Sect 7.1 - Cardiovascular

Angina (Angina Pectoris)

chest pain due to decreased O2 to the heart

Ischemia

lack of blood supply/decreased oxygenation

Necrosis

tissue death

Plaque

accumulated deposits of fats/other substances in blood vessels & start causing problems

Arteriosclerosis

narrowing & hardening of blood vessels

results from healing process and normal part of aging (scar forms from healing of damaged tissue = hardening)

Atherosclerosis

accumulation of fatty plaques inside blood vessels

as the plaques grow, cause partial/complete occlusions

Thrombosis

formation of blood clot in blood vessel

Embolism

blood clot has broken free & traveling in blood vessels of body

Myocardial Infarction

heart attack

aka MI/AMI

Heart

A hollow, four-chambered muscular organ that pumps blood throughout the body

mediastinum

The heart is located in thoracic cavity between the lungs in

Epicardium, Myocardium, Endocardium

3 layers of the heart

Epicardium

outer layer of heart

contains nerve fibers

Myocardium

middle layer of heart

heart muscle; contraction

Endocardium

inner layer of heart

blood vessels that supply blood to middle layer

upper right and left atria

lower right and left ventricles

4 chambers of the heart

left ventricle

Which ventricle is more muscular to help pump oxygenated blood out of the heart to the tissues

Coronary circulation

Right and left coronary artery

Coronary sinus

3 sources of blood

Coronary circulation

flow of blood to and from the tissues of the heart

heart receives oxygenated blood from 2 main sources, which feed directly off the aorta

Right and Left Coronary Artery

both branch into 2 arteries, which supply both ventricles, as well as the right and left atrium

provide oxygenated blood to heart

Coronary sinus

collective name given to the location where all the veins of the heart (containing deoxygenated blood) drain into

drains into the heart through an opening in the right atrium

Cardiac cycle

the events surrounding the filling and emptying of the chambers of the heart, which are coordinated by an electrical conductive system

1. Sinoatrial Node (SA node)

2. Atrioventricular node (AV node)

3. Atrioventricular bundle (bundle of HIS)

4. Purkinje fibers

Components of the Cardiac Cycle

Sinoatrial node (SA node)

pacemaker of the heart

initiates cardiac cycle, by producing an electrical pulse that spreads over both atria and causes them to simultaneously contract and force blood into the ventricles

Purkinje fibers

stimulation causes ventricles to contract simultaneously

Acute Myocardial Infarction

sudden heart attack that results from dead heart muscle tissue that is unable to contract in rhythm

occlusion of blood flow due to clot or dislodged particle(s) that prevent blood flow to tissue

Non-modifiable risk factors of CHD

family history (first degree)

gender

age

Modifiable risk factors of CHD

smoking

diet & nutrition

elevated blood pressure

obesity

exercise

lifestyle

stress

endogenous cholesterol

cholesterol manufactured in the liver

exogenous cholesterol

cholesterol obtained from diet

saturated fats and trans fats

fats that are solid at RT

raises cholesterol levels, causing atherosclerosis

unsaturated fats

fats that are liquid at RT

lower plaque-forming cholesterol

"good" mono: olive, canola, omega-3 oils

"good" poly: soybean, sunflower, corn oils

pancreatic lipase

enzyme that breaks down exogenous cholesterol in small intestine

lipoprotein lipase (LPL)

Exogenous fats are broken down further in the blood by what enzyme?

breakdown of chylomicrons → chylomicrons remnants or VLDL, then VLDL → LDL

HMG-CoA reductase

enzyme responsible for the synthesis of endogenous cholesterol (VLDL and HDL) in the liver

Lipid functions in the body

Hormone production (steroid hormones (fat-based))

Structural (cells have phospholipid cellular membrane)

Vitamin Transport

Insulation (maintain body temp)

Skin maintenance (protect/maintain health skin)

Organ and nerve production (myelin sheath made of lipids; provides cushion for organs to prevent damage)

Energy source (can use lipids for energy)

Satiation (feeling of fullness in body)

insoluble; solube

Lipids are __________ in plasma and _________ in organic solvents

Chylomicrons, VLDL, LDL, HDL

4 types of lipoproteins

protein, cholesterol esters, cholesterol, triglycerides, phospholipids

components that make up each type of lipoproteins

Fatty Acid-Binding Protein (FABP)

Soluble protein that binds to lipids that are broken down in the intestine so they can be transported through the blood as micelle-like structures to the liver

Chylomicrons

lipoprotein synthesized in the small intestines

after synthesis, delivered to muscle / fat tissue or returns to liver for excretion or recycling

largest lipoprotein

highest fat (triglycerides) content

lowest density/protein

triglycerides

Chylomicrons predominately combine with which fat?

VLDL, LDL, HDL

Which lipoprotein(s) are made in the liver?

Very Low Density Lipoprotein

What does VLDL stand for?

VLDL

lipoprotein synthesized in the liver

"very lousy" lipoprotein

comes from chylomicrons

second highest percent of triglycerides

Low Density Lipoprotein

What does LDL stand for?

LDL

lipoprotein synthesized in the liver

"lousy" lipoprotein

comes from breakdown of VLDL by LPL

highest percent of cholesterol & cholesterol esters

High Density Lipoprotein

What does HDL stand for?

