muscles of pelvis and vessels can be use to take lecture

this lecture can be downloaded to take lecture of MBBS

1. MUSCLES AND VESSELS OF PELVIS

2. Muscles of the pelvis Obturator Internus Levator ani Piriformis Coccygeus

3. OBTURATOR INTERNUS Is a thick fan shape muscle covering almost entire pelvis. ORIGIN Obturator membrane Margin of obturator foramen Pelvic surface of ilium INSERTION All the fibres converges and forms a thick band like ligament and is inserted into medial surface of greater trochanter. NERVE SUPPLY Nerve to obturator internus ACTION Stabilize the hip joint Lateral rotator of femur.

4. PIRIFORMIS ORIGIN It arise from the pelvic surface of the middle 3 pieces of the sacrum by 3 digitations. INSERTION Fibres converges, passes through the greater sciatic foramen to enter the gluteal region where it is inserted into tip of greater trochanter. NERVE SUPPLY It is supplied by the ventral ramus of first and second sacral nerve. ACTION a) Stabilizes the hip joint. b) Lateral rotator of femur when hip joint is extended and abductor when the joint is flexed.

5. LEVATOR ANI The two muscles are wide and curved and thin sheet of muscle and fuse with each other in the median plane. ORIGIN It takes origin from the pelvic surface of the body of pubis, a tendinous arch of obturator fascia and the pelvis surface of ischial spine. INSERTION The anterior fibres are forms a sling around the prostrate or vagina (sphincter vaginae) and are inserted into perineal body in front of anal canal.( The intermediate fibres (puborectalis) forms a sling around the anorectal junction and are inserted into anococcygeal raphe. The posterior fibres (iliococcygeus) are inserted into anococcygeal raphe and coccyx.

6. NERVE SUPPLY From pelvic surface:- by perineal branch of S4. From perineal surface:- by perineal branch of pudendal nerve. ACTION a)Supports the pelvic viscera and maintain continence of faeces in both sexes and vagina in female

7. COCCYGEUS (Ischiococcygeus) Is a small triangular muscle situated behind the levator ani muscle. ORIGIN It arises by its apex from the pelvic surface of ischial spine and sacrospinous ligament. INSERTION From its base into the side of upper two pieces of coccyx and the last piece of sacrum. NERVE SUPPLY Ventral ramus of S4 and S5. ACTION 1.Assist levator ani to support pelvic viscera. 2. Minor movement of coccyx.

8. PELVIC DIAPHRAGM It is a muscular diaphragm formed between true pelvis and the perineum. It is formed by the large levator ani and small coccygeus muscle of two side . It is incomplete anteriorly to allow passage for the urethra in the male and urethra and vagina in female. ROLE The diaphragm provide principal support to the pelvic viscera and act as a sphincter for rectum and vagina. It increases the pressure at the time of micturition, defecation and parturition.

9. OPENING IN PELVIC DIAPHRAGM Hiatus urogenitalis :- gap between the anterior fibres of the two side of levator ani. It is closed below by the urogenital diaphragm. Provide passage to urethra in male and urethra and vagina in female. b ) Hiatus rectalis :- opening between perineal body and anococcygeal raphe. It gives passage to anorectal junction.

10. INTERNAL ILIAC ARTERY E ach artery arise from the common iliac artery opposite the Lumbo sacral articular disk and in front of sacroiliac joint. The artery consist of a trunk and anterior and posterior division. The trunk passes down ward in front of sacro-illiac joint and on reaching the upper margin of Greater sciatic foramen it divides into anterior and posterior division. The anterior division extends as a continuation of the trunk upto The ischial spine & the posterior division passes downward and backward in the region of greater sciatic foramen.

11. BRANCHES A.FROM ANTERIOR DIVISION i ) O bliterated umbilical artery ii)Superior vesical artery iii)Inferior vesical artery iv)Middle rectal artery v)Obturator artery vi) Uterine artery vii)Vaginal artery viii)Inferior gluteal artery ix)Internal pudendal artery

12. B-FROM POSTERIOR DIVISION illio-lumbar artery Superior gluteal artery Lateral sacral artery

13. OBLITERATED UMBILICAL ARTERY I t is in fact the continuation of the internal iliac artery in the intrauterine life, where it reaches to the placenta through the umbilical cord and conveys deoxygenated fetal blood to the chorionic villi. W ith the fixation of placental circulation after birth the distal part of umbilical artery is obliterated to form corresponding medial umbilical ligament and the proximal part remain patent as superior vesical artery.

14. SUPERIOR VESICAL ARTERY It is derived from non obliterated proximal part of umbilical artery and consists of two or three vessels which supplies the upper surface of urinary bladder. One vessel accompanies the vas deference supplies it and reached the testis where it anastomosis with testicular artery.

15. INFERIOR VESICAL ARTERY It arises either separately or in common with middle rectal artery and supplies the base of urinary bladder, terminal part of ureter, seminal vesicle, ampulla of vas deference and prostrate .It corresponds with vaginal artery in female .

16. MIDDLE RECTAL ARTERY Each artery passes downward and medially through the pelvi- rectal space within the lateral ligament of rectum and supplies the lower part of rectum also it give few twig to the bladder and seminal vesicle.

