CIRCULATORY SYSTEM
1. INTRODUCTION
The circulatory system is also known as the cardiovascular system. This system is a double circulatory closed system which transports blood via arteries, veins and capillaries to the lungs through the pulmonary circulation and to the rest of the body tissues in the systemic circulation. Since the blood travels to varying distances around the body, the blood vessels have to be adapted to overcome different pressures. The pressure changes in the four chambers on the heart (two atria’s and two ventricles) allow the blood to continuously flow in one direction. This is also aided by the valves (artioventricular and semi lunar valves). The circulatory system consists of the heart as well. The heart is a complex
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The vessels make up two systems which are closed that begins and ends at the heart. However, based on the structure and function, the vessels are put into categories such as arteries and veins.
ARTERY
These are vessels carrying blood away from the heart. These carry oxygenated blood from the heart to the rest of the blood tissues. However, there is one artery which does not carry oxygenated blood, and that the pulmonary artery. The pulmonary artery carries deoxygenated blood from the heart to the lung, where the blood gets oxygenated. Since, the blood is in high pressure, the artery has some structural modifications that help in overcoming the pressure exerted and not to burst. The artery is composed of tunica externa, tunica media, and tunica intima. It also has a relatively narrow lumen.
The tunica externa is the furthermost, strong outer covering of the artery. It is composed of connective tissues, collagen and elastic fibres. The collagen in the artery helps the wall to be stable and not collapse. The elastic fibre helps the walls to stretch and recoil when necessary.
The tunica media is the middle covering of the artery. It consists of smooth muscle, collagen and elastic
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These receive blood directly from the heart. These are the Aorta and the pulmonary artery. The Aorta transports blood from the heart to the rest of the body tissues, whereas the pulmonary artery transports blood from the right ventricle of the heart to the lungs. The arteries need to be elastic because the diameter is small compared to the actual size of the artery. When the heart contracts and pours blood in these arteries, the walls need to stretch to house the blood. The arterial hydrostatic pressure that results from ventricular contraction is the systolic blood pressure. The period between the heart constrictions, the elastic walls recoil to maintain the blood pressure. The arterial hydrostatic pressure between contractions is the diastolic blood pressure. The walls of these have a lot of elastin .Elastin is a fibre which is made up of proteins. However, these arteries have three main walls. These are the tunica externa, tunica media and tunica
Veins transport blood to the heart and lungs at low pressure after receiving it from the capillaries. Valves inside the veins keep blood moving in one direction. The human body's arterial system branches out from one main artery, the dorsal aorta. Like veins, arteries have three layers: an outer layer of tissue, an inner layer of epithelial cells and a layer of muscle in between.
Section A – Part II Cardiac cycle or heartbeat Blood enters and fills both atriums at the same time. When full the pressure causes the tricuspid and bicuspid valves to open and flows into the ventricles. Contraction (systole) of each atrium now forces any remaining blood into the ventricles. The ventricles now contract (systole) and atriums relax (diastole). The pressure closes the tricuspid and bicuspid valves (causes the first sound of the heart beat).
The heart is a double sided muscular pump nestled between the two lungs in the centre of the chest, behind the breastbone. The muscular organ keeps the blood circulating around the body. The mammalian circulatory system is known as a double circulatory system because, on every circuit of the body, blood passes through the heart twice. The mammalian heart consists of four chambers: the right and left atria (singular atrium) and the right and left ventricles.
The Human Body System AC 2.1. Explain the structure and function of at least 3 to 4 systems 1) The Circulatory System; This system transports blood, full of oxygen and nutrients to and from the heart, and all around the rest of the human body. At the same time it transports out carbon dioxide and other unwanted material such as harmful minerals, waste material resulting from cellular breakdown, nitrogenous waste in liquid form, and food additives. These are then taken to the liver where they get transformed, or to the kidneys so that they can be excreted out as urine, or through the intestines.
The pulmonary and systemic circuits carry blood to the organs in the body. The pulmonary circuit is on the right half of the heart. The pulmonary circuit carries blood to the lungs for gas exchange and returns it to the heart. It pumps oxygen poor blood into the pulmonary trunk, which immediately divides into the right and left pulmonary arteries. The pulmonary arteries transport blood to the air sacs of the lungs, where carbon dioxide is unloaded and oxygen is picked up.
Brochure information Anatomy and physiology of the cardiovascular system Cardiovascular System According to (smith.A2013). The cardiovascular system includes the heart, blood vessels and also blood. Its role is to deliver nutrients and takes away any by-products from a person’s body.
Cardiovascular diseases (CVDS) Cardiovascular diseases comprise ailments that include the blood vessels (veins, arteries and capillaries) or the heart, or together or diseases that disturb the cardiovascular system. The cardiovascular system, also named as the circulatory system, is the system that transports blood all over the human body. It is composed of the heart, arteries, veins, and capillaries.
Their tunica media is much thicker than any other blood vessel. It consists of many collagen fibers and a few elastic fibers dispersed
High blood pressure is a common condition that a lot of people sufferer from. This is when the force of blood on the walls of your arteries is either too high. Arteries are blood vessels that carry blood away from the heart to supply your tissues with oxygen and nutrients. In the hearts two chambers called ventricles contact with each other heart beat to push blood to the lungs and through the arteries the body. As blood flows through them three main factors affect pressure on your artery walls the first is the cardiac output or the amount of blood your ventricles push out of your heart every few minutes.
The heart is the only organ that is composed of cardiac muscle. As the heart has a life time job in pumping the blood throughout the body. The vigorous muscle contains cell that appear to be striated. The interlocking cells allow the heart to contract and relax when pumping blood. The cardiac muscle is involuntary.
This is why medicine is often injected into veins rather than arteries or capillaries. This, in summary, is how the healthy circulatory system works. The heart pumps blood to the lungs where it is oxygenated, then the blood goes back through the heart into the arteries, which push the blood through blood vessels to carry it around the body, and then veins carry the blood back to the heart to be sent to the lungs again. In summary, that is how a healthy circulatory system operates. Atherosclerosis is a slow progressive disease that usually worsens in the victims 30s, but becomes dangerous in the 50s and 60s.
The correct side of the heart, including the correct chamber and ventricle, gathers and pumps blood to the lungs through the pneumonic conduits. The lungs revive the blood with another supply of oxygen. The lungs additionally inhale out carbon dioxide, a waste item. Oxygen-rich blood then enters the left half of the heart, including the left chamber and ventricle.
Similarly to the pulmonary artery, the pulmonary vein has very thin walls although the vein’s walls are even thinner than those of the pulmonary artery due to the wider lumen and low pressure of the blood. The pulmonary vein also contains little elastic fibres as the shape of the veins do not need to be maintained as rigidly as those of the artery due additionally to the low blood
The heart, blood, and blood vessels all form the circulatory system, also known as the cardiovascular system. As one of the most important systems in the human body, the circulatory system transports oxygen and nutrients to tissues and removes any waste products. Without the circulatory system, your organs wouldn 't be able to function, causing death. With the blood vessels taking blood around the body, the heart pumps all this blood.
The circulatory system dispenses oxygen, carbon dioxide, nutrients, waste products, hormones and heat from the body to the tissues. It consists of the heart and blood vessels. The main function of the circulatory -system is to transport oxygen, hormones, and nutrients. The heart, which is the hardest working organ is located in the body’s thoracic