pectinate line (dentate line)

Introduction

The mucocutaneous junction at the rectum.

It is an irregular line at the base of the anal valves where the intestinal mucosa is continuous with the anal pecten (non-keratinized squamous epithelium).

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Clinical significance

• the pectinate line divides the anal canal into upper (2/3) & lower (1/3) parts, which are supplied by different neurovascular structures.
• the upper part is derived from the embryonic hindgut, the lower part from the ectoderm of the proctodeum
• the line serves to divide hemorrhoids into internal hemorrhoids (above the pectinate line) & external hemorrhoids (below the pectinate line)

More general terms

• linea

Additional terms

• rectum