Human Anatomy And Physiology: Cardiovascular System (PDF)

General Physiology & Pathophysiology with Family Planning CARDIOVASCULAR SYSTEM Blood The Heart Blood Vessels and Circulation Cardiovascular System Circulatory system Functions of the Heart Generating blood pressure Contraction of the Heart Routing blood Pulmonary and...

General Physiology & Pathophysiology with Family Planning CARDIOVASCULAR SYSTEM Blood The Heart Blood Vessels and Circulation Cardiovascular System Circulatory system Functions of the Heart Generating blood pressure Contraction of the Heart Routing blood Pulmonary and systemic circulation Ensuring one-way blood flow Tricuspid valve Pulmonary valve “Try Pulling My Aorta” Mitral/Bicuspid valve Aortic valve Regulating blood supply Rate and force of contraction Size, Shape, and Location of the Heart ▪ Shaped like a blunt cone ▪ Size of a close fist ▪ 250g females; 300g males ▪ Sedentary < active ▪ Decreases at age 65 ▪ @ mediastinum 7-9cm to the left of sternum; Medial to midclavicular line Anatomy of the Heart Heart Walls  Anatomy of the Heart Pericardium: double layered sac that anchors and protects the heart Fibrous pericardium: prevents overdistension; anchors heart Serous pericardium: Parietal: part lining of fibrous Visceral: covers heart surface Pericardial cavity: space around the heart Pericardial fluid: reduces friction  Heart wall layers Epicardium Thin; Outer surface of the heart Myocardium Thick; Middle layer; for heart’s contractility Endocardium Deep Layer; smooth inner surface of the heart 🡪 easy flow of blood Anatomy of the Heart  Anatomy of the Heart C H R Atrium Receives deoxygenated blood from: Superior & Inferior Vena Cava, Coronary sinuses A R Ventricle Has superior outflow route near midline of heart: M pulmonary trunk B L Atrium Receives oxygenated blood from: pulmonary veins E L Ventricle Has superior outflow route near midline of heart: R aorta. Hass thicker wall for contraction. S Interatrial Separates R and L septum atria Intraventricular Separates R and L septum ventricles  Anatomy of the Heart Atrioventricular valves ensure blood flows from the atria into the (AV valves) ventricles; prevents backflow Semilunar valves (SL between each ventricle and its associated valves) great artery; prevents backflow  Anatomy of the Heart Tricuspid valve Between R atrium & R ventricle; 3 cusps/leaflets; prevents back flow of blood_____ Pulmonary valve Between R ventricle & pulmonary artery; 3 cusps; prevents back flow of blood_____ Mitral/Bicuspid Between L atrium & L ventricle; 2 cusps; valve prevents back flow of blood_____ Aortic valve Between L ventricle and aorta; 3 cusps; prevents back flow of blood  Anatomy of the Heart Superior Vena returns deoxygenated blood from the upper Cava portion of the body (head, neck, arms, chest) to R atrium Inferior Vena Cava returns blood to the heart from the lower portion of the body (abdomen, pelvis, legs, feet) to R atrium Pulmonary trunk transports blood from the R ventricle to the pulmonary arteries; directly connected to pulmonary valve; GREAT ARTERY Pulmonary Veins deliver deoxygenated blood to the respective lung Pulmonary Artery deliver oxygenated blood to the L ventricle Aorta carries blood from the L ventricle to the body; GREAT ARTERY Anatomy of the Heart  Anatomy of the Heart Auricle ear-shaped appendage of either atrium of the heart; R auricle (extensive broad triangular muscular pouch projecting anteriorly, near ascending aorta); L auricle (longer, narrower and more hooked, near pulmonary trunk) Coronary sulcus Runs obliquely; separates atria from the ventricles; AKA. Atrioventricular groove Interventricular Separates the left and right ventricle; extends from the sulcus coronary sulcus toward the apex of the heart Papillary muscle @ ventricles; contracts to prevent regurgitation Chordae Tendineae Connects the cusps to the papillary muscles Anatomy of the Heart blood supply of the Heart Ant. Interventricular Ant. Part of heart L marginal Lateral wall of L ventricle Circumflex Post. wall of heart R marginal Lateral wall of R ventricle Post. Intraventricular Post. And Inf. part of heart Blood flow through the Heart  Blood flow through the Heart “Real Reach People Lie: Life, Love, Age, Body” Histology of the Heart Electrical Properties Skeletal muscle Cardiac muscle Conducting System Conducting System Conducting System Conducting System Conducting System Cardiac Cycle ▪ Repetitive pumping ▪ From high to low pressure ▪ Contraction of heart ▪ 0.25-0.3 sec in newborn ▪ 1/> sec in athletes ▪ 0.7=0.8 sec normal  Cardiac Cycle ▪ refers to one complete heartbeat 1. 