Cardiovascular System: Blood Vessels, Heart, and Circulation - PDF

Cardiovascular System Activity 3 and 4 : Pharma 121L Objectives 1. To identify the anatomical structures of the heart and describe their functions. 2. To describe blood flow through pulmonary and systemic circulation, listing major heart structures involved. 3. To differentiate art...

Cardiovascular System Activity 3 and 4 : Pharma 121L Objectives 1. To identify the anatomical structures of the heart and describe their functions. 2. To describe blood flow through pulmonary and systemic circulation, listing major heart structures involved. 3. To differentiate arteries, veins, and capillaries. 4. To describe the blood flow through pulmonary and systemic circulation. 5. To explain the occurrence of pulse and identify pulse sites in the human body. 6. To study cardiac output, the factors affecting such, and relate it to blood pressure. 7. To measure systolic and diastolic blood pressure. 8. To discuss the factors that maintain systemic blood pressure. 9. To explain the intrinsic and nervous mechanisms involved in the regulation of blood pressure. Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Topics to Discuss: I. Physiology of Heart and Blood vessels II. Circulatory Routes III. The Conduction System IV.Pulse and Blood Pressure V. Pathophysiology of CV Disorders Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Physiology of the Heart Heart - Located in the mediastinum, the heart is enclosed by the pericardium, consisting of an outer fibrous layer and an inner serous layer. - The heart wall has three layers: Epicardium: Outer layer Myocardium: Thick middle layer of cardiac muscle Endocardium: Inner lining - Contains four chambers: two atria (upper) and two ventricles (lower). Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Heart Valves Blood Flow Through the Heart Blood Vessels Three layers: Tunica interna (intima): Inner lining in direct contact with blood. Tunica media: Middle layer of smooth muscle and elastic fibers; regulates vessel diameter. Tunica externa: Outer layer providing support and protection. Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy  Blood Vessels Characteristic Arteries Veins Capillaries Allow exchange of gases, nutrients, Carry blood away from the General Function Carry blood toward the heart and wastes between blood and heart tissues Single layer of endothelial cells Thick, muscular, and elastic Thin walls with less muscle Structure of Wall (tunica intima) for rapid exchange of walls and elasticity substances Narrow lumen (smaller than Wider lumen (larger than Extremely small lumen, just wide Lumen (Inner veins) to maintain high arteries) to accommodate enough for single red blood cells to Diameter) pressure slow-moving blood pass through No valves (except in the aorta Have valves to prevent Valves and pulmonary artery, which backflow of blood due to low No valves have semilunar valves) pressure Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Circulatory Routes Pulmonary Circulation Systemic Circulation Coronary Circulation Hepatic Portal Circulation Fetal Circulation  Conduction System of the Heart Conduction System - An inherent and rhythmical electrical activity is the reason for the heart’s lifelong beat. - Autorhythmic fibers in the SA node would initiate an action potential about every 0.6 second, or 100 times per minute. - The action potential initiated by the SA node travels along the conduction system and spreads out to excite contractile fibers. Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy The Action Potential Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Pulse and Blood Pressure  Pulse - The pulse is the rhythmic expansion and recoil of arteries caused by the pressure waves of blood being ejected from the heart during systole (ventricular contraction). - Normal: 60-100 beats per minute (bpm). - fast pulse : tachycardia - slow pulse : bradycardia Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy  Blood Pressure - the force exerted by circulating blood against arterial walls as it moves through the circulatory system - Two Components: Systolic Pressure : pressure in arteries when the heart contracts and pumps blood. Diastolic Pressure : pressure when the heart relaxes between beats. - Normal < 120/80 mmHg - BP is determined by cardiac output, blood volume, and vascular resistance. Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy  Blood Pressure BP = CO x VR Cardiac Output (CO) = HR x SV - volume of blood pumped out by the ventricle per minute (mL/ minute) Heart Rate - Heart conductivity Stroke Volume (SV) - Volume of blood pumped out by the ventricles per contraction/ beat - Affected by preload, heart rate (chronotropy) and force of contraction (inotropy) Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy  Blood Pressure BP = CO x VR Cardiac Output (CO) = MAP/PVR - volume of blood pumped out by the ventricle per minute (mL/ minute) Mean arterial pressure (MAP) = diastolic BP + 1/3 (systolic BP − diastolic BP) - the average blood pressure in arteries Vascular Resistance (VR) - aka: afterload - the opposition to blood flow due to friction between blood and the walls of blood vessels - depends on size of the blood vessel lumen, blood viscosity, and total blood vessel length. Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy  Control of Blood Pressure A. Neural Control (Autonomic Nervous System) 1. Baroreceptor Reflex (Pressure Sensors) -Found in the carotid sinuses and aortic arch. -Detects pressure changes 2. Chemoreceptor Reflex (Chemical Sensors) -Also in carotid and aortic bodies. -Detects changes in O₂, CO₂, and pH levels. Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy  Control of Blood Pressure B. Hormonal Control (Endocrine System) 1. Renin–angiotensin–aldosterone system (RAAS) 2. Epinephrine and norepinephrine 3. Antidiuretic hormone (ADH) 4. Atrial natriuretic peptide (ANP) Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy  Control of Blood Pressure B. Hormonal Control (Endocrine System) 1. Renin–angiotensin–aldosterone system (RAAS) Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Did you know? Cancer cells can "hijack" the body's angiogenesis process to create new blood vessels that supply tumors with oxygen and nutrients. This is why anti-angiogenic drugs are used in cancer treatment to starve tumors! The beat of the song "Stayin’ Alive" by the Bee Gees (100-120 bpm) matches the ideal rate for chest compressions during CPR. Did you know that the first blood pressure measurement (in 1733) was done on a horse? British clergyman and scientist Stephen Hales inserted a glass tube into a horse’s artery to observe how high the blood would rise! Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Did you know? IV (intravenous) drugs go into veins and work within seconds to minutes, but IA (intra- arterial) drugs are rarely used except for targeted therapies like chemotherapy for brain tumors or certain emergency treatments. This is because IA routes deliver drugs directly to an organ, making them more potent but riskier! Which Increases More After Exercise: Systolic or Diastolic BP? Systolic blood pressure (SBP) increases more than diastolic BP during exercise. During exercise the heart pumps more blood per beat (higher stroke volume) → This raises systolic BP significantly (often to 160-200 mmHg). Diastolic BP stays the same or rises slightly because blood vessels dilate to improve blood flow to muscles, reducing vascular resistance. After exercise, systolic BP can double, while diastolic BP changes very little! Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Heart and BV Disorders Hypertension -also known as HIGH BLOOD PRESSURE, is a condition in which the blood vessels have persistently raised pressure (WHO). -if untreated it damages blood vessels, accelerates atherosclerosis, and produces left ventricular hypertrophy -these abnormalities contribute to the development of IHD, stroke, heart failure, renal failure, which are among Reading Assignment: Gestational HTN the most common causes of death worldwide. Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Hypertension Feature Primary (Essential) Hypertension Secondary Hypertension High blood pressure due to an underlying Definition High blood pressure with no identifiable cause medical condition Onset Develops gradually over time Develops suddenly and severely Caused by kidney disease, endocrine disorders, Causes Unknown, but linked to genetics, lifestyle, and aging sleep apnea, medications, or pregnancy Often asymptomatic ("silent killer"), sometimes mild May include vision problems, chest pain, Symptoms headaches or dizziness shortness of breath, and severe headaches Specific medical conditions (e.g., kidney Age, family history, high salt diet, obesity, smoking, Risk Factors disease, hormonal imbalances) or certain stress, inactivity medications Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Postural Hypotension - aka: Orthostatic Hypotension - is a condition where blood pressure (BP) drops significantly when a person stands up from a sitting or lying position - leads to dizziness, lightheadedness, or even fainting due to inadequate blood flow to the brain - can be caused by: Antihypertensives (beta-blockers, ACE inhibitors). Diuretics (reduce blood volume). Antidepressants (tricyclics, SSRIs). Vasodilators (e.g., nitrates). Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Ischemic Heart Disease -also known as Coronary Artery Disease (CAD), occurs when coronary arteries become narrowed or blocked, reducing blood flow and oxygen supply to the myocardium. This leads to ischemia, which can cause angina, and heart failure (myocardial infarction). Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Ischemic Heart Disease Treatment Function Examples Antiplatelets Prevent clot formation Aspirin, Clopidogrel (Plavix) Anticoagulants Prevent new clots from forming Heparin, Warfarin Beta-Blockers Reduce heart rate and oxygen demand Metoprolol, Atenolol Lower blood pressure, prevent heart ACE Inhibitors Lisinopril, Ramipril remodeling Lower cholesterol and reduce plaque Statins Atorvastatin, Rosuvastatin buildup Nitrates Dilate blood vessels and reduce chest pain Nitroglycerin Furosemide, Diuretics Reduce fluid overload and lower BP Hydrochlorothiazide Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Angina Pectoris -a symptom of IHD characterized by paroxysmal chest pain that is felt beneath the sternum, and commonly radiates down the left arm and/or shoulder. It can also radiate or originate in the neck or upper back. Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy  Angina Pectoris Type Definition Cause Triggers Chest pain that occurs predictably during Partial blockage due to Exercise, stress, Assignment: atherosclerosis, Stable Angina physical exertion or reducing blood supply cold weather, stress and relieves with heavy meals. during activity. rest. Chest pain that occurs at Severe narrowing or rest, unpredictably, or rupture of a plaque, Occurs anytime, Unstable Angina lasts longer than stable leading to partial clot even at rest. angina. formation. Variant Angina Rare type caused by Sudden spasm of Cold exposure, coronary artery spasm, coronary arteries, (Prinzmetal’s temporarily reducing usually in healthy or smoking, stress, Angina) drugs (cocaine). blood flow. young patients. Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Arrhythmia - an irregular heartbeat caused by disruptions in the heart’s electrical system - it can make the heart beat too fast, too slow or irregularly Disrupted Signal Generation: The SA node misfires (too fast or too slow).Other parts of the heart take over the pacemaker role inappropriately. Abnormal Signal Conduction: Electrical signals get blocked or delayed, leading to slow or skipped beats. Extra signals cause the heart to beat too fast or irregularly. Reentry Circuits (Electrical Loops): A signal keeps reactivating the heart muscle, causing rapid, uncoordinated beats (common in atrial fibrillation or ventricular tachycardia). Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Arrhythmia Bradycardia Sick Sinus Syndrome, Heart Block Supraventricular Tachycardia (SVT), Tachycardia Ventricular Tachycardia Atrial Fibrillation (AFib), Ventricular Fibrillation Fibrillation (VFib) Premature Atrial/Ventricular Extrasystoles Contractions (PACs, PVCs) Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Arrhythmia Class Mechanism of Action Examples Used For Block Na⁺ channels, slow depolarization I (Na⁺ Blockers) Quinidine, Lidocaine, Flecainide Atrial & Ventricular arrhythmias (Phase 0) Block β-adrenergic receptors, slow SA/AV II (Beta-Blockers) Metoprolol, Atenolol, Esmolol SVT, AFib, Post-MI protection node conduction Block K⁺ channels, prolong repolarization III (K⁺ Blockers) Amiodarone, Sotalol, Dofetilide AFib, Ventricular tachycardia (Phase 3) Block Ca²⁺ channels, slow AV node IV (Ca²⁺ Blockers) Verapamil, Diltiazem SVT, AFib rate control conduction SVT, AFib, Torsades Others Various Adenosine, Digoxin, Magnesium Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Heart Valve Disorders Stenosis – The valve becomes stiff and narrowed, restricting blood flow. Insufficiency - The valve does not close properly, allowing blood to leak backward Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy Shock - a life-threatening condition where the body’s tissues do not receive enough oxygen-rich blood, leading to organ failure and, if untreated, death. Type of Shock Cause Key Features 1. Hypovolemic Severe fluid or blood loss, Most common type; caused by hemorrhage, Shock reducing circulation volume dehydration, burns 2. Cardiogenic Heart failure, reducing its ability to Often due to heart attack (MI), arrhythmias, Shock pump blood or cardiomyopathy 3. Distributive Widespread vasodilation, causing Includes septic shock, anaphylactic shock, Shock blood pooling and low BP neurogenic shock 4. Obstructive Caused by pulmonary embolism, cardiac Physical blockage of blood flow Shock tamponade, tension pneumothorax Pharma 121L| A.Albay © 2025 Saint Louis University | Department of Pharmacy