sign in sign up
<<
Home , Circulatory system, Systemic venous system

INTRODUCTION OF

CIRCULATORY SYSTEM PROCESS

Qi Lin

The Pennsylvania State University

INTRODUCTION OF PROCESS

Introduction Cardiovascular Circulation The circulatory system (shown in Figure An average adult has a (shown in 1), is an system that allows to Figure 2) that is about 14cm long by 9 cm circulate and transport , , wide. It’s approximately the size of a man’s , , and blood cells to closed fist. The heart pumps approximately provide nourishment, fight disease, stabilize 7,000 L of blood every day. Statistics show , and maintain . The that the heart will contract about 2.5 billion circulatory system, as simply a highway for times in an average person’s life. It contains blood, is made up of three independent four chambers in total: systems that work together: the heart (cardiovascular circulation),  Left - the upper left chamber (); and , , of the heart and coronary and portal vessels (systemic  Left - the lower left circulation). The circulatory systems of chamber of the heart are close, which means that the blood  Light atrium - the upper right in humans’ body never leaves the network of chamber of the heart blood vessels. In contrast, oxygen, carbon  Right ventricle - the lower right dioxide and nutrients diffuse cross the blood chamber of the heart and cells. There is one atrium and one ventricle involved in each circulation in the heart. For systemic circulation, the left ventricle and the right atrium important roles. The left ventricle receives the oxygenated blood from the lungs. Then, the blood in the left ventricle will be pumped out to the body through the and return to the right atrium. For pulmonary circulation, the right ventricle and the left atrium play important roles. The right ventricle receives the deoxygenated blood from the body. Then, the blood in the right ventricle will be transferred to the lungs through the left and right pulmonary .

Figure 1: The diagram of the circulatory system INTRODUCTION OF CIRCULATORY SYSTEM PROCESS

The blood from the left ventricular pumps into the aorta, the body’s largest artery. The aorta branches into major arteries at the upper part of the body before passing through the diaphragm. Then, these major arteries branch further into smaller arteries and at the lower parts of the body, and finally . During the process of systemic circulation, waste and carbon dioxide diffuse out of the into the blood, while oxygen in the blood diffuses out into the cell. The deoxygenated blood continually travel through the capillaries, which merge into , then veins, and finally the vena

cava, to begin the pulmonary circulation, Figure 2: The diagram of the cardiovascular exchanging the carbon dioxide and oxygen circulation with the alveoli in the lungs.

Systemic Circulation The systemic circulation (shown in Figure 3) is the circulation of the blood to all parts of the body except the lungs. The main components of the systemic circulation including the aorta and its branches which emitted from the left ventricle, and the vena cava and it branches veins which returned to the heart. The branches of the aorta include arteries and arterioles, and the branches of the vena cave include veins and venules. The can be divided into three major systems: the system, the inferior vena cava system and the coronary system. The superior vena cava is the that collects the blood from the head, neck, and upper chest and brings back to the heart. The inferior vena cava is the blood vessel that collects the blood from the lower part of the body including abdomen, pelvic and lower extremity. The Figure 3: The diagram of the systemic circulation cardiac is the blood vessel that collects the venous blood in the heart. INTRODUCTION OF CIRCULATORY SYSTEM PROCESS

Pulmonary Circulation Pulmonary circulation (shown in Figure 3) is the circulation of the blood from the heart the lungs for oxygenation, then back to the heart again. After the process of the systemic system, oxygen-depleted blood from the body enters the right atrium through the superior and inferior vena cava. The blood is then pumped into the right ventricle. The pulmonary circulation is composed of two main parts: pulmonary arteries and veins. The pulmonary arteries are filled with the venous blood, which are the only arterial vessels in the body used to transport the deoxygenated blood. The right ventricle in Figure 4: The diagram of the pulmonary the heart transports the deoxygenated blood circulation to the capillaries through the pulmonary arteries. The deoxygenated blood in the lung capillaries exchanges with gas within the Key terms alveoli to inhale the oxygen and exhale the Alveoli: Tiny sacs within lungs that allow oxygen carbon dioxide. Through this process, the and carbon dioxide to move between the lungs deoxygenated blood changes from dark red to and bloodstream. bright red. Then, it will return to the left atrium through the pulmonary veins, Aorta: The largest artery in the body, supplying completing the pulmonary circuit. Pulmonary oxygenated blood to the circulatory system. veins are the only venous vessels in the body Arteries: Elastic vessels able to carry blood away that contain oxygenated blood. Once entering from the heart under high . the left atrium, the blood flows into the left ventricle. From the left ventricle, the blood is Arterioles: A small diameter blood vessel in the that extends and branches out pumped into the aorta to begin the systemic from an artery and leads to capillaries. circulation, delivering oxygenated blood to the body. Atrium: The upper chambers of the heart; they receive blood returning to the heart. Capillaries: The smallest blood vessel in a ; any of the fine branching blood vessels that form a network between the arterioles and venules. Deoxygenated blood: The blood with a low of oxygen. Homeostasis: The property of a system in which variables are regulated so that internal conditions remain stable and relatively constant. INTRODUCTION OF CIRCULATORY SYSTEM PROCESS

Inferior vena cava: Along with the superior vena cava, one of the two largest veins in the body; it is formed by the joining of the common iliac veins. Nourishment: The food or other substances necessary for growth, , and good condition. Oxygenated blood: The blood with a high concentration of oxygen. Superior vena cava: Along with the inferior vena cava, one of the two largest veins in the body; it is formed by the joining of the brachiocephalic veins. Veins: The blood vessels that carry blood back to the atrium; they are less elastic than arteries. Ventricles: The lower chambers of the heart; they receive blood from the atria, which they pump out into the arteries. Venules: Macroscopic vessels that link capillaries to vein.

References: Jones, and Bartlett. and of the Cardiovascular System. "Systemic and Pulmonary Circulation - Boundless Open Textbook." Boundless.