Nutrition and Human Physiology
Nutrition and Human Physiology.
Nutrition is usually defined as the sum total of all the processes involved in the intake and utilization of food substances. These processes include ingestion, digestion, absorption, transport, and metabolism of all the nutrients found in food. The council of Food and Nutrition of The American Medical Association defines nutrition as ‘ The science of food; the nutrients and the substance therein; their action, interaction, and balance in relation to health and disease; and the process by which the organism (i.e. body) ingests, digests, absorbs, transports, utilizes, and excretes food substances”. This definition makes clear that this wide field of science draws upon knowledge from several biological and social disciplines. In order to understand the nature of nutrients, to grasp the way in which they perform their roles, to perceive the consequences of their deficiency on their imbalance in diet and to be able to prepare nutritionally adequate diets it is necessary to draw upon knowledge from discipline such as biochemistry, chemistry, physiology, biophysics, genetics, microbiology, endocrinology. It is well recognized fact that dietary habits have a cultural origin, that the socioeconomic status of families may influence choice of food, and that psychological factors may play a fundamental role in an individual’s food consumption pattern. However, from the standpoint of health and physical well being, it is the biochemical and physiological function of food that is important.
The basic structural unit in the body is the cell. The body is composed of millions and millions of different types of specialized cells which perform specific functions. Each cell is a lining entity, Within the cell are large numbers of organelles which perform various functions. The cells is enclosed within a membrane which helps in maintaining the Internal environment by regulating the flow and direction of substances into and out of the cell. All cells of the same type, except for red blood cells, join together using intercellular substance to form tissues such as muscle, and bones. One or more tissues combine to form more complex structures known as organs. Thus heart which is an organ contains muscles tissue and nerve tissue. All Organs are important for the nutritional well being of an individual and they all work together in a coordinated manner. Several organs work together for a common purpose by collectively forming a system such as the digestive system, circulatory system, nervous system. All the different systems also work together in a well coordinated manner for the normal functioning of the human body. This coordination is mainly brought about by various hormones. Food provides the cells with essential nutrients. The body’s tissues, organs, and systems must work efficiently use these nutrients optimally.
Functions related to nutrition: Transporting nutrients, waste products, gases, hormones, Major role in immune response and control of body temperature.
Major Components: Lymph vessels, nodes and other lymph organs.
Function related to nutrition: Removes foreign substance from blood and lymph, combats disease, maintain tissue fluid balance, and aid in fat absorption
Major Components: Brain, Spinal cord, nerves, and sensory receptors.
Functions related to nutrition: Regulatory system: detects sensations, control movements, and controls physiological and intellectual functions.
Major Components: Endocrine glands including pituitary, thyroid, and adrenal.
Functions related to nutrition: Regulatory system: regulating metabolism, reproduction, and other functions through hormones.
Major Components: White blood cells, lymph vessels and nodes, spleen, thymus gland, and other lymph tissues.
Functions related to nutrition: Defense against foreign bodies and formation of white blood cells.
Major Components: Mouth, esophagus, stomach, intestines, and related organs.
Functions related to nutrition: Mechanical and chemical digestion of food, absorption of nutrients, and excretion of waste products.
Major Components: Kidney, bladder, and the urine carrying ducts.
Functions related to nutrition: Removing waste products from blood, regulating blood acid base balance, overall ionic and water balance.
Major Components: Skin, hair, nails, and the sweet glands.
Functions related to nutrition: Protection, regulation of body temperature, preventing water loss, production of vitamin D.
Major Components: Bones, Cartilage, and joints.
Functions related to nutrition: Support, allowing body movements, production of blood cells, and storage of minerals.
Major Components: Smooth, cardiac, and skeletal muscles.
Functions related to nutrition: Maintaining body posture, producing movements, and producing body heat.
Major Components: Lungs, respiratory passages.
Functions related to nutrition: Exchange of gasses and regulation of blood acid-base balance.
Major Components: Gonads, and genitals of males and females.
Functions related to nutrition: Process of reproduction and influencing sexual function and behavior.