THE CIRCULATORY SYSTEM
The circulatory system consists of the heart and blood vessels.
The heart is a muscular organ which serves as the circulatory pump. The blood vessels aid the transport of blood into the heart and out of the heart.
STRUCTURE OF THE HEART?
The heart is lubricated by a fluid-filled cavity called the pericardial cavity. This helps to lubricate the heart and prevent friction.
The serous membrane covering this fluid-filled cavity is known as the pericardium.
The Epicardium is the membrane layer that covers and lubricates the outer part of the heart.
The Myocardium is the muscular part of the heart. It is important in the process of pumping blood from the heart.
The Endocardium is the smooth layer that lines the inside part of the heart.
Did you know: THE SIZE OF THE HEART IS ABOUT A CLOSED FIST.
THE HEART CHAMBERS:
The heart consists of four chambers, namely:
The Left atrium
The Right atrium
The Left Ventricle
The Right ventricle
The atria are involved in carrying oxygenated blood into the heart. The ventricles are involved in carrying de-oxygenated blood away from the heart.
THE CONDUCTIVE SYSTEM OF THE HEART
For the heart to function optimally, the cardiac cells are involved in contraction and transmission of signals within the heart in order to maintain it characteristics. This function is enabled by the presence of the conductive system of the heart also known as the pacemaker of the heart. This includes;
The Purkinje fibre
The bundle of His
The AV node
The SA node.
The Sino Atrial node is responsible for setting the pace of the pacemaker of the heart. It first sends signals to the Atrio-ventricular node, which then transmits it to other parts of the conductive system of the heart.
We continue from here.