2. Gb Dd ▪ Systole = contraction/depolarization ▪ Diastole = relaxation/repolarization ▪ Average heart rate is approximately 75 beats per minute ▪ Cardiac cycle length is normally 0.8 second - Starts at diastole  Cardiac Cycle A. DIASTOLE I. Atrial diastole and systole (ventricular 1. Gb filling) 2. Dd ▪ Period of rapid filling of ventricles - Heart is relaxed ▪ 1st third of diastole- 75% blood flows passively into the atria and into ventricles ▪ middle 3rd of diastole- continuous blood flow ▪ last 3rd of diastole- 25% of blood from atrium to ventricle via “atrial kick/systole” ★ Atrioventricular valves open and Semilunar valves are closed B. SYSTOLE II. Isovolumetric contraction ▪ Atrial systole ends; ventricular systole 1. 2. Gb Dd Begins ▪ Blood in the ventricles ▪ Ventricular pressure rises ▪ For a moment, the ventricles are completely closed chambers ★ AV valve and SL valves both closed ★ closing of AV valves is beginning of systole (lubb) III. Ventricular systole (ejection phase) ▪ RV- pressure exceed 8 mmHg (pulmonary 1. 2. Gb Dd artery) LV- pressure exceed 80 mmHg (Aorta) ▪ Intraventricular pressure now surpasses the pressure in the major arteries leaving the heart ▪ Blood is ejected from the ventricles ★ SL valves open, AV valves (closed) IV. Isovolumetric relaxation ▪ Ventricular diastole begins 1. 2. Gb Dd ▪ Pressure falls below that in the major arteries ▪ Semilunar valves close ▪ For another moment, the ventricles are completely closed chambers ★ SL valves (close) to prevent backflow, AV valves (close)...(open) ★ closing of SL valves is beginning of diastole (dubb)D Cardiac Cycle (summary) 1. Systole: Isovolumetric Contraction all valves closed closing of AV valves is beginning of systole (lubb) 2. Systole: Ejection semilunar valves opened AV valves closed 3. Diastole: Isovolumetric relaxation all valves closed closing of SL valves is beginning of diastole (dubb)D 4. Diastole: Rapid Inflow (1st 1/3) SL valves closed; AV valves opened fills 70-80% capacity Diastole: Diastasis (middle 1/3) SL valves closed; AV valves opened little change in ventricular volume 5. Diastole: Atrial Systole (last 1/3) SL valves closed; AV valves opened adds 20-30% more volume Heart Sounds Aortic R 2nd Intercostal space Pulmonic L 2nd Intercostal space Erb’s Point L 3rd Intercostal space Tricuspid L 4th Intercostal space Mitral/Apex L 5th Intercostal space  Heart Sounds S1 Lubb Closure of AV valves Loudest at the apex Beginning of ventricular Longer than S2 systole Carotid pulse S2 Dubb Closure of AV valves Loudest at the base if End of ventricular systole the heart S3 Ventricular Prediastolic gallop Heard in CHF Gallop Early diastole Heard in some people Rapid ventricular filling (thin et young) S4 Atrial Gallop Late diastole Heard in HTN, aortic Atrial kick into a stenosis, acute MI, etc noncompliant ventricle Baroreceptor and Chemoreceptor Reflexes HUMAN ANATOMY AND PHYSIOLOGY CARDIOVASCULAR SYSTEM Blood Vessels and Circulation Function of the Circulatory System Carries blood Blood Vessels Exchange nutrients, waste products, and gases with tissues Transports substances Hormones Molecules Helps regulate BP Directs blood flow to tissues Structural Features Structural Features  Structural Features Arteries Veins Capillaries Function Sends blood Sends blood to Material exchange from heart heart with tissues; connects arteries to veins Pressure High Low Low Lumen Narrow Wide Extremely narrow Diameter Wall Thick Thin Extremely thin Thickness Wall layers Adventitia, Adventitia, Intima Media, Intima Media, Intima Muscle & Large amounts Small amounts None Elastic Fibers Valves No Yes No  Arteries carry blood away from the heart Elastic arteries: -Conducting arteries -Largest arteries -BP is high/ fluctuates between higher systolic & lower diastolic -Recoils Muscular arteries: -Distributing arteries -Medium-sized and small arteries -Characterized by well-defined internal elastic lamina Arterioles: -Resistance vessels -Smallest arteries -Regulate blood flow to the capillary networks.  Veins vessels that carry blood toward the heart Venules, small veins: -Venules: smallest vein; collect blood from the capillaries, transport it to small veins then to medium veins -Small vein: vessels with 0.2-0.3mm diameter increase Medium, Large veins: -Medium: collect blood from small veins and deliver it to large veins -Large: transport blood from the medium veins to the heart  Veins vessels that carry blood toward the heart Portal veins: -connects primary to secondary capillary network; no pumping action Hepatic Portal Vein Hypothalamohypophysial portal veins  Veins vessels that carry blood toward the heart Portal veins: -connects primary to secondary capillary network; no pumping action Renal nephron portal systems  Veins vessels that carry blood toward the heart Valves -for veins >2mm diameter; allows blood flow to heart but not in opposite