release peptides from their basal surface (domain). The goblet cells are uni-
cellular mucus-secreting glands analogous to the enteroendocrine cells that
are unicellular endocrine glands. Enteroendocrine cells secrete into the
bloodstream (endocrine function) or into the local area to affect nearby
cells (paracrine function). The enteroendocrine cells may be identified by
their staining response to silver or chromium stains, hence the older terms
argentaffin and enterochromaffin, respectively. Examination of such prepa-
rations indicates that the enteroendocrine cells are rare compared with
other mucosal cell types, including the mucous cells. Enteroendocrine and
goblet cells and release granules by a regulated exocytotic secretion
(answer b).Both cells are formed by stem cells in crypt base of both the
small and large intestinal glands [(of Lieberkühn) answers c and d].
204.The answer is b.(Kierszenbaum, pp 404–405, 430. Junqueira, pp 300,
- Ross and Pawlina, pp 521, 530, 534.)The enteroendocrine cells and the
enteric (intrinsic) nervous system secrete similar peptides and are found
throughout the gastrointestinal tract (answer e). Enteroendocrine cells are
derived from the same stem cell as other epithelial cell types and originate
embryonically from the endoderm. These cells turn over at a slower rate than
other epithelial cell types. In contrast, the cells that compose the enteric ner-
vous system are neurons, derived from neural crest (answer a). There is lit-
tle cell replacement except in the glial populations (answer d). The enteric
nervous system, particularly the myenteric (or Auerbach’s) plexus, is respon-
sible for the intrinsic rhythmicity of the gut and peristalsis (answer c). The
enteroendocrine cells function in local paracrine regulation of the mucosa
(e.g., acid secretion in the stomach, mucosal growth, small intestinal secre-
tion, and turnover).
205.The answer is b.(Kierszenbaum, p 395. Avery, pp 285–287. Moore
and Dalley, pp 1098, 1100.)Piercing of the tongue can result in complaints
of pain, numbness, and loss of taste when eating. The loss of taste is asso-
ciated with damage to the taste buds, which are shown in the photomicro-
graph. Taste from the anterior two-thirds of the tongue as shown in the
accompanying photomicrograph are innervated by the VIIth (facial) cranial
nerve. The Vth (trigeminal) cranial nerve (answer a) is responsible for
transmitting general sensation from the anterior two-thirds of the tongue.
The taste buds from the posterior one-third of the tongue are innervated by
the IXth (glossopharyngeal) cranial nerve (answer c)specifically by the
330 Anatomy, Histology, and Cell Biology