CVS Final 1 (Heart Coverings and Wall) PDF

1 Body Regions  Head  Neck  Trunk (Torso)  Thorax  Abdomen  Pelvis  Upper Extremities  Lower Extremities 2 Body Regions  Head  Facial Region  Eyes (Orbital)  Nose (Nasal)  Mouth (Oral)  Ear (Auricular)  Cranial Region...

1 Body Regions  Head  Neck  Trunk (Torso)  Thorax  Abdomen  Pelvis  Upper Extremities  Lower Extremities 2 Body Regions  Head  Facial Region  Eyes (Orbital)  Nose (Nasal)  Mouth (Oral)  Ear (Auricular)  Cranial Region  Cranium (Skull)  Neck  Cervical Region 3 Cardiovascular System  Circulatory system  Cardio Vascular System  Lymphatic System  Cardio Vascular System  Heart  Muscular Pumping Device  Vessels  Arteries  Veins  Capillaries 4 Heart  Four chambered muscular organ  Cone shaped and about the size of a fist  Starts beating early in 4th week  Contracts 42 million times a year  Pumps 700,000 gallons of blood  Location of heart  Human heart lies in the mediastinum1, or middle region of thorax, just behind the body of sternum and extends obliquely for 12-14 cm (5 inches) from 2nd rib to the 5th inter costal space.  About two-third of heart is located to LEFT of midline  One-third is to RIGHT. 5 Heart  Orientation  Rests on superior surface of diaphragm  Anteriorly -->  Lies anterior to Vertebral Column against bodies of 5th to 8th thoracic vertebrae  Posteriorly --> It lies behind the sternum  Laterally --> Lungs flank the heart and partially cover it 6  Heart  Base  Broad superior end where the large vessels attach  Just below the 2nd rib  9cm (3.5 inches) wide and directed towards the right shoulder  Apex  A blunt point at lower end of the heart that lies on the diaphragm pointing downwards  PMI (Point of maximal Intensity)  The space between the 5th and 6th rib, just below the left nipple, where apex touches the chest wall  Cardiopulmonary Resuscitation (CPR)  Rhythmic compression the heart with the heel of the hand 7 8  9 Heart  Weight, size and Shape of the Heart  Weight  Infants  1/130th of body weight  Adults  1/300th of body weight  Adults Range: 225-350g  Male Avg: 310g  Female Avg: 225g  Heart attains full adult shape and weight between puberty and 25 years of age.  Size  Approximated Dimensions are;  Length -- > 12 cm (4.75 inches)  Width -- > 9 cm (3.5 inches)  Depth -- > 6 cm (2.5 inches)  Shape  Tall, thin individuals Elongated (Greater length)  Short individuals Transverse (Greater width)  Average height individuals Neither Long nor transverse (intermediate) 10  11 Coverings of the Heart  Pericardium (Peri=around, cardi= heart)  Double walled sac that encloses the heart  Fibrous Pericardium  Serous Pericardium  Fibrous Pericardium  Composed of dense connective tissue  Tough, loose-fitting and inelastic covers heart loosely.  Functions  Protects heart  Anchors it to Surrounding structures  Prevents overfilling of heart with blood 12  Coverings of the Heart  Serous Pericardium  A thin slippery, two layered membrane  Parietal Layer  Lines inner surface of the fibrous Pericardium  Visceral layer (Epicardium)  Adheres to the outside of the heart  Pericardial Cavity:  Between the parietal and visceral layers of the serous pericardium  Contains few drops of fluid called PERICARDIAL Fluid.  Provides lubrication  Prevents from friction  Pericarditis  Inflammation of the pericardium 13 Coverings of the Heart Pericardium Viscseral pericardium 14  Heart Wall  The wall of the heart is composed of three distinct layers, richly supplied with blood vessels.  Epicardium  Myocardium  Endocardium  Epicardium (on the heart)  Superficial layer  Visceral layer of the serous pericardium  It is often infiltrated with fat, especially in older people. 15 Myocardium  Middle Layer  Forms the bulk of heart  Thick, contractile, constructed of cardiac muscles  Layer that contracts  In this layer, the branching cardiac muscle cells are tethered to one another by crisscrossing connective tissue fibers and arranged in spiral or circular bundles. 16  Endocardium  Inner most Layer  Delicate layer composed of endothelial tissue (resembels simple squamous epithilium)  Continuous with the endothelial linings of the blood vessels leaving and entering the heart.  Covers the beamlike projection of myocardial tissue called trabeculae. 1 17 18 19