Exam 3

Coronary Artery Disease

• Major risk factor for atherosclerosis is excess of low-density lipoprotein (LDL)
– Defective LDL receptors in the arterial walls
– Increased ingestion of LDL
• Unavoidable risk factors: heredity, aging, being male
• Preventable risk factors: obesity, smoking, lack of exercise, anxiety, stress, aggression,
and diet
• Treatment
– Coronary bypass surgery
• Great saphenous vein
– Balloon angioplasty
– Laser angioplasty

Cardiovascular system
– Heart and blood vessels
• Circulatory system
– Heart and blood vessels PLUS the blood itself
• RBC, WBC, platelets, plasma/serum

The Pulmonary and Systemic Circuits
• Systemic circuit: left side of
heart
– Oxygenated blood sent to all
organs of the body via aorta
• Pulmonary circuit: right side
of heart
– Deoxygenated blood sent to
lungs via pulmonary trunk

Position, Size, and Shape
of the Heart
• Located in the
mediastinum
• Base—wide, superior
portion of heart,
blood vessels attach
• Apex—inferior end,
tilts to the left, tapers
to point

The Pericardium
• Pericardium—double-walled sac (pericardial sac) that encloses the
heart
– Allows heart to beat without friction, provides room to expand, yet
resists excessive expansion
• Parietal pericardium—outer wall of sac
– Superficial fibrous layer of connective tissue
– Deep, thin serous layer
• Visceral pericardium (epicardium)—heart covering
• Pericardial cavity—space inside the pericardial sac filled with 5 to 30
mL of pericardial fluid
• Pericarditis—inflammation of the membranes
– Painful friction rub with each heartbeat

The Heart Wall
• Epicardium (visceral pericardium)
– Serous membrane
– Adipose
– Coronary blood vessels travel
• Myocardium
– Layer of cardiac muscle
• Muscle spirals around heart
– Fibrous skeleton: framework of collagenous and elastic fibers
• Structural support and attachment
• Electrical insulation between atria and ventricles
• Endocardium
– Smooth inner lining of heart and blood vessels
– Covers the valves and is continuous with endothelium

Cardiac muscle
• has branching, striated cells, each with
a single nucleus.
• occurs in the wall of the heart.
• functions in the pumping of blood.
• is involuntary

Cardiac Muscle
• Cardiomyocytes (myocardiocytes or cardiocytes)—striated,
branched cells, one central nucleus surrounded glycogen
• Intercalated discs—join cardiocytes
– Interdigitating folds: folds interlock with each other, and increase
surface area of contact
– Prevents cardiocytes from being pulled apa