What is atherosclerosis?
Atherosclerosis is the narrowing and hardening of the arteries which slowly blocks the blood flow through the arteries. It is one of the causative agents of heart attacks, strokes, and peripheral vascular disease (PVD). Arteries are blood vessels that carry oxygenated blood from the heart to different sites in the body. a thin layer of cells called the endothelium lines that blood vessels. This endothelial works to keep blood flowing without issue. Development of atherosclerosis begins by damaging the endothelium within the blood vessel. Damage can occur in a variety of ways, high blood pressure, smoking, and high cholesterol have all been linked to atherosclerosis. Formation of plagues begin to form in the endothelium and they cause the blood vessel to become rigid and restricts blood flow. Low-density-lipoprotein (LDL) or "bad" cholesterol crosses the endothelium and enters the wall of the artery, with that comes lymphocytes that aid in digestion of those LDL particles and those become lodged in the artery wall as well. This creates a plague within the artery wall. Over time this plague gets bigger and causes blockages. This is the basic pathophysiology of atherosclerosis. These plaques can rupture and travel to different sites in the body causing strokes or narrowing of the arteries in peripheral extremities.
What is the difference between the ABO blood system and the Rh blood system in terms of antibodies and transfusion reactions?
Both blood group systems can cause transfusion reactions, but with ABO incompatibility, the reaction is immediate and severe. With an Rh incompatibility, there is often a delayed transfusion reaction and it is often a mild reaction. Another difference is that the antibodies that one develops to the ABO system are naturally occurring and are IgM antibodies. Naturally occurring means that If an individual is type B, they will have Anti-A antibodies in their serum. The Rh system consists of the D, E, C, e, and c antigens. The antibodies of the Rh antibodies are IgG and are not naturally occurring antibodies. They are not naturally occurring so if someone does not have the D antigen, that means that they will not necessarily develop Anti-D.
What is DNA and RNA, How are they made up and how are they different?
DNA and RNA are nucleic acids. Nucleic acids are made up of sequences of nucleotides. The structure of nucleotides is composed of one molecule of sugar; deoxyribose in the case of DNA and ribose in RNA which is bound to one molecule of phosphate and then to one nitrogenous base. Adenine, thymine, cytosine and guanine are the four nitrogenous bases for DNA. Adenine, uracil, cytosine and guanine are the four nitrogenous bases for RNA. As you can see in RNA uracil replaces thymine as a nitrogenous base. DNA is a double-stranded helix where nitrogenous bases are connected via the intermolecular bonds called hydrogen bonds. Adenine must bind to thymine, and guanine must bind to cytosol. RNA is a single-stranded nucleotide chain.