By K. Yugul. State University of New York College at Cortland. 2018.
The continuous one- lining order 200 mg cefixime overnight delivery, a thick and bulky interlining discount cefixime 200mg overnight delivery, and an outer layer of way circuit of blood through the body in the blood ves- a third fabric buy cefixime 100 mg on line, so the heart wall has three tissue layers sels is known as the circulation purchase 100 mg cefixime overnight delivery. This organ The Pericardium is located between the lungs in the center and a bit to the The pericardium (per-ih-KAR-de-um) is the sac that en- left of the midline of the body (Fig. The broad, superior base is the area of at- outermost and heaviest layer of this sac is the fibrous tachment for the large vessels carrying blood into and out pericardium. Anatomi- cally, the outer layer of this serous membrane is called the parietal layer, and the inner layer is the visceral layer, Right Left also known as the epicardium, as pre- lung lung viously noted. Normally the visceral and parietal layers are very close together, but fluid may accumulate in the region between them, the pericardial cavity, under certain disease conditions. THE HEART AND HEART DISEASE ✦ 285 Table 14•1 Layers of the Heart Wall LAYER LOCATION DESCRIPTION FUNCTION Endocardium Innermost layer of the Thin, smooth layer of epithelial Lines the interior of the chambers and heart wall cells covers the heart valves Myocardium Middle layer of the heart Thick layer of cardiac muscle Contracts to pump blood into the arteries wall Epicardium Outermost layer of the Thin serous membrane Covers the heart and forms the visceral heart wall layer of the serous pericardium Heart wall Epicardium (visceral pericardium) Myocardium Endocardium 14 Visceral pericardium Pericardial cavity Serous pericardium Parietal pericardium Fibrous pericardium Figure 14-2 Layers of the heart wall and pericardium. Table 14•2 Layers of the Pericardium LAYER LOCATION DESCRIPTION FUNCTION Fibrous pericardium Outermost layer Fibrous sac Encloses and protects the heart; anchors heart to surrounding structures Serous pericardium Between the fibrous Doubled membranous sac with fluid Fluid reduces friction within the pericardium and the between layers pericardium as the heart functions myocardium Parietal layer Lines the fibrous Serous membrane Forms the outer layer of the serous pericardium pericardium Visceral layer Surface of the heart Serous membrane Forms the inner layer of the serous pericardium; also called the epi- cardium 286 ✦ CHAPTER FOURTEEN the human heart is really a double pump (Fig. The superior vena cava brings blood Special Features of the Myocardium Head and arms Cardiac muscle cells are lightly stri- Superior Left ated (striped) based on alternating vena cava pulmonary actin and myosin filaments, as seen in artery skeletal muscle cells (see Chapter 8). These intercalated (in-TER- atrium cah-la-ted) disks are actually modified Left plasma membranes that firmly attach atrium adjacent cells to each other but allow for rapid transfer of electrical impulses Left between them. The right side of the heart pumps blood through the pulmonary circuit to the lungs to be oxygenated; the left side of the heart Healthcare professionals often refer to pumps blood through the systemic circuit to all other parts of the body. THE HEART AND HEART DISEASE ✦ 287 Brachiocephalic artery Left common carotid artery Pulmonary valve Left subclavian artery Superior vena cava Aortic arch Pulmonary trunk Right pulmonary Left pulmonary artery artery (branches) (branches) Ascending Left aorta pulmonary Right veins pulmonary Left atrium veins Aortic valve Left AV Right (mitral) atrium valve Right AV (tricuspid) Left valve ventricle Right ventricle 14 Inferior vena cava Endocardium Apex Blood high in oxygen Myocardium Interventricular Epicardium Blood low in oxygen septum Figure 14-5 The heart and great vessels. A third vessel large pulmonary trunk, which then divides into right that opens into the right atrium brings blood from the and left pulmonary arteries, which branch to the heart muscle itself, as described later in this chapter. Note that the pulmonary arteries Table 14•3 Chambers of the Heart CHAMBER LOCATION FUNCTION Right atrium Upper right chamber Receives blood from the vena cavae and the coronary sinus; pumps blood into the right ventricle Right ventricle Lower right chamber Receives blood from the right atrium and pumps blood into the pulmonary artery, which carries blood to the lungs to be oxygenated Left atrium Upper left chamber Receives oxygenated blood coming back to the heart from the lungs in the pulmonary veins; pumps blood into the left ventricle Left ventricle Lower left chamber Receives blood from the left atrium and pumps blood into the aorta to be carried to tissues in the systemic circuit 288 ✦ CHAPTER FOURTEEN in Figure 14-5 are colored blue because they are car- Four Valves One-way valves that direct blood flow rying deoxygenated blood, unlike other arteries, through the heart are located at the entrance and exit of which carry oxygenated blood. The exit valves are the semilunar (sem-e- red because they