Pelvis Flashcards
AP diameter limits
Midpoint sacral promontory
Upper border pubic symphysis
Transverse diameter limits
Two similar points on opposite sides of pelvic brim
Oblique diameter limits
Ilio pubic eminence to lowest point of cobra lateral sacroiliac joint
Pelvis brim/ inlet borders
Sacral ala and promontory posterior
Arcurate line laterally and pectineal line anterolaterally
Superior pubic rami, body of pubis and pubic symphysis anteriorly
4 elements of pelvic outlet
Coccyx posteriorly
PS anteriorly
2 ischial tuberosities laterally
Insertions of sacrotuberous ligaments
Sacrum coccyx
Ischial tuberosities
Shape of inlet
Wide transverse oval
Position if fetal head entering pelvis
AP diameter across transverse diameter of pelvis
Articulations of the pelvis
Sacroiliac joints
Between sacrum and coccyx
Symphysis pubis
Ligaments of sacroiliac joint
Ventral (thickening of joint capsule)
Dorsal
Interosseus
Dorsal sacroiliac ligament attachments
Intermediate/lateral crests of sacrum
Pass down to
PSIS and inner lip of iliac crest
Lower part may form a separate structure - long posterior SI ligament
Interosseus ligament attachments
Which ligament covers the interosseus?
From depressions on sacrum to depressions on iliac tuberosity
Deep and superficial strata
Covered by dorsal SI ligament
Dorsal primary rami of sacral nerves and vessels between
Ligament formed by superficial fibres of interosseus
Short posterior iliac
Between superior articular process and lateral crest of first two sacral segments to the ilium
Pubic symphysis joint type
Secondary cartilaginous
Symphysis pubis structure
Fibrocartilaginous disc
Superior pubic ligament
Arcuate pubic ligament
Between which structures does the deep vein of the clitoris enter the pelvis?
Urogenital diaphragm and arcuate pubic ligament
Muscles of the anterior abdominal wall and importance in labour
External oblique
Internal oblique
Transversus abdominus
Rectus abdominus
Obliques act in compression
Attachments of external obliques
Outer surface lower 8 ribs
Fibres interdigitate with serratus anterior and lat dorsi
Fibres from lower 2 ribs pass vertically down to anterior part of iliac crest, from others down and medial becoming aponeurotic level with tip of 9th rib
Site of interdigitate on of two external obliques
Limits of this structure
Linea alba, tendinous raphe
Xiphoid process to pubic symphysis
Components of lines alba
2 obliques
Transversus abdominus
Interrupted by umbilicus
Structures transmitted by umbilicus
Umbilical vessels –> medial UL and ligamentum teres
Vitelline duct
Urachus –> median UL
Position of lower fibres of external obliques aponeurosis
ASIS to pubic tubercle
Thickened and folded in on itself to form floor of inguinal canal
Lacunar ligament position and structure
Fibres from medial end of inguinal ligament pass backwards and medially to pectineal line
Forms medial boundary of femoral ring
Internal oblique attachments
Thinner than external
Arises from lumbar fascia, lateral inguinal ligament and anterior iliac crest
Posterior fibres ascend vertically to lower ribs (continuous with external intercostals)
Fibres from iliac crest pass up and medial meeting in midline at linea alba
Fibres from inguinal ligament arch down and medially crossing round ligament, become aponeurotic. Insert behind round ligament to pubic crest and medial pectineal line together with similar fines from transversus abdominus forming falx inguinalis (conjoined tendon) behind superficial inguinal ring
Falx inguinalis: Alternative name Components Function Position
Conjoined tendon
Internal oblique fibres from lateral inguinal ligament passing down and medially
Transversus abdominus fibres
Medially continuous with anterior wall of rectus sheath
Lies behind superficial inguinal ring
Strengthens weak point of abdominal wall
Occasionally continuous laterally with band of aponeurotic fibres - interfoveolar ligament giving additional strength (fibres from lower border transversus abdominis to superior pubic ramus)
Transversus abdominis origin
Deep to internal oblique from lumbar fascia, lateral inguinal ligament and anterior iliac crest
ALSO fibres arise from inner lower 6 ribs and interdigitate with diaphragm
Transversus abdominis fibre orientation
Horizontal
Meeting in midline at linea alba
Transversus abdominus fibres passing behind rectus
Aponeuroses in upper 4/5
Transversus abdominus fibres passing in front of rectus abdominis
Lower 1/5 arising from inguinal ligament and iliac crest
Rectus abdominis origin and insertion
Crest and tubercle of pubis
Broadens and inserts onto ribs 5-7
3 transverse tendinous intersections of recti muscles
Level of xiphoid process
Umbilicus
Midway between these two
