Cardiovascular System Anatomy Theory PDF

Cardiovascular Cardiovascular system system Assistant Lec. Dr. Mustafa A. Zainel Master Degree in Human Anatomy Ph.D. Candidate in Clinical Anatomy HMU – College of Medic...

Cardiovascular Cardiovascular system system Assistant Lec. Dr. Mustafa A. Zainel Master Degree in Human Anatomy Ph.D. Candidate in Clinical Anatomy HMU – College of Medicine TOPIC HUMAN ANATOMY – THEORY CODE PP626 CLASS 2ND YEAR SEMESTER 1ST LEC. 1 # 3 Introduction to the Cardiovascular System The cardiovascular system (CVS) is an essential network responsible for maintaining homeostasis by transporting oxygen, nutrients, hormones, and waste products to and from the body’s tissues. A deep understanding of the CVS is crucial for pharmacy students, as many drugs interact with this system, making it a frequent target for therapeutic interventions. Cardiovascular system 2 Anatomy of the Heart Cardiovascular system 3 Introduction to the Cardiovascular System The cardiovascular system (CVS) is an essential network responsible for maintaining homeostasis by transporting oxygen, nutrients, hormones, and waste products to and from the body’s tissues. A deep understanding of the CVS is crucial for pharmacy students, as many drugs interact with this system, making it a frequent target for therapeutic interventions. Cardiovascular system 4 1. Anatomy of the Heart ▪ Location & Structure ▪ Location: The heart is located in the mediastinum, between the lungs, slightly tilted to the left. ▪ Size: Approximately the size of a fist. ▪ Weight: About 250-350 grams. Cardiovascular system 5 1. Anatomy of the Heart ▪ Chambers of the Heart ▪ Atria: The upper two chambers, the right and left atria, receive blood. The right atrium receives deoxygenated blood from the body via the superior and inferior vena cava, while the left atrium receives oxygenated blood from the lungs via the pulmonary veins. ▪ Ventricles: The lower two chambers, the right and left ventricles, pump blood. The right ventricle pumps deoxygenated blood to the lungs via the pulmonary artery, and the left ventricle pumps oxygenated blood to the body via the aorta. The left ventricle has a thicker wall because it needs to generate more force to pump blood through the systemic circulation. Cardiovascular system 6 1. Anatomy of the Heart ▪ Valves of the Heart ▪ These structures ensure unidirectional blood flow: ▪ Atrioventricular Valves: ▪ Tricuspid Valve: Located between the right atrium and right ventricle. ▪ Bicuspid/Mitral Valve: Between the left atrium and left ventricle. ▪ Semilunar Valves: ▪ Pulmonary Valve: Between the right ventricle and pulmonary artery. ▪ Aortic Valve: Between the left ventricle and the aorta. Cardiovascular system 7 1. Anatomy of the Heart ▪ Heart Wall Layers ▪ Epicardium: The outermost layer, a thin layer of connective tissue. ▪ Myocardium: The muscular middle layer responsible for contraction. ▪ Endocardium: The innermost layer lining the chambers and valves. Cardiovascular system 8 Heart Wall Layers Cardiovascular system 9 1. Anatomy of the Heart ▪ Cardiac Cycle ▪ The cardiac cycle consists of two main phases: ▪ Systole: Ventricular contraction pumps blood out of the heart. ▪ Diastole: Ventricular relaxation allows blood to flow into the heart. ▪ The heart rate (HR) is determined by the frequency of this cycle, and the typical resting HR is 60-100 beats per minute. Cardiovascular system 10 1. Anatomy of the Heart ▪ Heart Sounds ▪ S1 ("Lub"): Produced by the closure of the tricuspid and mitral valves during ventricular systole. ▪ S2 ("Dub"): Produced by the closure of the aortic and pulmonary valves during ventricular diastole. Cardiovascular system 11 1. Anatomy of the Heart ▪ Conduction System ▪ The heart has a specialized electrical system that controls its rhythm: ▪ Sinoatrial (SA) Node: Located in the right atrium, it acts as the pacemaker, initiating the impulse for contraction. ▪ Atrioventricular (AV) Node: Receives the impulse from the SA node and delays it slightly to allow complete filling of the ventricles. ▪ Bundle of His: Conducts the impulse through the interventricular septum. ▪ Purkinje Fibers: Spread the impulse to the ventricles, triggering contraction. Cardiovascular system 12 1. Anatomy of the Heart ▪ Conduction System Cardiovascular system 13 2. Blood Vessels ▪ Arteries ▪ Carry oxygen-rich blood away from the heart, except for the pulmonary artery which carries deoxygenated blood to the lungs. ▪ Structure: Thick muscular walls with an elastic layer to withstand the high pressure of blood being pumped by the heart. ▪ Aorta: The largest artery in the body, branching off into smaller arteries that carry blood to various parts of the body. Cardiovascular system 14 2. Blood Vessels Veins Carry deoxygenated blood back to