Cardiovascular System

• Cardiovascular System - a closed pumping system comprising the heart, blood, & blood vessels.
• The Heart - a pumping organ.
• The Heart - a blunt cone shape and is approximately the size of our fist.
• The blunt, rounded point of heart is the apex and the larger, flat part at the opposite end of the heart is the base.
• Apex - directly inferior to the left and is located at the 5th intercostal space.
• Base - directly posterior and superior to the right and is located deep at sternum extending at the 2nd intercostal space.
• Base - fixed position because its attachment to the great vessel.
• Apex - position is free to move.
• Male: 250-390 gm
• Female: 200-275 gm
• Functions of the Heart:

  • Generating blood pressure
  • Routing blood
  • Ensuring one-way blood flow
  • Regulating blood supply
• Pericardial cavity - this is where the heart lies.
• Pericardial cavity - is formed by the pericardium, or pericardial sac.
• Pericardium - a connective tissue that covers and protects the heart.
• Pericardium is made up of?

  1. Fibrous pericardium
  2. Serous pericardium
• Fibrous pericardium - tough inelastic outer layer of dense regular connective tissue.
• Fibrous pericardium - prevents overstretching of the heart.
• Fibrous pericardium - provides protection and anchors the heart in the mediastinum.
• Serous pericardium - inner layer of epithelial cells; thinner and more delicate membrane that forms double layer around the heart..
• Serous pericardium is made up of:

  1. Parietal pericardium
  2. Visceral pericardium
• Parietal pericardium - the portion of the serous pericardium fused to fibrous pericardium.
• Visceral pericardium - also called epicardium; inner layer that adheres tightly to the surface of the heart.
• Pericardial fluid - a slippery secretion produced by serous pericardium that reduces friction between membranes as the heart moves within the pericardium.
• Two superior chambers - right atrium and left atrium.
• Right atrium receives deoxygenated blood through 3 major openings:

  • superior vena cava
  • inferior vena cava
  • coronary sinus
• Left atrium receives oxygenated blood through 4 pulmonary veins, which drain blood from the lungs.
• Interatrial septum - the partition between two atria.
• Two inferior chambers - right ventricle and left ventricle.
• Atria of the heart - receive blood from veins.
• Atria of the heart - function primarily as reservoirs, where blood returning from veins collects before it enters the ventricles.
• Ventricles of the heart - the major pumping chambers.
• Ventricle of the heart - eject blood into the arteries and force it to flow through the circulatory system.
• Right ventricle - pumps deoxygenated blood into the pulmonary trunk.
• Left ventricle - pumps oxygenated blood into the aorta.
• Valves of the heart - flaplike folds called cusps of the endocardium.
• Atrioventricular (AV) valves - valves between the atrium and ventricle.
• Tricuspid valves - prevents backflow of the blood from the right atrium and right ventricle.
• Bicuspid valve - prevents backflow of the blood from the left ventricle to left atrium.
• Other term for bicuspid valve?

  Mitral valve
• Semilunar valve - valves between the ventricle and an artery.