Small intestine (labels) - histology illustration

Vertical section of a human aggregated lymphatic nodule, injected through its lymphatic canals. a. Villi with their chyle passages. b. Intestinal glands. c. Muscularis mucosæ. d. Cupola or apex of solitary nodule. e. Mesial zone of nodule. f. Base of nodule. g. Points of exit of the lacteals from the villi, and entrance into the true mucous membrane. h. Retiform arrangement of the lymphatics in the mesial zone. i. Course of the latter at the base of the nodule. k. Confluence of the lymphatics opening into the vessels of the submucous tissue. l. Follicular tissue of the latter.

Histology illustration courtesy of Gray's Anatomy.