BAI GIANG HE TUAN HOAN (circulation)

circulatory system Color angiogram of a healthy heart C.L Standfield.2011 Principles of Human Physiology, 4th edition Circulation system Structure of the heart and heart muscle to function as a pump generating driving force for the bulk flow of the blood autorhythmicity of the heart Heart cycle and its phases Cardiac out and factors affect cardiac output Vasculature : arteries, arterioles, veins and their function Arterioles and the distribution of blood flow to organs Mean arterial pressure (MAP) as the driving force for the blood flow Bulk flow of fluid across capillary walls Role of the lymphatic circulation Specific terms • Cardio– Cardiology – Cardiologist – Electrocardiogram (ECG) • Vasculature – Vascular disease – Cardiovasculature – Cardiovascular system Functions of Cardiovascular System Carrying of oxygen and carbon dioxide Carrying of fuel, hormones etc Immunity Heat Transfer Components of a circulatory system • Circulatory fluid: blood, lymph • Pump (heart): generates the driving force for the bulk flow of blood • Vessels • Valves – Keep the blood flowing in one direction Circulatory systems in human • Cardiovascular system (Hệ tuần hoàn máu) • Lymphatic system (Hệ tuần hoàn bạch huyết) Cardiovascular system Blood flow in the circulation is bulk flow • Q= ΔP/R •Contraction of the heart generates the driving force for the flow •Path of blood flow: right atrium->right ventricle- > pulmonary arteries->pulmonary veins->left atrium>right trium->aorta-> systemic veins->venae cavae>right atrium •The valves in the heart help the blood flow in one direction •Blood pressure values: Pulmonary Circulation = 24/8 mm Hg (Systolic/Diastolic) Systemic Circulation = 120/80 mm Hg(Systolic/Diastolic) Huyết áp loại mạch tuần hoàn phổi tuần hoàn hệ thống Location of the heart in the thoracic cavity Xương ức 40o 8-12 cm C.L Standfield.2011 Principles of Human Physiology, 4th edition Extrinsic control of arteriole Radius and mean arterial pressure • The autonomous nervous system: – The sympathetic nervous system -> norepinephrine –α adrenergic receptor -> vasoconstriction – Epinephrine- α receptor – vasoconstriction – Epinephrine- beta receptor – vasodilation – The parasympathetic nervous system innervate only arteriolar smooth muscles of external genitalia -> acetylcholine -> vasodilation • Hormonal control: – Vasopressin (ADH) – vasodilation – Angiotensin II: vasoconstriction Arterioles - sites for control of blood flow distribution to organs •Blood flow in the circulation is parallel flow • With parallel flow every organ can be supplied by the same flow given the resistance is the same in each organ •By changing its own resistance, each organ can receive a desired blood flow matching its metabolic need -> at any given time blood flow can be increased to more organs and decreased to less active organ •Arterioles are sites where resistance for blood flow to each organ can be regulated by intrinsic factors Blood flow distribution to organs changes on organ’s need C.L Standfield.2011 Principles of Human Physiology, 4th edition Capillaries – sites of material exchange between blood and tissues Capillaries • 1mm long , 5-10 um in diameter • Thin walls (0.5 um) contain one layer of endothelial cells and basement membrane -> facilitates diffusion • Branching structures: 10-40 billion capillaries -> 600 m2 exchanging surface • Greatest total crosssectional area -> Slowest velocity of blood flow C.L Standfield.2011 Principles of Human Physiology, 4th edition Regulation of blood flow through capillaries •1mm long, 5-10micrometer thick •10-40 billion cappilaries – 600 m2 •Capilalary bed •Microcirculation •precapillary sphinters regulate the blood flow to tissues: •precapillary sphinters are affected by local controls : metabolites produced by local tissues – increased CO2 , decreased O2 -> sphinters relax -> increased blood flow and vice versa – Metarteriole connect arteriole với venule có vòng bị tác động yếu tố nội sinh co để thay đổi dòng chảy C.L Standfield.2011 Principles of Human Physiology, 4th edition • Continuous capillaries (Mao mạch kín): permeable to small molecules and lipophilic molecules (O2, CO2, steroid hormones) • Fenestrated capillaries (Mao mạch thấm): permeable to proteins, cells, small hydrophilic molecules C.L Standfield.2011 Principles of Human Physiology, 4th edition The bulk flow across capillary walls maintains balance between interstitial fluid and plasma • As capillary walls are permeable to water and small solutes-> fluid can move from blood to interstitial fluid: filtration or from interstitial fluid to blood: absorption • Starling forces is the driving forces for the movemnet of fluid into or out of capillaries : capillary hydrostatic pressure (PCAP) and the interstial hydrostatic pressure t (P IF); capillary osmotic pressure (π CAP) , interstitial osmotic pressure (π IF) • NFP (net filtration pressure- Áp lực lọc thực ) NFP = Filtration pressure – Absorption Pressure NFP = (PCAP + π IF) – (π CAP + PIF) + if NFP>0 : filtraion occurs -> fluid moves from thecapillary into interstitial spaces + If NFP fuid moves from interstitial spaces in to the capillary C.L Standfield.2011 Principles of Human Physiology, 4th edition NFP= 12 mmHg NFP= -10 mmHg Blood flow through a capillary is filtrated at the arteriole end and