Exchange of materials. Intensity of metabolic processes in the body

1. Exchange of materials. Intensity of metabolic processes in the body

2. Protein • Foods such as meat, eggs, and beans consist of large molecules of protein that must be digested by enzymes before they can be used to build and repair body tissues.

3. Digestibility of common proteins foods

4. BV of some common proteins • Table 2 presents the BV of some common proteins. • Considering the high protein intakes of most strength athletes (2.0 g/kg or higher) it is hard to see how BV will play a meaningful role in rating proteins in this population. In all likelihood, any decent quality protein will be as good as any other at these types of protein intakes.

5. Extracting Energy from Glucose • Two different pathways are involved in the metabolism of glucose: one anaerobic and one aerobic. • The anaerobic process occurs in the cytoplasm and is only moderately efficient. • The aerobic cycle takes place in the mitochondria and is results in the greatest release of energy. As the name implies, though, it requires oxygen.

6. Aerobic Metabolism • Pyruvate is the starting molecule for oxidative phosphorylation via the Krebb's or citric acid cycle. • In this process, all of the C-C and C-H bonds of the pyruvate will be transferred to oxygen.

7. Summary of metabolism of glucose • Basically, the pyruvate is oxidized to acetyl coenzyme A, which can then bind with the four carbon oxaloacetate to generate a six carbon citrate. • Carbons and hydrogens are gradually cleaved from this citrate until all that remains is the four carbon oxaloacetate we started with. In the process, four NADHs, one FADH and one GTP are generated for each starting pyruvate.

8. Fats • Fat molecules are a rich source of energy for the body. The first step in digestion of a fat is to dissolve it into the watery content of the intestinal cavity.

11. Notion about basal metabolism

12. Poikilothermic and homeothermic organisms • Invertebrates generally cannot adjust their body temperatures and so are at the mercy of the environment. In vertebrates, mechanisms for maintaining body temperature by adjusting heat production and heat loss have evolved. These species are called "cold-blooded" (poikilothermic) because their body temperature fluctuates over a considerable range. • In birds and mammals , the ' 'warm-blooded ' ' (homeothermic) animals, a group of reflex responses that are primarily integrated in the hypothalamus operate to maintain body temperature within a narrow range in spite of wide fluctuations in environmental temperature.

13. Temperature balance • The balance betweenheat production and heat loss is continuously beingdisturbed, either by changes in metabolic rate (exercisebeing the most powerful influence) or by changesin the external environment that alter heat loss or gain. • The resulting changes in body temperature are detectedby thermoreceptors, which initiate reflexes thatchange the output of various effectors so that heat productionand/or loss are changed and body temperatureis restored toward normal.

14. Sensory Nerve Endings in the Skin

20. Heat Exchange in the Skin

21. Scheme of reflex arc

23. Head Thermogram • Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of radio waves. The name means "below red" (from the Latininfra, "below"), red being the color of visible light of longest wavelength. Infrared radiation spans three orders of magnitude and has wavelengths between approximately 750nm and 1 mm

24. Infrared thermography • Infrared thermography is a non-contact, non-destructive test method that utilizes a thermal imager to detect, display and record thermal patterns and temperatures across the surface of an object.

25. Thermography in medical practice • Right breast cancer

26. Clothing and body temperature • Clothing is important not only at low temperaturesbut also at very high temperatures. When the environmentaltemperature is greater than body temperature,conduction favors heat gain rather than heat loss. • Heat gain also occurs by radiation during exposure tothe sun. People therefore insulate themselves in suchsituations by wearing clothes. The clothing, however,must be loose so as to allow adequate movement of airto permit evaporation. White clothing iscooler since it reflects more radiant energy, which darkcolors absorb. Loose-fitting, light-colored clothes arefar more cooling than going nude in a hot environmentand during direct exposure to the sun.

28. Summary of Effector Mechanisms in Temperature Regulation