Lymphoid nodules of the appendix
Last reviewed: 23.04.2024
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
The lymphoid nodules of the appendix (noduli lymphoidei appendicis vermiformis) during their maximum development (after birth and up to 16-17 years of age) are located in the mucosa and submucosa throughout the entire body - from its base (near the cecum) up to the top. The total number of lymphoid nodules in the wall of the appendix in children and adolescents reaches 600-800. Often, the nodules are arranged on top of each other in 2-3 rows. The transverse dimensions of one nodule do not exceed 1.0-1.5 mm. Between the nodules are the reticular and collagen fibers, as well as deep intestinal glands penetrating here.
[Development and age specific features of the lymphoid nodules of the appendix
The lymphoid nodules in the walls of the developing appendix are found in the fetus on the 4th month. Nodules appear first in the mucosa, and then in the submucosa. At the 5th month of intrauterine life, nodules are well formed and represent rounded clusters of lymphoid tissue. Immediately prior to birth or shortly thereafter, breeding centers appear in the nodules. The transverse size of the nodules in the newborn is 0.5 to 1.25 mm, and the number of them in the walls of the appendix is 150-200. In children older than 10 years in the submucosa of the appendix there are groups of fat cells, the amount of collagen and elastic fibers increases; the reticular fibers become thicker. In the period from 16 to 18 years, the number of lymphoid nodules decreases and the mass of adipose tissue increases. Especially noticeable increase in fat tissue in the walls of the appendix in 20-30 years. In people older than 50-60 years in the walls of the appendix, the number of lymphoid nodules decreases.
Vessels and nerves
Arterial vessels approach the lymphoid nodules from branches that supply blood to the walls of the appendix (the artery of the appendix), and the nerves from the vegetative nervous plexuses. Venous blood from lymphoid nodules flows into the vein of the appendix. Lymphatic vessels that form in the walls of the appendage are sent to the cecal and ileum-colon lymph nodes.