An opening between the pelvis

Pelvis

In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...

 and the posterior thigh, the foramen is formed by the sacrotuberous ligament

Sacrotuberous ligament

The sacrotuberous ligament is situated at the lower and back part of the pelvis. It is flat, and triangular in form; narrower in the middle than at the ends....

 which runs between the sacrum

Sacrum

In vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...

 and the ischial tuberosity and the sacrospinous ligament

Sacrospinous ligament

-External links: - "Posterior view of the bones and ligaments of the hip joint."*...

 which runs between the sacrum and the ischial spine

Ischial spine

From the posterior border of the body of the Ischium there extends backward a thin and pointed triangular eminence, the ischial spine, more or less elongated in different subjects.It can serve as a landmark in pudendal anesthesia.-Surfaces:...

.

Boundaries

The lesser sciatic foramen has the following boundaries:

• Anterior: the tuberosity of the ischium
  Tuberosity of the ischium
  -External links: - "The Female Perineum: Bones" - "Major Joints of the Lower Extremity: Hip bone "...
  
  
• Superior: the spine of the ischium and sacrospinous ligament
  Sacrospinous ligament
  -External links: - "Posterior view of the bones and ligaments of the hip joint."*...
  
  
• Posterior: the sacrotuberous ligament
  Sacrotuberous ligament
  The sacrotuberous ligament is situated at the lower and back part of the pelvis. It is flat, and triangular in form; narrower in the middle than at the ends....
  
  

Alternatively, the foramen can be defined by the boundaries of the lesser sciatic notch

Lesser sciatic notch

Below the ischial spine is a smaller notch, the lesser sciatic notch; it is smooth, coated in the recent state with cartilage, the surface of which presents two or three ridges corresponding to the subdivisions of the tendon of the Obturator internus, which winds over it.It is converted into a...

 and the two ligaments.

Contents

It transmits the following structures:

• the tendon of the Obturator internus
• internal pudendal artery
  Internal pudendal artery
  The internal pudendal artery is an artery that branches off the internal iliac artery, providing blood to the external genitalia.The internal pudendal artery is the terminal branch of the anterior trunk of the internal iliac artery...
  
  
• internal pudendal veins
  Internal pudendal veins
  The internal pudendal veins are the venæ comitantes of the internal pudendal artery.They begin in the deep veins of the penis which issue from the corpus cavernosum penis, accompany the internal pudendal artery, and unite to form a single vessel, which ends in the hypogastric vein.They receive the...
  
  
• pudendal nerve
  Pudendal nerve
  The pudendal nerve is a sensory and somatic nerve in the pelvic region which is a large branch of the sacral plexus that innervates the external genitalia of both sexes, as well as sphincters for the bladder and the rectum...
  
  
• nerve to the obturator internus