- Health Encyclopedia

The cardiovascular system

Pulmonary Arteries - function and definition

What is Pulmonary Arteries, Definition and Function Pulmonary Arteries - The large BLOOD vessels that carry blood from the HEART to the LUNGS. The main pulmonary ARTERY arises from the right ventricle and immediately branches into the right and left pulmonary arteries. The pulmonary arteries are the only arteries in the body that transport deoxygenated

The Blood and Lymph System

Hemoglobin - what is, definition, levels

What is Hemoglobin and Definition Hemoglobin is a combined protein within erythrocytes (red BLOOD cells) that is crucial to the OXYGEN-CARBON DIOXIDE EXCHANGE. Two proteins come together to form hemoglobin: heme, a reddish pigment that contains iron, and globin. Hemoglobin bonds loosely with oxygen and carbon dioxide molecules, depending on which is in

Infectious Diseases

Gonorrhea in women/men - symptoms and treatment

What is Gonorrhea Gonorrhea - a sexually transmitted disease (STD) resulting from INFECTION with the bacterium Neisseria gonorrhoeae. N. gonorrhoeae infects 350,000 Americans each year, though public health officials believe another 350,000 people have gonorrhea that goes undiagnosed because they do not know they are infected. Gonorrhea is highly

Birthmark - types, symptoms, removal and treatment

Birthmark is a discoloration on a newborn’s SKIN present at, or that emerges within a few weeks of, birth. Birthmarks are either vascular (composed of BLOOD vessels and red in color) or pigment (patches of skin that differ in color from the surrounding skin). Though some birthmarks, especially large ones, may be permanent, many fade to become faint or

Alopecia (hair loss) - types, causes, symptoms and treatment

Alopecia is the clinical term for HAIR loss. There are numerous forms and causes of alopecia, which may be localized or widespread, temporary or permanent. Though alopecia is emotionally traumatic for many people, it does not affect health in any way though may reflect underlying health conditions. Common forms of alopecia include the

What is Esophagitis, symptoms and treatment

Esophagitis - INFLAMMATION of the ESOPHAGUS. The most common cause of esophagitis is irritation from STOMACH contents that backflow into the esophagus, such as occurs with GASTROESOPHAGEAL REFLUX DISORDER (GERD) and ACHALASIA. INFECTION resulting from HERPES SIMPLEX, CYTOMEGALOVIRUS (CMV), or yeast (Candida) also can involve the esophagus to cause

Antidiarrheal Medications - drugs - information and complications

Antidiarrheal Medications - medications that relieve DIARRHEA. Antidiarrheal medications work by slowing the activity of the gastrointestinal tract or by absorbing more fluid in the COLON (large intestine). Though diarrhea is unpleasant, doctors recommend letting the body restore its balance without medications in most circumstances of acute diarrhea. Acute

Orphan Drug definition

Orphan Drug is a DRUG to treat a rare condition. The US Orphan Drug Act of 1983 (ODA) established criteria in the United States to encourage pharmaceutical manufacturers to investigate new drugs and continue to produce approved drugs to treat conditions, such as HUNTINGTON’S DISEASE and some forms of MUSCULAR DYSTROPHY, that affect fewer than 200,000

Aging, urinary system changes that occur with

At birth the structures of the urinary system are fully developed and function under the automatic control of the NERVOUS SYSTEM. The newborn’s KIDNEYS filter BLOOD and make URINE. The BLADDER collects the urine and, when it fills to a point that triggers the micturition REFLEX, it empties to drain urine via the URETHRA to outside the body. Voluntary

Ectopic beat - additional heartbeat - definition

What is Ectopic beat An extra or additional heartbeat. Ectopic beats can be atrial, called premature atrial contractions (PACs), or ventricular, called premature ventricular contractions (PVCs). PACs are nearly always benign (do not require treatment). Though most PVCs are also benign, persistent PVCs can cause symptoms that do require treatment. CAFFEINE

Congenital Anomaly - definition

Congenital Anomaly is a physical abnormality present at birth. Congenital anomalies, also called BIRTH DEFECTS, can affect nearly any structure in the body and may be hereditary or random. GENETIC DISORDERS and exposure to teratogens (substances, such as drugs, that alter the development of the embryo or fetus) account for the majority of congenital

Cecum - definition and function

Cecum - the first segment of the COLON (large intestine) into which the ILEUM, the final segment of the SMALL INTESTINE, empties digestive matter. The cecum is a pouchlike structure located in the lower right abdomen that absorbs water from the waste, returning fluid to the body and consolidating the waste for its journey through the end stage of digestion.