are carrying oxygenated blood, un- LU-nar) valves, so named because each flap of these like other veins, which carry deoxygenated blood. This blood goes first into the aorta (a-OR- ◗ The right atrioventricular (AV) valve is also known as tah), the largest artery, and then into the branching the tricuspid (tri-KUS-pid) valve because it has three systemic arteries that take blood to the tissues. The cusps close when the left ventricle begins to POSTERIOR POSTERIOR Chordae Left AV Cusps of Right AV tendineae valve open right AV valve closed valve Left AV valve closed Aortic Cusps of valve left AV Right AV closed valve valve open Coronary artery Cusps of aortic valve Coronary Cusps of Pulmonary Aortic valve Pulmonary artery pulmonary valve valve closed open valve open ANTERIOR ANTERIOR A Relaxation phase (diastole) B Contraction phase (systole) Figure 14-6 Valves of the heart (superior view from anterior, atria removed). THE HEART AND HEART DISEASE ✦ 289 Table 14•4 Valves of the Heart VALVE LOCATION DESCRIPTION FUNCTION Right AV valve Between the right atrium Valve with three cusps; tricuspid valve Prevents blood from flowing back and right ventricle up into the right atrium when the right ventricle contracts (systole) Left AV valve Between the left atrium Valve with two cusps; bicuspid or mi- Prevents blood from flowing back and left ventricle tral valve up into the left atrium when the left ventricle contracts (systole) Pulmonary semi- At the entrance to the Valve with three half-moon shaped Prevents blood from flowing back lunar valve pulmonary artery cusps into the right ventricle when the right ventricle relaxes (diastole) At the entrance to the Valve with three half-moon shaped Prevents blood from flowing back Aortic semilunar aorta cusps into the left ventricle when the valve left ventricle relaxes (diastole) contract; this closure prevents blood from returning to the left atrium and ensures the forward flow of blood into the aorta. The higher pressure in the pulmonary artery, described as Right ventricle Left ventricle back pressure, closes the valve and prevents blood from returning to the Inferior vena cava ventricle. Blood from the systemic circuit pressure closes the aortic valve and enters the right atrium (1) through the superior and inferior venae cavae, flows through the right AV (tricuspid) valve (2), and enters the right ventricle (3). Blood returns from the lungs in the pulmonary veins, enters the left atrium (5), and Figure 14-7 traces a drop of blood flows through the left AV (mitral) valve (6) into the left ventricle (7). This active phase is called systole (SIS-to- Only the endocardium comes into contact with the blood le), and in each case, it is followed by a resting period that flows through the heart chambers. One complete sequence of myocardium must have its own blood vessels to provide heart contraction and relaxation is called the cardiac cycle oxygen and nourishment and to remove waste products. The main arteries that supply The contraction phase of the cardiac cycle begins with blood to the muscle of the heart are the right and left contraction of both atria, which forces blood through the coronary arteries (Fig. They receive blood when the heart relaxes be- Atrial contraction is completed at the time ventricular cause the aortic valve must be closed to expose the en- contraction begins. After passing through gins in the atria at the same time that a contraction (sys- capillaries in the myocardium, blood drains into a system tole) begins in the ventricles. Although both upper and lower chambers Superior Superior Aortic arch vena cava vena cava Left pulmonary Right artery pulmonary Left veins Left atrium pulmonary Right veins atrium Right Great Inferior atrium cardiac vena vein cava Right coronary Left Coronary artery coronary sinus artery Small cardiac Left vein Right ventricle ventricle Right ventricle A Anterior B Posterior Figure 14-8 Blood vessels that supply the myocardium. THE HEART AND HEART DISEASE ✦ 291 When the ventricle relaxes, backflow of Blood flow blood closes valve and causes filling of Right Left coronary arteries coronary coronary artery artery Pulmonary valve To heart muscle (myocardium) Right AV Aortic Left AV A Ventricular contraction B Ventricular relaxation valve valve valve (aortic valve open) (aortic valve closed) Figure 14-9 Opening of coronary arteries in the aortic valve (anterior view). It is the prod- uct of the stroke volume (SV)—the volume of blood A unique property of heart muscle is its ability to adjust the ejected from the ventricle with each beat—and the heart strength of contraction to the amount of blood received. Thus, as CO HR SV Diastole Atrial systole Ventricular systole Atria fill with blood, which begins to Contraction of atria pumps blood into Contraction of ventricles pumps flow into ventricles as soon as their the ventricles. They may be fine Based on a heart rate of 75 beats/minute and a stroke volume at rest but quickly become short of breath or fatigued when of 70 ml/beat, the average cardiac output for an adult at rest is exercising or even when carrying out the simple tasks of daily about 5 L/minute.
