The Structure and Functions of the Arteries
Arteries are blood vessels that convey blood from the heart to the
tissues of the body.
The arteries expand and then constrict with each beat of the heart, a
rhythmic movement that may be felt as the pulse. Arteries are usually
named from the part of the body that they are found, for example;
brachial artery found in the arms, metacarpal artery found in the
wrist; or from the organ which they supply as the hepatic artery
supplies the liver, pulmonary artery brings deoxygenated blood the
lungs. The facial artery is the branch of the external carotid artery
that passes up over the lower jaw and supplies the superficial portion
of the face; the haemorrhoidal arteries are three vessels that supply
the lower end of the rectum; the intercostal arteries are the arteries
that supply the space between the ribs; the lingual artery is the
branch of the external carotid artery that supplies the tongue.
The structure of the artery enables it to perform its function more
efficiently. The walls of arteries are made up of three layers same as
veins. Its inner endothelium is composed of epithelial cells which is
very smooth. This layer helps minimise the friction. The tunica media
provides strength and elasticity. It contains smooth muscles, collagen
and large amount of elastic fibres. Elastic fibres enable the wall to
stretch as blood surge through at high pressure. Tunica externa is the
outer layer of connective tissues containing elastic and collagen
fibres. It provides support for the blood vessel and attaches it to
whatever other tissue it runs through.
Artery walls are very thick and strong. The tunica media which is the
thickest part of the wall contains huge amount of elastic fibres which
enables the wall to stretch and withstand the blood surging out at
high pressure. The elasticity of the walls is important because it
reduces the possibility of them bursting. Also as blood rushes out the
heart in high pressure the walls stretch and become wider reducing the
O’Rourke [13] describes the pulse wave shape as: “A sharp upstroke, straight rise to the first systolic peak, and near-exponential pressure decay in the late diastole.” Arteries are compliant structures, which buffer the pressure change resulting from the pumping action of the heart. The arteries function by expanding and absorbing energy during systole (contraction of the cardiac muscle) and release this energy by recoiling during diastole (relaxation of the cardiac muscle). This function produces a smooth pulse wave comprising a sharp rise and gradual decay of the wave as seen in Figure 5. As the arteries age, they become less compliant and do not buffer the pressure change to the full extent. This results in an increase in systolic pressure and a decrease in diastolic pressure.
The arteries have a thick inner layer of muscle and elastic fibres. This means that they can stretch a lot more than the veins that have a thin inner layer, this means that they are more compact.
The cardiovascular system - The cardiovascular system is responsible for transporting nutrients and removing gaseous waste from the body. It consists of the heart, which powers the whole process, the veins, arteries, and capillaries, which deliver oxygen to tissue at the cellular level. The cardiovascular system carries blood that is low in oxygen away from the heart to the lungs via arteries, where oxygen levels are restored through the air once oxygenated, this blood is then carried throughout the body via arteries, keeping our organs and tissue alive. The cardiovascular system is the workhorse of the body, continuously moving to push blood to the cells. If this important system ceases its work, the body dies.
The arterial duplex ultrasound of the right lower extremity performed on 3/30/2016 revealed a mild to moderate atherosclerotic plaque in the visualized arteries with limited visualization and a large probable hematoma. A follow-up study was suggested to ensure resolution of the hematoma and for better arterial visualization. (Norman Regional Health System 1 379 )
The source expands on three major groups of muscular systems. They are skeletal muscle, Cardiac muscle and smooth muscle. Skeletal muscles are made up of muscle tissue, connective tissue, nerves and blood vessels that is attached to tendons and bones. Cardiac muscles are small with short wide T-tubules and is only found in heart. Smooth muscles are long, slender and spindle shaped with no T tubules, myofibrils or sarcomeres that arrange the blood vessels in some organs. All these three types of muscles are grouped together with fibers that
The endothelium is a cell layer that is lined on the interior surface of lymphatic vessels and blood vessels, which are made up of endothelial cells (Dorland, 2012).
