The Human Heart and Blood Flow

 Located in the Thoracic Cavity, between the two lungs and slightly to the left  About the size of a clenched fist.  Weighs around a ½ pound The Human Heart 147_1.htm

 Pericardium – protective membrane around the heart  Made up of 3 layers:  Epicardium – outermost layer, reduces friction  Myocardium – thick layer, contains cardiac muscle  Endocardium – innermost layer, contact with blood Pericardium: Protecting the Heart

 Has two sides with two chambers.  Is divided into a right and left side  The right atrium and right ventricle.  The left atrium and left ventricle Chambers of the Heart

 Blood flows through the chambers of the heart in one direction.  Valves control the blood flow and to prevent blood from back-flowing.  Blood is pumped through the system of arteries and veins.  Arteries carry blood away from the heart.  Veins carry blood toward the heart. Blood Flow

Heart pumps blood through the body through contraction. What do valves do for our heart? Heart Pumping MRI at Charite Mitte, Berlin File:Cardiac_mri_ani_sagittal_bionerd.gif MRI of a Human Heart

The Heart has four valves  Bicuspid (mitral)  Tricuspid  Pulmonary  Aortic Heart Valves

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One-way valves are vital to move blood in the correct direction Heart Valves 2006 Patrick J. Lynch, medical illustrator ee_tricuspid_valve.jpg Tricuspid Valve Cross section of the heart, focusing on the Aortic Valve 2006 Patrick J. Lynch, medical illustrator

The Heart and the Path of Blood Exterior View of the Heart

The Heart

The Heart and the Path of Blood Interior View of the Heart, with the path of the blood

Ventricular Septal Defect The most common congenital heart defect Muscular wall (septum) separating the bottom ventricles doesn’t fully form. The hole allows oxygen rich blood to leak from the left ventricle into the right ventricle, instead of moving into the aorta and on to the body.

Possible complications of VSD:  Heart failure  Pulmonary Hypertension (high blood pressure in the lungs)  Endocarditis (infection of the heart)  Arrhythmias (irregular heartbeats)  Delayed growth Ventricular Septal Defect

Treatment  Small holes heal on their own or cause no symptoms  Larger holes may require surgery to stitch the hole closed or to cover the hole with a patch. Ventricular Septal Defect

 There is a hole in the muscular wall (septum) separating the top two chambers of the heart and doesn’t close properly.  Oxygen rich blood from the left atrium flows into the right atrium. Atrial Septal Defect

 Minor cases of ASD may cause no symptoms and may not require treatment.  Large defects may require surgery or cardiac catheterization to repair the hole. Atrial Septal Defect

Patent Ductus Arteriosus Before birth, a blood vessel called ductus arteriosus connects the pulmonary artery and aorta. Before birth this ductus allows blood to bypass the lungs because the baby receives oxygen through the placenta and umbilical cord.

 The ductus normally closes right after birth, however, if it does not it is called a patent ductus.  Blood that should flow through the body goes to the lungs. Patent Ductus Arteriosus

Complications & Treatment  Heart failure  Endocarditis Treatment  Infants it can be closed with medications  In older children and adults, surgery is performed to close the vessel. Patent Ductus Arteriosus

Pulmonary Valve Stenosis Blood flow from the right ventricle is slowed by narrowing at the pulmonary valve. The narrowing (stenosis) causes the right ventricle to pump harder to get the blood into the pulmonary artery.

Pulmonary Valve Stenosis Complications & Treatment Most cases are mild and do not require treatment. Often can be corrected by a balloon (pulmonary valvuloplasty) which opens the narrowed valve. Surgery might be necessary for people with multiple heart defects.

Aortic Stenosis  Defect that narrows/blocks the aortic valve opening  Makes it difficult for the heart to pump blood into the aorta, which also makes it hard to pump blood to the rest of the body.

Aortic Stenosis Complications  Heart can get bigger (hypertrophy)  Left-sided heart failure  Arrhythmias  Endocarditis  Fainting

Aortic Stenosis Treatments  Surgery to repair or replace the valve  Widening of the valve through balloon valvuloplasty

Coarctation of the Aorta  Narrowing in the hearts main artery (aorta).  Forces the heart to pump harder

Coarctation of the Aorta Complications Life threatening defect Severe high blood pressure Aortic Aneurysm (bulge in the aorta that can burst) Endocarditis Brain Hemorrhage Stroke Heart failure

Coarctation of the Aorta Treatments  Repair is recommended before 1o years of age.  Surgically remove the affected portion.  Widening the narrowed area with balloon angioplasty  Placement of a stent (holds the aorta open)

Congenital Heart Defects Transposition of the Great Vessels Tetralogy of Fallot

Common Causes of Heart Diseases Coronary Artery Disease  #1 Killer in America  Occurs from plaque buildup in your arteries (atherosclerosis).  Plaque blocks the flow of blood and increases the risk for heart attack and stroke.

Hypertension  Systolic pressure is greater than 140 mm Hg and Diastolic pressure is greater than 90 mm Hg  Common causes  Stress, anxiety, obesity, high-salt intake, aging, kidney disease, thyroid deficiency.  If left untreated can lead to stroke, kidney disease, hypertrophy and heart disease.

Congestive Heart Failure  The heart ability to pump adequately slowly diminishes  Fluid accumulates and is retained in the tissues Complications & Symptoms  Increased heart rate, greater force of contractions  Retention of fluid by kidneys  Enlargement of the heart (hypertrophy)

Myocardial Infarction  Also referred to as a heart attack  Necrosis (death) of heart muscle as a result of prolonged ischemia. Causes  Elevated cholesterol levels, which can lead to plaque build up in the coronary arteries.  Saturated fats (found mostly in meats)  Trans fat (found in meats and some oils)

 Also known as a stroke and is the No. 4 cause of death in the U.S.  Is a disease that affects the arteries leading to and within the brain.  Blood vessels that carry oxygen and nutrients to the brain is either blocked by a clot or burst (ruptures).  Blockage/rupture prevents blood & oxygen from getting to the brain. Cerebrovascular Attack

Uncontrollable risk factors for heart disease are:  Age  Men  Heredity  Post-menopausal  Race (African Americans, American Indians & Mexican Americans) Common Risk Factors

Controllable risk factors for heart disease:  Lifestyle habits (smoking)  High LDL (low density lipids) “bad” cholesterol and low HDL (high density lipids) “good” cholesterol  Uncontrolled hypertension  Lack of exercise  Obesity  Uncontrolled diabetes  Uncontrolled stress and anger Common Risk Factors

 Quit smoking  Improve your diet- Diet low in cholesterol, saturated fats, trans fat and simple sugars  Regular exercise  Control high blood pressure  Manage stress What can you do to reduce your risk?