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:
The correct answer will be option-A
Explanation:
Electrocardiogram or ECG is the recording and representation of the electrical changes that are taking place during the cardiac cycle.
The QRS complex is preceded by the P wave or atrial systole or atrial depolarization after which the electrical signals are passed on to the AV node.
As soon as the AV node passes the electrical signals to bundle of His, it is observed in as the QRS interval which represents the atrial diastole and the onset of ventricular depolarization.
Thus, option-true is the correct answer.
Flexor digitorum longus muscle
The four tissue types that have intercellular junctions are;epithelial tissue, connective tissue, muscle tissue andnervous tissue.