Xanthelasma - definition and removal

Xanthelasma - deposits of fatty plaque that form blisterlike lesions on the eyelids, usually the upper eyelids near the corner of the NOSE. The lesions are yellowish in color and often indicate HYPERLIPIDEMIA (elevated BLOOD levels of cholesterol and triglycerides). Though harmless, the lesions can cause the eyelid to droop, obscuring vision when an upper

Oliguria - definition

What is Oliguria and Defintion Oliguria is significantly reduced URINE production that occurs as a consequence of RENAL FAILURE, DEHYDRATION, hemorrhage (massive BLOOD loss), or SHOCK. Normal adult urinary output is 1500 milliliters to 3000 milliliters per day. In oliguria urinary output is 500 ml per day or less. Oliguria indicates that the KIDNEYS are

Sudden Infant Death Syndrome (SIDS)

Sudden Infant Death Syndrome (SIDS) - the unexpected and unexplainable death of an infant under age one year, most commonly between the ages of two and four months. Researchers do not know what causes SIDS, though believe a malfunction occurs in the infant’s basic metabolic regulatory mechanisms that allows BLOOD PRESSURE, BREATHING, and body

Tamponade, cardiac - definition

Tamponade is a life-threatening compression of the HEART that prevents it from expanding to fill with BLOOD. Cardiac tamponade is most often a complication of PERICARDITIS and develops when fluid rapidly accumulates within the layers of the PERCARDIUM. The pericardium’s fibrous outer layer does not readily expand, which forces the fluid to press

Wheal - raised, blisterlike lesion on the skin

Wheal is a raised, blisterlike LESION on the SKIN that usually results from an intradermal injection such as for ALLERGY skin testing or the tuberculin skin test. Wheals also may occur in response to insect stings and topical allergic reactions (URTICARIA or hives). Wheals associated with urticaria typically itch, sometimes intensely. Wheals usually do not

Hypospadias - definition, treatment, repair and surgery

What is Hypospadias, Definition and Treatment Hypospadias is a CONGENITAL ANOMALY in which the URETHRA is shorter than normal and exits along the underside of the PENIS in a boy or into the VAGINA in a girl. Though uncommon overall, hypospadias is very rare in girls. In boys, CHORDEE (severely curved penis) often accompanies hypospadias. The preferred

Health Education

Health Education - health experts consider instruction about health and disease to be a fundamental dimension of preventive medicine. Health education formalizes such instruction within structured settings such as schools, workshops, and classes. At its most basic level, health education the form of the fundamental instruction children receive in school

Intravenous Pyelogram (IVP)

What is Intravenous Pyelogram (IVP) and Definition A diagnostic imaging procedure to evaluate the flow of BLOOD and URINE through the KIDNEYS, ureters, BLADDER, and URETHRA. IVP requires moderate preparation that typically includes taking a laxative the night before the scheduled procedure to empty the intestines so the IVP provides clear visualization of

Polydactyly - extra fingers or toes

Polydactyly is extra fingers or toes. Polydactyly may occur spontaneously and isolated (without apparent cause) or in conjunction with GENETIC DISORDERS such as PATAU’S SYNDROME (trisomy 13). Most often the extra digit is on the little finger or little toe side of the hand or foot, respectively, and is so rudimentary as to be functionless. Nearly

Retina - definition, function and diseases

Retina - the innermost layer of the EYE. The retina receives light images and converts them to NERVE impulses the OPTIC NERVE conveys to the BRAIN. The retina is two tissue-thin layers that together are less than 1⁄2 millimeter in thickness. The outer pigment layer provides a completely light-absorbing, nonreflective lining. The inner sensory layer