Coronary heart disease is defined by the hardening of the epicardial coronary arteries. The buildup of plaque in the arteries slowly narrows the coronary artery lumen. In order to better understand the physiology of the disease, it is important to first know the basic anatomy of the human heart. The aorta, located in the superior region of the heart, branches off into two main coronary blood vessels, otherwise known as arteries. The arteries are located on the left and right side of the heart and span its surface. They subsequently branch off into smaller arteries which supply oxygen-rich blood to the entire heart (Texas Heart Institute, 2013). Therefore, the narrowing of these arteries due to plaque buildup significantly impairs blood flow throughout the heart.
Hypertension can be defined as a force exerted against the wall of blood vessels. However, high blood pressure occurs when there is high pressure at the time of ventricle contraction during the systolic phase against decrease contract during diastolic phase as the ventricles relax and refill. This can be recorded as systolic over diastolic in millimeters of mercury. (Wallymahmed, M. 2008).
The heart is one of the most unique organs in the human body. Its capabilities and functions truly are amazing. The heart 's function is to pump blood throughout the body supplying oxygen and nutrients to tissues. The heart is the size of your fist and weighs roughly 8-12 ounces depending if you’re male or female. The heart pumps through 100 kilometers of blood vessels for blood that is 3 to 4 times thicker than water at 60 to 80 times minute for a total volume of 5 million liters a year at rest. A basic diagram of the heart includes, right coronary, superior vena cava, aorta, pulmonary artery, pulmonary vein, right atrium, right ventricle, left atrium, left ventricle. There are more in
The heart serves as a powerful function in the human body through two main jobs. It pumps oxygen-rich blood throughout the body and “blood vessels called coronary arteries that carry oxygenated blood straight into the heart muscle” (Katzenstein and Pinã, 2). There are four chambers and valves inside the heart that “help regulate the flow of blood as it travels through the heart’s chambers and out to the lungs and body” (Katzenstein Pinã, 2). Within the heart there is the upper chamber known as the atrium (atria) and the lower chamber known as the ventricles. “The atrium receive blood from the lu...
The heart is two sided and has four chambers and is mostly made up of muscle. The heart’s muscles are different from other muscles in the body because the heart’s muscles cannot become tired, so the muscle is always expanding and contacting. The heart usually beats between 60 and 100 beats per minute. In the right side of the heart, there is low pressure and its job is to send red blood cells. Blood enters the right heart through a chamber which is called right atrium. The right atrium is another word for entry room. Since the atrium is located above the right ventricle, a mixture of gravity and a squeeze pushes tricuspid valve into the right ventricle. The tricuspid is made up of three things that allow blood to travel from top to bottom in the heart but closes to prevent the blood from backing up in the right atrium.
The heart is a pump with four chambers made of their own special muscle called cardiac muscle. Its interwoven muscle fibers enable the heart to contract or squeeze together automatically (Colombo 7). It’s about the same size of a fist and weighs some where around two hundred fifty to three hundred fifty grams (Marieb 432). The size of the heart depends on a person’s height and size. The heart wall is enclosed in three layers: superficial epicardium, middle epicardium, and deep epicardium. It is then enclosed in a double-walled sac called the Pericardium. The terms Systole and Diastole refer respectively and literally to the contraction and relaxation periods of heart activity (Marieb 432). While the doctor is taking a patient’s blood pressure, he listens for the contractions and relaxations of the heart. He also listens for them to make sure that they are going in a single rhythm, to make sure that there are no arrhythmias or complications. The heart muscle does not depend on the nervous system. If the nervous s...
The arteries supply blood rich in oxygen to the body, the veins direct deoxygenated blood from the capillaries back to the heart. These roles make up the circulatory function. Blood flow through these blood vessels can be disrupted resulting in peripheral vascular diseases. These diseases occur as a result of narrowing or blocking of the blood vessels. The risk factors of peripheral vascular diseases include diabetes, smoking, high level of cholesterol, overweight, high blood pressure etc. these risk factors result to aneurysms, Raynaud’s diseases, Buerger’s disease, renal artery disease etc. With this diseases, the peripheral vascular system should be assessed to enable nurses and other health personnel make good
Your Heart and Blood Vessels – Illustrations and facts of the anatomy of the heart.