RISK FACTORS FOR HEART DISEASE
a) Nicotine constricts small blood vessels which raises blood pressure.
b) Weight gain causes the development of more capillaries through which
your heart must pump blood. There are 180 miles of blood vessels in every
pound of adipose. The greater the number of blood vessels, the higher
the necessary blood pressure to pump blood through them.
Below is an image of blood vessels developing atherosclerotic
c) Cholesterol & Fats
Cholesterol and triglycerides are nonpolar molecules that will not dissolve
in blood on their own; they must be transported by water-soluble lipoproteins
(made in the liver and the intestines). These lipoproteins are divided
into groups depending on their density (the more protein, the higher the
--Low density lipoproteins (LDLs) deliver cholesterol to all body parts,
bind to receptors (located on most body cells). If there aren't enough
receptors, cholesterol can't be removed from the blood.
--High density lipoproteins (HDLs) take excess cholesterol to the liver
to be metabolized. The higher the concentration of HDLs, the lower the
likelihood of heart disease.
--Very low density lipoproteins (VLDLs) carry triglycerides synthesized
in the liver to be deposited in adipose. A high fat diet increases VLDL
production; VLDLs may later be converted to LDLs.
Most of the cholesterol in the body is synthesized by the liver and cholesterol
may be synthesized from saturated fats.
Atherosclerosis is a complex chain of events leading to the development
of lipid plaques on blood vessel walls which raise blood pressure, increase
the formation of blood clots, and may block blood flow to an organ.
1) It initiated by damage to the endothelial lining (many phenomena may
cause this including high lipid content, cytomegalovirus, prolonged high
blood pressure, CO from cigarettes, homocysteine, hereditary factors).
2) This damage causes proliferation of smooth muscle and leukocytes called
monocytes invade the area. Both the smooth muscle and monocytes (and even
endothelial cells lining the blood vessel) begin to absorb lipids, primarily
cholesterol. This step occurs to some degree in everyone in childhood,
often before one year of age.
3) As a lipid plaque grows, it becomes a fibrous plaque: the lesion becomes
full of calcium, fibrous connective tissue, and debris. The smooth muscle
cells and monocytes full of lipids may die and release toxic compounds
which damage other cells; it obstructs the vessel. As the endothelial
cells are stretched, some may break off and be swept away by circulation;
with collagen exposed, blood clots form. Middle aged men who smoke, have
high blood pressure, and high cholesterol levels are 4x as likely to have
a heart attack.
SHOCK is an acute circulatory crisis
marked by low blood pressure and inadequate peripheral blood flow. As
blood pressure decreases, skin becomes clammy (pale & cool due to
decreased flow). Disorientation occurs due to inadequate brain flow and
acidosis due to lactic acid generation. After about 35% blood is lost,
heart is damaged and causes of shock become worse; it can result in death.