Exchange Of Heat With The Environment Conduction

As shown in Fig. 2, heat exchange with the environment occurs primarily across the skin by three processes: conduction to or from the air molecules or other substances in contact with the skin, radiation by infrared rays to or from bodies that are colder or hotter than the skin, and evaporation of water vapor in the form of sweat or respiratory secretions. Conductive heat exchange can also occur by ingestion or infusion of hot or cold substances. For example, during hemodialysis or plasma phoresis, the extracorporeal circulation of the blood normally exposes it to a cooler environment, resulting in a decrease in temperature that chills the patient unless the blood is warmed. Radiation and conduction can occur either to or from the skin, leading to either heat gain or heat loss from the body, depending on whether the temperature of the skin surface is less than or greater than that of the environment. On the other hand, evaporation from the skin always results in a heat loss. Conductive and evaporative heat exchange with the air is increased by convection, the bulk movement of air around the body. As discussed later, all these heat exchange mechanisms, as well as the rate of metabolic energy production, are regulated by the body's homeostatic mechanisms to ensure the maintenance of a constant total body heat content and, thus, a constant body temperature.

Figure 2 Heat exchange with the environment. The skin serves as an insulating layer between the body core and the environment. Heat exchange with the environment occurs by radiation to and from objects, conduction to and from the air and objects in the environment, and evaporation of water from the skin and respiratory passages.

Figure 2 Heat exchange with the environment. The skin serves as an insulating layer between the body core and the environment. Heat exchange with the environment occurs by radiation to and from objects, conduction to and from the air and objects in the environment, and evaporation of water from the skin and respiratory passages.

Heat conduction occurs by the transfer of kinetic energy between the molecules on the surface of the skin and those adjacent to the skin (e.g., air molecules and the molecules in articles of clothing). The rate of heat conduction in kilocalories per hour (jQ,cond) between the skin and the surrounding molecules is proportional to the difference in temperature between the skin and these molecules according to the relation:

Get Rid of Gallstones Naturally

Get Rid of Gallstones Naturally

One of the main home remedies that you need to follow to prevent gallstones is a healthy lifestyle. You need to maintain a healthy body weight to prevent gallstones. The following are the best home remedies that will help you to treat and prevent gallstones.

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