In the human embryo, the first site of blood formation is the yolk sac. Later in embryonic life, the liver becomes the most important red blood cell-forming organ, but it is soon succeeded by the bone marrow, which in adult life is the only source of both red blood cells and the granulocytes. Their job is to transport oxygen to the body's tissues in exchange for carbon dioxide, which is carried to and eliminated by the lungs. Red blood cells are formed in the red bone marrow of bones. Stem cells in the red bone marrow called hemocytoblasts give rise to all of the formed elements in blood. Erythroid (red blood) cells are the first cell type to be specified in the postimplantation mammalian embryo and serve highly specialized, essential functions throughout gestation and postnatal life. The existence of 2 developmentally and morphologically distinct erythroid lineages, primitive (embryonic) and definitive (adult), was described for the mammalian embryo more than a century ago. Cells of the primitive erythroid lineage support the transition from rapidly growing embryo to fetus, whereas definitive erythrocytes function during the transition from fetal life to birth and continue to be crucial for a variety of normal physiologic processes. Over the past few years, it has become apparent that the ontogeny and maturation of these lineages are more complex than previously appreciated. In this review, we highlight some common and distinguishing features of the red blood cell lineages and summarize advances in our understanding of how these cells develop and differentiate throughout mammalian ontogeny.
Eating before exercising can cause cramps. she should’ve ate after her jog
it is the james-lange theory, which states that This theory suggests that when you see an external stimulus that leads to a physiological reaction. Your emotional reaction is dependent upon how you interpret those physical reactions which means that you don't tremble because you are scared, you are scared because you are scared.
Some of the errors that a Medical Assistant can introduce could be errors in getting patient's profile and medical history. Others can include giving of wrong advise that can put the patient in danger. To reduce errors in taking vital signs first one should make sure that the equipment to be use is working properly. There should also be precautions like when taking blood pressure, one should put the cuff 1-2 inches above the antecubital and should not be too lose or too tight to avoid false reading. For temperature, one should also compare the reading at the thermometer and touch the patient if he or she is warm or cold and for the pulse rate and respiratory rate, one should count on full minute not just 15 seconds multiply it to 4 to get a one minute.
