Human body circulatory system

Stolwijk s model [19] has made mueh advaneement compared to previous multi-node models as it is not only eapable of ealeulating the spatial temperature distribution for eaeh node, but also has improved the representation of the human s circulatory system sinee the blood circulation is the most important function of human body. This model has been validated with the good agreements between the experimental and predicted results of most cases. The limitation of this model is that it cannot be used for die highly non-uniform environmental situations caused from the negligence of spatial tissue temperature gradients. 

The second example of an air pollutant that affects the total body burden is carbon monoxide (CO). In addihon to CO in ambient air, there are other sources for inhalation. People who smoke have an elevated CO body burden compared to nonsmokers. Individuals indoors may be exposed to elevated levels of CO from incomplete combustion in heating or cooking stoves. CO gas enters the human body by inhalation and is absorbed directly into the bloodstream the total body burden resides in the circulatory system. The human body also produces CO by breakdown of hemoglobin. Hemoglobin breakdown gives every individual a baseline level of CO in the circulatory system. As the result of these factors, the body burden can fluctuate over a time scale of hours. 

The human body can be considered to be made up of a series of anatomically discrete compartments connected to each other through the circulatory system and by physiological and biochemical links. When... 

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). 

Traditionally the technique of the medical physicist, magnetic resonance imaging (MRI) has long been used to investigate the internal structure of the human body and the transport processes occurring within it for example, MRI has been used to characterize drug transport within damaged tissue and blood flow within the circulatory system. It is therefore a natural extension of medical MRI to implement these techniques to study flow phenomena and chemical transformations within catalysts and catalytic reactors. 

Primary routes of entry of toxicants to the human body are dermal, gastrointestinal, and respiratory. Methods for studying these different routes are numerous, but they are perhaps best developed for the study of dermal absorption because this route is subject to more direct methodology, whereas methods for studying respiratory or gastrointestinal absorption require more highly specialized instrumentation. Additional routes encountered in experimental studies include intraperitoneal, intramuscular, and subcutaneous routes. When direct entry into the circulatory system is desired, intravenous (IV) or intra-arterial injections can be used to bypass the absorption phase. Information from this more direct route of entry (e.g., IV) should, however, be used in addition to data from the extravascular route of interest to adequately assess the true extent of absorption of a toxicant. 

Acute intravasation of barium sulfate into the circulatory system of an adult female patient following a barium enema procedure caused the compound to be deposited in blood vessels throughout the body, including the lungs, and resulted in respiratoryfailure (Cove and Snyder 1974). Acute parenteral administration of barium compounds to animals has been shown to result in paralysis of the respiratory muscles (Roza and Berman 1971). Similar respiratory paralysis is frequently encountered in cases of acute exposure in humans and animals by ingestion or inhalation. Intratracheal administration of barium sulfate into rat lungs produced a mild inflammatory reaction (Huston et al. 1952). Barium sulfate could not be removed by either polymorphonuclear leukocytes or monocytes. A tissue reaction followed however, no fibrosis was observed. Since this mode of entry is similar to inhalation, these results may be significant for cases of inhalation exposure. 

Another system that is so close to us that we seldom think of it as such is the human body. We refer to the circulatory, respiratory, or limbic systems. 

There are eleven organ systems within the human body integumentary, skeletal, muscular, nervous, endocrine, circulatory, lymphatic, respiratory, digestive, urinary, and reproductive. 

In partnership with ascorbic acid, GSH constitutes the body s major antioxidant defence system [31]. The liver is a main source of circulating GSH. It has been estimated that approximately 45 mmol (or 14 g) of GSH are released into the circulatory system of humans during a 24 h period [32]. 

Of the total amount of calcium in the human body, most (about 1 kg) is stored in the bones, whereas only 1 g is found in the circulatory system. Cellular Ca++ level is strictly controlled by hormones, cytokines and growth factors, and exerts an effect on bone formation and resorption by osteoblasts and osteoclasts, respectively (Raisz, 1988 Canalis et al., 1988, 1989 Suda et al.,... 

The human heart is a marvel of efficiency and dependability. [n a typical day an adults heart pumps more than 7000 L of blood through the circulatory system, usually with no maintenance required beyond a sensible diet and Lifestyle. We generally think of the heart as a mechanical device, a muscle that circulates blood via regularly spaced muscular contractions. However, more than two centuries ago, two pioneers in electricity, Luigi Galvani (1729-1787) and Alessandro Volta (1745-1827), discovered that the contractions of the heart are controlled by electrical phenomena, as are nerve impulses throughout the body. The pulses of electricity that cause the heart to beat result from a remarkable combination of electrochemistry and the properties of semipermeable membranes. (Section 13.5)... 

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