CARDIO-VASCULAR SYSTEM Principles Structures Two circuits Pulmonary Systemic Fetal Circulation Heart Details Other details Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy What Does C-V System do? Circulate blood throughout entire body for Transport of oxygen to cells Transport of CO2 away from cells Transport of nutrients (glucose) to cells Movement of immune system components (cells, antibodies) Transport of endocrine gland secretions Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy How does it do it? Heart is pump Arteries and veins are main tubes (plumbing) Arteries Away from Heart Veins to Heart Diffusion happens in capillaries (oxygen, CO2, glucose diffuse in or out of blood) Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Overall Organization of System Heart/Great Vessels--1 Route Smaller aa. vv.--many routes (collateral circulation) Capillaries—network where diffusion occurs Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Collateral Circulation Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Walls of Arteries and Veins Tunica externa Outermost layer CT w/elastin and collagen Strengthens, Anchors Tunica media Middle layer Circular Smooth Muscle Vaso-constriction/dilation Tunica intima Innermost layer Endothelium Minimize friction Lumen pg 546 Larry M. Frolich, Ph.D.,Human Anatomy

Artery/Vein differences Arteries (aa.) Veins (vv.) Direction of flow Blood Away from Heart Blood to Heart Pressure Higher Lower Walls THICKER: Tunica media thicker than tunica externa THINNER: Tunica externa thicker than tunica media Lumen Smaller Larger Valves No valves Valves (see next) Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Capillaries Microscopic--one cell layer thick Network Bathed in extracellular matrix of areolar tissue Entire goal of C-V system is to get blood into capillaries where diffusion takes place Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Two circulatory paths Systemic Pulmonary Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy GREAT VESSELS Aorta IVC, SVC Pulmonary Trunk Pulmonary Veins Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Heart Chambers and Valves Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Right Heart Chambers: Pulmonary Circuit Right Atrium (forms most of posterior of heart) Receives O2-poor blood from body via IVC, SVC, Coronary sinus Ventral wall = rough Pectinate muscle Fossa Ovalis- on interatrial septum, remnant of Foramen Ovale Right Ventricle Receives O2-poor blood from right atrium through tricuspid valve Pumps blood to lungs via Pulmonary Semilunar Valve in pulmonary trunk Trabeculae Carnae along ventral surface Papillary Muscle-cone-shaped muscle to which chordae tendinae are anchored Moderator Band-muscular band connecting anterior papillary muscle to interventricular septum Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Left Heart Chambers: Systemic Circuit Left Atrium Receives O2-rich blood from 4 Pulmonary Veins Pectinate Muscles line only auricle Left Ventricle (forms apex of heart) Receives blood from Left Atrium via bicuspid valve Pumps blood into aorta via Aortic Semilunar Valve to body Same structures as Rt Ventricle: Trabeculae carnae, Papillary muscles, Chordae tendinae No Moderator Band Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Heart Valves: Lub*-Dub** *Tricuspid Valve: Right AV valve 3 Cusps (flaps) made of endocardium and CT Cusps anchored in Rt. Ventricle by Chordae Tendinae Chordae Tendinae prevent inversion of cusps into atrium Flow of blood pushes cusps open When ventricle in diastole (relaxed), cusps hang limp in ventricle Ventricular contraction increases pressure and forces cusps closed *Bicuspid (Mitral) Valve: Left AV valve 2 cusps anchored in Lft. Ventricle by chordae tendinae Functions same as Rt. AV valve **Semilunar valves: prevents backflow in large arteries Pulmonary Semilunar Valve: Rt Ventricle and Pulmonary Trunk Aortic Semilunar Valve: Left Ventricle and Aorta 3 cusps: blood rushes past they’re flattened, as it settles they’re pushed down (valve closed) Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Another View Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Location of Heart in Thorax pg 523 Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Location of Heart in Chest Oblique Position Apex = Left of Midline (5th ICS), Anterior to rest of heart Base (posterior surface) sits on vertebral column Superior Right = 3rd Costal Cartilage, 1” right midsternum Superior Left = 2nd Costal Cartilage, 1” left midsternum Inferior Right = 6th Costal Cartilage, 1” right midsternum Inferior Left = 5th Intercostal Space at Midclavicular line Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Epicardium (most superficial) – Visceral pleura Myocardium (middle layer) Cardiac muscle Contracts Endocardium (inner) Endothelium on CT Lines the heart Creates the valves Heart Wall How does heart muscle get blood supply? pg 524 Larry M. Frolich, Ph.D.,Human Anatomy

Blood supply to heart wall Rt and Lft Coronary Arteries Branch from Ascending Aorta Have multiple branches along heart Sit in Coronary Sulcus Coronary Heart Disease Cardiac Veins Coronary Sinus (largest) Many branches feed into sinus Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Heart Innervation Heart receives visceral motor innervation Sympathetic (speeds up) Parasympathetic (slows down) p. 534 Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Fetal Circulation No circulation to lungs Foramen ovale Ductus arteriosum Circulation must go to placenta Umbilical aa., vv. Larry M. Frolich, Ph.D.,Human Anatomy

Adult remnants of fetal circulation Fetus Fossa ovale Foramen ovale Ligamentum arteriosum Ductus arteriosus Medial umbilical ligaments Umbilical aa.(within fetus) Round ligament (ligamentum teres) of liver Umbilical v.(within fetus) Ligamentum venosum Ductus venosus Medial umbilical ligament Umbilical cord (leaving fetus) Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Hepatic Portal System Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Lymphatic System…The Players: Lymph- clear fluid from loose areolar CT around capillaries Lymphatic capillaries (near blood capillaries)  Lymph collecting vessels (small, 3 tunicas, valves) Lymph nodes (sit along collecting vessels)-clean lymph of pathogens, they are NOT glands Lymphatic trunks (convergence large collecting vessels) Lumbar, intestinal, bronchomediastinal, subclavian, jugular Lymphatic ducts  empty into veins of neck Larry M. Frolich, Ph.D.,Human Anatomy

Larry M. Frolich, Ph.D.,Human Anatomy Lymphatic System--Function Function: to collect excess tissue fluid collecting at arteriole end and return leaked blood proteins to blood (maintain osmotic pressure needed to take up water into bloodstream) Lymph moved through vessels Pulse of nearby arteries Contraction of surrounding skeletal muscle Regular movement of body (wiggling legs) Muscle in Tunica Media Lacteals-lymphatic capillaries w/unique function In mucosa of small intestine, receive digested fat from intestine Fatty lymph becomes milky = Chyle Chyle goes to bloodstream Larry M. Frolich, Ph.D.,Human Anatomy