____________ are distributed throughout the body, making up the monocyte-macrophage system or reticuloendothelial system.
Since this is not my area of expertise, I searched Google under the key words "reticuloendothelial" to get these possible sources:
http://en.wikipedia.org/wiki/Reticuloendothelial_system
http://www.thefreedictionary.com/reticuloendothelial+system
http://www.britannica.com/EBchecked/topic/499989/reticuloendothelial-system
http://www.answers.com/topic/reticuloendothelial-system
In the future, you can find the information you desire more quickly, if you use appropriate key words to do your own search. Also see http://hanlib.sou.edu/searchtools/.
I hope this helps. Thanks for asking.
To determine the answer to this question, we can break it down into two parts: understanding the terms involved and then finding out how these components are distributed throughout the body.
1. Monocyte-Macrophage System: Monocytes are a type of white blood cell that is produced in the bone marrow and released into the bloodstream. When monocytes enter various tissues and organs, they mature into macrophages. Macrophages are large immune cells that play a crucial role in engulfing and destroying bacteria, viruses, and other foreign substances as part of the body's defense mechanism.
2. Reticuloendothelial System: The term "reticuloendothelial system" refers to a network of cells found throughout the body that includes monocytes as well as other specialized cells like Kupffer cells in the liver, microglial cells in the brain, and histiocytes in connective tissues. These cells collectively function to remove foreign particles, breakdown old or damaged red blood cells, and maintain proper immune responses.
Now, let's answer the main question: How are these components distributed throughout the body?
The distribution pattern of the monocyte-macrophage system or reticuloendothelial system is not uniform. The cells of this system are found in various tissues and organs. Some examples include:
1. Liver: Kupffer cells are present in the liver sinusoids, where they act as phagocytes to help filter and remove debris, bacteria, and old red blood cells from the blood.
2. Spleen: This organ contains specialized macrophages called splenic macrophages. They play a critical role in filtering the blood, removing old or damaged red blood cells, and helping in the immune response.
3. Lungs: Alveolar macrophages are found in the air sacs of the lungs. They help protect the lungs by engulfing and removing inhaled particles, bacteria, or allergens.
4. Lymph nodes: Macrophages are present in lymph nodes, where they help in filtering lymph fluid and attacking pathogens or foreign substances present in the lymphatic system.
5. Bone marrow: Monocytes are produced in the bone marrow and enter circulation, ultimately reaching various tissues and organs to differentiate into macrophages.
Therefore, the monocyte-macrophage system, or reticuloendothelial system, is distributed throughout the body, with different cells present in specific locations to perform their respective functions.