LIPIDS

Here's what I understand :-

Our bodies require fat to survive as it is used in the manufacture of certain vitamins/hormones/creation of new cells
and repair of damaged cells. Without fat we would simply die. If we take a sample of blood and remove everything
except the liquid, this will be mostly made up of water. Water and fat cannot mix and this is why the body makes
particular types of cells called lipids, to transport fat around the blood. When we sleep, the Liver makes tiny
submarines and packs them with fat for transportation around the body. Most of the fat is actually made from other
substances by the Liver and less than half is actually from consumed foods. Lipids (submarines) are not sticky
and will actually happily move around the blood stream without a problem. If they are sticky, we would all be dead
of Atherosclerosis by the age of 3. Fractures in artery linings are formed through high blood pressure/drugs/free
radicals/age and herediatary problems. When fractures form, the body has to repair them quickly to prevent an
aneurysm forming and so the immune system jumps into action. Huge white cells break down cholesterol lipids to
access the fat inside to repair the artery lining. These turn into foam cells and then chemically change into a harder
substance similar to chalk (plaque). This is used to temporarily repair the damage in the artery lining until new
tissue grows over it, covering the plaque. If a piece of the plaque breaks free however, it can lodge in a coronary
artery causing heart attack or in the brain causing a stroke. Where the plaque broke free, a rough irregularity is
detected by platelet cells which will believe the artery is damaged from the outside. These will attach to the area
and form a clot, chemically signalling millions of other platelets to join in the activity. This clot will cause a secondary
blockage and will likely end up in heart failure if plaque is also blocking a coronary artery. This is why Aspirin and
stronger anti-clotting drugs are administered asap. Once plaque is lining the artery, it can only be covered with a
stent to fully open the vessel. Non drug-eluting stents will usually become coated with further plaque. Drug eluting
stents release a chemical which prevents plaque build up. Rotablation is the process of using a tiny 3mm diamond
cutter drill. It has a jet of fluid expelled from the front to push away the obliterated plaque. It leaves the artery lining
rough, so stenting is always required after. However, it removes all traces of plaque. Laser can also be used to
destroy plaque and this too requires stenting afterwards. If plaque was built up across the junction of two vessels,
a bypass was performed to overcome this. Now stenting is more common as a hole is punched through the side
of the stent to allow blood flow into the second vessel. Stents can collapse but this is very rare, around 5%.
Veins tend to last 10-15 years in some patients, 3 months in some and rarely last more than 15 years. There is
no doubt that a Vein is not up to the task of an artery which is why the left internal mammary artery is often used.
This lies between the ribs and is one of a pair, so one can be spared. It is simply cut at one end and hung down
to be grafted onto the heart. There is also the right internal mammary artery that can be used.
Coronary arteries are directly connected to the output of the left side of the heart which has very high levels of
oxygen. This blood has just returned from the lungs. It has been estimated that around 80% of the oxygen taken
with each breath is used by the heart. When a coronary artery requires bypassing, the Lima/Rima is not directly
connected to the Aorta and so I wonder if the oxygen content is high enough. Perhaps/perhaps not. Maybe this
is why many people still suffer angina post bypass surgery.

I hope this is of interest to some, and I hope it answers some of your questions.