1. Marilyn Rose
Pelvis

2. Bony Pelvis- sacrum
Formed by the sacrum, coccyx and two os caxae/ innominate bones
Sacrum-5 fused vertebral segments
First segment
sacral promontory- landmark-separates abdominal cavity/ pelvic cavity
The 5 segment transverse processes combine to form the lateral mass or ala(sacral foramina= nerve passageway) articulates with the os the sacroiliac joints
The fifth segment articulates with the coxxyx (3-5) small fused bony segments.

3. Os caxae- innominate 3 bones- ilium, pubis and ishium
Ilium- larges, superior- ala- iliac fossa
Superior ridge of the ala= iliac crest
Slopes down to form ASIS and AIIS
Body of the ilium creates the upper acetabulum, which articulates with the femoral head

4. OS caxae-innominate Pubis- pubic bone
Forms the lower anterior acetabulum
Body, superior and inferior pubic rami
Bodies of the two pubic bones form the-symphysis pubis

5. Ox caxae- innominate Ischium- inferior os caxae Body and two rami
Body- forms lower,posterior acetabulum
Sup ramus- posterior/inferior
forms ischial tuberosity
Inf ramus- anterior, medial
Forms ischial spine
Union of the pubic rami and ishium surrounds the obturatior foramen- obturator muscles pass

6. Bony Pelvis

7. Pelvic Inlet and Outlet
False/ Greater Pelvis
Above the pelvic brim
True/Lesser Pelvis
Below pelvic brim
Pelvic Inlet
Superior- true pelvis- sacral promontory to the crest of the pubic bone.
Pelvic Outlet
Inferior- tip of coccyx to inferior margin of pub symphysis or between the ischial tuberosities.

8. Pelvis- Tumor Location?
osteosarcoma of the ilium

9. Pelvic CT/ MRI
Female
Male

10. Pelvis-

11. Gunshot wound to pelvis….

12. Muscles of the pelvis Extra-pelvic Pelvic diaphragm Pelvic Wall
Rectus abdominis- ant abd
Psoas-lat L spine
External/internal oblique- lat abdomen- ribs-iliac crest
Hip muscles:
Gluteus- maximus, medius, minimus-
abduct, rotate, extend the thigh
Pelvic Wall
Piriformis-ilium to > troch
Obturator internus- pubic bone to > troch
Obturator externus
Iliacus + psoas= iliopsoas
To <<< troch
Makes walking possible!!!
Pelvic diaphragm
Majority of the pelvic floor
Levator ani- sym pub-ischial spine to coccyx
Coccygeus- posterior floor- ischial spine- coccyx

13. Muscles

14. Muscles Psoas (8) Rectus abdominus (10) Maximus (24) and medius (25)
Obturator internus/exturnus (39,40)
Ishial
Tuberosity (44)

15. Vasculature

16. Pelvic vasculature-arterial
Descending AO- bifurcates at L4 into
RT/LT common iliac arteries
Each common bifurcates into Internal/External iliac arteries
Internal iliac- smaller- supplies O2 blood to pelvis
External iliac- larger- extends along pelvic brim and exits the iliac fossa and supplies arterial blood to the leg(s)
External iliac becomes the femoral artery at the ASIS!
Wow! A handy landmark!!!

17. External Iliac femoral

18. Imaging example
External iliac
Common femoral

19. Pelvic arterial supply

20. Venous drainage Internal iliac veins-main drainage for pelvis
Superior rectal, median sacral and gonadal also are present
Ascend pelvis medial to internal iliac artery
Venous plexuses drain into the internal iliac vein
External iliac- extension of of femoral- return blood from legs
Medial to external iliac artery
Move posteriorly as they join common iliac vein at SI joint
Common iliac vein- posterior to common iliac from the junction of int/ext iliacs
IVC at L5 right of midline- after the union of the common iliac veins

21. Pelvis examples
Key: #1 = L5 #2 = Ascending Colon #3 = Descending Colon #4 = Ureters (left & right) #5 = Iliac Crest #6 = Gluteus Medius #7 = Iliacus Muscle #8 = Psoas Muscle #9 = Rectus Abdominis #10 = Common Iliac Arteries #11 = Common Iliac Veins

