant. Societal attitudes and the level of support provided by local and national authorities are important factors determining the quality of life of people with autism.Characteristics of autism may be detected in early childhood, but autism is often not diagnosed until much later.People with autism often have co-occurring conditions, including epilepsy, depression, anxiety and attention deficit hyperactivity disorder as well as challenging behaviours such as difficulty sleeping and self-injury. The level of intellectual functioning among autistic people varies widely, extending from profound impairment to superior levels. Order a copy now!

PREVIEWAn autoimmune disease is a condition in which your immune system attacks your body.The immune system usually guards against bacteria and viruses. When it senses these foreign invaders, it sends out an army of fighter cells to attack them.Usually, the immune system can tell the difference between foreign cells and your own cells.In an autoimmune disease, the immune system mistakes part of your body, like your joints or skin, as foreign. It releases proteins called autoantibodies that attack healthy cells.Some autoimmune diseases target only one organ. Type 1 diabetes damages the pancreas. Other diseases, like systemic lupus erythematosus (SLE), or lupus, can affect the whole body.We've partnered with Cue Health, a healthcare company that makes lab-quality, portable diagnostic tests for at-home and professional use, to bring you this overview of autoimmune disease. Order a copy now!

PREVIEWAsthma is an inflammatory disease of the airways to the lungs. It makes breathing difficult and can make some physical activities challenging or even impossible.According to the Centers for Disease Control and Prevention (CDC), about 25 million AmericansTrusted Source have asthma. It's the most common chronic condition among American children: 1 child out of every 12Trusted Source has asthma.To understand asthma, it's necessary to understand a little about what happens when you breathe. Normally, with every breath you take, air goes through your nose or mouth, down into your throat, and into your airways, eventually making it to your lungs.There are lots of small air passages in your lungs that help deliver oxygen from the air into your bloodstream.Asthma symptoms occur when the lining of your airways swells and the muscles around them tighten. Mucus then fills the airways, further reducing the amount of air that can pass through.These conditions can then bring on an asthma "attack," which is the coughing and tightness in the chest that's typical of asthma. Oder a copy now!

PREVIEWThe kidneys are a pair of bean-shaped organs on either side of your spine, below your ribs and behind your belly. Each kidney is about 4 or 5 inches long, roughly the size of a large fist.The kidneys' job is to filter your blood. They remove wastes, control the body's fluid balance, and keep the right levels of electrolytes. All of the blood in your body passes through them about 40 times a day.Blood comes into the kidney, waste gets removed, and salt, water, and minerals are adjusted, if needed. The filtered blood goes back into the body. Waste gets turned into urine, which collects in the kidney's pelvis -- a funnel-shaped structure that drains down a tube called the ureter to the bladder.Each kidney has around a million tiny filters called nephrons. You could have only 10% of your kidneys working, and you may not notice any symptoms or problems.If blood stops flowing into a kidney, part or all of it could die. That can lead to kidney failure. Order a copy now!

PREVIEW In every whispered interaction between insulin and cells, there lies a profound connection to the rhythms of life itself. Embracing insulin resistance is an act of profound self-love, honoring the very essence of your existence.Just like the gentle ebb and flow of the ocean's tide, insulin resistance teaches us the value of balance and adaptation. It is a reminder that we, too, are a part of nature's grand design, continuously adjusting to the changing tides of life.Embrace the beauty of insulin resistance, and you will find a newfound appreciation for the miraculous complexities of your body. Witness the symphony of health unfold before your very eyes, as your cells respond with grace and wisdom to the dance of insulin. Order a copy now!

PREVIEWPleural effusion, sometimes referred to as "water on the lungs," is the build-up of excess fluid between the layers of the pleura outside the lungs. The pleura are thin membranes that line the lungs and the inside of the chest cavity and act to lubricate and facilitate breathing. Normally, a small amount of fluid is present in the pleura.The seriousness of the condition depends on the primary cause of pleural effusion, whether breathing is affected, and whether it can be treated effectively. Causes of pleural effusion that can be effectively treated or controlled include an infection due to a virus, pneumonia or heart failure. Two factors that must be considered are treatment for associated mechanical problems as well as treatment of the underlying cause of the pleural effusion. Order a copy now!