Rectus sheath components in upper part
Aponeuroses of the obliques muscles and transversus abdominis
Transversus aponeurosis lies posterior
Internal oblique divides into two laminae - one deep and one superficial to muscle
External oblique aponeurosis lies anterior
Medial to the recti muscles the aponeurotic layers reunite to form the linea alba
Point of change in structure of rectus sheath
Component of rectus sheath posteriorly below this point
Midway between symphysis pubis and umbilicus at the arcuate line
Transversal is fascia deep to transversus abdominus
Point of access of inferior epigastric vessels to rectus sheath
Arcuate line
Position of transversal is fascia
Between transversus abdominis and parietal peritoneum
Plane of lower 6 intercostal nerves
Between transversus abdominis and internal oblique
Position of inguinal canal
Between abdominal cavity and labia majora, obliquely between superficial and deep inguinal rings
Just superior to medial half of inguinal ligament
Contents of inguinal canal
Round ligament of uterus
Ilioinguinal nerve
Boundaries of inguinal canal
Floor: inguinal ligament united with transversalis fascia
Roof: arching fibres of transversus abdominis and internal oblique
Anterior: skin, superficial fascia, external oblique aponeurosis; fibres of internal oblique also contribute to most lateral part
Posterior: transversalis fascia, reinforced by conjoint tendon and reflected part of inguinal ligament
Deep inguinal ring components and position
Transversalis fascia
Midway between ASIS and pubic symphysis
Transversus abdominus fibres arch over superiorly
Inferior epigastrics immediately medial
Internal oblique contraction with increased intra abdominal pressure acts as valve to close deep inguinal ring
Superficial inguinal ring components and position
Above inguinal ligament
Just lateral to pubic tubercle
Opening in aponeurosis of external oblique, margins thickened to form lateral and medial crura of the ring
Round ligament covering
Internal spermatic fascia as passes through transversalus fascia at level of deep ring
Cremasteric fascia on passing through internal oblique
External spermatic fascia as external oblique aponeurosis
Ilioinguinal nerve accompanies round ligament
Round ligament course
Through transversalis fascia at deep inguinal ring
Ilioinguinal nerve origin
Anterior primary ramus L1
Course of ilioinguinal nerve
Emerges from lateral psoas border
Crosses qudratus laborum
Perforated transversus abdominis close to anterior iliac crest
Runs in this plane until piercing internal oblique
Enters inguinal canal
Emerges through superficial ring
Distributed to skin of medial thigh, mond pubis and labia majora.
Also supplies IO and TA muscles
Which structure does damage to the ilioinguinal nerve weaken?
Conjoint tendon due to contribution of IO and TA muscle fibres which it supplies
This can result in a direct hernia
Structure of superficial fascia of inguinal region
2 layers
Superficial continuous with abdominal superficial fascia
Deep fuses with fascia lata (deep fascia of thigh) just below inguinal ligament and contributes to saphenous opening
Structures lying between superficial and deep layers of inguinal region fascia
Superficial inguinal nodes
Long saphenous vein
Facia lata thickening forms wich tract?
Iliotibial
Proximal and lateral thickening
Bladder innervation
1.
2.
- Fine medullated fibres from S3,4
2. Non-medullated fibres from hypo gastric plexus
Connects bladder to pelvic wall
Fascia endopelvina
Course of urachus
Vertex of bladder to umbilicus
Level of the tendinous arch
Another name for this structure
Line extending from lower part if symphysis pubis to ischial spine in upper diaphragmatic part of pelvic fascia
White line of the pelvic fascia
Attachments of superficial layer of fascia lata
Entire length of inguinal ligament
ASIS
Pectineal line of pubis
Position of superficial fascia lata
Lateral to saphenous opening
Reflected inferolaterally from pubic tubercle forming falciform margin of opening
SL
Position of deep layer fascia lata
Medial to saphenous opening
Continuous with superficial layer at lower margin
Continues upwards to cover adductors, behind femoral sheath and attaches to pectineal line
Relation if fascia lata layers to femoral sheath
Superficial layer anterior
Deep layer fascia
Components of femoral sheath
Transversalis fascia anterior to femoral vessels
Iliacus muscle behind these vessels
Layers terminate by fusing with fascia on the outer layers of the femoral vessels
Shape of femoral sheath
Funnels shaped, wider at proximal end
Which nerve pierces lateral wall of femoral sheath?
Femoral branch of genitofemoral
Which vessel pierces medial wall of femoral sheath?
Which vessel does this drain into?
