Muscle heart

The structure of heart muscle is similar to striated skeletal muscle but has significantly more mitochondria and sarcoplasm. 

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Targets and spirals have been observed in the CIMA/CDIMA system [13] and also in dilute flames (i.e. flames close to their lean flammability limits) in situations of enlianced heat loss [33]. In such systems, substantial fiiel is left unbumt. Spiral waves have also been implicated in the onset of cardiac arrhytlnnia [32] the nomial contractive events occurring across the atria in the mannnalian heart are, in some sense, equivalent to a wave pulse initiated from the sino-atrial node, which acts as a pacemaker. If this pulse becomes fragmented, perhaps by passing over a region of heart muscle tissue of lower excitability, then spiral structures (in 3D, these are scroll waves) or re-entrant waves may develop. These have the incorrect... 

Repeated exposures of animals to high (near-lethal) concentrations of vapors result in inflammation of the respiratory tract, as weU as degenerative changes in the Hver, kidneys, and heart muscle. These effects arise at concentrations far above those causing irritation. Such effects have not been reported in humans. The low odor threshold and irritating properties of acrylates cause humans to leave a contaminated area rather than tolerate the irritation. 

Fig. 4. Myocardial infarction occurs during insufficient delivery of oxygen to a portion of the heart muscle.

Cardiomyopathy. Cardiomyopathy, or diseased heart muscle, may reach a point at which the heart can no longer function. It arises from a combination of factors, including hypertension, arrhythmias, and valve disease. Other problems, such as congestive heart failure, cause the interrelated heart—lung system to break down. Because the heart can no longer adequately pump, duid builds up in the lungs and other areas. 

Fig. 5. In coronary bypass, an autologous saphenous vein is used to provide critical blood to the heart muscle, bypassing a blockage in the coronary artery.

Ascorbic acid is involved in carnitine biosynthesis. Carnitine (y-amino-P-hydroxybutyric acid, trimethylbetaine) (30) is a component of heart muscle, skeletal tissue, Uver and other tissues. It is involved in the transport of fatty acids into mitochondria, where they are oxidized to provide energy for the ceU and animal. It is synthesized in animals from lysine and methionine by two hydroxylases, both containing ferrous iron and L-ascorbic acid. Ascorbic acid donates electrons to the enzymes involved in the metabohsm of L-tyrosine, cholesterol, and histamine (128). 

There can be a number of underlying causes of CHE. The most prevalent is the lack of oxygenated blood reaching the heart muscle itself because of coronary artery disease with myocardial infarction (111). Hypertension and valvular disease can contribute to CHE as well, but to a lesser extent in terms of principal causes for the disease. 

When cells lie adjacent to each other in animal tissues, they are often connected by gap junction structures, which permit the passive flow of small molecules from one cell to the other. Such junctions essentially connect the cells metabolically, providing a means of chemical transfer and communication. In certain tissues, such as heart muscle that is not innervated, gap junctions permit very large numbers of cells to act synchronously. Gap junctions also provide a means for transport of nutrients to cells disconnected from the circulatory system, such as the lens cells of the eye. 

Four different kinds of muscle are found in animals (Figure 17.10). They are skeletal muscle, cardiac (heart) muscle, smooth muscle, and myoepithelial cells. 

FIGURE 17.31 Electron micrograph of a dog heart muscle. The terminal cisterna of the SR (TC-SR) is associated with the t-tnbnle (TT) by means of foot strnctnres (FS), forming a dyad junction. ME indicates the location of myofilaments. LT-SR signifies the longitudinal tubule of the SR. (From Fteischer,. S ., and Inni, M., 1989. Amiual Review of Biophysics and. Biophysical Chemisti y 18 333-364.)... 

Heart muscle, Laetobaeillus Pig heart, wheat germ Spinach... 

Pseudomonas Rat liver mitochondria, pig heart Pseudomonas Pig heart Heart muscle... 

Many local anesthetics have a selective depressant action on heart muscle when given system cally. This is useful in t.reatment of cardiac arrhythmias, and a 1 idocaine-1 ike drug with this kind of action is tocainide (2). ... 

We hear a lot these days about the relationships between saturated fats, cholesterol, and heart disease. What are the facts It s well established that a diet rich in saturated animal fats often leads to an increase in blood serum cholesterol, particularly in sedentary, overweight people. Conversely, a diet-lower in saturated fats and higher in polyunsaturated fats leads to a lower serum cholesterol level. Studies have shown that a serum cholesterol level greater than 240 mg/dL (a desirable value is <200 mg/dL) is correlated with an increased incidence of coronary artery disease, in which cholesterol deposits build up on the inner walls of coronary arteries, blocking the flow of blood to the heart muscles. 

Cardiolipins are a group of lipids found in heart muscles. What products would be formed if all ester bonds, including phosphates, were saponified by treatment with aqueous NaOH ... 

A reversible attack of chest discomfort, usually caused by an imbalance between the oxygen demand of the working heart muscle and the insufficient supply through narrow, atherosclerotic coronary arteries. 

GLUT4 is a glucose transporter exclusively expressed in tissues with insulin-sensitive glucose uptake (heart, muscle, fat). Under basal conditions, GLUT4 is predominantly located in intracellular vesicles, and is... 

Heart Blood vessels Increase in heart rate, heart muscle contractility, increase in speed of atrioventricular conduction P Decrease in heart rate, decrease in heart muscle contractility... 

The cardiotonics are dm used to increase the efficiency and improve the contraction of the heart muscle which leads to improved blood flow to all tissues of the body. The drug s have long been used to treat congestive heart failure (CHF), a condition in which the heart cannot pump enough blood to meet the tissue needs of the body. While the term congestive heart failure continues to be used by some, a more accurate term is simply heart failure. ... 

Q Decreased Cardiac Output related to decreased contradibility ot the heart muscle, adverse reactions (cardiac arrhythmias)... 

Hypokalemia makes the heart muscle more senstive to digitalis thereby increas ng thepossbility of developing digitalis toxicity. The nurse must closely, and at frequent intervals observe patients with hypokalemia forsgnsofdigitalistoxicity. 

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