Cardiovascular System Basics

Cardiovascular System

• The cardiovascular system consists of the heart, blood vessels, and blood.
• It performs three main functions: transport, protection, and regulation.

Heart Anatomy

• The heart is located in the mediastinum, a median cavity in the thorax.
• The mediastinum is divided into superior and inferior parts at the level of the sternal angle.
• The inferior mediastinum is further subdivided into anterior, middle, and posterior parts.
• The heart is enclosed within the middle mediastinum, which contains the pericardium, root of great vessels, and heart and lungs.
• The heart extends obliquely from the 3rd rib to the 5th intercostal space, anterior to the thoracic vertebrae, and posterior to the sternum.
• It is bordered by the 2 lungs and rests on the diaphragm.
• Two-thirds of its mass lies to the left of the midsternal line.

The Pericardium

• The pericardium is a fibroserous membrane that covers the heart and the root of great vessels.
• It is a double-walled closed sac that contains a film of lubricating serous fluid.
• The pericardium consists of two parts: fibrous pericardium and serous pericardium.
• The fibrous pericardium is a tough, outer dense connective tissue that protects the heart, anchors it to surrounding structures, and prevents overfilling.
• The serous pericardium is a one continuous sheet with two layers: parietal layer (lines the internal surface of the fibrous pericardium) and visceral layer (epicardium, covers the external heart surface).

Gross Features of Heart

• The heart has two atrias (superior) that are thin-walled receiving chambers.
• Each atrium has a small, protruding appendage called auricles, which increase atrial volume.
• The interatrial septum divides the left and right atria.
• The right atrium has muscle bundles called pectinate muscles in its wall, and receives blood from the superior vena cava, inferior vena cava, and coronary sinus.
• The left atrium has a smooth internal anterior and posterior wall, and receives blood from four pulmonary veins (oxygenated blood).

This quiz covers the fundamental components and functions of the cardiovascular system, including the heart, blood vessels, and blood flow.