Fundamentals of pelvis, perineum and male genitalia anatomy. contains short notes with atlas. easy for self study of preclinical and clinical students and residents. clinically important common correlations are included. well animated power point presentation.

1. By: Addisu Alemu, MD

2.  to review the significant anatomy of the
pelvic walls relative to clinical problems.
 age and sexual differences and to the
anatomic features associated with pelvic
examinations.
 Identify the structures of the male Perineum
and reproductive systems
2

3.  Pelvis
◦ Greater pelvis
◦ Lesser pelvis
 Perineum
3

4.  Bear the weight of the upper body when
sitting and standing
 transmits body weight from the vertebral
column to the femurs
 it contains, supports, and protects the
pelvic viscera and provides attachment for
trunk and lower limb muscles
4

5. 5

6. 6

7. ischiopubic rami 7

8. 8

9. 9
terminal line

10. 10

11. Anteroposteror diameter of pelvic
outlet (varies 9.5-11.5cm because
of mobility of coccyx)
Transverse diameter of
pelvic outlet (~11cm)
11

12. 12

13.  increases in size of interpubic disc
 Increased levels of sex hormones and
relaxin hormones
◦ Increased movement at the pelvic joints
◦ coccyx is also able to move posteriorly.
◦ Relaxation of the sacro-iliac joints and pubic
symphysis permits 10–15% increase in diameters
(mostly transverse, including the interspinous
distance.
 True (obstetrical) diameter remains
unchanged
13

14. 14

15. 15

16.  Weak areas of the pelvis,
◦ are the pubic rami,
◦ the acetabula ,
◦ the region of the sacro-iliac joints
◦ the alae of the ilium.
16

17.  Minor fracture
◦ Pieces of pelvis break off with intact pelvic ring
 Major fracture
◦ Opens the pelvic ring often multiple fracture
Open book fracture. Straddle fracture Vertical shear fracture
17

18. 18

19. pelvis muscles form two groups.
1. Piriformis and obturator internus,
◦ are part of the walls of the pelvis,
◦ primarily considered muscles of the lower limb
19

20. 2. Levator ani and coccygeus form the pelvic
diaphragm and delineate the lower limit of the
true pelvis
 The fasciae investing the muscles are
continuous with visceral pelvic fascia above,
perineal fascia below and obturator fascia
laterally.
 Ischiococcygeus (coccygeus)
◦ may be nearly completely tendinous
20

21. 21

22. according to attachments and fiber course
1. Puborectalis – forms puborectal sling
2. Pubococcygeus
◦ anococcygeal body - fibrous raphe formed by
merged medial fibers
◦ pubovaginalis or puboprostaticus puboperinealis–
extending medially and blending with the fascia
around midline structures
3. Iliococcygeus -arises from the posterior
tendinous arch and ischial spine and blends
with the anococcygeal body posteriorly
22

23. 23

24. 24

25. 25

26. 26

27. 27
Male

28.  is connective tissue that occupies the space
between the membranous peritoneum and
the muscular pelvic walls and floor not
occupied by the pelvic viscera.
 Continuation endoabdominal fascia
28

29.  parietal pelvic fascia
◦ lines the inner walls and floor of the pelvis
◦ named for the muscle that is covered
◦ Continuous with transversalis and iliopsoas fascias.
29

30.  visceral pelvic fascia –
◦ ensheathes the pelvic organs (forming the
adventitial layer)
◦ become continuous with parietal layer where the
organs penetrate the pelvic floor froming
thickened condensations of connective tissue -
tendinous arch of pelvic fascia - running from
the pubis to the ??sacrum
 Parts of tendinous arch of pelvic fascia
◦ puboprostatic ligament in males; pubovesical
ligament in females – anteriormost part
◦ sacrogenital ligaments - posteriormost part
- Extends from sacrum to prostate or vagina
30

