|
The human body consists of many interacting systems. Each system contributes to the maintenance of homeostasis, of itself, other systems, and the entire body. A system consists of two or more organs, which are functional collections of tissue. Systems do not work in isolation, and the well-being of the person depends upon the well-being of all the interacting body systems. Some combining systems are referred to by their joint names such as the nervous system and the endocrine system known together as the neuroendocrine system. Organ Systems I.jpg Organ Systems II.jpg System Clinical study Physiology Human brain NIH.jpg The nervous system consists of the central nervous system (the brain and spinal cord) and the peripheral nervous system. The brain is the organ of thought, emotion, memory, and sensory processing, and serves many aspects of communication and controls various systems and functions. The special senses consist of vision, hearing, taste, and smell. The eyes, ears, tongue, and nose gather information about the body's environment. neuroscience, neurology (disease), psychiatry (behavioral), ophthalmology (vision), otolaryngology (hearing, taste, smell) neurophysiology Skelett-Mensch-drawing.jpg The musculoskeletal system consists of the human skeleton (which includes bones, ligaments, tendons, and cartilage) and attached muscles. It gives the body basic structure and the ability for movement. In addition to their structural role, the larger bones in the body contain bone marrow, the site of production of blood cells. Also, all bones are major storage sites for calcium and phosphate. This system can be split up into the muscular system and the skeletal system. orthopedics (bone and muscle disorders and injuries) cell physiology, musculoskeletal physiology, osteology (skeleton), arthrology (articular system), myology (muscular system)[9] Diagram of the human heart (cropped).svg The circulatory system or cardiovascular system comprises the heart and blood vessels (arteries, veins, and capillaries). The heart propels the circulation of the blood, which serves as a "transportation system" to transfer oxygen, fuel, nutrients, waste products, immune cells, and signalling molecules (i.e., hormones) from one part of the body to another. The blood consists of fluid that carries cells in the circulation, including some that move from tissue to blood vessels and back, as well as the spleen and bone marrow. cardiology (heart), hematology (blood) cardiovascular physiology[10][11] The heart itself is divided into three layers called the endocardium, myocardium and epicardium, which vary in thickness and function.[12] Heart-and-lungs.jpg The respiratory system consists of the nose, nasopharynx, trachea, and lungs. It brings oxygen from the air and excretes carbon dioxide and water back into the air. pulmonology respiratory physiology Stomach colon rectum diagram.svg The digestive system consists of the mouth including the tongue and teeth, esophagus, stomach, gut (gastrointestinal tract, small and large intestines, and rectum), as well as the liver, pancreas, gallbladder, and salivary glands. It converts food into small, nutritional, non-toxic molecules for distribution by the circulation to all tissues of the body, and excretes the unused residue. gastroenterology gastrointestinal physiology Skin-no language.PNG The integumentary system consists of the covering of the body (the skin), including hair and nails as well as other functionally important structures such as the sweat glands and sebaceous glands. The skin provides containment, structure, and protection for other organs, but it also serves as a major sensory interface with the outside world. dermatology cell physiology, skin physiology Gray1120.png The urinary system consists of the kidneys, ureters, bladder, and urethra. It removes water from the blood to produce urine, which carries a variety of waste molecules and excess ions and water out of the body. nephrology (function), urology (structural disease) renal physiology Male anatomy.png The reproductive system consists of the gonads and the internal and external sex organs. The reproductive system produces gametes in each sex, a mechanism for their combination, and a nurturing environment for the first 9 months of development of the infant. gynecology (women), andrology (men), sexology (behavioral aspects) embryology (developmental aspects), obstetrics (partition) reproductive physiology PBNeutrophil.jpg The immune system consists of the white blood cells, the thymus, lymph nodes and lymph channels, which are also part of the lymphatic system. The immune system provides a mechanism for the body to distinguish its own cells and tissues from alien cells and substances and to neutralize or destroy the latter by using specialized proteins such as antibodies, cytokines, and toll-like receptors, among many others. immunology immunology Sobo 1909 605.png The main function of the lymphatic system is to extract, transport and metabolize lymph, the fluid found in between cells. The lymphatic system is very similar to the circulatory system in terms of both its structure and its most basic function (to carry a body fluid). oncology, immunology oncology, immunology Illu endocrine system.png The endocrine system consists of the principal endocrine glands: the pituitary, thyroid, adrenals, pancreas, parathyroids, and gonads, but nearly all organs and tissues produce specific endocrine hormones as well. The endocrine hormones serve as signals from one body system to another regarding an enormous array of conditions, and resulting in variety of changes of function. There is also the exocrine system. endocrinology endocrinology Homeostasis The term homeostasis refers to a system that regulates its internal environment and maintains a stable, relatively constant condition; such as maintaining an equal temperature or pH. This is required for the body to function sufficiently. Without a relatively constant pH, temperature, blood flow, and position, it would be impossible for the human to survive. Many interacting systems and mechanisms act to maintain the human's internal environment. The nervous system receives information from the body and transmits this to the brain via neurotransmitters. The endocrine system may release hormones to help regular blood pressure and volume. Cell metabolism may help to maintain the blood's pH. |
About us|Jobs|Help|Disclaimer|Advertising services|Contact us|Sign in|Website map|Search|
GMT+8, 2015-9-11 21:59 , Processed in 0.135551 second(s), 16 queries .
