The Heart

Functions of the heart Blood pressure Blood pressure Routing blood Routing blood One-way blood flow One-way blood flow Regulate blood supply Regulate blood supply

superior vena cava aortic arch right atrium

atria) Coronary Arteries (away) and Veins (to atria) nourish the heart itself, since it is lined inside and acts mainly as a pump. - CA feeds the heart. - CA feeds the heart. CV takes old blood from myocardium - CV takes old blood from myocardium.

Heart - located within the thoracic cavity in the area between the pleural membranes (lungs) called the mediastinum.

Superior vena cava Aorta Right Atrium Tricuspid valve Right ventricle Inferior vena cava

Right Pulmonary artery Left pulmonary artery Left pulmonary veins Bicuspid AV valve Left Ventricle Interventricular septum

Rt. pulmonary artery Rt. Pulmonary veins Interventricular septum Descending aorta Semi-lunar valves

Biscuspid valve Biscuspid valve is also called a “Mitral valve” as it resembles a bishop’s mitre.

Heart with pace- maker in cadaver.

Superior vena cava Inferior vena cava Right Atrium

Tricuspid valve Right Ventricle

Pulminary semilunar valve Pulminary trunk

Left atrium Pulminary veins

Bicuspid (mitral) valve Left ventricle

Aortic (semilunar) valve Aorta

Superior Vena Cava - Inferior Vena Cava - Right Atrium A D E B F G C D.P ulmonary Artery - Left Artium - Left Ventricle

Tricuspid valve ---  Right Ventricle A. --D. --D. E. E. B. B. C. C. Aortic Arch (Aorta) -----> D. Pulmo nary nary <-Veins <-Veins <-Bicuspid valve valve

Know the path of blood through each part of the heart.

Blood flow through the heart

Blood to lower body through the diaphragm : Descending Aorta Descending Aorta – blood to body Inferior Vena Cava – blood to heart ESOPHAGUS is only other tube through diaphragm.

Slightly larger than your fist.

Chordae tendinae Chordae tendinae keep AV valves from prolapsing.

Tricuspid valve chordae tendinae in action Tricuspid valve and chordae tendinae in action in action in action

Heart Arteries Arterioles CapillariesVenules Veins Blood path through the “plumbing.” Insert: Smart Art

Click on the picture at right to see more animations of the heart to better understand heart sounds and how the heart operates.

Murmurs Murmurs: Abnormal heart sounds due to faulty, leaky valves. – “lubbswish” Blood leaking back through the valve. Stenosis: Abnormal heart sound due to STIFF valves. 1st - “swishlubb” Valve is slower to close at the onset. eractive/cardiology-virtual- lab

Pericardium (epicardium) is the serous membrane surrounding the heart.

Myocardium Myocardium is the musclular (myo – muscle) portion of the heart.

Endocardium – simple squamous epithelial lining of the heart.

Endocarditis -Inflammation of the endocardium, affecting heart valves mainly. May lead to scarring and stenoses. Stenosed heart valve - A narrowing of a valve due to scarring or damage, causing a “swishing” sound prior to closure of the stenosed valve.

Tachycardia - FAST heart rate (>100 BPM) Toxins, fever, or other nervous stimulants. Bradycardia Bradycardia - SLOW heart rate (<60 BPM) Athlete’s, poor SA node function, nerve disorder.

Atrial fibrillation : Atrial fibrillation : Disorder in about 2.2 million Americans. During atrial fibrillation, the atria quiver instead of beating effectively. Blood isn't pumped completely out, so it may pool and clot. If a blood clot leaves the atria and lodges in an artery in the brain (thrombosis), a stroke results. ~15 percent of strokes occur in people with atrial fibrillation

Angina pectoris Angina pectoris is recurring chest pain caused by decreased blood supply to the heart. - Common symptom of coronary artery disease. (Accumulation of plaque on the inner walls of the coronary artery restricting blood flow to the heart.)

Myocardial infarction Myocardial infarction - commonly called a heart attack, is the death of heart muscle resulting from the sudden blockage of a coronary artery by a blood clot. Blockage deprives the heart of blood and oxygen.

Read your textbook and familiarize yourself with other heart conditions. e_pictures_slideshow/article.htm.

“Blue Baby” Syndrome.

Tetralogy of Fallot (Blue Baby): Characterized by several congenital heart defects: ♥ Ventricular septal defect (hole in interventricular septum) ♥ Aorta slightly displaced ♥ Pulmonary semilunar valve is narrow ♥ Thicker right ventricle myocardium.

Interventricular septum has a hole in it, allowing low O 2 blood to go to left ventricle, back to body prior to being reoxygenated via lungs.

Electrical Activity of the Heart 1.Sinoatrial (SA) node – “Pacemaker” Produces action potentials to stimulate heart contractions. 2.Atrioventricular (AV) node – slower action potential to ensure ventricles beat after atria.

A B C D