17. OBTURATOR ARTERY It passes forward and downward along the lateral pelvic wall accompanied by the obturator nerve above and the corresponding vein below. It leaves the pelvis through the obturator canal and there after the artery divides into anterior and posterior branches around the margin of obturator foramen. Within the pelvis the obturator artery give branches to the urinary bladder, nutrient vessels to the ilium and pubic branch & later anastomosis with the pubic branch of the inferior epigastric artery.

18. UTERINE ARTERY It is fairly large vessel in female and initially accompanies the lateral side of pelvic part of ureter. O n approaching the supra-vaginal part of uterine cervix the artery crosses above and in front of ureter from lateral to medial side and then passes upward through the lower attached margin of the broad ligament, where the artery runs tortuously upward along the lateral margin of the body of uterus. finally it turns laterally below the uterine tube enters the ovary through the Mesovarium and anastomosis with the ovarian artery. The uterine artery supplies the urinary bladder, terminal part of ureter, vagina, uterus, part of uterine tube, ovary and other content of broad ligament .

19. VAGINAL ARTERY It corresponds with the inferior vesical artery of male and passes downward and medially to the vagina where it divides into several small branches. The vaginal artery supplies the vagina, bulb of vestibule, urinary bladder and rectum.

20. INFERIOR GLUTEAL ARTERY It is one of the terminal branch of anterior division of internal iliac artery. The artery passes downward and backward between the ventral rami of the first and second sacral nerves or between the second and third sacral nerves. I t's finally leaves the pelvis through the greater sciatic foramen below the piriformis and appears in the gluteal region.

21. INTERNAL PUDENDAL ARTERY It is the other terminal branch of the anterior division and leaves the pelvis through the greater sciatic foramen between the piriformis and coccygeus muscles. The artery crosses the dorsal surface of ischial spine where it is related medially with the pudendal nerve. Thereafter the artery enters the perineum through the lesser sciatic foramen. Passes forward through the pudendal canal in the lateral wall of the ischio-rectal fossa and appears in the deep perineal pouch along the ischio-pubic ramus where it divides into 2 terminal branches :- Deep and dorsal arteries of penis or clitoris.

22. In the perineum, the internal pudendal artery gives the following branches: (a) Inferior rectal artery (b) Perineal branch (c) Artery to the bulb of penis or vestibule (d) Urethral artery pierces the perineal membrane and supplies the urethra upto the glans penis (e) Deep artery of penis or clitoris

23. FROM POSTERIOR DIVISION A.-ILIO-LUMBAR ARTERY It passes upwards and laterally in front of ala of sacrum between the lumbo sacral trunk and the obturator nerve, and then divides into iliac and lumbar branches. The iliac branch passed beneath the psoas major and iliacus muscles, reaches the iliac fossa and provides branches to the aforesaid muscles and nutrient branch to the ilium. The lumbar branch ascends through the substance of psoas major, anastomoses with the fourth lumbar artery and sends a spinal branch through the inter vertebral foramen between the fifth lumbar vertebra and the sacrum.

24. B- SUPERIOR GLUTEAL ARTERY It is the largest branch. of the internal iliac artery, passes backwards between the lumbo-sacral trunk and first sacral nerve, leaves the pelvis through the greater sciatic foramen above the piriformis and appears in the gluteal region.

25. C- LATERAL SACRAL ARTERIES- Usually they consist of upper and lower branches. The upper branch enters through the first or second pelvic sacral foramen. The lower branch descends in front of the piriformis and sacral plexus of nerves along the lateral margins of the pelvic sacral foramina. Both arteries provide spinal branches through the pelvic sacral foramina which supply the contents of the sacral canal, and finally emerge through the dorsal sacral foramina.

26. SACRAL PLEXUS

27. FORMATION The sacral plexus is formed by the ventral rami of the fourth and fifth lumbar, and upper four sacral nerves (roots of six spinal nerves : L4, L5, S1, S2,S3,S4). It lies in front of piriformis deep in true pelvis. The ventral rami of sacral nerve emerge from ventral sacral foramina and unite in front of piriformis where they are joined by the lumbosacral trunk.

28. BRANCHES NERVE ARISING FROM ROOT i ) Muscular Branches: - To pyriformis (S1,S2) ,to levator ani and coccygeus (S3,S4) ii) Pelvic Splanchnic nerve (Nervi Ergentis):- S2,S3,S4 They are the pathway of sacral outflow of parasympathetic system. They cause constriction of the sphincter vesicae and sphincter ani externus and dilatation of arteries of the erectile tissue of the penis and clitoris during erection.

29. TERMINAL BRANCHES OF PLEXUS Sciatic Nerve (L4,L5,S1,S2,S3) Pudendal Nerve ( S2,S3,S4)

30. NERVE FROM PELVIC SURFACE OF PLEXUS Nerve to quadratus femoris (L4,L5,S1) Nerve to obturator internus (L5,S1,S2)

31. NERVE FROM DORSAL SURFACE OF PLEXUS Superior gluteal nerve (L4,L5,S1) Inferior gluteal nerve (L5,S1,S2) Posterior cutaneous nerve of thigh (S1,S2,S3) Perforating cutaneous nerve (S2,S3) Perineal branch of fourth sacral nerve