Answer:
Kupffer cells, also known as stellate macrophages due to their particular structure while viewed under a microscope, were first identified by scientist Karl Wilhelm von Kupffer, after whom the cells were named, in 1876.
These cells, whose origin is in the yolk sack during fetal development, later on move to the liver where they will stay and further differentiate into their mature versions.
These cells are part of the liver cells, and are found particularly on the walls of the sinusoids, where they perform their two most important tasks. First, these cells are part of the immune system, as they are essentially macrophages. However, their role is pretty unique, as they are responsible not just for phagocytosis of invading bacteria, and other pathogens, and initiating immune responses, but also, this cell plays a role in decomposing red blood cells who are dying, and taking up the hemoglobin from them to further break that into reusable globin, and the heme group, from which iron is further extracted to be re-used and also to create bilirrubin, a part of bile.
Finally, these cells have been found to be connected to hepatic cirrhosis, as in their process of detoxifying ethanol, they produce toxins that force the liver cells to produce collagen, and thus to become fibrous.
Answer:
Oxygen passes quickly through this air-blood barrier into the blood in the capillaries. Similarly, carbon dioxide passes from the blood into the alveoli and is then exhaled.
Explanation:
Answer and Explanation:
Doctors must complete a four-year undergraduate program, along with four years in medical school and three to seven years in a residency program to learn the specialty they chose to pursue. In other words, it takes between 10 to 14 years to become a fully licensed doctor.