PREVIEWLeukemia is a cancer of the blood, characterized by the rapid growth of abnormal blood cells. This uncontrolled growth takes place in your bone marrow, where most of your body's blood is made. Leukemia cells are usually immature (still developing) white blood cells. The term leukemia comes from the Greek words for "white" (leukos) and "blood" (haima).Unlike other cancers, leukemia doesn't generally form a mass (tumor) that shows up in imaging tests, such as X-rays or CT scans.There are many types of leukemia. Some are more common in children, while others are more common in adults. Treatment depends on the type of leukemia and other factors. Order a copy now

PREVIEWInterstitial cystitis (IC), often called painful bladder syndrome, is a tricky condition. It's tough to diagnose, and though treatments can make life with it better, there's no cure.Because IC has such a wide range of symptoms and severity, most experts think it might be several diseases. If you have urinary pain that lasts for more than 6 weeks and is not caused by other conditions like infection or kidney stones, you may have IC.No matter what it's called, interstitial cystitis symptoms bring a lot of challenges. The disease can affect your social life, exercise, sleep, and even your ability to work.Despite this, you can still arm yourself with facts and treatments to keep symptoms in check. Order a copy now

PREVIEWDehydration occurs when more water and fluids leave the body than enter it. Even low levels of dehydration can cause headaches, lethargy, and constipation.The human body is roughly 75 percent water. Without this water, it cannot survive. Water is found inside cells, within blood vessels, and between cells.A sophisticated water management system keeps our water levels balanced, and our thirst mechanism tells us when we need to increase fluid intake.Although water is constantly lost throughout the day as we breathe, sweat, urinate, and defecate, we can replenish the water in our body by drinking fluids. The body can also move water around to areas where it is needed most if dehydration begins to occur.Most occurrences of dehydration can be easily reversed by increasing fluid intake, but severe cases of dehydration require immediate medical attention. Order a copy now!

PREVIEWHypoglycemia is a condition in which your blood sugar (glucose) level is lower than the standard range. Glucose is your body's main energy source.Hypoglycemia is often related to diabetes treatment. But other drugs and a variety of conditions - many rare - can cause low blood sugar in people who don't have diabetes.Hypoglycemia needs immediate treatment. For many people, a fasting blood sugar of 70 milligrams per deciliter (mg/dL), or 3.9 millimoles per liter (mmol/L), or below should serve as an alert for hypoglycemia. But your numbers might be different. Ask your health care provider.Treatment involves quickly getting your blood sugar back to within the standard range either with a high-sugar food or drink or with medication. Long-term treatment requires identifying and treating the cause of hypoglycemia. Order a copy now!

PREVIEWA headache is a pain in your head or face that's often described as a pressure that's throbbing, constant, sharp or dull. Headaches can differ greatly in regard to pain type, severity, location and frequency.Headaches are a very common condition that most people will experience many times during their lives. They're the most common form of pain and are a major reason cited for days missed at work or school, as well as visits to healthcare providers.While most headaches aren't dangerous, certain types can be a sign of a more serious condition. Order a copy now!

PREVIEWAtrial fibrillation (A-fib) is an irregular and often very rapid heart rhythm (arrhythmia) that can lead to blood clots in the heart. A-fib increases the risk of stroke, heart failure and other heart-related complications.During atrial fibrillation, the heart's upper chambers (the atria) beat chaotically and irregularly - out of sync with the lower chambers (the ventricles) of the heart. For many people, A-fib may have no symptoms. However, A-fib may cause a fast, pounding heartbeat (palpitations), shortness of breath or weakness.Episodes of atrial fibrillation may come and go, or they may be persistent. Although A-fib itself usually isn't life-threatening, it's a serious medical condition that requires proper treatment to prevent stroke.Treatment for atrial fibrillation may include medications, therapy to reset the heart rhythm and catheter procedures to block faulty heart signals.A person with atrial fibrillation may also have a related heart rhythm problem called atrial flutter. Although atrial flutter is a different arrhythmia, the treatment is quite similar to atrial fibrillation. Order a copy now!

PREVIEWHyperthyroidism is a set of disorders that involve excess synthesis and secretion of thyroid hormones by the thyroid gland, which leads to the hypermetabolic condition of thyrotoxicosis. [1, 2] The most common forms of hyperthyroidism include diffuse toxic goiter (Graves disease), toxic multinodular goiter (Plummer disease), and toxic adenoma. In thyrotoxicosis, thyroid hormone levels are elevated with or without increased thyroid hormone synthesis. The most common forms of thyrotoxicosis are caused by excess intake of the thyroid hormone medication levothyroxine or result from a temporary excess release of thyroid hormone due to subacute thyroiditis. The most reliable screening measure of thyroid function is the thyroid-stimulating hormone (TSH) level. Treatment of hyperthyroidism includes symptom relief, as well as antithyroid pharmacotherapy, radioactive iodine-131 (131I) therapy (the preferred treatment of hyperthyroidism among US thyroid specialists), or thyroidectomy. Thyrotoxicosis from subacute thyroiditis is temporary and self-resolving, and the treatment is also symptom relief. Order a copy now!

PREVIEWEczema is a condition that causes your skin to become dry, itchy and bumpy. This condition weakens your skin's barrier function, which is responsible for helping your skin retain moisture and protecting your body from outside elements.Eczema is a type of dermatitis. Dermatitis is a group of conditions that cause skin inflammation. Order a copy now!