Types of Blood Oxygenators

Recently developed blood oxygenators are disposable, used only once, and can be presterilized and coated with anticoagulant (e.g., heparin) when they are constructed. Normally, membranes with high gas permeabilities, such as silicone rubber membranes, are used. In the case of microporous membranes, which are also used widely, the membrane materials themselves are not gas permeable, but gas-liquid interfaces are formed in the pores of the membrane. The blood does not leak from the pores for at least several hours, due to its surface tension. Composite membranes consisting of microporous polypropylene and silicone rubber have also been developed. 

All of the above-mentioned blood oxygenators are used outside the body, and hence are referred to as extracorporeal oxygenators. They are mainly used for heart surgery, which can last for up to several hours. However, blood oxygenators are occasionally used extracorporeally to assist the pulmonary function of the patients in acute respiratory failure (ARF) for extended periods of up to a few weeks. This use of extracorporeal oxygenators is known as extracorporeal membrane oxygenation (ECMO). 

Intracorporeal oxygenators are an entirely different type of blood oxygenator that can be used within the body to temporarily and partially assist the lung functions of patients with serious pulmonary diseases. No blood pump is necessary. 

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Bone marrow is the spongy tissue inside the cavities of our bones. Bone marrow stem cells grow and divide into the various types of blood cells white blood cells (leukocytes) that fight infection, red blood cells (erythrocytes) that transport oxygen, and platelets that are the agents for clotting. 

Red blood cells—Type of blood cell filled with the red protein hemoglobin that carries oxygen to tissues. 

A hollow-fiber-type membrane blood oxygenator, in which blood flows inside the hollow fibers, has a total membrane area (outside fibers) of 4.3 m". The inside diameter, membrane thickness, and length of the hollow fibers are 200 pm, 25 pm, and 13 cm, respectively. When venous blood (Ht = 40%, pQ. = 36 mmHg)... 

How a chemical affects your health depends on how much you are exposed to and for how long. As the level and length of your exposure increase, the effects are likely to become more severe. Rats that breathed dusts of 4-nitrophenol for 2 weeks developed a blood disorder which reduces the ability of the blood to carry oxygen to tissues and organs. However, these abnormalities disappeared a few days after exposure stopped. Chemicals like the nitrophenols cause a similar blood disorder in humans, and so humans exposed for weeks or longer to high levels of nitrophenols may develop the same types of blood disorders that animals do. Experimental studies have shown that 4-nitrophenol is more harmful than 2-nitrophenol in animals. There is no information on the effects on human health from breathing dusts of 2-nitrophenol or 4-nitrophenol. 

In a hollow-fiber-type membrane blood oxygenator, the blood flows outside and across the hollow fibers. The total membrane area (outside fibers) is 4m2. From the data of physical oxygen absorption into water at 20 °C, the following... 

Erythrocytes—red blood cells are the most common type of blood cell and are used to deliver oxygen to tissue through the circulatory system. 

Anemia is a decrease in the number of red blood cells (RBCs), a decrease in die amount of hemoglobin in RBCs, or bodi a decrease in die number of RBCs and hemoglobin. When diere is an insufficient amount of hemoglobin to deliver oxygen to die tissues, anemia exists. There are various types and causes of anemia For example, anemia can be die result of blood loss, excessive destruction of RBCs, inadequate production of RBCs, and deficits in various nutrients, such as in iron deficiency anemia Once the type and cause have been identified, die primary health care provider selects a method of treatment. 

Many different types of sensory receptors are located throughout the body. These receptors monitor the status of the internal environment or that of the surroundings. Sensory receptors are sensitive to specific types of stimuli and measure the value of a physiological variable. For example, arterial baroreceptors measure blood pressure and chemoreceptors measure the oxygen and carbon dioxide content of the blood. The information detected by these sensors then travels by way of afferent neuronal pathways to the central nervous system (CNS). The CNS is the integrative portion of the nervous system and consists of the (1) brain and the (2) spinal cord. 

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