31. 31

32.  Is a fascia between parietal and visceral pelvic
fascia which froms a connective tissue matrix
for pelvic viscera.
 Considered as extraperitoneal or
subperitoneal endopelvic fascia
 which could be
◦ loose areolar (fatty) tissue – in retropubic,
retrorectal spaces
◦ fascial condensations or pelvic “ligaments” -
Hypogastric sheath
32

33. Hypogastric
(neurovascular)
sheath
Presacral (potential) space
Retropubic (prevesical) spaceSuperior vesical artery
in lateral ligament of
bladder
lateral rectal ligament
(middle rectal vessels)
Cardinal
ligament
Tendinous arch
of levator ani
Tendinous arch
of pelvic fascia
Rectovaginal
(potential) space
33
uterine artery
Lateral pubovesical
ligament
Medial pubovesical
ligament
Internal iliac
vessels
Vesicocervical fascial
Fibers (paracolpium)

34. 34

35.  Pelvic Arteries
 main arteries entering the lesser pelvis
◦ internal iliac and ovarian arteries (females only)
are paired
◦ median sacral and superior rectal arteries are
unpaired
 multiple anastomoses occur, providing
an extensive collateral circulation
35

36.  is the principal artery of the pelvis supplying
most of the blood to pelvic viscera and some
to the musculoskeletal part
 Branches from the anterior trunk supply
pelvic viscera, perineum, gluteal region,
adductor region of the thigh, in the fetus,
the placenta
 Branches from the posterior trunk supply
lower posterior abdominal wall, posterior
pelvic wall, gluteal region
36

37. 37

38.  Iliolumbar and
Lumbar
 median sacral and
lateral sacral
 superior rectal and
middle rectal
 inferior gluteal and
deep artery of the
thigh
38

39.  Pelvic veins follow the
course of all branches
of the internal iliac
artery except for the
umbilical artery
(absent) and the
iliolumbar artery
(drain into the
common iliac veins)
39

40.  The various plexuses unite and are
drained
◦ mainly by tributariesinternal iliac veins
◦ some drain through
 superior rectal vein into inferior
mesenteric vein - portacaval shunt
 lateral sacral veins into internal vertebral
venous plexus
 median sacral vein
 ovarian veins (in females)
40

41.  Lymphatic drainage follows a pattern that
generally follows the pattern of venous
drainage through variable minor and major
sets of lymph nodes
◦ Exception = the superior parts of the middle to
anterior pelvic organs → External iliac lymph
nodes
 However, pelvic lymph nodes are highly
interconnected that the pattern is not
sufficiently predictable to allow the
progress of metastatic cancer from pelvic
organs to be anticipated or staged
41

42. 42

43.  Pelvic structures are innervated mainly by
the sacral (S1 -S4) and coccygeal spinal
nerves and the pelvic part of autonomic
nervous system
 Sacral plexus
◦ Originates from the anterior rami of L4,
L5, S1–S4
◦ Branches from the plexus supply:
 pelvic muscles
 muscles of the hip
 skin of buttock and the back of thigh
43

44. 44

45. 45

46. 46
 Leaves the pelvis through the greater sciatic
foramen
 Then hooks around the ischial spine and
sacrospinous ligament and enters the
perineum through the lesser sciatic foramen
 Accompanied by the internal pudendal vessels
 Innervates skin and skeletal muscles of the
perineum, including the external anal and
external urethral sphincters
◦ Mediates the act of erection
◦ Voluntary control of urination

47. 47

48. 1. Sacral sympathetic trunks
 are the inferior continuation of the lumbar
sympathetic trunks
 descend on the pelvic surface of the sacrum just
medial to the pelvic sacral foramina
 converge to form the small median ganglion
impar (coccygeal ganglion).
 send communicating branches (gray rami
communicantes) to each of the anterior rami of
the sacral and coccygeal nerves
 also send branches to the median sacral artery
and the inferior hypogastric plexus
 Function: provide postsynaptic fibers to the
sacral plexus for sympathetic innervation of the
lower limb
48