the heart, except for the pulmonary veins which carry oxygenated blood from the lungs. Structure: Thinner walls than arteries, with less smooth muscle. They contain valves that prevent the backflow of blood. Vena Cava: The superior and inferior vena cava are the largest veins in the body, draining blood into the right atrium. Cardiovascular system 15 2. Blood Vessels Cardiovascular system 16 2. Blood Vessels Capillaries Microscopic vessels that connect arteries and veins. Their thin walls (one-cell thick) allow for the exchange of oxygen, nutrients, and waste products between the blood and tissues. Cardiovascular system 17  3. Blood Composition ▪ Plasma: ▪ Makes up about 55% of blood and consists mostly of water, electrolytes, proteins (albumin, globulins, fibrinogen), glucose, hormones, and waste products. ▪ Formed Elements: ▪ Red Blood Cells (Erythrocytes): ▪ Main function: Transport oxygen from the lungs to tissues and carbon dioxide back to the lungs. ▪ Contain hemoglobin, a protein that binds oxygen. ▪ White Blood Cells (Leukocytes): ▪ Part of the immune system, protecting the body from infection. ▪ Include neutrophils, lymphocytes, monocytes, eosinophils, and basophils. ▪ Platelets (Thrombocytes): ▪ Small cell fragments involved in blood clotting. They work with clotting factors to prevent excessive bleeding. Cardiovascular system 18 4. Circulatory Pathways Systemic Circulation Oxygenated blood is pumped from the left ventricle to the aorta and distributed throughout the body. After exchanging oxygen for carbon dioxide at the tissue level, deoxygenated blood returns to the right atrium via the superior and inferior vena cava. Pulmonary Circulation Deoxygenated blood is pumped from the right ventricle to the lungs via the pulmonary artery. In the lungs, blood exchanges carbon dioxide for oxygen and returns to the left atrium via the pulmonary veins. Coronary Circulation The heart has its own blood supply via the coronary arteries. Blockage in these arteries can result in a myocardial infarction (heart attack). Cardiovascular system 19 5. Pharmacological Aspects ▪ Drugs Affecting the Heart: ▪ Antiarrhythmics: ▪ Used to correct abnormal heart rhythms by influencing the electrical activity of the heart. ▪ Example: Amiodarone (class III antiarrhythmic) prolongs the action potential duration. ▪ Beta-Blockers: ▪ Reduce heart rate and contractility by blocking the effects of epinephrine and norepinephrine on beta-adrenergic receptors. ▪ Example: Propranolol, used in hypertension, arrhythmias, and heart failure. Cardiovascular system 20 5. Pharmacological Aspects ▪ Drugs Affecting the Heart: ▪ Calcium Channel Blockers: ▪ Decrease the force of contraction and dilate blood vessels by inhibiting calcium ion influx in cardiac and smooth muscle cells. ▪ Example: Amlodipine. Cardiovascular system 21 5. Pharmacological Aspects ▪ Drugs Affecting Blood Vessels: ▪ Vasodilators: ▪ Dilate blood vessels, decreasing blood pressure and reducing the workload on the heart. ▪ Example: Nitroglycerin, used in angina by increasing coronary blood flow. ▪ ACE Inhibitors: ▪ Inhibit the angiotensin-converting enzyme, reducing the production of angiotensin II, leading to vasodilation and lower blood pressure. ▪ Example: Lisinopril. Cardiovascular system 22 5. Pharmacological Aspects ▪ Drugs Affecting Blood Vessels: ▪ Angiotensin II Receptor Blockers (ARBs): ▪ Block the effects of angiotensin II on its receptors, resulting in vasodilation. ▪ Example: Losartan. Cardiovascular system 23 5. Pharmacological Aspects ▪ Anticoagulants & Antiplatelets: ▪ Anticoagulants: ▪ Prevent blood clot formation by inhibiting clotting factors. ▪ Example: Warfarin, Heparin. ▪ Antiplatelets: ▪ Inhibit platelet aggregation to prevent clot formation. ▪ Example: Aspirin, Clopidogrel. Cardiovascular system 24 6. Clinical Relevance for Pharmacists ▪ Hypertension: ▪ Defined as chronic high blood pressure, often managed by lifestyle changes (diet, exercise) and medications like diuretics, beta-blockers, ACE inhibitors, and ARBs. ▪ Atherosclerosis: ▪ Characterized by the buildup of plaques (lipid deposits) in arterial walls, leading to narrowed arteries and reduced blood flow, which can result in ischemic heart disease. ▪ Myocardial Infarction (Heart Attack): ▪ Occurs when coronary arteries are blocked, preventing oxygen from reaching the myocardium, leading to tissue death. Emergency treatment often includes thrombolytics (clot-busting drugs), anticoagulants, and pain management. ▪ Heart Failure: ▪ A condition in which the heart is unable to pump sufficient blood to meet the body’s needs. Medications include ACE inhibitors, diuretics, beta-blockers, and digitalis. Cardiovascular system 25 Thanks Mustafa AbdulMona’am Zainel 0750 974 2354 [email protected] Cardiovascular system 26