direction Vasa Vasorum -supplies nutrients for arteries/veins >1mm  Capillaries Material exchange; most common type of blood vessel Continuous capillaries -continuous tube -found in Nervous Sys, fat & muscle tissue  Capillaries Material exchange; most common type of blood vessel Fenestrated capillaries -composed of small -found in intestinal villi, ciliary processes of the eyes, choroid plexuses, glomeruli of the kidneys. Sinusoids -wider and more winding than other capillaries -found in bone marrow, liver, spleen, anterior pituitary, and parathyroid and adrenal glands  Representative Diseases and Disorders of the Heart Condition Description Inflammation of Heart Tissue Inflammation of the endocardium; affects the valves more Endocarditis severely than other areas of the endocardium; may lead to scarring, causing stenosed or incompetent valves Pericarditis Inflammation of the pericardium Reduced Blood Flow to Reduces the amount of blood the coronary arteries can Cardiac Muscle deliver to the myocardium Coronary heart disease Myocardial infarction Damaged cardiac muscle tissue resulting from lack of blood flow to the myocardium; often referred to as a heart attack Congenital Heart Diseases Hole in the septum between the left and right sides of the (occur at birth) heart, allowing blood to flow from one side of the heart to Septal defect the other and greatly reducing the heart’s pumping effectiveness Patent ductus arteriosus Ductus arteriosus fails to close after birth, allowing blood to flow from the aorta to the pulmonary trunk under a higher pressure, which damages the lungs; also, the left ventricle must work harder to maintain adequate systemic pressure  Representative Diseases and Disorders of the Heart Condition Description Cyanosis (sıˉ- -noˉ′sis; cyan, blue + Symptom of inadequate heart function in babies with congenital osis, condition of) heart disease; the infant’s skin appears blue because of low oxygen levels in the blood in peripheral blood vessels Heart Failure Progressive weakening of the heart muscle, reducing the heart’s pumping action; hypertension leading to heart failure due to increased afterload; advanced age, malnutrition, chronic infections, toxins, severe anemias, hyperthyroidism, and hereditary factors can lead to heart failure  Septal defect HUMAN ANATOMY AND PHYSIOLOGY CARDIOVASCULAR SYSTEM Blood  Functions of the Blood Transport of gases, nutrients and waste products Oxygen Carbon Dioxide Transport of processed molecules Vitamin D Transport of regulatory molecules Hormones Regulation of pH and osmosis Normal range: 7.35-7.45 Maintenance of body temperature Protection against foreign substances WBC Clot formation Composition of Blood  Hematopoiesis Blood cell production Embryo: yolk sac, liver, thymus, spleen, lymph nodes, red bone marrow After Birth: red bone marrow, lymphatic tissue RBC RBC > WBC > platelet ▪ Biconcave shape ▪ O2 transport: Hemoglobin 98.6%, plasma 1.5% ▪ CO2 transport: plasma 7%, hemoglobin 23%, bicarbonate ions 70% Hemoglobin ▪ 2 Alpha globins (different by 1 amino acid) ▪ 1 Beta globin ▪ 2 Gamma globins ▪ 1 Delta globin ▪ 3 embryonic globins Hemoglobin ▪ Has 4 subunits with Globin and Heme ▪ Globin: involved in binding and/or transporting O2 ▪ Heme: has iron; binds/picks up O2 from the lungs then to tissues. Red Blood Cell process ▪ Takes 4 days ▪ Erythropoietin: a glycoprotein by kidney; RBC regulator; ↑ secretion if ↓ blood O2 level. Negative/Positive feedback? ▪ Lifespan: 120 days males; 110 days female ▪ No nuclei ▪ Hemolysis: rupture B cells: stimulated by bacteria or toxins; has cells that produce antibodies Antibodies: destroys bacteria T cells: attacks and destroys the cells; destruction of tumor cells and in tissue graft rejections.  WBC Granulocytes o has large cytoplasmic granules and lobed nuclei; stains with dyes Neutrophil: acidic and basic dyes Eosinophil (red): acidic dyes Basophil (dark purple): basic dyes Agranulocytes o no granules (too small) Lymphocytes: smallest; in the lymphatic tissues: lymph nodes, spleen, tonsils, lymphatic nodules, thymus Monocytes: largest  Platelet ▪ Disc shaped and average about 3 μm in diameter. ▪ Has glycoprotein and proteins on surfaces 🡪 allows attachment. ▪ Life span of 5-9 days Hemostasis: cessation of bleeding. Positive/Negative feedback? Vascular spasm Vasoconstriction of damaged blood vessels reduces blood loss. Platelet plug formation accumulation of platelets that can seal small breaks in blood vessels Platelet adhesion platelets bind to collagen in damaged tissues Platelet release reaction platelets release chemicals that activate additional platelets. Platelet aggregation platelets bind to one another to form a platelet plug Coagulation formation of a blood clot.