Question

question 13
1 pts
the walls of the gl tract are composed of ____ layers of tissue.
two
three
four
five
question 14
1 pts
which of the following organs has a mucosal layer that is composed of columnar epithelium with a brush border of microvilli to enhance absorption?
esophagus
large intestine
small intestine
stomach
question 15
1 pts
the numerous small elevations on the surface of the tongue that support taste buds are called:
cilia.
rugae.
villi.
papillae.

Explanation:

Question 13

The walls of the gastrointestinal (GI) tract are composed of four layers of tissue: the mucosa, submucosa, muscularis externa, and serosa (or adventitia in some regions). So the correct option is the one with "four".

The small intestine has a mucosal layer with columnar epithelium that has a brush border of microvilli. This brush border greatly increases the surface area for absorption, which is a key function of the small intestine. The esophagus has stratified squamous epithelium, the large intestine has columnar epithelium but no brush border for the same level of absorption, and the stomach has glandular epithelium. So the correct organ is the small intestine.

The small elevations on the tongue's surface that support taste buds are called papillae. Cilia are hair - like structures in other parts (e.g., respiratory tract), rugae are folds in the stomach, and villi are in the small intestine. So the correct term is papillae.

Answer:

C. four

Question 14