What forms the posterior border of the anal triangle?

What forms the posterior border of the anal triangle?

• A. Pubic symphysis
• B. Coccyx
• C. Ischial tuberosities
• D. Sacrum

Answer: (B)

The posterior border of the anal triangle is the coccyx. The anal triangle is the posterior half of the perineum, with its front boundary set by the line between the two ischial tuberosities and its rear boundary at the coccyx, which marks the end of the anal canal and serves as the attachment site for nearby structures. The pubic symphysis lies at the front, not the back; the ischial tuberosities form the lateral edges; and the sacrum, while part of the pelvic posterior wall, does not define the immediate posterior border of the anal triangle.

The posterior border of the anal triangle is the coccyx. The anal triangle is the posterior half of the perineum, with its front boundary set by the line between the two ischial tuberosities and its rear boundary at the coccyx, which marks the end of the anal canal and serves as the attachment site for nearby structures. The pubic symphysis lies at the front, not the back; the ischial tuberosities form the lateral edges; and the sacrum, while part of the pelvic posterior wall, does not define the immediate posterior border of the anal triangle.