Final answer:
The correct order of the GI tract layers from inside to outside is Mucosa, Submucosa, muscularis externa, and Serosa. The correct option is 1) Mucosa, Submucosa, muscularis externa, Serosa
Step-by-step explanation:
The layers of the wall of the GI tract, in order from inside to outside, are Mucosa, Submucosa, muscularis externa, and Serosa. To elucidate, the mucosa is the innermost layer that is in direct contact with the lumen and is responsible for secretion and absorption.
Next, the submucosa consists of dense connective tissue containing blood lymphatic vessels, and nerves. The muscular externa, which is composed of an inner circular layer and an outer longitudinal layer of muscle, is vital for mechanical digestion and peristalsis. Lastly, the serosa is the outermost layer that separates the GI tract from the surrounding cavities with connective tissue. The correct option is 1) Mucosa, Submucosa, muscularis externa, Serosa