Question Video: Identifying the Thymus in the Human Body Biology

Video Transcript

The organs of the immune system are scattered throughout the body, as shown in the figure. What is the name of organ X?

The picture shows several organs of the immune system. For us to correctly identify organ X, let’s have a quick look at the different organs that it shows.

The tonsils are two immune organs associated with the digestive system that are found on either side of the back of the throat. The tonsils are like two guards, alerting the rest of the immune system to any potential threats arising from the food we eat or the air we breathe.

Peyer’s patches are clusters of immune cells called lymphoid follicles, located in the lower portion of the small intestine. Peyer’s patches monitor the bacteria found in the small intestine to ensure it remains balanced and to detect any harmful bacteria that may have entered the small intestine.

The thymus is an organ found near the trachea just behind the sternum, or breastbone, between the lungs in the upper chest cavity. The thymus is where certain immune cells named T cells, or T lymphocytes, mature and differentiate.

The spleen is an organ in the abdominal cavity on the left side of the body, which filters blood, removing old and damaged red blood cells to be broken down. The spleen also contains many white blood cells that can recognize antigens on the surface of foreign cells to initiate the adaptive immune response and eliminate pathogens.

Bone marrow is a type of tissue found inside our bones. There are two types of bone marrow: red and yellow. And red bone marrow is where new red blood cells and white blood cells are made.

The lymph nodes are organs found at junctions throughout the lymphatic system, which can range in size from the point of a pinhead to the size of a bean. Lymph nodes are scattered throughout the body, but they are particularly common in the trunk area, such as in the armpits, neck, chest, and groin.

Looking at the original picture provided by the question, we can see that organ X is located near the chest area, close to the lungs. By looking at the descriptions of the organs we’ve discussed and their locations, we can see that that the thymus is located behind the sternum in the chest cavity. Using this information, we can deduce that organ X is the thymus.