They are initially A Review of 100 Cases and a New Rating System for separate but begin to fuse early in pregnancy cefixime 100mg free shipping. PO Box Amniocentesis is usually performed in the second 8923 generic cefixime 200 mg mastercard, New Fairfield cheap 100mg cefixime, CT 06812-8923 200mg cefixime free shipping. Common effects of aneuploidy include an and prevents the fetus, or parts of it, from becoming increased risk for pregnancy loss or, in live borns, for attached to the amnion. Fetal Down syndrome is the most common form of ane- cells, primarily derived from the skin, digestive system, uploidy in live born infants, occurring in approximately and urinary tract, are suspended within the fluid. In women smaller number of cells from the amnion and placenta are who are 35 years old, the risk of having a child with also present. Finally, the fetus produces a number of dif- Down syndrome is higher, or roughly one in 385 at deliv- ferent chemical substances that also pass into the amni- ery. These substances may be used, in some the only chromosome abnormality that may occur. Other higher-risk pregnancies, either to assess fetal lung matu- numerical abnormalities are possible, yielding genetic rity or to determine if the fetus has a viral infection. In the conditions that may be either more or less severe than second trimester of pregnancy, one particular protein, Down syndrome. Thus, a woman is often given a risk, called alpha-fetoprotein, is commonly used to screen for based solely on her age, of having a child with any type certain structural birth defects. At age 35, this total risk is It is possible to perform amniocentesis in a twin approximately one in 200. Amniocentesis in some higher-order pregnan- increased to one in 65, and, at age 45, this risk is one in cies, such as triplets, has also been reported. The dye will temporarily a previous child with, a known genetic condition; abnor- tinge the fluid blue-green. A second needle is inserted mal prenatal screening results, such as ultrasound or a into the next amniotic sac with ultrasound guidance. If blood test; or one parent with a previously identified the fluid withdrawn is pale yellow, a sample from the structural chromosome rearrangement. In the case of may make it more likely for a couple to have a child with monoamniotic (in one amniotic sac) twins or triplets, the a genetic condition. Side effects Women who have had an amniocentesis often Indications for amniocentesis describe it as uncomfortable, involving some mild pres- Amniocentesis has been considered a standard of sure or pain as the needle is inserted. This medicine has no effect on the fetus, that amniocentesis be offered to all expectant mothers but may help the mother feel more comfortable during age 35 and older. An experienced physician can, on average, because advancing maternal age is associated with an perform amniocentesis in approximately one to two increasing risk of having a baby with a numerical chro- minutes. At age 35, this risk is approxi- Common complaints after amniocentesis include mately equivalent to the risk of pregnancy loss associated mild abdominal tenderness at the site of needle insertion with amniocentesis. These usually go away within one to A person normally has a total of 46 chromosomes two days. More serious complications are significantly in each cell of his or her body, with the exception of less common but include leakage of amniotic fluid, vagi- sperm or egg cells, which each have only 23. These complications get older, there is an increased risk of producing an egg are estimated to occur in fewer than 1% of pregnancies. This leads to an egg cell In some women, complications after amniocentesis may with 24 chromosomes rather than the normal 23. Aneuploidy results in a con- out amniocentesis, is approximately 2–3% in her second ceptus (product of conception) with either too much or trimester. This, in turn, leads to abnormal or technician, the risk for an amniocentesis-related preg- 74 GALE ENCYCLOPEDIA OF GENETIC DISORDERS KEY TERMS Amnion—Thin, tough membrane surrounding the Fetus—The term used to describe a developing embryo and containing the amniotic fluid. The term embryo is Anesthetic—Drug used to temporarily cause loss of used prior to the third month. An anesthetic may either be general, associated with a loss of con- Fibroid—A non-cancerous tumor of connective tis- sciousness, or local, affecting one area only without sue made of elongated, thread-like structures, or loss of consciousness. Anesthetics are administered fibers, which usually grow slowly and are contained either via inhalation or needle injection. Fibroids are firm in con- sistency but may become painful if they start to Chorion—The outer membrane of the amniotic sac.
