Home pregnancy tests are a qualitative test and measure whether or not hCG -- the pregnancy hormone human chorionic gonadotropin -- is present in your urine, explains Stephen Rechner, M.D., the Division Chief of General Obstetrics and Gynecology at Spectrum Health in Grand Rapids.
After breathing in carbon monoxide, it enters your bloodstream and mixes with haemoglobin (the part of red blood cells that carry oxygen around your body), to form carboxyhaemoglobin. When this happens, the blood is no longer able to carry oxygen, and this lack of oxygen causes the bodyâs cells and tissue to die.
The H+ in the blood, however, cannot cross the blood-brain barrier, and thus cannot influence the medullary chemoreceptors. Carbon dioxide in the arterial blood can cross the blood-brain barrier and, through the formation of carbonic acid, can lower the pH of cerebrospinal fluid (fig. 16.30).n increase in blood CO2 stimulates breathing indirectly by lowering the pH of blood and cerebrospinal fluid (CSF). This figure illustrates how a rise in blood CO2 increases the H+ concentration (lowers the pH) of CSF and thereby stimulates chemoreceptor neurons in the medulla oblongata.