22. Pelvic examples CFA/V- #20 Troch- #37 Ischial spine- #35 Rectum- #30
Prostate-#32

23. Pelvis

24. What is it??

25. Urinary Bladder Rests on pelvic floor -posterior to symphysis pubis
Neck of the bladder- internal urethral sphincter (bladder control)
Trigone= openings in the floor of the bladder- ureters and urethra
Female urethra- 3-4 cm- external opening
Male urethra cm-
Prostatic, membranous and penile urethra
Dual function

26. Rectum Terminal portion of the large intestine
S3- to tip of coccyx- 15 cm in length
Anteroposterior curve (sacral flexure) of sacrum and then ends by turning inferiorly/ anteriorly to become anal canal (perineal flexure)
Between two flexures is the transverse rectal fold- Kohlrausch’s fold- 5-8 cm from anus.
Landmark for males prostate exam and the vault of the vagina in females
Involuntary internal anal sphincter and voluntary external anal sphincter

27. Female Reproductive organs
Sex hormones, ova and protect and support a developing embryo
Uterus, ovaries, fallopian tubes, vagina
Uterus-
endometrium, myometrium and perimetrium
Stabilized by suspensory ligaments-
Round, uterosacral and lateral cervical ligaments
Broad ligament-(peritoneal fold) - encloses the ovaries, fallopian tubes and uterus
Two pouches- areas where fluid can accumulate
Vesicouterine pouch- btw ut and post wall of bladder
Rectouterine pouch (pouch of Douglas)- posterior, between uterus and rectum

28. Female contd. Ovaries- paired on each side of uterus
Fallopian tubes- muscular tubes extending laterally form body of UT to peritoneum-supported by broad lig
Vagina- anteroinferiorly from cervix of UT to external vaginal orifice- between bladder and rectum

29. Female pelvis

30. Male reproductive organs
testis, epididymis, vas deferens, ejaculatory duct, seminal vesicle, prostate gland, bulbourethral gland (Cowper’s) and penis
All structures except testes and penis are located within pelvic cavity.
Scrotum-
pouch that encloses the testis, epididymis and lower spermatic cord- the epididymis is tightly coiled tubular structure at the superoposterior surface of each testis-composed of a head, body and tail.
Vas deferens and ejaculatory duct-
Posterior spermatic cord- courses up inguinal canal and over ureter into and into the posterior surface of the bladder- it joins with the duct of the seminal vesicle to form the ejaculatory duct which empties into the prostatic urethra
Seminal vesicles- paired glands lateral to vas deferens and on the posterior/inferior surface of the bladder-superior to the prostate
Penis-
made of 3 cylindric tissues bundles- 2 corpora cavernosa and one corpus spongiosum

31. Male pelvis

32. Male pelvis 1, rectus abdominis m. 2, bladder 3, pubis 4,
1, rectus abdominis m. 2, bladder 3, pubis 4,
ischium 5, testis 6, corpus cavernosum
1, sartorius m. 2, femoral a. 3,femoral v. 4, left pectineus m. 5, pubis 6, symphysis pubis 7, spermatic cord 8,
right pectineus m. 9, obturator internus m. 10, gemellus inferior m.
1, rectus abdominis m. 2, symphysis pubis 3, corpus cavernosum 4, corpus spongiosum 5,
prostate 6, bladder 7,seminal vesicle 8, rectum 9, sacrum

33. Prostate
Largest accessory gland of male reproductive system- secretes seminal fluid
Inferior to the bladder and surrounds the prosthetic urethra
Base- adjacent to the bladder neck
Apex- urogenital diaphragm
Two lateral lobes, middle lobe and anterior fibromuscular portion- 4 zones
Second most common cancer in men over 55

34. Male Pelvis Axial T2-weighted image obtained through the midprostate
shows the prostatic urethra (P) in the posterior prostate
prostatic urethra (P) in the posterior prostate
bulbous urethra (B) traversing the midline
within the corpus spongiosum
Normal MR imaging anatomy of the
male urethra in a 59-year-old man.

35. Lymph nodes Nodal chains Correspond to pelvic vessels
Obturator nodes- along midpoint of obturator internus muscle
Internal/External nodes
Sacral nodes
Inguinal nodes
Pelvic nodes are pathologically enlarged when they exceed 10 mm in short axis