Physiology is the study of the processes that make life possible; Anatomy is the architecture or structure where these processes take place. Your epidermis is showing! Skin --as part of the integumentary system-- is the most familiar and forms the border between self and other. This system protects the inner viscera from infection and damage. The integumentary system with all its layers --epidermis, dermis, and subcutaneous fat-- provides information about the environment. Direct information such as touch, temperature, pressure, and vibration. Moreover, the integumentary system helps provide structure and protection for special senses such as vision, hearing, smell, and taste. Sensory information is transported by the nervous system to the brain. The brain is a matrix of neurons that is the processor of information, regulate the body, and produce thought. The spinal cord is the central neural highway connecting the brain to the periphery. Some information doesn't need to go the brain and can be managed at this level in the form of a spinal reflex. The brain controls movement through motor neurons connecting to the musculoskeletal system. Some bone groups like the skull and ribs protect delicate organs like the brain and lungs. Skeletal muscle provides voluntary movement through changes in skeletal position. This lever and fulcrum system allow us to walk, talk and breathe. Cardiac muscle makes up the heart and smooth muscle makes gastrointestinal system and other hollow viscera move. Peristalsis is the movement of food through the gastrointestinal system -- from mouth to anus. This system processes food by absorbing nutrients, separating and excreting solid waste. Liquid waste is filtered by kidneys and transported for excretion (micturition) by the urinary collecting system -- the ureters, bladder, and urethra. Located nearby is the reproductive system. For propagation of species, humans can be divided into male and female. This division allows for specialized male reproductive organs to produce and transport sperms and female reproductive organs to produce eggs. Moreover, the female provides the sperm fertilized egg the environment to continue to grow and develop until birth. The process by which a boy develops into a man and a girl develops into a woman is a long-term process that in great part is regulated by hormones such as testosterone and estrogen. This longer-term regulation of the body is part of the endocrine system. Endocrine glands don't have ducts and release hormones directly into the blood. Examples of these glands are the hypothalamus, pituitary, pineal glands in the brain and the thyroid and parathyroid glands in the neck. Oxygen is the currency of life on Earth. The brain signals the phrenic and other nerves to stimulate the diaphragm and other chest muscles to contract causing the chest wall and lungs to expand. Negative pressure, suction, causes atmospheric air to enter the lungs -- an inhalation is born. Oxygen, part of the air, makes its way through smaller air tubes until reaches the air sac-- an alveoli where there are small vascular structures called capillary beds. Here gasses go from greater to lesser concentrations. The metabolic waste gas carbon dioxide is brought by the venous part of the circulatory system. Hemoglobin is the chemical wallet in the red blood cell that carries the spent carbon dioxide to the lungs for exhalation and picks up the inhaled oxygen The heart is the muscle pump that circulates blood. The arterial system takes oxygenated blood to the peripheral organs; the venous system takes deoxygenated blood (with carbon dioxide) to the lungs. On the way back to heart. blood must fight gravity and the fluid part of blood can leak out into the tissue space -- the interstitial compartment. The lymphatic system helps regulate this space by returning excess fluid to the blood. This system also includes lymph nodes and structures including the bone marrow, spleen and thymus. The lymphatic system is also i intimately involved with immune system which fights infection e.g. helminths, amoebas, fungal, bacteria and viruses. This system also helps regulate the body’s own cellular division and proliferation.
Work Step by Step
All of these body systems work together to maintain homeostasis- the condition of balance in body processes and conditions. For example, when one eats a piece of fruit or vegetable --or any food one eats-- it moves through the digestive system where various enzymes promote catabolism of the complex food chemicals into the simpler nutrient molecules like glucose and fatty acids. The simple nutrients are transported by the circulatory system to tissues of other systems, such as the nervous, and respiratory systems. The nourishment enables the other systems to function normally so we are able to breathe ( respiratory system), feel (nervous system), move (musculoskeletal system), excrete ( urinary system) and defend our internal environment (integumentary and immune systems). The endocrine and reproductive systems that are so important for production and growth of offspring are also dependent on nutrition and respiration. Most important of all for our functions as human beings are the processes of the central nervous system, especially those of the cerebral cortex. These are the processes that make us human. They, also, depend on the balanced, normal working of the other physiological processes of the body.