Word List
Blood
| electrolyte | электролит |
| albumin | альбумин |
| enzyme | фермент |
| erythrocyteы | эритроцит |
| leukocytes | лейкоцит |
| platelets (thrombocytes) | тромбоцит |
| hemoglobin | гемоглобин |
| erythropoietin | эритропоэтин (белок, усиливающий эритропоэз) |
| red bone marrow | красный костный мозг |
| phagocytosis | фагоцитоз |
| hemostasis | гемостаз, остановка кровотечения |
| coagulation | коагуляция, свертывание |
| serum | сыворотка |
Blood vessels
| artery | артерия |
| arteriole | артериола, мелкая артерия |
| vein | вена |
| venule | венула, мелкая вена |
| capillary | капилляр |
Arteries
| aorta | аорта |
| abdominal aorta | брюшная аорта, вентральная аорта |
| brachial artery | плечевая артерия |
| carotid artery | сонная артерия |
| femoral artery | бедренная артерия |
| pulmonary artery | легочная артерия |
| radial artery | лучевая артерия |
| subclavian artery | подключичная артерия |
| axillary artery | подмышечная артерия |
| ulnar artery | локтевая артерия |
| common iliac artery | подвздошная общая артерия |
Veins
| anterior tibial veins | передние большеберцовые вены |
| brachial vein | плечевая и головная вены |
| cephalic vein | головная вена |
| common iliac vein | подвздошная общая вена |
| great saphenous vein | подкожная большая вена ноги |
| inferior vena cava | нижняя полая вена |
| superior vena cava | верхняя полая вена |
| jugular vein | яремная вена |
| pulmonary vein | легочная вена |
The cardiovascular (CV) systemis composed of the heart, which is essentially a muscular pump, and an extensive network of tubes called blood vessels. The main purpose of the CV system, also called circulatory system, is to deliver oxygen, nutrients, and other essential substances to the cells of the body and to remove the waste products of cellular metabolism. Delivery and removal of these substances are achieved by a complex network of blood vessels: the arteries, capillaries, and veins – all of which are connected to the heart. Without a healthy CV system that provides adequate circulation, tissues are deprived of oxygen and nutrients. In addition, waste removal ceases. When this happens, an irreversible change in the cells takes place that may result in a person’s death. The CV system is vital for survival.
Because the lymphatic system does not have a pump, it depends on the pumping action of the heart to circulate its substances. The lymphatic system is composed of lymph nodes, lymph vessels, and lymph fluid. It is responsible for draining fluid from the tissues and returning it to the bloodstream.
Text 1
B. Blood and blood vessels
Blood
Blood circulates through the vessels, bringing oxygen and nourishment to all cells and carrying away waste products. The total adult blood volume is about
5 liters. Whole blood can be divided into two main components: the liquid portion, or plasma (55%), and formed elements, or blood cells (45%).
Plasma is about 90% water. The remaining 10% contains nutrients, electrolytes (dissolved salts), gases, albumin (a protein), clotting factors, antibodies, wastes, enzymes, and hormones. A host of these substances are tested for in blood chemistry tests. The blood cells are erythrocytes, or red blood cells; leukocytes, or white blood cells; and platelets, also called thrombocytes. All blood cells are produced in red bone marrow. Some white blood cells multiply in lymphoid tissue as well.
Erythrocytes
The major function of erythrocytes is to carry oxygen to cells. This oxygen is bound to an iron-containing pigment within the cells called hemoglobin. Erythrocytes are small, disk-shaped cells with no nucleus. Their concentration of about 5 million per μL (cubic millimeter) of blood makes them by far the most numerous of the blood cells. The hemoglobin that they carry averages 15 g per deciliter (100 mL) of blood. A red blood cell gradually wears out and dies in about 120 days, so these cells must be constantly replaced. Production of red cells in the bone marrow is regulated by the hormone erythropoietin(EPO), which is made in the kidneys.
Leukocytes
White blood cells all show prominent nuclei when stained. They total about 5,000 to 10,000 per μL, but their number may increase during infection. There are five different types of leukocytes, which are identified by the size and appearance of the nucleus and by their staining properties. White blood cells protect against foreign substances. Some engulf foreign material by the process of phagocytosis;others function as part of the immune system. In diagnosis it is important to know not only the total number of leukocytes but also the relative number of each type because these numbers can change in different disease conditions.
Platelets
The blood platelets (thrombocytes) are fragments of larger cells formed in the bone marrow. They number from 200,000 to 400,000 per μL of blood. Platelets are important in hemostasis, the prevention of blood loss, a component of which is the process of blood clotting, also known as coagulation. When a vessel is injured, platelets stick together to form a plug at the site. Substances released from the platelets and from damaged tissue then interact with clotting factors in the plasma to produce a woundsealing clot. Clotting factors are inactive in the blood until an injury occurs. To protect against unwanted clot formation, 12 different factors must interact before blood coagulates. The final reaction is the conversion of fibrinogen to threads of fibrin that trap blood cells and plasma to produce the clot. What remains of the plasma after blood coagulates is serum.
Blood Types
Genetically inherited proteins on the surface of red blood cells determine blood type. More than 20 groups of these proteins have now been identified, but the most familiar are the ABO and Rh blood groups. The ABO system includes types A, B, AB and O. The Rh types are Rh positive (Rh+) and Rh negative (Rh−). In giving blood transfusions, it is important to use blood that is the same type as the recipient’s blood or a type to which the recipient will not show an immune reaction, as described below. Compatible blood types are determined by cross-matching. Whole blood may be used to replace a large volume of blood lost, but in most cases requiring blood transfusion, a blood fraction such as packed red cells, platelets, plasma, or specific clotting factors is administered.
Blood vessels
The vast network of blood vessels (made up of arteries and arterioles, veins and venules, and capillaries) begins at the heart and spans out through the entire body to the far reaches of the fingertips and toes. Together, these different types of vessels work to carry blood pumped by the heart through the body.
Arteries take care of clean, oxygenated blood. Veins handle the movement of deoxygenated blood. The capillaries, serve as mini bridges between the two types of vessels.
Arterial system
The arterial system is composed of arteries and arterioles (smaller arteries). Starting with the largest artery, the aorta, the arteries carry oxygenated blood away from the heart to the arterioles, and then on to the capillaries, where the exchange of gases (oxygen and carbon dioxide) takes place.
The pulmonary artery, with its two branches, is the exception of the arterial
world. Instead of carrying oxygen-filled blood to other parts of the body, its branches carry oxygen-deprived blood to the right and left lungs.
Venous system
The venous system is made up of veins and venules(little veins). The veins are the workhorses of the vessel system, carrying oxygen-depleted blood back to the heart. The journey ends with the blood from the head and upper body being returned to the heart via the body’s largest veins, the superior vena cava, and from the lower body via the inferior vena cava, received into the right atrium. The pulmonary veins carry oxygen-rich blood from the lungs back to the heart.
Capillaries are incredibly small and look tiny, like hair. These super-tiny vessels (one cell thick, to be exact) bridge the gap between arterioles and venules to keep blood flowing in a continuous motion.