1. Pelvis

2. Bony pelvis
Composition: formed by paired hip bones, sacrum, coccyx, and their articulations
Two portions
Greater pelvis
Lesser pelvis
Terminal line ( pelvic inlet): formed by promontory of sacrum, arcuate line, pectin of pubis, pubic tubercle, upper border of pubic symphysis
Pelvic outlet: formed by tip of coccyx, sacrotuberous ligament, ischial tuberosity, ramus of ischium, inferior ramus of pubic symphysis

3. Identify the bony walls and ligamentous landmarks of the pelvis.
Iliopectineal Line
Sacrotuberous Ligament
Greater Sciatic Foramen
Sacrospinous Ligament
Lesser Sciatic Foramen
Sacrospinous Ligament
Sacrotuberous Ligament
Pubic Symphysis
Pubic Arch
Ischial Tuberosity
Sacrotuberous Ligament
Pelvic Outlet
Tip of Coccyx
Ant. Sup. Iliac Spine
Pubic symphysis
Coccyx 1

4. Sacrotuberous Ligament Piriformis Muscle Greater Sciatic Foramen
Muscular Walls
Sacrotuberous Ligament
Piriformis Muscle
Greater Sciatic Foramen
Piriformis Muscle
Sacrospinous Ligament
Sacrotuberous Ligament
Ischial Tuberosity
Lesser Trochanter
Greater Trochanter
Gemellus Superior & Inferior
Obturator Internus

5. Muscles of pelvic wall
Piriform
Obturator internus
Iliacus

6. Piriform muscle
Arise from the ant surface of the lateral mass of the sacrum and enter the gluteal region by passing through the greater sciatic notch to be inserted on to the upper border of the greater trochanter of the femur.
It’s a lateral rotator of the hip
Receives nerve supply from
sacal plexus.

7. Obturator internus
Arises from the pelvic surface of the obturator membrane and the adjoining part of the hip bone.
Muscle fibres from a tendon which exit the pelvis through lesser sciatic foramen and gets inserted on to the greater trochanter.

8. Iliacus
The iliacus arises from the iliac fossa on the interior side of the hip bone, and also from the region of the anterior inferior iliac spine (AIIS). It joins the psoas major to form the Iliopsoas and gets inserted on to the lesser trochanter of the femur. 
The iliopsoas is innervated by the femoral nerve and direct branches from the lumbar plexus.

10. Muscles of the Pelvic Floor (Pelvic Diaphragm)
The pelvic diaphragm is composed of two paired muscles – levator ani and coccygeus
These muscles:
Close the inferior outlet of the pelvis
Support the pelvic floor
Elevate the pelvic floor to help release feces
Resist increased intra-abdominal pressure
PD is is pierced by the rectum and urethra and vagina in females
Region inferior to the pelvic diaphragm is the perineum

11. Muscles of the Pelvic Floor: Pelvic Diaphragm
Figure 10.12a

12. Levator ani
The levator ani is a broad, thin muscle, situated on the side of the pelvis.
It is attached to the inner surface of the side of the lesser pelvis, and unites with its fellow of the opposite side to form the greater part of the floor of the pelvic cavity
The levator ani is divided into three parts:
Iliococcygeus muscle
Pubococcygeus muscle
Puborectalis muscle

13. Iliococcygeus
The Iliococcygeus arises from the inner side of the ischium and from the posterior part of the tendinous arch of the obturator fascia, and is attached to the coccyx and anococcygeal raphé.

14. Pubococcygeus
stretches from the pubic bone to the coccyx.

15. Puborectalis
The fibers which form a sling for the rectum are named the Puborectalis or Sphincter recti.
They arise from the lower part of the pubic symphysis, and from the superior fascia of the urogenital diaphragm.
They meet with the corresponding fibers of the opposite side around the lower part of the rectum, and form for it a strong sling. Relaxation reduces the angle between rectum and anus, allowing defecation in conjunction with relaxation of the internal and external sphincters.

16. Coccygeus
The Coccygeus is a muscle of the pelvic wall (i.e. peripheral to the pelvic floor), located posterior to levator ani and anterior to thesacrospinous ligament.
It is a triangular plane of muscular and tendinous fibers, arising by its apex from the spine of the ischium and sacrospinous ligament, and inserted by its base into the margin of the coccyx and into the side of the lowest piece of the sacrum.

18. Muscles Inferior to the Pelvic Floor: The Urogenital Diaphragm
Stretches between two sides of the pubic arch in the anterior half of the perineum
Contains
Deep transverse perineal muscle
Extrnal urethral sphincter muscle
The ischiocavernosus and bulbospongiosus assist in erection of the penis and clitoris; lie superficial to the urogenital diaphragm

19. Muscles of the Pelvic Floor

20. Muscles of the Pelvic Floor

21. Thank you