Heart and Peripheral vessels

• Cardiovascular System

  Aka Circulatory System, an organ system that permits blood to circulate and transport nutrients, oxygen, carbon dioxide, hormones, and blood cells to and from the cells in the body
• Functions of the Cardiovascular System

  • Provide nourishment
  • Help in fighting diseases
  • Stabilize temperature and pH
  • Maintain homeostasis
• Heart


  A muscular pump that forces blood through a system of vessels made of arteries, veins and capillaries
• Location of the Heart

  Positioned obliquely between the lungs in the mediastinum, lies in the pericardial cavity

  
• Functions of the Heart

  • Generate Blood Pressure
  • Route Blood
  • Ensure One-way Blood Flow
  • Regulation of Blood Supply
• Size of the Heart

  Size of a fist, hollow, cone-shaped heart has a mass of 250 to 350 grams—less than a pound
• Mediastinum


  The central compartment of the thoracic cavity surrounded by loose connective tissue, as region that contains a group of structures within the thorax
• Precordium

  The part of the front of the chest wall that overlays the heart and the epigastrium

  
• Pericardium

  Surrounds the heart and anchors it within the mediastinum, has a fibrous layer and a serous layer

  
• Fibrous Pericardium

  Layer of connective tissue that provides support and protection for the heart, attachments to the diaphragm, the sternum, and the vertebral column
• Serous Pericardium


  Contains the pericardial fluid, has a parietal layer and a visceral layer (epicardium)
• Layers of the Heart

  • Epicardium (visceral pericardium)
  • Myocardium
  • Endocardium

  
• Chambers and Internal Anatomy of the Heart

  Humans have a 4 chambered heart - 2 atria and 2 ventricles, left and right sides divided by the septum

  
• Heart Valves


  • Atrioventricular Valve - Tricuspid Valve, Bicuspid (Mitral valve)
  • Semilunar Valves - Pulmonic Semilunar Valves, Aortic Semilunar Valves
• Chordae Tendinae


  Tendon-resembling fibrous cords of connective tissue that connect the papillary muscles to the tricuspid valve and the bicuspid valve in the heart
• Coronary System


  Circulation of blood that supply oxygen to the myocardium, includes coronary arteries and coronary veins
• Sequence of Systemic Blood Circulation

  Not provided
• Heart Conduction System


  Consists of special electrical cells that generate and coordinate electrical impulses to the myocardial cells, includes properties like rhythmicity, automaticity, conductivity, contractility, and excitability
• Components of Heart Conduction System

  • Sinoatrial Node (SA Node)
  • Atrioventricular Node (AV Node)
  • Bundle of His / Atrioventricular Bundle
  • Left and Right Bundle Branches
  • Purkinjie Fibers
• Examples of Arrhythmia


  • Not provided
• Electrocardiogram (ECG/EKG)


  Procedure that measures electrical signals in the heart, can show if the heart is beating at a normal rate and strength, and help show the size and position of the heart's chambers

  
• Normal Heart Beat


  60-100 beats per minute
• Normal Heart Sounds


  Lubb (S1) - Lower in pitch, occurs at the beginning of ventricular systole, results from closure of AV valves

  Dubb (S2) - Occurs at the beginning of ventricular diastole, results from closure of the semilunar valves
• Cardiac Cycle


  Refers to the filling and emptying of heart chambers, has two phases - Diastole (filling, relaxation of ventricles) and Systole (emptying, contraction of ventricles)
• Phases of Cardiac Cycle

  • Atrial Systole
  • Ventricular Systole
  • Atrial Diastole
  • Ventricular Diastole
• Cardiac Output


  Volume of blood pumped by either ventricle per minute, calculated as Stroke Volume x Heart Rate
• Stroke Volume


  Volume of blood pumped per ventricle each time the heart contracts, approximately 70mL per beat
• Heart Rate


  Number of times the heart contracts per minute, approximately 72 beats/min for normal adults
• Points of Auscultation


  • Aortic Area
  • Pulmonic Area
  • Erb's Point
  • Mitral (Apical Area)
  • Tricuspid Area
• How to Auscultate
• Heart Sounds


  • S1 (lubb) - Closure of AV valves

  S2 (dubb) - Closure of semilunar valves

  S3 (ventricular gallop) - Passive filling of left ventricle

  S4 (atrial gallop) - Active filling of noncompliant left ventricle
• Blood Vessels


  Tubular structures carrying blood through the tissues and organs, including veins, arteries, and capillaries
• Functions of Blood Vessels

  • Carry Blood

  Exchange Nutrients, Waste Products and Gases

  Transport Substances

  Help Regulate Blood Pressure

  Direct Blood Flow to the Tissues
• Layers of Blood Vessels

  Tunica Adventitia/Externa, Tunica Media, Tunica Intima
• Arteries


  Carry blood away from the heart, carry oxygenated blood, classified as elastic, muscular, and arterioles
• Capillaries


  Extremely small blood vessels located within the body tissues, where gases, nutrients, and fluids are exchanged
• Capillary Exchange


  Most exchange across the capillary wall occurs by diffusion, affected by blood pressure, capillary permeability and osmosis
• Veins


  Carry deoxygenated blood back to the heart, veins with diameter over 2mm contain valves to prevent backflow
• Venules, Small Veins, Veins

  Venules are smallest in diameter, slightly larger than capillaries, small veins are slightly larger than venules, veins are large in diameter
• Varicose Veins


  Swollen, twisted veins that can be seen just under the skin, caused by weakened valves or walls of the veins