The circulatory system in anatomy and physiology is the process of blood circulation passing through the different parts of the circulatory system such as the capillaries, veins and later upon its complete cycle, returns to the most important part of the cardiovascular system---the heart.
Another important part of the circulatory system is the blood vessel. They are either, capillaries, arteries and arterioles, veins and the venules. The physiological structures of all types of blood vessels are almost the same. In all of these types, the interior of the blood vessels is called Endothelium.This inner layer is made up of squamous cells that layer the lining of the interior of the blood vessel itself.
The whole network of the circulatory system, every artery, vein or capillary is made of ethelial cells. Other connective tissues are called the subendthelial cells that cover the entire blood vessel. The smallest tubular structures that transport blood are called capillaries, which is responsible for the delivery of finer nutrients. The capillary is comprised of single-layered endothelium. These are thin hair-like strands that diffuse elements into the physiological body.The endothelial cells of the capillaries and all the types of blood vessels are important in immunity action of the body against certain diseases; it serves as regulator of the vessel to clasp immune cells to effectuate the immune system in our body.
Further, the capillaries have significant and complex function and system. In the Sunny Medical Center journal capillaries and its basic structure was described: “The walls of the capillary vessels consist of a layer of flattened endothelial cells, pericytes, a basement membrane and a few associated connective tissue fibers.The lumen of the smallest capillaries is just large enough to allow the passage of erythrocytes in single file. Exchange of materials across the capillary wall depends on the nature of the vessel; in discontinuous capillaries the endothelial cell poses no barrier; in continuous capillaries transport involves facilitated transfer across the endothelial cell by vesicles. Fenestrated capillaries have pores which are usually covered by a diaphragm and are intermediate in permeability between continuous and discontinuous capillaries.
” (SUNY, Downstate, 2007) Another type of a blood vessel, which is the largest of all, is the artery.Arteries transport oxygenated blood to almost all of the human body tissues and veins brings deoxygenated blood back to the heart. This is with the exception of pulmonary veins and the portal veins of the system. The cardiovascular system has one large artery and that is aorta. Positioned at the left ventricle of the heart, the aorta is responsible for the delivery oxygenated blood to various parts and organs of the body.
The aortic artery is divided into five sections: the ascending aorta, arch of aorta, descending aorta, thoracic aorta and abdominal aorta. This type blood vessel is actually elastic and flexible.Necessarily, its elasticity is crucial in the contraction of the left ventricle to supply the food it needed. When it contracts it supports the infusion of blood and during its expansion it helps to regulate blood pressure in diastole. The importance of regulation of the blood pressure gives the impression of normal circulation.
The internal structure of large blood vessels, in this case the arteries can be linked to their function. The blood vessels that pumps blood from the heart, commonly called the elastic arteries, which have thick, strong walls to hurdle the sudden high pressure produced during diastole.The elasticity they possess is a manifestation that they can handle the normal functions of everyday life. The arteries have thick, collagenous layer as connective tissue whose strength halts the excessive-distension of the blood vessels’ elasticity.
The property of the blood vessel is primarily utilized to sustain the uninterrupted flow of blood to smaller blood vessels during high blood pressure. Another artery is the muscular arteries provide the control of the level of blood flowing into a region. In the arterial system these elastic structures slowly reduce the flow of blood.In the middle layer, tunica media is imposed and concentrated in circles.
Interesting to cite that in the parts of the body where gravity might be greater, the arterial valves adapt the force of gravity. Vena cavas are exemptions to the presence of valve in blood vessel structures. Commonly, the breakage of these valves and the flow of blood will be visible from the tissues, thus the varicose veins appear. Another type of blood vessel is the veins, which have three, walled- layers.
The major function of which is to transport blood in the entire body.Due to its function, the physiological make-up of veins such as its width however is not comparable to the arterial dimensions. The physical structures of veins and arteries have positive correlation with the blood pressure it contains. Inside the veins were stop-close valves that permit the inward flow but never the backward flow of blood. The veins, as discussed above transports blood from the minute and hair-thin structures, called capillaries to the heart.
It is noted that as it gears and progress toward the heart, the veins that lead thereto correspondingly increase it size.Venules, as the smallest veins connect the capillaries the movement of the veins goes straight and in similar directions with the arteries around the cardiovascular systems. The number of veins outnumbers the arteries which were caused by the bigger areas to drain. After discussing the types of blood vessels, it is important to note the fluid that passes through them—the blood.
Needless to say, the regular flow of blood sustains life and its circulation is one of the most important functions of the circulatory system.The circulation of blood in the cardio-vascular system cycles this way: de-oxygenated blood as being transported by the arteries, enters the right atrium of the heart and passage to the heart’s right ventricle. The lungs on the other hand were being pumped through the pulmonary arteries. The entry and passage initially begins with the right ventricle.
Pulmonary veins give back the oxygenated blood to the heart. It goes to the left atrium before it streamed out into the left ventricle. From the left ventricle the oxygenated blood is propel out via the aorta and to different and countless organs of the body.Whenever the blood and its needed, oxygen dispersers from the blood into cells covering the capillaries, and carbon dioxide strewn into the blood from the capillary cells.
De-oxygenated blood accumulate in the venous system which amalgamates into two major veins in the heart: 1. the superior vena cava , whereby the position is commonly the area above the heart, and the inferior vena cava , the positions that were common is the area below the heart. The heart drains both of the vena cavas and sublimates these vessels into the right atrium of the heart.However, the circulatory system works that the coronary sinus draws the empties itself back to the right atrium.
Between the two, the right atrium is the larger than the left atria, despite its size, it considerably obtains the same amount of blood same as the left atrium, both receive the same amount of blood Later, the tricuspids valve is pumped in the atrioventricular valve. From that ventricle the blood is pumped through the pulmonary semi-lunar valve directly to the pulmonary artery. The blood that travels through the lungs, (actually each lung) is deoxynized in and travels back to the lungs through the veins.It goes back again , where it is oxygenated and then streams once more, into the pulmonary veins.
The oxygen as it enters the left atrium impels through the mitral and the atrioventricular valve going to the left ventricle this time Coming from the left ventricle, the aorta through the aortic semi-lunar valve pumps more blood. The aorta arches and disseminates to all major arteries going to the upper body before penetrating the diaphragm to provide the lower parts of the body the necessary nutrients and oxygen it need.The moment the blood flows into the peripheral tissues all food, oxygen and nutrients are taken from it. Furthermore, carbon dioxide and other wastes will be collected again in the veins and the entire cycle continues, almost without stopping.
The blood deoxygenate were not products of Peripheral tissues, as they do not deoxygenate this component. Consequently, venous blood contains oxygen only that its concentration is lower than those in arterial blood. The physical composition of the left ventricle is viscous and muscularly extensive due to the fact that it pumps blood at higher pressure.It also pumps blood to whole part of the body, On the other hand, right ventricle pumps only, all of its blood directly to the lungs During the process of circulation, pressure from the body is inevitably needed.
Blood pressure maintenance and the control of flow of blood into the capillary beds is modified through the acts of nervous and humoral agents: the arterioles, the smallest vessels in the arterial system. It must be noted that the agents to act in the pressure of blood so that it can reach and pump nutrients must be monitored. The arterioles and other nervous agents must be free from clogging and impairment.
