Circulatory+System+and+Blood

=Circulatory System =

The circulatory system is comprised of the cardiovascular system which distributes blood throughout the whole body. People also consider the lymphatic system, which returns excess filtered blood plasma from the interstitial fluid (between cells) as lymph.

What are the different types of circulations?
 Pulmonary Circulation: The flow of deoxygenated blood from the right ventricle to the lungs and the return of oxygenated blood from the lungs to the left atrium.

 Systemic Circulation: The routes through which oxygenated blood flows from the left ventricle through the aorta to all the organs of the body and deoxygenated blood returns to the right atrium.

 The components of blood are as follows:

 Red Blood Cells (RBCs) or erythrocytes - Contain the oxygen-carrying protein hemoglobin, which is a pigment that gives whole blood its red colour.

 White Blood Cells (WBCs) or leukocytes - Have nuclei and a full complement of other organelles but they do not contain hemoglobin. WBCs are classified as either granular or agranular, depending on whether they contain conspicuous chemical-filled cytoplasmic granules (vesicles) that are made visible by staining then viewed through a lig  ht microscope.

 Platelet - A fragment of cytoplasm enclosed in a cell membrane and lacking a nucleus; found in the circulating blood; plays a role in hemostasis.

 Plasma - The extra celular fluid found in blood vessels; blood minus the formed elements.

 How is blood produced in the body?

 Every single, moment of a human being’s life, the body produces 10 million new red blood cells. As well as white blood cells, platelets and nutrients are made in the body, together producing the important substance known as blood. 50% of blood is made from red blood cells, white blood cells which are made in the bones. Red blood cells give oxygen to the body. A hormone called   erythropoietin directs the marrow in our bones to produce a fresh supply of red blood cells when alerted by a chemical alarm from our kidneys. As well, the white blood cells protect our bodies from disease as they fight bacteria, combat allergic reactions while being attracted to our immune system. Whenever you are cut or have a break in your skin, platelets move to the area and form a clot or scab to stop the bleeding. They also prevent us from bleeding out of capillaries. Plasma is a fluid that carries the blood cells throughout the body. Plasma is 55% of your blood supply. Plasma makes the blood viscous so we do not bleed to death.

<span style="font-family: Arial,Helvetica,sans-serif;"> What roles do the spleen and bone marrow have within the circulatory system?

<span style="background-color: #ffffff; display: block; font-family: Arial,Helvetica,sans-serif; text-align: left;">The spleen is a multifunctional organ. In the circulatory system, its main role is to destroy and remove old or defective red blood cells and cell debris or bacteria from the blood stream. It also produces red blood cells when required, as well as lymphocytes, plasma cells, and antibodies. It therefore acts as both a storage reservoir for stem cells and mature blood cells, which it will release into the blood circulation when the body requires it (e.g. to fight infections). It also acts as a filtration system to purify blood. Although it has many seemingly important functions, the human body is capable of surviving without a spleen, or with a spleen that is damaged.The marrow is the spongy red-yellow tissue found inside most human bones, especially bones of the hip and thigh, and is the site where blood cells are made. The marrow consists of many types of cells, such as fat (lipid) cells, bone-forming osteoblasts and blood-forming hematopoietic stem cells. The latter are able to grow into every type of white and red blood cell in the human body, from erythrocytes (red blood cells), to macrophages, neutrophils, and mast cells. Millions of blood cells are produced here everyday, and the bone marrow also serves as the site where they are stored and matured before they enter the circulatory system.

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<span style="font-family: Arial,Helvetica,sans-serif;"> The circulatory system is interdependent with the other systems in our bodies. <span style="font-family: Arial,Helvetica,sans-serif;"> For our muscular system, we need our circulatory system to provide muscles with oxygen and nutrients. Our skeletal system produces red blood cells in the marrow. Our respiratory system provides oxygen and takes wastes. The digestive breaks down the nutrients and is then put into the bloodstream and then distributed throughout the body. <span style="font-family: Arial,Helvetica,sans-serif;"> How does the heart beat? <span style="font-family: Arial,Helvetica,sans-serif;">

<span style="font-family: Arial,Helvetica,sans-serif;"> The heart has four chambers, two atria and two ventricles. In order for our hearts to beat it responds to an electrical signal which causes the heart to beat normally. These electrical impulses contract parts of the heart, allowing blood to go through it. The heart beating is something the brain controls involuntarily.

