Tissue Look Alikes #1

Left Tissue Section

These tissues are often confused for each other - can you identify them?

This slide is an example of the type of questions one might ask when trying to identify these tissues.

Examine the uppermost surface of the tissue. What type of epithelium is seen? [ + ]

Stratified squamous non-keratinized epithelium - must be a moist surface

What layers are visible in this tissue? [ + ]

The wall of what tissues has these features? [ + ]

GI tract – the layers are:

Where does a stratified squamous non-keratinized epithelium occur in the GI tract? [ + ]

Esophagus
(MH 109 Esophagus)

Does it look like the left section? [ + ]

Yes, except for the presence of mucous glands (muscularis externa is also missing)

Where in the GI tract do glands occur in the submucosa? [ + ]

Esophagus and duodenum

Which has a stratified squamous non-keratinized epithelium? [ + ]

Esophagus
(MH 109 Esophagus)
[duodenum has villi with a simple columnar epithelium]

Examine the surface of the section. What type of epithelium is it? [ + ]

Stratified squamous non-keratinized epithelium - must be a moist surface

What type of tissue underlays the epithelium? [ + ]

Lamina propria
Two thick, indistinct layers of smooth muscle (inner - circular, outer - longitudinal)

Absence of muscularis mucosae - not part of the GI tract (in particular, the esophagus)

Where does this occur? [ + ]

Vagina
(MH 173 Vagina)