Great saphenous vein
Femoral vein
Boundaries if femoral triangle
Superior
Lateral
Medial
Inguinal ligament
Medial border sartorius
Medial border adductor longus
ILSAL
Components of femoral triangle floor
Lateral border adductor longus
Iliacus
Psoas major
Pectineus
Contents of femoral sheath from medial to lateral
Immediate lateral relation to sheath
Femoral canal
Femoral vein
Femoral artery
Femoral nerve
Contents of femoral canal
Lymph vessels
Deep inguinal lymph nodes
Proximal opening of femoral canal
Medial aspect of this opening
Femoral ring
Lacunar ligament
Origin and termination of round ligament
Uterine fundus
Labia majora
Relation of round ligament to Fallopian tube
Inferior and anterior
Path of the round ligament
Arises from uterine fundus inferior and anterior to Fallopian tube
Runs through broad ligament passing over external iliac vessels and psoas muscle
Through inguinal canal
Fibres fan out to form labium majora
Obturator foramen shape in male/female
More triangular in female, ovoid in male
Supra pubic arch in male/female
50-60 degrees
80-85 degrees
Orientation of iliac blades in female
More vertical that male
Reasons femoral hernias more common in women
Femoral ring larger
Due to greater width of pelvis and smaller femoral vessels
Which structure lies lateral to femoral sheath?
Femoral nerve
Which structure passes over the femoral vein just above the femoral ring?
Where is this structure travelling?
Round ligament as it enters the deep inguinal ring
2 groups of pelvic muscles
Obturator internist and piriformis line the walls
Pelvic diaphragm or floor: levator ani and coccygeus
Bony attachments of levator ani
Origin of fibres between these points
Pubic bone inner surface
Spine if ischium medial aspect
Fascia overlying obituary or externus
Name of anterior part if levator ani
Origin and direction if fibres
Originate at body of pubis
Pass A-P to perineal body
Pass across sides of vagina (form a supplementary sphincter)
Insert into anterior surface of coccyx
Name of anterolateral part of levator ani
Origin and direction of fibres
Puborectalis
Fibres arise more laterally than pubovaginalis
Pass back, down and medially meeting fibres from opposite side
Form sling round junction between rectus and anus
Fibres intermingle with deep fibres of EAS and perineal body
Iliococcygeus origin and insertion
Medial aspect ischial spines
Pass lateral to medial
Fascial covering of levator ani
Which fascia does this contribute to?
Which other structure does this give rise to?
Superior fascia of pelvic diaphragm
Fascia covering obituary or internist above
Tendinous arch of the levator ani
Which structure does the tendinous arch of the pelvic fascia give rise to?
Attachment of the lateral supporting ligament if the urinary bladder
Which artery supplies levator ani?
Inferior gluteal
Components if levator ani
Function
Iliococcygeus
Pubococcygeous
Puborectalis
Supports pelvis viscera
Constricts rectum and vagina
Innervation of levator ani
Pudendal nerve
Perineal nerve
Inferior rectal nerve
Sacral spinal nerves S3, S4
Coccygeus origin and insertion
Ischial spine and deep surface of sacrospinous ligament
Coccyx and lateral margin 5th scral segment
Vertebral level of common iliacs
L4-L5
How much longer is R common iliac than L?
Which vertebra does it pass directly in front of?
1cm
L5
What separates common iliacs from small intestine?
Parietal peritoneum
Which muscle lies laterally to common iliacs?
Psoas
Which nerve fibres form a mesh work over common iliacs?
Superior hypogastric plexus
Common iliac veins unite to form which vessel?
IVC
Relation of left common iliac artery to vein
Anterolateral
Level of division of common iliacs
Sacroiliac joint
Which muscle is external iliac related to?
Medial border of psoas
Which structure does external iliac artery pass under to enter thigh?
At what landmark?
Inguinal ligament
Midway between PS and ASIS at Mid inguinal point (1cm medial to midpoint of inguinal ligament)
Which structure crosses anteriorly at point of division of common iliac artery?
Ureter
Where do internal iliacs divide into anterior and posterior divisions?
Upper margin of greater sciatic notch
Which foramen does posterior internal iliac pass through?
Greater sciatic
Terminal branches of posterior division of external iliac
Superior gluteal
Lateral sacral
Iliolumbar
Anterior division of internal iliac direction
Towards ischial spine
Anterior relations of anterior division of internal iliac at division
Ureter
Ovarian artery
Film brisk end of tube
Ovary
Relation of internal iliac veins to internal iliac arteries
Posterior
Relation of external iliac veins to external iliac arteries
Below and medial
Relation of obturator nerve to psoas muscle and division of common iliac
Emerges from medial aspect of psoas lying first at the division
Then on pelvis side wall above obturator vessels before passing through obturator canal to enter medial compartment of thigh
Umbilical artery is a branch of ___?
What does it supply?