<span style="font-family: Arial,Helvetica,sans-serif;"> Major functions of the circulatory system: <span style="font-family: Arial,Helvetica,sans-serif;"> The circulatory system is a system that consists of the heart, blood and blood vessels. Its main functions are :

<span style="font-family: Arial,Helvetica,sans-serif;"> What is the significance of blood pressure?
 * <span style="font-family: Arial,Helvetica,sans-serif;">Glucose is transported through it
 * <span style="font-family: Arial,Helvetica,sans-serif;">It transports gases such as oxygen from the lungs and distributes it to cells, while also taking carbon dioxide from the cells and returning it to the lungs.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Helps maintain the body temperature.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Contains cells that help fight infections.

<span style="font-family: Arial,Helvetica,sans-serif;"> Blood Pressure (BP): Force exerted by blood against the walls of blood vessels due to contraction of the heart and influenced by the elasticity of the vessel walls; clinically, a measure of the pressure in arteries during ventricular systole and ventricular diastole. <span style="font-family: Arial,Helvetica,sans-serif;"> Blood pressure is recorded as two numbers—the systolic pressure (as the heart beats) over the diastolic pressure (as the heart relaxes between beats).The measurement is written one above or before the other, with the systolic number on top and the diastolic number on the bottom. <span style="font-family: Arial,Helvetica,sans-serif;"> For example, a blood pressure measurement of 120/80 mmHg (millimeters of mercury) is expressed verbally as "120 over 80." Normal blood pressure is less than 120 mmHg systolic and less than 80 mmHg diastolic.

<span style="font-family: Arial,Helvetica,sans-serif;"> List of Common Heart Diseases:

<span style="font-family: Arial,Helvetica,sans-serif;"> <span style="font-family: Arial,Helvetica,sans-serif;">Coronary Disease - Is the narrowing or blockage of the coronary arteries, usually caused by atherosclerosis. <span style="font-family: Arial,Helvetica,sans-serif;"> including [|smoking], [|radiotherapy] to the chest, chest pains, [|hypertension] , [|obesity] , [|diabetes] , high alcohol consumption, lack of exercise, inability to manage stress, and [|hyperlipidemia]. Cor pulmonale - a failure of the right side of the heart as a response to increased resistance or high blood pressure in the lungs
 * Causes are Obstructive sleep apnea ** (OSA) or ** obstructive sleep apnea syndrome ** is the most common type of [|sleep apnea] and is caused by obstruction of the [|upper airway] . It is characterized by repetitive pauses in breathing during sleep, despite the effort to breathe, and is usually associated with a reduction in [|blood oxygen saturation] . These pauses in breathing, called ** [|apneas]  ** (literally, "without breath"), typically last 20 to 40 seconds.


 * <span style="font-family: Arial,Helvetica,sans-serif;"> Peripheral vascular disease **

<span style="font-family: Arial,Helvetica,sans-serif;"> refers to the obstruction of large [|arteries] // not // within the [|coronary], [|aortic arch] vasculature, or [|brain] <span style="font-family: Arial,Helvetica,sans-serif;"> causes are s moking - tobacco use in any form is the single most important modifiable cause of PVD internationally also [|Hypertension] - elevated blood pressure is correlated with an increase in the risk of developing PAD, as well as in associated coronary and cerebrovascular events (heart attack and stroke).

What is hypertension?

hypertension or high blood pressure <span style="background-color: #ffffff; color: #333333; display: block; font-family: Arial,Helvetica; font-size: 14px; text-align: left;"> is a condition in which the blood pressure in the arteries is chronically elevated. With every heart beat, the heart pumps blood through the arteries to the rest of the body. <span style="background-color: #ffffff; color: #333333; display: block; font-family: Arial,Helvetica; font-size: 14px; text-align: left;">Blood pressure is the force of blood that is pushing up against the walls of the blood vessels. If the pressure is too high, the heart has to work harder to pump, and this could lead to organ damage and several illnesses such as Heart attack,stroke, heart failure and aneurysm What is atherosclerosis? <span style="background-color: #ffffff; color: #222222; font-family: arial,sans-serif; font-size: small;">A disease of the arteries characterized by the deposition of plaques of fatty material on their inner walls.