The Heart The Cardiovascular System Principles of Health Science

Objectives Identify the main elements of the circulatory system Identify the basic anatomy of the cardiovascular system Define and decipher common terms associated with the cardiovascular system Describe the flow of blood through the heart Recognize diseases/disorders of the cardiovascular system

Facts The heart is a muscular organ that pumps blood through the body, circulating a continuous supply of oxygen and nutrients to the cells. The Heart is fully formed by the 4th week of embryonic development It will continue to pump endlessly until death. Size -approximately the size of a person’s fist The Heart is located in the mediastinum

Facts According to the American Heart Association: Your heart beats an average of about 70 beats a minute Therefore our heart beats about 100,000+ times in one day and about 35 million times in a year. During an average lifetime, the human heart will beat more than 2.5 billion times.

Scenario A 54-year-old man is experiencing chest pain and shortness of breath. The pain started approximately 45 minutes ago. The patient states the pain, which feels like tremendous pressure, is mostly on the left side of his chest and radiating down his left arm. He has taken two Nitroglycerin tablets with no relief. You notice he is pale and diaphoretic. He is most likely experiencing… ???

Anatomy-The Heart Wall There are three layers of tissue are surrounded by a double- membrane sac called the pericardium The epicardium is the first layer of the heart The myocardium is the middle muscular layer of the heart The endocardium is the inner layer and also forms the heart valves

Anatomy of the Heart Atria-The two upper chambers of the heart Ventricles-The two bottom chambers of the heart Septum -the muscular wall dividing the heart into right and left halves Heart valves -prevents the backflow of blood Superior and inferior vena cava -the largest veins in the body; receive deoxygenated blood from all parts of the body Pulmonary arteries -carry deoxygenated blood to the lungs from the right ventricle Pulmonary veins -carry oxygenated blood to the left atrium from the lungs Aorta-the largest artery in the body; carries oxygenated blood to distribute to all parts of the body

How Does Blood Flow Through the Heart? Blood flow through the heart begins in the right atrium, which receives deoxygenated blood from the inferior and superior vena cava The right atrium contracts, and blood passes through the tricuspid valve into the right ventricle. The right ventricle contracts, and blood passes through the pulmonary valve and into the lungs via the pulmonary artery (the only artery in the body that carries deoxygenated blood).

How Does Blood Flow Through the Heart? Oxygenation occurs in the lungs, and the blood returns to the left atrium through the pulmonary veins (the only veins in the body that carry oxygen-rich blood). The left atrium contracts, and blood passes through the mitral (bicuspid) valve into the left ventricle. The left ventricle contracts, and oxygen-rich blood is sent out to the body through the aortic valve and out to the aorta (the largest artery in the body).

What is Blood Pressure? Blood Pressure is a measurement of the force on the walls of your arteries as your heart pumps blood through your body and is measured by mmhg. There is a top and a bottom number. Systole-is the top number and it is the maximum pressure formed during a ventricular contraction Diastole-is the bottom number and it is the minimum pressure during ventricular relaxation and during atrial contraction. Normal blood pressure is about 120/80. Normal Ranges: Systolic = 100 – 140 mm Hg Diastolic = 60 – 90 mm Hg Abnormal Ranges: Hypotension is a systolic pressure of < 90 mm Hg Hypertension is a systolic pressure of > 150 mm Hg and / or diastolic > 90 mm Hg

Diseases of the Heart Arteriosclerosis-hardening of the arteries due to calcium deposits Atherosclerosis-Hardening of the arteries due to fatty deposits which are caused by: * increase in blood lipids (fats) *High blood pressure *Smoking *Obesity *Physical inactivity Hypertension- high blood pressure which increases the workload of the heart

Other Diseases of the Cardiovascular System Aneurysm – a weak section in the wall of an artery that balloons out and ruptures from the pressure of the blood Thrombus – a fixed clot composed of fatty plaques or calcium deposits Stroke – brain infarct caused by decreased oxygen supply to the brain due to a clot or hemorrhage

Cardiovascular System Abbreviations Angi/o -- vessel Arteri/o -- artery Atri/o -- atrium Ather/o -- fatty plaque Cardi/o – heart Cor/o OR coron/o –heart Emia -- blood or blood condition Hem/a OR hem/o OR hemat/o – blood Thromb/o – clot Valv/o -- valve (leaf) Vas/o – vessel Ven/o OR ven/a OR ven/I – vein

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