absorbed at the venule end • one day: 20 L of fluid are filtered and 17 L of fluid are absorbed -> L of fluid moves out of the blood vessels each day ! - > roles of the lymphatic system Veins function as volume reservoirs • Veins are thin walled • Veins are equipped with one-way valves • Veins have high compliance as they are thin walled and easily stretched -> can accommodate a large blood volume with little change in blood pressure -> at rest 60% of the total blood volume is stored in the systemic veins C.L Standfield.2011 Principles of Human Physiology, 4th edition • Veins have higher compliance than arteries Factors affect venous pressure and venous return • skeletal muscle pump (bơm cơ) • respiratory pump (bơm hô hấp ) • Blood volume • Venomotor tone C.L Standfield.2011 Principles of Human Physiology, 4th edition • Venous pressure and venous return indirectly affect cardiac output (CO) and MAP Lymphatic system (tuần hoàn bạch huyết ) • Drains the fluid leaked out from the cardiovascular system (CS) back to the CS • Direction of lymph flow: fluid from interstitium -> lymphatic cavity -> lymphtic veins-> the right lymphatic duct -> thoracic duct-> blood vessels C.L Standfield.2011 Principles of Human Physiology, 4th edition [...]... sinh): regulation of the heart by neural input, circulating hormones and factors originating from outside the heart • Intrinsic control (Điều khiển nội sinh): regulation of the heart by factors originating from the heart CO = HR x SV Factors affecting the heart rate neural control of the heart rate •autonomous nervous system •sympathetic nervous system (Thần kinh giao cảm): sympathetic nerves project... push the blood through the vasculature •valvesLeft ventricle- Aorta, right ventricle-pulmonary artery Brief Overview of Electrical Activity of the Heart There are three main types of heart cells: •Heart muscle cells‐ These are the contractile cells of the heart •Conducting cells‐ Modified muscle cells that rapidly conduct electrical charge •Pacemaker Cells‐ Located in Sinoatrial Node (SAN) these cells... autorhythmicity of the heart • • The heart can generate signals triggering its own contraction on a periodic basic – the heart has autorhymthmicity because it has a conduction system (contractile activity of cardiac muscle is said to be myogenic) Conduction system of the heart contains autorhythmic cells: – Pacemaker cells can generate action potential and establish the heart rhymth: • Sinoatrial node... set the pace or rhythm of the heart rate In order for heart muscle cells to mechanically contract or generate forc they must first be electrically excited Myocardium/ cardiac muscle • properties of both skeletal muscle and smooth muscle • Striation appearance • Cardiac muscle cells are interconnected by intercalated discs -> action potential is transmitted rapidly The autorhythmicity of the heart... tim) -ECG is a record of the overall spread of electrical current through the heart as a function of time during the cardiac cycle -ECG reflects patterns of AP firing in entire population of heart muscle cells - recorded by electrodes placed on the skin -Willem Einthoven ‘s techmique -Einthoven’s triangle: right arm, left arm, left leg: - Limb electrodes: Lead I, II, III -Chest electrodes: V1-V6 http://www.bmb.leeds.ac.uk/illingworth/myopath/heart.htm... transmit action potential through the heart in highly coordinated manner - Bundle of His - Purkinje fibers Hạch xoang Hạch nhĩ thất Bó His Sợi Purkinje Spread of action potential between cardiac muscle cells Electric current/action potential (ions) can be passed from one cells to other rapidly through gap junctions (intercalated disks) The spread of action potentials through the heart Stanius experiment 1... Principles of Human Physiology, 4th edition Abnormal ECG Cardiac cycle (Chu kì hoạt động của tim/chu chuyển tim) Cardiac cycle • Cardiac cycle contains all the events associated with the flow of blood through the heart during a single complete heart beat Duration of a cardiac cycle • 0,8 second (human) • 2 stages: - systole (tim co/tâm thu); - diastole (tim giãn/ tâm trương) Atria contraction: 0.1... mạch trung bình Changes in ventricular volume during the cardiac cycle Thể tích cuối tâm trương Thể tích tống máu Thể tích cuối tâm thu At rest: EDV = 130ml, ESV = 60ml -> SV = 130-60= 70 ml Ejection Fraction (Tỷ lệ tống máu) EF = SV/EDV = 70/130 = 0.54 Heart sounds • “lupp-DUPP • Sounds caused by the turbulent rushing of blood through the valves as they are narrowing and about to close – 1st sound: “lubb”... closing – 2nd sound: “DUPP” – semilunar valves are closing Cardiac Output- CO • Heart rate (HR): the number of contractions (beats) per minute • Stroke volume-SV (Thể tích tâm thu ): the volume of blood being pumped from each ventricle with one heart beat ( 60-80ml) • Cardiac output- CO (lưu lượng tim/thể tích phút): the volume of blood being pumped from each ventricle in one minute CO= HR x SV For...Structure of the heart Tĩnh mạch chủ trên Cung động mạch chủ Động mạch phổi Van động mạch phổi Tâm nhĩ phải Tâm nhĩ trái Van bán nguyệt Van 2 lá Van 3 lá Tâm thất phải Vách nhĩ thất Tâm thất trái Mỏm tim Động mạch chủ dưới Tĩnh mạch chủ dưới •4 chambers, 2 halves (right and left), each half contains: •Atrium :receives blood coming back to the heart from the vasculature •Ventricle: receives