The Heart

Our heart is located within the left side of our chest cavity, just slightly behind the sternum and is protected within the confinements of the ribcage. It sits between our lungs and is surrounded by a double-layered membrane sac known as the pericardium.

The pericardium is suspended within the chest cavity by ligaments that attach it to the spinal column, diaphragm, and other parts of the body while the inner layer is attached to the heart. The heart is able to move around within the pericardium sac thanks to a serous fluid that separates the two membranes.

Within the heart, there are four chambers, which are separated by a thick wall of muscle known as the septum. The two upper chambers are known as the right and left atria and the two lower ones are known as the left and right ventricles.

The left ventricle is not only the largest portion of the heart, but also the strongest. Although its walls are barely a half-inch thick, it has enough strength to push our blood through the aortic valve and to the rest of the body.

There are three layers to the heart walls, which are: the endocardium, myocardium, and epicardium. These layers work together to send blood to the rest of the body. The endocardium is the most-inner layer, the myocardium is the muscular middle layer and the epicardium is the protective outer layer. The epicardium is also one layer of the pericardium.

Due to our heart being such a complex system, there are many different components of it that come together to perform its functions.

The hearts main function is to pump the blood needed for the body to function properly. In addition to this, the heart is also responsible for pumping vital substances and hormones to different parts of the body, maintaining blood pressure, and receiving the deoxygenated blood from cells and pumping it to the lungs for oxygenation.

The heart begins by receiving deoxygenated blood from the body through the right atrium. From here, it is pumped into the right ventricle where it is then sent to the lungs to be loaded up with oxygen. Once oxygen has been added to the blood, it is then sent back to the heart, but this time to the left atrium. Once in the left atrium, the blood is then pumped into the left ventricle, which is the strongest chamber within the heart. It is here where the blood is then finally pumped into the rest of the body, allowing for the oxygen-rich blood cells to travel to their intended location.

Between the heart chambers, there are four valves which are conductors of the flow of blood. These valves are the: aortic, mitral, pulmonary, and tricuspid valve. The first two valves are on the left side of the heart, and the last two on the right. In addition to these four valves, the heart receives its nutrients and oxygen supply from the coronary arteries that run along its surface.

In order for our heart to beat properly, it requires electrical signals to direct its muscle when to contract and relax. This electrical signal starts within the right atrium at the Sino-atrial node, and then crosses the atria, producing a contraction. This is the moment when blood is then pumped through the valves and into the ventricles.

There is a space where the atria’s meet the ventricles, and within this space there are a cluster of special cells that come together to create the atrio-ventricular node. That same electrical signal passes through here and courses throughout your heart muscle using its own conducting system. This forces the ventricles to contract, and the blood is then pushed into the main arteries. The Sino-atrial node produces another signal, and the whole process begins again.

Stress is known for the havoc it can wreak on the body over long periods of time, and when it comes to our heart health, it is no different.

Years of research has uncovered the impact that stress has on the cardiovascular system and our hearts health. What has been uncovered over the years is that stress is one of they key contenders found to raise our blood pressure. Increased blood pressure is a known associated risk factor for the development of strokes and heart attacks. Although stress may not be an official risk factor for such ailments, it is associated with some of the well-known risk factors. One can make an educated observation to connect the dots to see the possible correlation between the two.

A study published in The Lancet journal from 2017 looked into the relationship between the amygdala and cardiovascular events. The amygdala is one of the main systems within the stress response. Researchers examined brain scans from over 293 participants and found that activity within the amygdala significantly predicted the development of cardiovascular disease and increased arterial inflammation. Inflammation within the heart is a serious concern, as inflammation anywhere in the body over a period of time can lead to a serious disruption within functions.

Stress affects the heart in more ways than one could fit into this smaller section. In order to fully cover this area , we will be covering this more in-depth in upcoming articles.