Amsler Grid - macular degeneration test

Amsler Grid is a basic test to detect or monitor the progression of AGE-RELATED MACULAR DEGENERATION (ARMD), a condition in which the macula, the area on the RETINA responsible for fine detail vision, deteriorates. The Amsler grid is a square with evenly spaced horizontal and vertical lines, and a dot in the center of the grid. The grid’s four corners

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Urinary diversion - Urostomy - continent and incontinent

The Urinary System |

What is Urinary diversion and Definition A surgical procedure to create a method for the storage and passage of URINE from the body after cystectomy (surgical removal of the BLADDER). Though most often necessary following cystectomy to treat BLADDER CANCER or invasive cancer of the pelvic region, urinary diversion may be necessary after traumatic injury to

Ventricular assist devices (VADs)

The cardiovascular system |

What is Ventricular assist devices (VADs) Ventricular Assist Devices - Implanted mechanical pumps that aid the native HEART, taking over some of the workload of the ventricles. Several types of VADs are available, each with somewhat different features and functions. A VAD may assist the right or left ventricle, and in some cases both ventricles, as a

Inflammatory Bowel Disease (IBD) - Symptoms and Treatment

The Gastrointestinal System |

Inflammatory Bowel Disease (IBD) is a chronic disorder in which INFLAMMATION develops alongsegments of the gastrointestinal tract. There are two forms of IBD, Crohn’s disease and ulcerative colitis. Crohn’s disease can affect any portion of the intestinal tract though most commonly involves the lower SMALL INTESTINE and upper COLON. Ulcerative

Stethoscope definition

The cardiovascular system |

What is Stethoscope and definition Stethoscope is an instrument the doctor uses to listen to sounds within the body. The cardiologist uses a stethoscope to listen to the function of the valves in the HEART, to the HEART RATE, to the flow of BLOOD through the chambers of the heart, and for abnormal sounds, such as a pericardial rub or a HEART MURMUR, that

Valvular Heart Disease - symptoms and treatment

The cardiovascular system |

The collective term for the malformations and disorders that can affect the valves of the HEART. Valvular heart disease may affect any of the heart’s four valves: mitral, pulmonary, aortic, and tricuspid. The most common forms of valvular heart disease are stenosis, in which the valve does not open completely regurgitation, also called

Xanthoma definition

The Integumentary System |

Xanthoma is a fatty deposit that forms a benign (noncancerous) LESION beneath the SKIN, though also may occur in other tissues. Xanthomas develop in people who have chronic, untreated HYPERLIPIDEMIA (elevated BLOOD cholesterol and triglycerides levels). In their most common form, xanthomas appear as yellowish blebs beneath the skin, typically rounded or

Fracture of bone - types, symptoms and treatment

The Musculoskeletal System |

Fracture is a break in a BONE. The most common cause of bone fracture is traumatic injury. Spontaneous fracture may occur in people who have health conditions such as OSTEOGENESIS IMPERFECTA, severe OSTEOPOROSIS, or BONE CANCER. Fractures may take various forms, including Types of Fractures avulsion, in which a small chip of bone breaks away closed


The Urinary System |

What is Nephrotoxins / Nephrotoxic Nephrotoxins - Substances such as medications or environmental chemicals that damage the glomeruli and the tubules within the nephrons of the KIDNEYS. Among those most commonly associated with altered kidney function and RENAL FAILURE are heavy metals such as lead, mercury, cadmium, and arsenic; exposure to these

Toxic Epidermal Necrolysis - Stevens Johnsons Syndrome

The Integumentary System |

Toxic Epidermal Necrolysis is a life-threatening inflammatory condition affecting the SKIN and underlying connective tissues, also called Stevens-Johnson syndrome. Toxic epidermal necrolysis usually results as an adverse DRUG reaction though may occur as a complication of INFECTION or CANCER. Doctors believe toxic epidermal necrolysis develops when an

Sinoatrial (SA) node definition

The cardiovascular system |

What is Sinoatrial (SA) Node and Definition A small cluster of specialized NERVE and MUSCLE fibers located in the upper wall of the heart’s right atrium. The SA node initiates the electrical pacing impulse that causes the HEART to contract. In the healthy heart the electrical impulse spreads in an orderly and synchronized pattern through the two