The Cardiovascular System: An Overview of Blood, Vessels, and Heart – Healthy to Diseased
The cardiovascular system, also known as the circulatory system, consists of the heart, blood, and blood vessels (Mertz, 2004). The cardiovascular system moves oxygenated blood and nutrients through to and removes carbon dioxide and wastes out of the body’s cells. (Miracle of the Human Body, 2010) I will provide an overview how a healthy cardiovascular system does this by first discussing the anatomy of it, in a healthy state, and then the physiology of it, also in a healthy state, this will include how the pulmonary and systemic circuits work. Lastly, I will discuss what happens when the heart is in a diseased state and how it could lead to a heart attack. I will first start with the anatomy of blood. The Blood Blood is what carries nutrients to and wastes from the body’s cells. The blood also transports hormones to their target locations from the endocrine organs. Blood consists of plasma and the formed elements. Plasma makes up approximately fifty-five percent of whole blood but is the least dense component. The formed elements include the buffy coat and erythrocytes. Leukocytes and platelets are what the buffy coat is composed of and makes up less than one percent of whole blood. The densest components and what constitutes forty-five percent of whole blood are the erythrocytes. Blood is carried to and from cells via blood vessels. (Marieb, 2013) Blood Vessels Blood vessels are made up of arteries, arterioles, capillaries, venules, and veins. …show more content…
There are two types of large arteries, elastic and muscular. The elastic arteries are closest to the heart and lead into the muscular arteries. Arterioles are actually small arteries that stem from the larger muscular arteries. The arterioles branch into even smaller vessels called capillaries at capillary beds. Capillaries are the smallest blood vessels. The capillaries join to form the venules in every tissue and every organ, also at the capillary beds. Capillary beds are what unite the arterioles and venules. The venules converge to create veins, which continue to merge into larger and larger veins until they reach the heart. (Mertz, 2004) The Heart The heart is what pumps the blood through the vessels to and from the cells of tissues and organs. …show more content…
The heart is roughly the size of a fist, composed of a three layered wall, and separated into four chambers. The layers include the superficial epicardium, the middle myocardium, and the deepest layer called the endocardium. The four chambers consists of the right atrium, right ventricle, left atrium and left ventricle. The right and left atriums are separated by the interatrial septum and the interventricular septum divides the right and left ventricles. There are atrial-ventricular junctions that differentiate between the atriums and ventricles which contains atrioventricular valves. These valves, known as the tricuspid valve on the right side and mitral valve on the left side, are present to prevent backflow from the ventricles into the atrium. Three veins are connected to the right atrium – the superior vena cava, the inferior vena cava, and the coronary sinus; the pulmonary trunk stems from the right ventricle; the left atrium has four pulmonary veins the join it; and connected to the left ventricle is the aorta. (Farley, McLafferty, & Hendry, 2012) All these structures work together to make the cardiovascular system function. Next, I will describe how these structures function via the pulmonary and systemic circuits. The Pulmonary and Systemic Circuits Structures of the blood vessels and heart work together to circulate blood through the body to deliver nutrients and take out wastes from the body’s cells. The heart is a double pump, one of which pumps blood to and from the lungs and the other that transports blood throughout the rest of the body and back. These two different circulations are known as the pulmonary circuit and the systemic circuit. Pulmonary Circuit The pulmonary circuit is that which circulates blood through the lungs. The heart pumps deoxygenated, carbon dioxide inhabited, blood from the right ventricle out through the pulmonary trunk. The blood then flows from the pulmonary trunk up through the right and left pulmonary arteries and into the left and
The cardiovascular system, also known as the circulatory system, consists of the heart, blood, and blood vessels (Mertz, 2004). The cardiovascular system moves oxygenated blood and nutrients through to and removes carbon dioxide and wastes out of the body’s cells. (Miracle of the Human Body, 2010) I will provide an overview how a healthy cardiovascular system does this by first discussing the anatomy of it, in a healthy state, and then the physiology of it, also in a healthy state, this will include how the pulmonary and systemic circuits work. Lastly, I will discuss what happens when the heart is in a diseased state and how it could lead to a heart attack. I will first start with the anatomy of blood. The Blood Blood is what carries nutrients to and wastes from the body’s cells. The blood also transports hormones to their target locations from the endocrine organs. Blood consists of plasma and the formed elements. Plasma makes up approximately fifty-five percent of whole blood but is the least dense component. The formed elements include the buffy coat and erythrocytes. Leukocytes and platelets are what the buffy coat is composed of and makes up less than one percent of whole blood. The densest components and what constitutes forty-five percent of whole blood are the erythrocytes. Blood is carried to and from cells via blood vessels. (Marieb, 2013) Blood Vessels Blood vessels are made up of arteries, arterioles, capillaries, venules, and veins. …show more content…
There are two types of large arteries, elastic and muscular. The elastic arteries are closest to the heart and lead into the muscular arteries. Arterioles are actually small arteries that stem from the larger muscular arteries. The arterioles branch into even smaller vessels called capillaries at capillary beds. Capillaries are the smallest blood vessels. The capillaries join to form the venules in every tissue and every organ, also at the capillary beds. Capillary beds are what unite the arterioles and venules. The venules converge to create veins, which continue to merge into larger and larger veins until they reach the heart. (Mertz, 2004) The Heart The heart is what pumps the blood through the vessels to and from the cells of tissues and organs. …show more content…
The heart is roughly the size of a fist, composed of a three layered wall, and separated into four chambers. The layers include the superficial epicardium, the middle myocardium, and the deepest layer called the endocardium. The four chambers consists of the right atrium, right ventricle, left atrium and left ventricle. The right and left atriums are separated by the interatrial septum and the interventricular septum divides the right and left ventricles. There are atrial-ventricular junctions that differentiate between the atriums and ventricles which contains atrioventricular valves. These valves, known as the tricuspid valve on the right side and mitral valve on the left side, are present to prevent backflow from the ventricles into the atrium. Three veins are connected to the right atrium – the superior vena cava, the inferior vena cava, and the coronary sinus; the pulmonary trunk stems from the right ventricle; the left atrium has four pulmonary veins the join it; and connected to the left ventricle is the aorta. (Farley, McLafferty, & Hendry, 2012) All these structures work together to make the cardiovascular system function. Next, I will describe how these structures function via the pulmonary and systemic circuits. The Pulmonary and Systemic Circuits Structures of the blood vessels and heart work together to circulate blood through the body to deliver nutrients and take out wastes from the body’s cells. The heart is a double pump, one of which pumps blood to and from the lungs and the other that transports blood throughout the rest of the body and back. These two different circulations are known as the pulmonary circuit and the systemic circuit. Pulmonary Circuit The pulmonary circuit is that which circulates blood through the lungs. The heart pumps deoxygenated, carbon dioxide inhabited, blood from the right ventricle out through the pulmonary trunk. The blood then flows from the pulmonary trunk up through the right and left pulmonary arteries and into the left and