The form has a patient self-evaluation section and a physician assessment section purchase 100mg cefixime mastercard. The ASES standardized shoulder assessment form is offered as a baseline measure of shoulder function applicable to all patients regardless of diagnosis cheap 200 mg cefixime amex. Spaces are available to note the date of the assess- ment and the date of procedure cheap cefixime 200 mg fast delivery, if an operative procedure has been per- formed generic 100 mg cefixime with mastercard. An annotation is also present to indicate whether the patient is being seen for the first time and, if not, what the length of follow-up is. It is anticipated that many clinicians will wish to ªcustomizeº this por- tion of the form according to their needs and the format of patient de- mographic information at their parent institution. Patient self-evaluation The patient self-evaluation form is divided into three sections. The patients are asked to identify whether they are having pain in the shoulder and are asked to record the location of their pain on the pain diagram. Patients are asked whether they have pain at night and whether they take pain med- ication. The severity of pain is graded on a 10 cm visual analog scale that ranges from 0 (no pain at all) to 10 (pain as bad as it can be). The patient is asked to identify whether he or she experi- ences symptoms of instability (Fig. The sensation of instability ex- perienced by the patient is assessed quantitatively according to a visual analog scale. Patient self-evaluation: activity of daily living questionnaire Activities of daily living. The patients are asked to circle 0, if they are unable to do the activity, 1, if they find it very difficult to do the activity, 2, if hey find it somewhat difficult to do the activity, and 3, if they find no difficulty in performing the activity. The 10 questions include activities that are heavily dependant on a range of shoulder motion that is free from pain. The patients are also asked to identify their normal work and sporting activities. The cumu- lative activities of the daily living score is derived by totalling the scores awarded for each of the individual activities. Total (combined glenohumeral and scapulothoracic) shoulder motion is measured, because the ability to differentiate gleno- humeral from scapulothoracic motion is not consistent (Fig. Forward elevation is measured as the maxi- mum arm-trunk angle viewed from any direction. External rotation is measured with the arm comfortably at the side and also with the arm at 908 of abduction. Internal rotation is measured by noting the highest segment of spinal anatomy reached with the thumb. Cross-body adduc- tion is measured by measuring the distance of the antecubital fossa from the opposite acromion. Signs are graded 0 if not present, 1 if mild, 2 if moderate, and 3 if severe (Fig. Signs that are assessed include supraspinatus or greater tuberosity tenderness, acromioclavicular joint tenderness, and biceps ten- don tenderness or biceps tendon rupture. If tendon tenderness is present in other locations, the examiner is asked to note the location. Impinge- ment is assessed in three ways: (1) passive forward elevation of the shoulder in slight internal rotation; (2) passive internal rotation at 908 of flexion; and (3) at 908 of active abduction (the classic painful arc). The presence or absence of subacromial crepitus is noted as are the pres- ence or absence of scars, atrophy, and deformity. The examiner is asked to record the exact location of scars, atrophy, or deformity, if they do exist. Strength is measured in forward elevation, abduction, external rotation with the arm comfortably at the side, and internal rotation with the arm comfortably at the side. Instability is graded 0, if absent, 1, if mild (0- to 1-cm trans- lation), 2, if moderate (1- to 2-cm translation or translates to the gle- noid rim), 3, if severe (greater than 2-cm translation or over rim of gle- 228 19 Scores noid) (Fig. The presence of absence of anterior translation, poste- rior translation, inferior translation, and anterior apprehension are all noted and graded.
