Concept explainers
The only lymphatic organ with both afferent and efferent lymphatic vessels is
- a. the spleen.
- b. a lymph node.
- c. a tonsil.
- d. a Peyer patch.
- e. the thymus.

Introduction:
Lymphatic system contains a group of tissues and organs that protect our body from toxinsand unwanted materials.It contains a well-defined structure present in our body. The primary function of lymphatic system is to transport a lymphatic fluid containing white blood cells that fight against unwanted materials throughout the body. Red bone marrow, thymus, lymph nodes, tonsils, and spleen come under lymphatic organs.
Answer to Problem 1TYR
Correct answer:
Lymph node has both afferent and efferent lymphatic blood vessels. Therefore, option b is correct.
Explanation of Solution
Justify reasons for the correct statement:
Lymph node is the site where the B cell and T cell get activated and it also cleans the lymph from foreign matter. It consists of several apparent lymphatic blood vessels from where lymph flows slowly to the sinuses, cortex, and medulla and leaves efferent lymphatic blood vessels. Lymph node is the only organ that filters the lymph from impurities.
Option (b) is given as, “a lymph node”.
Lymph nodes are widely spread in our body but concentrated in particular locations.
Hence, option (b)is correct.
Justify reasons for the incorrect statements:
Option (a) is given as, “the spleen”.
The spleen is the largest lymphatic organ of our body. It consists of two tissues—red and white pulp. Red pulp consists of erythrocytes, whereas white pulp consists of macrophages and lymphocytes. In the spleen, matured and old RBC get destroyed. Hence, it is a wrong answer.
Option (c) is given as, “a tonsil”.
Tonsils are lymphatic tissues present in the entry of the pharynx. They prevent our body from ingested and inhaled pathogens. Hence, it is a wrong answer.
Option (d) is given as, “a Peyer patch”.
Peyer patches consist of nerve fibers that connect to B cells,T cells, and macrophages. These immune cells consist of many neurotransmitters that induce the immune cell activity. Hence, it is a wrong answer.
Option (e) is given as, “the thymus”.
Thymus is the birth place of all lymphocytes. The main function of the thymus is to filter the impurities or pathogenic microbes by secreting several signaling molecules that activates the T cells. Hence, it is a wrong answer.
Hence, options (a), (c), (d), and (e) are incorrect.
Lymph nodes are the sites of B and T lymphocytes and white blood cells. It acts as filters for pathogenic microbes and other foreign materials.
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