Understand the Cardiovascular System in under 10 minutes with CTE Skills’ latest video.

The Health Science Technology category and more specifically the Anatomy and Physiology category is one of CTE Skills’ most popular and fastest growing series of videos.

While there are many videos available to members of the CTEskills.com site , occasionally we like to offer something for free too. Watch this short video about the Cardiovascular System and see how easy it is to learn with CTE Skills.

The cardiovascular system, also known as the circulatory system, is the transportation system of the body. The major structures that make this possible are the heart, blood vessels and blood.

Simply put, the heart pumps the blood in order to move nutrients through the blood vessels to nourish and to remove metabolic wastes from the body.

The purpose of this video is to present a basic understanding of the Cardiovascular System. A more in depth study of the system will be presented in other CTE videos where we will look into each specific structure and function of the Cardiovascular system.

There are two major circuits within the circulatory pathway which work together to form a “closed” circulatory system.

The two pathways are…

1. The pulmonary pathway

2. The Systemic pathway

In the human organism, the right side of the heart pushes blood through the pulmonary circuit so that it can be oxygenated in the lungs. The left side of the heart pumps oxygenated blood to the entire body. The blood is then returned to the heart via the SYSTEMIC pathway…where the cycle begins again through the pulmonary pathway.

It can be said the heart is actually two pumps divided by a Septum (wall).

The Heart…As mentioned in the Muscular system video, is an involuntary muscle that works somewhat independently from the Nervous system. This will be explained in more detail later, but for now let’s take a look at what makes up the heart.

The Heart is a muscular organ with four hollow chambers. It consists of…

Two Atria – which are the upper chambers.

Two ventricles – these are the lower chambers.

The left and right side of the heart is divided by the SEPTUM

The heart is made up of three layers of tissues.

1. The innermost layer is the endocardium; which is the thin, smooth membrane that lines the inside of the chambers of the heart and forms the surface of the valves of which there are four.
2. The myocardium, which is the middle layer, is the muscular wall of the heart, or the heart muscle.
3. …and the Pericardium… is a tough double layered fibrous sac which covers the heart.

Blood Vessels

The word vessel has many meanings, but in Anatomy and Physiology, Blood Vessels are meant for carrying or transporting the blood throughout the body.

The Blood Vessels are similar to a two way highway system. One lane or direction is known as the arteries, and the other lane or direction is known as the veins.

Starting in the heart, the blood flows to the body through Arterial blood vessels. The largest of these arteries is known as the AORTA. These arteries provide the pathway for blood to travel to the body from the heart.

Arteries are further divided into Arterioles and (arterial) Capillaries.

Arterioles are smaller blood vessels that branch out from larger arteries and lead to the (arterial) capillaries, which are the smallest blood vessels in the body.

The arterial capillaries are connected to the venous capillaries…The arterial side of the capillaries is dropping off Oxygen and Nutrients TO the body’s cells and the venous side of the capillaries is picking up metabolic waste FROM the body’s cells.

Together they form a network, where arteries and veins connect completing the (closed) circulatory circuit. The blood flow from the venous capillaries will flow back from the body to the heart through venous blood vessels.

Similar to the arteries, only in reverse, the blood flows from the venous capillaries into a system of veins called the venules. These venules connect to larger veins which carry the blood back FROM the Body TO the heart, VIA the largest veins known as the Superior and Inferior Vena Cavas. Your arteries play a vital role in keeping your body functioning and healthy, however, if you do not keep your body fit and healthy, issues can arise affecting your arteries and other important connections in your body. If you consume food high in fats and sugar, and smoke regularly you are at higher risk of diseases like PAD – Peripheral Arterial Disease life-threatening if not treated as soon as possible. It can be caused by hereditary factors also, as well as genetics, that is why knowing your family history and recurring ailments can make you more aware of what could potentially happen.

Blood

Now that we have an understanding of how the blood moves throughout the body, we can discuss what it actually is. Blood is a fluid (or liquid) known as plasma. Plasma is made of up of 90 percent water. (This is why drinking a sufficient amount of HEALTHY water is absolutely necessary)

Blood contains many substances but the three main substances we will discuss in this video are the three different types of blood cells, each having its own particular function.

1. The first type of blood cell is called Erythrocyte, known as the red blood cell.
2. The second type of blood cell is the Leukocyte, known as the white blood cell.
3. The third type of cell is the thrombocyte, also known as the platelet.

The Heart Works Alone

The heart has its own electrical system designed to work on its own independent from the nervous system. If the nervous system is damaged and can not send signals to the skeletal muscles or to other major organs such as the brain, the heart will not be affected because it has its own chemical/electrical system that will continue to pump the blood throughout the body. People with brain damage are placed on life support for breathing not for pumping (contracting) the heart… The only thing that would stop this mechanism is the lack of oxygen and/or a blockage and/or direct injury to the heart. Blockages are what cause heart attacks, which are the most common cardiac ailment, and when these occur CPR can be used as part of a first aid response to keep the heart active until medical attention can be sought.

The conductive pathway within the heart has four main relay stations through which the electrical impulses move through in order for the heart to keep(continue) beating; which is roughly 100,000 times a day.

The conductive pathway begins with…the SA Node.

• The SA node, known as the pacemaker, is located in the right atria. It starts the spark and passes it on to the next relay station.
• The AV node which is located on the back wall of the heart between the right atria and the right ventricle. The spark is then passed unto the…next relay station… the
• … Bundle of HIS located in the heart’s septum…and then lastly to the
• purjinke fibers, the relay station which spreads the electrical charge throughout the myocardium, which is the cardiac muscle, and causes the heart to contract; atrias first then the ventricles…

After watching this video, you should now have a basic understanding of what the Cardiovascular System is, the basic functions, and the basic structures that define the heart.

Here’s a quick recap.

The Cardiovascular or Circulatory System is an organ system whose basic purpose is to circulate blood to and from cells in the body in order to transport nutrients and remove waste.

The heart pumps the blood to the body through arteries which branch off into smaller blood vessels called arterioles.

The Network of capillaries is where oxygen and other nutrients diffuse from the blood and into the cells.

As O2 and nutrients are diffused into the cells from the arterial capillaries, metabolic waste is diffused into the venous capillaries from the cells…the blood returns to the heart via the veins where the cycle begins again.

And remember that the heart has a beat of its own, through the electro/chemical circuit system and its 4 relay stations.

To sum it all up, the heart pumps blood to the BODY through the arteries and returns FROM the Body to the heart through the veins.

Unfortunately, The heart is also subject to diseases and conditions … in fact the number one reason for an early demise is still due to heart failure.. These conditions will be discussed further in future CTE videos.