bladder stromal layer - new synonym?

[dosumis]

According to https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0141437
"The bladder consists of four layers: a superficial mesothelial layer called the serosa; a smooth muscle layer; a connective tissue layer called the stroma; and an inner layer called the urothelium."

Uberon has:

I think suspect this refers to the submucosa: "A layer of dense irregular connective tissue that lines organs and supports the mucosa, as well as joins the mucosa to the bulk of underlying smooth muscle. "