The mucosal membrane, smooth muscle wall, and serosal coat are the three layers that make up the fallopian tube. Flattened mesothelial cells border the serosa. There are two layers to the muscularis mucosae: an outside longitudinal layer and an inner circular layer. In the intramural length of the tube, there is also an inner longitudinal layer that spans 2 cm laterally. The muscular coat’s bulk is formed by the inner circular layer. Smooth muscle cells are intermingled with loose connective tissue in the outer longitudinal layer.

Three histologic cell types comprise the epithelial layer: ciliated (20-30%), secretory (55-60%) and intercalary cells. Ciliated cells are believed to be more frequent in the ovarian end of the fallopian tube. The ciliated cell has a columnar shape and contains a oval or round nucleus, often located perpendicular or parallel to the long axis of the cell. The secretory cell is usually a more narrow columnar cell with approximately the same height as the ciliated cell. The nucleus is ovoid and perpendicular to the long axis of the cell. The chromatin is more dense and the nucleolus smaller than that seen in the ciliated cell. The intercalary cell, or peg cell is a columnar cell occupied chiefly by a thin, dark-staining nucleus.

Source: https://www.proteinatlas.org/learn/dictionary/normal/fallopian+tube