(Return to Courseware Index) Anal Triangle LAB MANUAL |Topic and Text Reference | Learning Objectives | Special Instructions | Clinical Exercises | Key Structures TOPIC AND TEXT REFERENCE: ANAL TRIANGLE PP. 96-99 LEARNING OBJECTIVES: Review the bony landmarks on the pelvis. Learn the difference between the "greater" (false) pelvis and the "lesser" (true) pelvis. Identify the division between pelvis and perineum. Understand how the perineum is divided into the urogenital triangle and the anal triangle. Learn the borders of the ischioanal fossa. Identify the sacrospinous and sacrotuberous ligaments and the foramina they help form. SPECIAL INSTRUCTIONS FOR LAB TODAY: Learning the pelvis geometry is difficult. Use models to help learn the orientation. There is essentially no active dissecting for you to do today. Please follow the dissector and find all the structures in bold. Pg. 98: The gluteus maximus has already been reflected for you. Pg. 99: The ischioanal fossa has been cleared of some of its fat and on each cadaver one can see the pudendal neurovascular bundle with its branches as well as the levator ani and external anal sphincter. Pg. 99: The pudendal canal will be difficult to identify because in most cases the obturator internus fascia has been removed. However one can see the direction in which the pudendal neurovascular bundles enters the perineum. CLINICAL EXERCISES: 1. How do males and females differ in their pelvis architecture and why are the differences important clinically? 2. What is the clinical relevance of the fact that the right and left ischioanal fossae communicate? KEY STRUCTURES: You should be able to identify in a cadaver all the structures listed under key words unless they have an asterisk. structure Netter's Gold Standard structure Netter's Gold Standard Arteries     Ligament     inferior rectal artery N1   sacrospinous ligament N1   internal pudendal artery N1   sacrotuberous ligament N1   Bones     Muscles     coccyx N1, N2   external anal sphincter-deep N1, N2   hip bone N1   external anal sphincter-superficial N1   ischial spine N1   external anal sphincter-subcutaneous N1   ischial tuberosity N1   gluteus maximus N1   pelvic brim N1   inferior surface of pelvic diaphragm N1   pelvis, greater and lesser N1   Nerves     promontory N1   inferior rectal nerve N1   pubic arch N1   internal pudendal nerves N1   pubic symphysis N1   Veins     sacroiliac articulation N1   inferior rectal vein N1   sacrum N1   internal pudendal vein N1   Canals     Other structures     pudendal canal N1   anal triangle N1   sacral canal N1   fascia of obturator internus N1   Foramen     ischioanal fossa N1   greater sciatic foramen N1         lesser sciatic foramen N1         obturator foramen N1         anterior sacral foramina N1                                   |Topic and Text Reference | Learning Objectives | Special Instructions | Clinical Exercises | Key Structures

|| Curriculum Homepage || Anatomy Homepage ||

Hippocrates Project

© New York University