49. 49

50.  superior hypogastric plexus –
◦ networks of sympathetic and visceral
afferent nerve fibers conveyed through (L3
and L4) splanchnic nerves.
◦ In pelvis Divides into right and left
hypogastric nerves and descend lateral to
the rectum within hypogastric sheaths to
merge with the pelvic splanchnic nerves to
form the right and left inferior hypogastric
plexuses.
50

51. 51

52.  The inferior hypogastric plexuses thus
contain both sympathetic and
parasympathetic fibers as well as visceral
afferent.
 This fibers continue through the lamina of
the hypogastric sheath as sub-plexuses
(pelvic –plexuses) supplying the pelvic
structures from lateral aspect
52

53. 3. Periarterial plexuses
 Sympathetic fibers enter the pelvis
surrounding superior rectal, ovarian, and
internal iliac arteries
4. Pelvic splanchnic nerves:
 Arise from anterior rami of spinal nerves
S2, S3, S4 of the sacral plexus
(presynaptic fibers)
 pathway for parasympathetic innervation
of pelvic viscera and descending and
sigmoid colon.
53

54.  All visceral afferent fibers conducting reflexive
sensation travel with parasympathetic fibers.
 pelvic pain line - the pelvic pain line corresponds
to the inferior limit of the peritoneum
◦ superior to the pain line follow sympathetic fibers
retrograde
◦ portions of viscera inferior to the pain line follow
the parasympathetic fibers retrograde to reach
cell bodies in the spinal sensory ganglia of S2–S4.
 Exception= the pain line occurs in the middle of
the sigmoid colon.
54

55.  Primary reproductive organs produce
gametes
 Secondary reproductive organs:
◦ Seminal fluid
◦ Storage of spermatozoa
 Internal Genital organs
 External Genital organs
55

56. 56

57.  Paired, posterior to urinary bladder
 Tubular (~ 5 cm)
 They secrete a thick alkaline fluid with
fructose, and a coagulating agent
 Blood supply: inferior vesical and middle
rectal arteries and vein
57

58.  It is approximately 2 cm x 3 cm x 4 cm in
size and weighs about 20 g
 Covered by indestinict, richly vascularized,
dense irregular collagenous fibromuscular
capsule
 The glandular part makes up
approximately two thirds of the prostate;
the other third is fibromuscular
 Prostatic urethra
58

59. 59

60. 60

61. Arteries
 Branches of the inferior vesical and middle
rectal arteries.
Veins
 prostatic venous plexus - are valveless
◦ Have Many connections with the valveless vertebral
veins
Nerve Supply
 Inferior hypogastric plexuses
61

62. 62

63.  Pea size, paired, at base of penis
 Produce about 10% of semen
 Alkaline mucus buffers the acid that may be
present in urine
63

64. 64

65.  Perineum is a diamond shaped region of
trunk inferior to fascia of pelvic diaphragm
 A transverse line joining the anterior ends
of the ischial tuberosities divides the
perineum into two triangles:
◦ Urogenital triangle
 contains external genitalia
◦ Anal triangle
 contains the anal canal, anus and ischioanal
fossa
65

66. 66

67.  Inferior pelvic aperture is closed by
◦ urogenital (UG) triangle - Urogenital diaphragm/
(perineal membrane)
◦ anal triangle - Pelvic diaphragm overlying
ischioanal fat
67

68. 68

69.  Is a fibromuscular mass located in the center
of the perineum
 is the site of convergence and interlacing of
fibers of several muscles, including the:
◦ Bulbospongiosus.
◦ External anal sphincter.
◦ Superfi cial and deep transverse perineal muscles.
◦ Smooth and voluntary slips of muscle from the
external urethral sphincter, levator ani, and
muscular coats of the rectum.
69

70.  Anteriorly, the
perineal body
blends with the
posterior border
of the perineal
membrane and
superiorly with the
rectovesical or
rectovaginal
septum
70