Side effects In addition to increasing the risk of photodermis generic cefixime 100 mg on line, an- Description gelica is considered to be a mild laxative and may cause Often described as a muscle spasm and choking sen- mild diarrhea cheap cefixime 100mg with amex. An episode of angina is not an actual heart attack order 100 mg cefixime, Interactions but rather pain that results when the heart muscle tem- No studies exist on interactions between angelica porarily receives too little blood order 200mg cefixime with amex. Given the history of may be the result of demanding activities such as exercise its long use in traditional Chinese medicine, it appears and does not necessarily indicate that the heart muscle is unlikely that there are any significant interactions with experiencing permanent damage. Angina can be subdivided into two categories: angi- Resources na of effort and variant angina. Montvale, New Jersey: Medical Angina of effort is a common disorder caused by the Economics Company, 1999. Electrocardio- vide the heart muscle (myocardium) adequate blood dur- grams are also useful in investigating other possible ab- ing rest but not during periods of exercise, stress, or ex- normal features of the heart, such as arrhythmia (irregu- citement. Patients with angina of effort have an in- For many individuals with angina, the results of an creased risk of heart attack (myocardial infarction). The stress test Variant angina is uncommon and occurs indepen- records information from the electrocardiogram before, dently of atherosclerosis, which may incidentally be pre- during, and after exercise in search of stress-related ab- sent. In some cases a more that variant angina is caused by coronary artery muscle involved and complex stress test (for example, thallium spasm that does not last long enough or is not intense scanning) is used to picture the blood flow in the heart enough to cause an actual heart attack. Angiogram Causes & symptoms The angiogram, which is a series of x rays of the Angina is usually caused by an underlying obstruc- coronary artery, has been noted as the most accurate diag- tion to the coronary artery due to atherosclerosis. In nostic test to indicate the presence and extent of coronary some cases, it is caused by spasm that occurs naturally or disease. In rare cases, angina is (catheter) is inserted into an artery located in the forearm caused by a coronary embolism or by a disease other or groin. This catheter is passed further through the artery than atherosclerosis that places demands on the heart. A dye is in- Most episodes of angina are brought on by physical jected through the catheter to make the heart, arteries, and exertion, when the heart needs more oxygen than is blood flow clearer on the x ray. Emotional series of “moving” x rays, shows the blood flowing stress, extreme temperatures, heavy meals, cigarette through the coronary arteries. This will reveal any possi- smoking, and alcohol can also cause or contribute to an ble narrowing that can cause a decrease in blood flow to episode of angina. Angina causes a pressing pain or sensation of heavi- ness, usually in the chest area under the breast bone Treatment (sternum). In most cases, the symptoms Controlling existing factors that place the individual at are relieved within a few minutes by resting or by taking risk is the first step in addressing artery disease that causes prescribed angina medications. These risk factors include cigarette smoking, high blood pressure, high cholesterol levels, and obesity. Diagnosis Once the angina has subsided, the cause should be determined and treated. Howev- marily including regular exercise, reduction of dietary er, other diagnostic testing is often required to confirm or sugar and saturated fats, and increase of dietary fiber. In recent years, several specific cholesterol-lowering treatments have gained the attention and interest of the public. One of the most recent popular treatments is garlic Electrocardiogram (ECG) (Allium sativum). Some studies have shown that garlic can An electrocardiogram is a test that records electrical reduce total cholesterol by about 10% and LDL (bad) cho- impulses from the heart. The resulting graph of electrical lesterol by 15%, and can raise HDL (good) cholesterol by GALE ENCYCLOPEDIA OF ALTERNATIVE MEDICINE 2 87 10%. Al- toms of angina by increasing the diameter of the blood though its effect on cholesterol is not as great as the effect vessels that carry blood to the heart muscle. Nitroglyc- achieved by medications, garlic may help in relatively erin is taken whenever discomfort occurs or is expected. Or it may be administered transdermally, by placing a medicated patch directly on the skin. In late 2001, a study reported that the drug ed States under the trade name Cholestin, has been used in Nicorandil had become the first to demonstrate a reduc- Chinese medicine to treat heart maladies for hundreds of tion in risk of angina and to improve symptoms in patients years. Additional herbal remedies that showed a significant decrease in cardiovascular death, may help lower cholesterol include oats (Avena sativa), al- nonfatal heart attack, and stroke compared to patients in a falfa (Medicago sativa), fenugreek (Trigonella foenum- control group that received a placebo and aspirin. In particular, hawthorn extract onto the blocked artery to bypass the blocked portion.
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