CARDIOVASCULAR SYSTEM

• Cardiovascular System is a closed system of the heart and blood vessels
• Cardiovascular System is also calld Circulatory system or vascular system
• heart as a single structure, it is actually two pumps in one.

  Right side pumps pulmonary circulation

  Left side pumps systemic circulation
• pulmonary circulation, which carries blood to the lungs, where CO2 diffuses from the blood into the lungs and O2 diffuses from the lungs into the blood.
• The left side of the heart then pumps blood through the systemic circulation, which delivers O2 and nutrients to all the remaining tissues of the body
• 4 functions of the heart

  1. Generating blood pressure
  2. Routing blood
  3. Ensuring one-way blood flow
  4. Regulating blood supply
• The adult heart is shaped like a blunt cone and is approximately the size of a closed fist, with an average mass of 250 g in females and 300 g in males
• The blunt, rounded point of the heart is the apex
• the larger, flat part at the opposite end of the heart is the base
• The heart is located obliquely in the mediastinum
• mediastinum is a midline partition of the thoracic cavity that also contains the trachea, the esophagus, the thymus, and associated structure
• The apex of the heart is directed to the left, so that approximately two-thirds of the heart’s mass lies to the left of the midline of the sternum
• The base of the heart is located deep to the sternum and extends to the second intercostal space
• The apex of the heart is located deep to the fifth intercostal space
• The base of the heart extends to the seconf intercostal space
• apex is the inferior portion of the heart
• base is the superior portion of the heart
• pericardium, or pericardial sac, is a double-layered, closed sac that surrounds the heart
• pericardium consists of 2 layers: fibrous pericardium and serous pericardium
• The fibrous pericardium is a tough, fibrous connective tissue layer that prevents overdistension of the heart and anchors it within the mediastinum.
• The serous pericardium is a layer of simple squamous epithelium and it consist of 2 parts: parietal and visceral pericardium
• The serous pericardium is a layer of simple squamous epithelium
• epicardium is the superficial layer of the heart wall
• The heart walls are epicardium, myocardium and endocardium
• The parietal pericardium is the part lining the fibrous pericardium.
• The visceral pericardium, also called the epicardium, is the part covering the heart surface
• The space between the visceral and parietal pericardia is the pericardial cavity
• pericardial cavity is filled with pericardial fluid
• pericardial fluid helps reduce friction as the heart moves within the pericardial sac
• Epicardium is a thin serous membrane that constitutes the smooth, outer surface of the heart.
• The serous pericardium is called the epicardium when considered a part of the heart and the visceral pericardium when considered a part of the pericardium.
• The parietal pericardium lines the fibrous pericardium, and the visceral pericardium (epicardium) covers the surface of the heart.
• myocardium is the thick, middle layer of the heart. It is composed of cardiac muscle cells and is responsible for the heart’s ability to contract.
• endocardium is deep to the myocardium; It consists of simple squamous epithelium over a layer of connective tissue.
• The endocardium forms the smooth, inner surface of the heart chambers, which allows blood to move easily through the heart.
• The endocardium also covers the surfaces of the heart valves
• Ridges formed by the myocardium can be seen on the internal surfaces of the heart chambers.
• pectinate muscles are the interior surfaces of the atria are mainly flat, the interior of both auricles and a part of the right atrial wall contain muscular ridges
• crista terminalis are the pectinate muscles of the right atrium are separated from the larger, smooth portions of the atrial wall by a ridge
• trabeculae carneae are the interior walls of the ventricles contain larger, muscular ridges and columns