A. Define homeostasis
Homeostasis is the natural ability of the body to balance the internal condition of the body with changes in the external environment. An example of the homeostatic ability of the body is when we shiver when it is cold. Shivering is a result of many physiological processes in the body that have the end objective of preserving internal bodily heat in response to a drop in external temperature. The body’s homeostatic ability is very important to survival because without it, humans can barely survive. The condition in which the body is unable to maintain its internal environment despite changes in the external environment is known as homeostatic imbalance.
B. Distinguish between the terms atom ion and molecule.
Matter is composed of atoms, so atom is the smallest particle that makes up matter. The atom contains a mix of positively and negatively charged particles called protons and electrons respectively that circle a central nucleus. Other than these particles, there are also neutral particles called neutrons. When an atom contains more electrons than neutrons, then it becomes negatively charged and is then considered a negative ion. If, on the other hand, there is an excess of protons, then it becomes a positively charge ion. If, in the case there is an equal number of both, the atom then does not have any charge at all and is therefore, no longer an ion; but when two atoms with a charge each bond together and become neutral they are then considered to be molecules. Strictly speaking, molecules are two or more atoms that bond together to form a neutrally charged particle.
C. Define the term nutrient, and outline the main groups of nutrients.
Nutrients are substances or chemicals that are freely occurring in the environment and are necessary for any living organism to survive. Nutrients are indispensable to human growth and development and serve to enrich physiological and biological functions within the body. Various nutrients have different functions such as repair damaged tissue, support the immune system or contribute to homeostasis. Nutrients are divided into six major groups; these are:
Protein – proteins serve to assist in the formation and development of muscle. Some proteins have special functions in breaking down other substances or in initiating physiological responses; these special groups of proteins are called enzymes.
Carbohydrates – carbohydrates help the human body as a good source of energy for strenuous activities or even just for regular routine bodily functions which require energy, such as sleeping.
Fats – are nutrients that allow the body to store heat. Fats also help in lubricating internal organs and padding joints.
Vitamins – are organic compounds that are needed by the body in small helpings. Vitamins have specific effects on the body, such as Vitamin C which helps in maintaining a healthy immune system.
Minerals – are inorganic substances that are also needed by the body to function properly; the mineral Iron for instance enhances the blood’s ability to store oxygen for consumption by many biological tissues.
Water – the human body is mostly water, 61.8% of its weight, to be specific. Water ingested helps in maintaining the water inside the body. It also aides in regular excretion of fluid waste as well as in moisturizing and lubricating the body. Most tissues in the body owe their elasticity to water.
D. Name 5 organs inferior to the clavicles and describe the function of each in only one sentence.
Heart – The heart is a muscular pump the size of the fist that functions mainly to circulate oxygenated blood throughout the body and return unoxygenated blood to the lungs for oxygenation.
Colon – The colon is the end part of the intestines also called the large intestines which function to temporarily store undigested food or materials that are no longer useful to the body before it is excreted as feces through the anus which is also the external part of the colon.
Kidneys – The kidneys are two bean shaped organs located to the left and right lateral sides of the lumbar vertebrae that filter out the impurities in the water taken in by the human body as well as functions in the metabolism and excretion of certain chemicals.
Bladder – The bladder is a large membranous sack that functions to store excess water in the body before it is excreted through urination.
Pancreas – The pancreas is a finger-shaped gland that functions as a regulator of blood sugar levels as well as in the production of the body’s insulin requirements.