The esophagus contains four layers—the mucosa, submucosa, muscularis, and tunica adventitia. The mucosa is made up of stratified squamous epithelium containing numerous mucous glands. The submucosa is a thick, loose fibrous layer connecting the mucosa to the muscularis.

The stomach comprises different layers of tissue – the submucosa (dense connective tissue), mucosa, muscularis (smooth muscle fibers), serosa, and Subserosa layers. Different types of tissues are – mesothelium, simple squamous epithelium, gastric submucosa, the mucosa consists of different types of epithelium.

The gallbladder is made up of layers of tissue: mucosa – the inner layer of epithelial cells (epithelium) and lamina propria (loose connective tissue) a muscular layer – a layer of smooth muscle.

References:
Digestive System. (2021 April). Health Direct. Retrieved from https://www.healthdirect.gov.au/digestive-system

Esophagus. (n.d.). Britannica. Retrieved from https://www.britannica.com/science/human-digestive-system/Esophagus

What Tissues Form the Stomach?. (n.d.). BYJU’s The Learning App. Retrieved from https://byjus.com/neet-questions/what-tissues-form-the-stomach

The gallbladder. (n.d.). Canadian Cancer Society. Retrieved from https://cancer.ca/en/cancer-information/cancer-types/gallbladder/what-is-gallbladder-cancer/the-gallbladder