[Biology Class Notes] on Human Cardiovascular System Pdf for EXAM

Let’s know what is the human cardiovascular system. 

• The human cardiovascular system is sometimes known as the blood-vascular, or simply known as the circulatory system.

• This system includes the heart, which is a muscular pumping device, and an enclosed system of vessels known as the arteries, veins, and capillaries.

• As the name human body cardiovascular system implies, the blood contained in the circulatory system is pumped by the heart around a closed circle or we can say around a circuit of vessels as it passes repeatedly through the various “circulations” of the body.

In adults, the survival of the developing embryo depends on the circulation of blood to maintain homeostasis as well as a favourable cellular environment. In response to this need, the human cardiovascular system emerges early in development and attains functional status long before any other major organ system and organs. Incredible as it seems, the primitive heart begins to beat regularly early basically in the fourth week following fertilization.

 

Cardiovascular System Anatomy and Role of the Cardiovascular System

• The important role of the human cardiovascular system is in maintaining homeostasis. It depends on the continued and controlled circulation of blood across the thousands of kilometres of capillaries that permeate each tissue and reach each and every cell of the body. 

• Blood performs its ultimate transport function in the microscopic capillaries.

• Nutrients along with other necessary materials pass from capillary blood into the liquids around the cells that the waste is removed.

Components of the Human Cardiovascular System

After discussing what is the cardiovascular system. Let’s discuss the components of the human cardiovascular system. 

• The human cardiovascular system has three main components: the heart, the blood vessel, and the blood itself. 

• The heart is the system’s pump and the blood vessels are said to be the delivery routes. 

• Blood can be said as a fluid that contains oxygen as well as the essential nutrients the body needs. Blood also carries the wastes which need to be removed. 

Heart

We have already discussed the cardiovascular system definition. 

• The heart is similar to a muscular pump that provides the force vital to circulate the blood to all the various tissues in the body.

• The function of the heart is vital because, to survive, the tissues need a continuous supply of oxygen as well as essential nutrients, and metabolic waste products have to be removed. 

• Deprived of these necessities, cells soon undergo irreversible changes which may lead to death. While blood is the means of transportation, the heart is the organ that keeps the blood moving across the vessels. The normal adult heart pumps around five litres of blood every minute of life.

Blood Vessels

Functions of Bloodstream and Circulation:

• Circulates oxygen and flushes out carbon dioxide.

• Delivers nutrients to cells.

• Removes metabolic waste from excretory organs and eliminates it.

• Protects the body from sickness and infection.

• Coagulation stops bleeding after being injured.

• Transports hormones into cells and target organs.

• Helps regulate body temperature.

Human Arterial System

Let’s discuss the human arterial system.

What are Arteries?

Arteries carry oxygen-rich blood away from your heart.  They are thick hollow tubes that are very elastic which enable them to dilate and constrict (narrow) as the blood is forced down through the heart. The arteries branch out and branch out, becoming smaller until small arterioles become even more elastic. Arterioles supply the capillaries with oxygen-rich blood. The aorta, being the major artery of the organism, rakes blood from the heart, branches in other arteries which deliver oxygenated blood to the rest of the body.

How Does the Cardiovascular System Work?

The human cardiovascular system is the heart, blood vessels, and blood. Blood contains oxygen as well as other nutrients which your body needs to survive. Blood is filled with oxygen and other nutrients your body needs to survive.  Simultaneously, the body dumps waste products like carbon dioxide back into the blood, so they can be eliminated. 

Maintaining blood flow to all the various parts of the body is one of the essential functions of this system. The veins transfer the used blood from the body into the heart and this blood is low in oxygen (as it has been taken out by the body) and the blood is high in carbon dioxide (as the body has unloaded it back into the blood). 

All the veins drain into the superior as well as inferior vena cava which then drain into the right atrium. The right atrium pumps blood through the right ventricular. Then the right ventricle pumps blood to the pulmonary trunk, through the pulmonary arteries, and then into the lungs. In the lungs, the blood recovers the oxygen that we breathe and then removes the carbon dioxide. The blood then becomes rich in oxygen.  From the lungs, blood drains into the left atrium and then is pumped into the left ventricle. Then the left ventricle pumps this oxygen-rich blood out into the aorta which then distributes it to the rest of the body through other arteries. The primary arteries that branch out of the aorta and take blood to specific areas of the body are given below:

• Carotid arteries, the artery which takes blood to the neck and head

• Coronary arteries,  the artery which provides blood supply to the heart itself

• Hepatic artery, the artery which takes blood to the liver with branches going to the stomach

• Mesenteric artery, the artery that takes blood to the intestines

• Renal arteries, the artery that takes blood to the kidneys

• Femoral arteries, the artery that takes blood to the legs

This allows the body to use the oxygen in the blood to perform its normal functions. That blood will come back to the heart again through the veins and the cycle continues.