Submitted By galina
Section: 1-Anatomy and Physiology
1.2 Discuss the meaning of Homeostasis.
Homeostasis is the ability of the body to maintain or restore its internal environment.
Homeostasis comes from two Greek words “HOMEO” meaning: THE SAME” and “STASIS” meaning “STANDING”. “Standing” or “Staying” the same is it literal meaning, but that doesn’t mean something to stay exactly the same all the time. Homeostasis means “a condition that may vary, but which is relatively constant.
Homeostasis involves the body maintaining internal equilibrium to adjust itself internally and physiologically, in response to the external environmental changes. Regulation of blood pressure, temperature, blood sugar levels, hormone levels, and enzyme levels are all a part of homeostatic processes in the human body. Problems with any of these processes can lead to serious health-hazards.
The organs which play an important role in maintaining homeostasis are the :
The kidneys are responsible for controlling blood water level and regulation of salt and ion content in the blood. The kidneys filter out small molecules from the blood to form urine. The kidneys reabsorb sugar, re-absorb as much salt as the body needs. The kidneys excrete the surplus material into the urine system.
The liver performs the function of stabilising carbohydrate metabolism and metabolising toxic substances.
The liver is the largest glandular organ of the body. It weighs about 3 lb (1.36 kg). Blood is carried to the liver via two large vessels called the hepatic artery and the portal vein. The heptic artery carries oxygen-rich blood from the. The portal vein carries blood containing digested food from the small intestine. These subdivide in the liver repeatedly, terminating in very small capillaries. Each capillary leads to a lobule. Liver tissue is composed of thousands of lobules, and each lobule is made up of hepatic cells, the basic metabolic cells of the liver.
The liver has many functions. Some of the functions are to:
1. produce substances that break down fats,
2. convert glucose to glycogen,
3. produce urea (the main substance of urine),
4. make the building blocks of proteins),
5. filter harmful substances from the blood (such as alcohol),
6. storage of vitamins and minerals (vitamins A, D, K and B12)
7. maintain a proper level or glucose in the blood.
The liver is also responsible for producing cholesterol.
The brain, helps in controlling the autonomic nervous system and endocrine system, which plays an important role in retaining the homeostasis. The brain acts as a processing centre, receiving information about the state of the body and triggering off an appropriate action of the body. One of the most important functions of homeostasis is in controlling the body temperature by sweating to cool the body and shivering to warm it up. Overheating of the body can cause sun stroke, lack of heat can cause hypothermia, Both of these can result in death.
(references: http://www.buzzle.com/articles/what-is-homeostasis.html http://www.kscience.co.uk/resources/ks4/21cscience/b4/specification.pdf http://www.mamashealth.com/organs/liver.asp)…...