CARDIO-VASCULAR SYSTEM::
Cardio-vascular system is a closed circulatory transport system that transports respiratory gases nutrients and excretory products through the medium of blood to various parts of the body it consists of the pumping station the heart and its channels the blood vessles
ANATOMY OF THE HEART
The human heart is a musculotendinous organ which lies on the left in the upper part of the chest its right border is underneath the right side of the stemum its apex is below and medial to the left nipple A normal heart in other words lies underneath the sternum and third fourth and fifth intercostal space on the left side of the chest
The heart consists of three layers The outer most layer is called pericardium pericardium forms a bag like structure the pericardial sac and contains a fluid called pericardial fluid The middle layer is the main stuff of the heart made up of myocytes (cardiac muscle cells) and fibroblasts (Interstitial cells) This layer is called myocardium The inner most layer is called endocardium
INTERNAL STRUCTURE OF THE HEART:::
The heart is made up of four chambers two atria and two ventricles the atria are filling chambers and therefore they have thin walls The ventricles are emptying chambers and so they have thick walls to push the blood in the circulatory system
The wall of the left ventricle is three times thicker than the wall of the right ventricle The left ventricle pushes the blood through the arteries in the whole body (systemic circulation) The right ventricles has to push the blood only in the pulmonary circulation of the chest and therefore its walls are not so thick as that of the left ventricle
0 Comments