HDL

lipoprotein synthesized in the liver

"GOOD" lipoprotein that removes plaque from tissues/arteries helping to decrease the risk of atherosclerosis

highest density/protein

Chylomicrons

lipoprotein responsible for thick and creamy appearance (lipemia) in serum of NON-FASTING pts

VLDL

lipoprotein responsible for thick and creamy appearance in serum of FASTING pts

LDL

lipoprotein that contributes to development of atherosclerosis

HDL

lipoprotein associated with a decrease risk of atherosclerosis

Lechin:Cholesterol Acyltransferase (LCAT)

enzyme responsible for the process of converting soluble lipoprotein molecules to less soluble molecules (turns into ester)

joins fatty acid to chylomicron, VLDL, or LDL molecules and esterifies them → less soluble → HDL binds → moves to liver (excreted / recycled)

Apoproteins

protein portion of lipoproteins that provide transport of lipids in the body

made in the liver

HDL and VLDL

apoproteins are made in the liver and are packed with which lipoproteins as they are released from the liver

Apolipoprotein A-I

apoprotein found on 90% HDL that activates LCAT

chromosome 11

Apoprotein A-I is found on what chromosome?

B-100

apolipoprotein found on LDL and VLDL

chromosome 2

B-48 and B-100 is found on what chromosome?

B-48

apolipoprotein found on chylomicrons

when chylomicron gets degraded in circulation it will stay attached which allows the liver to recognize and take care of it

Apoprotein C-1

activates LCAT and is located on chylomicrons, VLDL, and HDL

Apoprotein C-2

important cofactor for LPL and is located on chylomicrons, VLDL, and HDL

Apoprotein C-3

inhibitor of LPL

responsible for hydrolysis of triglycerides in chylomicrons to form remnants of chylomicrons or VLDL, and then LDL

Apoprotein E

aids in the uptake of chylomicron remnants in the liver and is located on chylomicrons, VLDL, and HDL

Primary/Familial and Secondary

2 types of Hyperlipoproteinemia

Primary/Familial Hyperlipoproteinemia

elevated lipids where no underlying disease is present

can be inherited

1. in-born errors of metabolism

2. increased levels of LDL and HDL

2 causes of Primary Hyperlipoproteinemia

Familial Hypercholesterolemia

Hypertriglyceridemia

Familial Hypertriglyceridemia

3 types of Primary Hyperlipoproteinemia

Familial Hypercholesterolemia

Metabolic disorder caused by problem with B-100 receptor molecule on the LDL molecule that results in body's inability to breakdown LDL molecules allowing them to accumulate

Results in increase in serum levels of LDL

1. decrease/complete absence of LDL receptors

2. inability of receptors to bind with LDL

3. inability of receptor to internalize LDL into cell

3 causes of Familial Hypercholesterolemia

Hypertriglyceridemia

excessive amount of triglycerides in the blood due to deficiency in LPL

increased levels of chylomicrons cause lipemic serum even in fasting state when LPL absent

elevated serum levels of triglycerides = 500 mg/dL

Familial Hypertriglyceridemia (FHTG)

amount of VLDL molecules is normal, but the size of the particle is enlarged

usually an increase in total cholesterol, but LDL levels are usually normal

fairly common disorder

Secondary Hyperlipoproteinemia

elevated lipids caused by an underlying disorder

results when excess lipids are not removed/used, and then deposit and accumulate in tissue and arterial walls, preventing blood flow to vital organs

Causes of Secondary Hyperlipoproteinemia

Diabetes mellitus

Medications

Nephrotic syndrome and Chronic renal failure

Hepatic disorders including biliary obstruction

Acute and Stress related conditions

Hypothyroidism

hyperlipidemia

present in ALL hyperproteinemia

clear

Interpretations of Serum Appearance

Triglycerides normal or near normal (

hazy to turbind

Interpretations of Serum Appearance

Triglycerides moderately elevated (approx. 300-500 mg/dL)

opaque to milky

Interpretations of Serum Appearance

Triglycerides exceeding 600 mg/dL

pre-menopausal women

people who exercise regularly

people who maintain a low but healthy weight

High HDL-cholesterol levels are associated with (3):

high LDL and low HDL

LDL and HDL levels in:

post menopause (low estrogen)

hypothyroidism (low thyroxine)

diabetes, type II (low insulin)

Hypoalphalipoproteinemia

the absence or a non-detectable level of Apolipoprotein A-I, leading to a decreased/absent levels of HDL

low HDL = no removal of bad lipids

Tangier's disease

Disease associated with absence or deficiency of A-I apoprotein

LCAT is unable to function and esterification of cholesterol is diminished → leads to increase LDL in circulation with no HDL action to remove

Atherosclerosis, MI, and strokes

resulting medical conditions of Tangier's disease

Coronary Heart Disease (CHD)

plaque build-up and blockage of blood vessels from excessive LDL

Apolipoprotein isoenzyme E4

apolipoprotein isoenzyme associated with Alzheimer's disease

Apolipoprotein isoenzyme E2

apolipoprotein isoenzyme that is a marker for increased atherosclerosis and possible stroke and MI

Abetalipoproteinemia

rare, genetic disorder with an absence of lipoproteins containing apolipoprotein B

diagnosed in infancy with fat absorption problems and difficulty gaining weight and growth (failure to thrive)

chylomicrons, VLDL, or LDL

Abetalipoproteinemia leads to no detectable levels of which lipoproteins?

acanthocytes

Hematological findings in abetalipoproteinemia include RBC membrane defects, including

severe vision, neurological and mobility problems

Without treatment, abetalipoproteinemia will lead to development of: