Page 21 - Herlihy: The Human Body in Health and Illness, 3rd Edition

What did we learn today?
­We learned about matter and energy.
­We learned that everything that surrounds us is the combination of some of the 112
elements that exist in our planet; 92 of those are natural elements. The reason that
matter is so different is the different proportion of those elements.
­We also learned that the four most abundant elements are Carbon, Hydrogen,
Oxygen, and Nitrogen.
­The most abundant element in our body is Oxygen.
­We found out that when elements combine, they form molecules or compounds that
are classified into organics and inorganic based in the presence or absence of Carbon,
the so called, “element of life”. The most important organic compounds are
Carbohydrates that our body uses as the main source of energy. Lipids or fats that our
body needs for insulating our body, to manufacture cell membranes and also hormones,
and proteins, that our body uses for building and repair.
­We learned that the elements combine with others by acquiring or donating electrons
(ionic bonding), by sharing electrons (covalent bonding), or because the attraction of
a positive and negative charges of hydrogen.
­We learned about the subatomic particles of the atom, the positive proton, the
negative electron, and the neutron that does not carry an electrical charge.
­We understood that elements have different names based in the number of protons
of the nucleus, (Atomic number). We also learned that some elements have isotopes,
which are the same elements, but with different number of neutrons. Example the
“heavy” hydrogen” that has one neutron and his atomic weight or mass is 2. ( The normal
Hydrogen has a atomic mass of 1. Atomic mass=to number of protons +number of
neutrons.)
­Finally, we learned about the PH scale. This is a scale the measures the acidic or the
alkalinity of a substance. PH stands for “pressure or concentration of Hydrogen ion”.
An ion is an element that carries an electrical charge. (When an element has different
number of protons and electrons, become an ion, cation is a +ion, anion is –ion.).
­We were explained that just like the body needs to have normal vital signs to be
considered in a homeostatic balance, a blood PH of 7.35 to 7.45, represents what is
normal for our body. CO2, a waste product produced for our body in order to create
ATP (energy), is highly associated with the blood PH. Any disorder that makes you
retain or remove CO2 excessively could alter your PH.
­One thing that I learned about the elements, is that they are represented by a symbol,
which usually is the first one or two letters of the name (Oxygen , O. Hydrogen, H.
Calcium, CA. ) There are others like Sodium, (Na), Potassium, (K) that do not fit the
description. Something also, I will not be ever intimidated any more by Na3H4CA5,
because basically is saying that is a compound that has 3 elements of Sodium, 4
elements of Hydrogen and 5 elements of Calcium.