71.  The perineal fascia consists of superficial
and deep layers
 deep perineal pouch
◦ Triangular, a trilaminar teaching view
◦ Lies between the superior and inferior
fasciae (perineal membrane) of the
urogenital diaphragm (Contains deep
transverse perineal muscle and the
sphincter urethrae, intermediate part of
the urethra)
71

72.  is continuous with the deep fascia covering
the external oblique muscle and the rectus
sheath.
 is also attached
◦ laterally - the ischiopubic rami
◦ Anteriorly - is fused to the suspensory ligament
of the penis
72

73.  Lies between the perineal membrane
and superficial perineal fascia (Colles'
fascia).
 Contains
◦ Root (bulb and crura) of the penis and associated
muscles (ischiocavernosus and bulbospongiosus).
◦ Proximal (bulbous) part of the spongy urethra.
◦ Superfi cial transverse perineal muscles.
◦ Deep perineal branches of the internal pudendal
vessels and pudendal nerves.
73

74. 74

75. The subcutaneous tissue of the perineum
 In males, the fatty layer is greatly diminished in the
urogenital triangle, being replaced altogether in the
penis and scrotum with smooth (dartos) muscle.
 is continuous posteriorly with ischio-anal fat pad
75

76. 76

77.  rupture of the intermediate part of the urethra
◦ from separation of the pubic symphysis and
puboprostatic ligaments
 rupture of the spongy urethra
◦ straddle injury
77
Sleeve Hematoma

78. 78

79.  The male perineum includes
◦ external genitalia (urethra, scrotum, and
penis)
◦ perineal muscles
◦ anal canal
 Testes and epididymis
◦ considered internal genital organs on the
basis of their developmental position and
homology with the internal female gonads
(ovaries)
79

80.  Scrotum consists of
◦ Skin, fascia
◦ Dartos muscle (smooth)
◦ Tunica vaginalis
◦ Median raphé
 Allows the testes to remain ~3°C cooler than
core temperature
 Involuntary contraction of dartos and
cremaster muscles (cremasteric reflex) in
response to cold or sexual arousal
 Blood supply: Anterior scrotal, Posterior
scrotal arteries and veins
80

81. 81

82.  Develop adjacent to kidneys
 Descend into scrotum through inguinal canal
(function of gubernaculum testis) before birth
 Blood Supply via gonadal arteries
 Parietal peritoneum is carried along lining of
scrotum
 Spermatic cord: bundle containing all the
“duct work”
82

83. Undescended testicle
Testicular torsion
83

84.  Head-superior, receives
spermatozoa
 Body-distal and inferior
 Tail-leads to
ductusdeferens
 Functions:
1. Monitors and adjusts
tubular fluid
2. Recycles damaged
spermatozoa
3. Stores sperm and facilitates
maturation (capacitation)
84

85.  Can be palpated as it passes over the pubic brim.
85

86.  consists of a root, body, and glans.
 Prepuce= foreskin –partially covers glans and
surrounds external urethral meatus(removed in
circumcision)
 Preputial glands -produce smegma
86

87. 87

88.  Shaft (Body) of penis
◦ Corpus Cavernosum(2)
◦ Corpus Spongiosum
◦ Penile Urethra
◦ tunica albuginea
◦ Dorsal Artery and Vein
◦ deep fascia of the penis
(Buck fascia) –
continuation of the deep
perineal fascia
◦ Superficial (dartos) fascia
88

89.  Prostatic
 Intermediate
(membranous)
 Spongy (penile)
89

90. 90
Hypospadias
PARAPHIMOSIS

91.  Moore clinically oriented anatomy 7th Ed
 Grays anatomy, the anatomical bases of
clinical practice, 40th Ed
 Atlas of Human anatomy, Frank H. Netter MD,
6th Ed
 Grays atlas of Anatomy 2nd Ed
 BRS, Gross Anatomy 6th Ed
 Clinical anatomy, Richard S. Snell, 9th Ed
91

92. 92