Muscular body

Exposure to excessive amounts of lead over a long period of time (chronic exposure) increases the risk of developing certain diseases. The parts of the body which may be affected include the blood, nervous system, digestive system, reproductive system, and kidneys. These effects include anemia, muscular weakness, kidney damage, and reproductive effects, such as reduced fertiHty in both men and women, and damage to the fetus of exposed pregnant women. 

The human body has more than 600 muscles. The body s movement is performed by muscle contractions, which are stimulated by the nervous system. This system links muscle tissue to the spinal cord and brain. The network of nerve cells which carries the brain s signals directs the flow of muscular energy. Most muscular activity occurs beyond the range of the conscious mind. The body, working through the neuromuscular network, manages... 

Do not abruptly discontinue use of the antiparkinsonism drugs Neuroleptic malignant-like syndrome may occur when the antiparkinsonism drugs are discontinued or the dosage of levodopa is reduced abruptly. The nurse carefully observes the patient and reports the following symptoms muscular rigidity, elevated body temperature, and mental changes... 

Skeletal muscle utilizes glucose as a fuel, forming both lactate and CO2. It stores glycogen as a fuel for its use in muscular contraction and synthesizes muscle protein from plasma amino acids. Muscle accounts for approximately 50% of body mass and consequently represents a considerable store of protein that can be drawn upon to supply amino acids for gluconeogenesis in starvation. 

Table 8 5 shows that each of the four common s-block ions is abundant not only in seawater but also in body fluids, where these ions play essential biochemical roles. Sodium is the most abundant cation in fluids that are outside of cells, and proper functioning of body cells requires that sodium concentrations be maintained within a narrow range. One of the main functions of the kidneys is to control the excretion of sodium. Whereas sodium cations are abundant in the fluids outside of cells, potassium cations are the most abundant ions in the fluids inside cells. The difference in ion concentration across cell walls is responsible for the generation of nerve impulses that drive muscle contraction. If the difference in potassium ion concentration across cell walls deteriorates, muscular activity, including the regular muscle contractions of the heart, can be seriously disrupted. 

Potassium is the second most abundant cation in the body and is found primarily in the intracellular fluid. Potassium has many important physiologic functions, including regulation of cell membrane electrical action potential (especially in the myocardium), muscular function, cellular metabolism, and glycogen and protein synthesis. Potassium in PN can be provided as chloride, acetate, and phosphate salts. One millimole of potassium phosphate provides 1.47 mEq of elemental potassium. Generally, the concentration of potassium in peripheral PN (PPN) admixtures should not exceed 80 mEq/L (80 mmol/L). While it is safer to also stick to the 80 mEq/L (80 mmol/L) limit for administration through a central vein, the maximum recommended potassium concentration for infusion via a central vein is 150 mEq/L (150 mmol/L).14 Patients with abnormal potassium losses (e.g., loop or thiazide diuretic therapy) may have higher requirements, and patients with renal failure may require potassium restriction. 

Manometry Measurement of pressures within organs of the body. Manometry is often used to indicate muscular activity in motile tubes such as the esophagus. 

Symptoms of intoxication in humans caused by accidental ingestion of Kou-Wen plants have been described as follows. The effect on the digestive system starts with loss of appetite and turn of the stomach, and continues to severe abdominal pain and intestinal bleeding. The effect on the respiratory system presents as breathing difficulties which finally lead to death by respiratory failure. The effect on muscle innervation usually results in generalized muscular weakness and paralysis of the limbs. The effect on the circulatory system starts with heartbeat disorders and a drop in blood pressure, but heart failure is not a common cause of death. In addition to dilation of pupils, a drop in body temperature and proliferation of white blood cells have also been obseryed (70). 

Fig. 8.6 The muscular structure and endocrine glands of man with some specially required elements indicated. (Adapted from Purves et al., Life - the Science of Biology (5th ed.). Associates, Inc. and W.H. Freeman, Sunderland, MA.) Note that organs such as liver are rich in other elements, for example, iron. The large part of the body is linked by internal bones.

The Body Mass Index (BMI) is used to determine whether a person is at a healthy weight, overweight or obese. BMI has some limitations, in that it can overestimate body fat in people who are very muscular and it can underestimate body fat in people who have lost muscle mass, such as many elderly. 

Figure 1.1 The body mass index (BMI) is a formula that calculates whether a person is an ideal body weight, overweight, or obese. The formula used to calculate BMI considers a person s weight and height. BMI has some limitations. It may not be accurate for people who are very muscular, such as bodybuilders, and people with very little muscle mass, such as the elderly. BMI is one of several factors health-care providers consider when they determine whether a person is overweight or obese. Note that this BMI chart is designed for adults who are age 20 or older.

BMI (and percentile of BMI) is only one factor in determining a person s weight-related health risk. Having a BMI in the healthy range does not necessarily mean that a person is fit and healthy. BMI does not take into account lean body mass or body frame. A muscular, large-framed person s BMI could indicate that he or she is obese, but other factors would show that this is not the case. 

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