What happens at its distal end
Internal iliac
Umbilical artery –> superior vesical branches Supply superior aspect of bladder and distal ureter
Becomes fibrous, ascends to umbilicus covered in parietal peritoneum and raises a fold on each side of inner surface of abdominal wall - medial umbilical ligament
Branches of internal iliac artery
Obturator
Umbilical –> superior vesical and medial umbilical ligament
Uterine and vaginal
Middle rectal (can be elusive, arises in common with inferior vesicle) –> lower rectum
Inferior vesical –> fundus of bladder, distal ureter
Internal pudendal
Inferior gluteal
Path of obturator artery
Relation to obturator nerve
Passes forward on lateral pelvic wall to enter obturator canal 2-3cm below pelvic brim
Lies inferior to nerve in canal
Path of uterine artery
First lies on fascia over levator ani
Turns medially towards cervix crossing above and in front of ureter
Ascends in broad ligament to junction of uterine body and tube
Branches turn laterally to anastomose with ovarian artery
Blood supply of vagina
Branches if uterine artery (from internal iliac anterior branch)
Terminal branches if internal iliac
Which is the larger?
Internal pudendal
Inferior gluteal larger
Path of internal pudendal artery
Leaves pelvis through lower greater sciatic foramen between coccygeal and piriformis
Winds around ischial spine between pudendal nerve medially and nerve to obturator internus laterally
Enters perineum through lesser sciatic foramen
Lies in pudendal (Alcock’s) canal within the perineum
Location of pudendal canal
Alternative name
Relation with other fascia
Lateral wall of ischioanal fossa (Alcock’s)
Fascias sheath forms roof and lateral wall of fossa
Fuses with part of obturator fascia
Continuous with inferior fascia of pelvic diaphragm and falciform process if sacrotuberous ligament
Which structures accompany internal pudendal artery in the pudendal canal?
Which artery branches from internal pudendal at start of canal?
Pudendal nerve - lies between terminal branches at the anterior end (dorsal nerve of clitoris above and perineal nerve below)
2 veins
Inferior rectal
Origin of inferior rectal artery
Structures supplied by it
Internal pudendal artery
Just superior to ischial tuberosity emerges from medial wall of sheath crossing ischioanal fossa
Supplies skin and muscles of anal region
Which arteries arise from internal pudendal?
Inferior rectal
Perineal
Path of the perineal artery
Arises from pidendal at anterior end of pudendal canal
Through inferior fascias layer of urogenital diaphragm to enter superficial perineal space
Path of inferior gluteal artery
Larger terminal branch of internal iliac
Leaves pelvis posterior to internal pudendal
Also passes between piriformis and coccygeus in lower greater sciatic foramen
Supplies gluteal region and posterior thih structures
Pelvic lymphatic drainage
Which structures does this include?
Which structures have different drainage?
Passes to nodes along internal iliac veins
To paravertebral or lateral aortic nodes in lateral aspects if vertebral bodies (also receive lymph from ovaries/kidneys/adrenals/posterior abdo wall muscles)
To cisterna chyli posterior to aorta at L1-L2
To thoracic duct
Uterus and vagina
Which plexuses inner ate the pelvis?
Lumbar and sacral
Which nerves form the lumbar plexus?
Where is this plexus formed?
Anterior primary rami of T12-L4
Within substance of psoas major
Which nerves does the lumbar plexus give rise to?
Femoral - posterior divisions L2,3,4 Obturator - anterior divisions L2,3,4 Subcostal Iliohypogastric Ilioinguinal Genitofemoral
Path of femoral nerve
Emerges lateral psoas
Runs between psoas and iliacus until inguinal ligament
Passes on anterior surface of iliopsoas as this muscles passes under inguinal ligament
Separated by psoas from external iliac and femoral artery by psoas superiorly but immediately lateral to femoral artery in the thigh
Divisions of femoral nerve
Within pelvis supplies iliacus and nerve to pectineus (from medial aspect near inguinal ligament, passes behind femoral sheath)
In thigh divides into anterior and posterior to supply muscles and skin
Path of obturator nerve
Emerges from medial border of psoas (OM, FL)
Lies behind common iliacs at pelvic brim
Continues lateral to internal iliacs on obturator internus
Above obturator artery through obturator canal
Exits pelvis to supply adductors and skin of medial thigh
Why can pain from the ovary be referred to the medial thigh?
Parietal peritoneum near ovary is also supplied by obturator nerve
Path of subcostal and iliohypogastric
Cross quadratus lumborum
Pierce transversus abdominis
Run in neurovascular plane between transversus abdominis and internal oblique
What structures are supplied by the subcostal and iliohypogastric nerves?
What is the origin of these nerves?
Transversus abdominis
Internal oblique
Skin of lower abdomen
Lumbar plexus
Path of genitofemoral nerve
Structures supplied by it
Anterior surface if psoas
Divides into femoral and genital branches
Femoral branch passes below inguinal ligament to supply skin over femoral triangle
Genital branch passes through deep inguinal ring to supply cremaster
What structure unites lumbar and sacral plexuses?
Which roots?
Lumbo sacral trunk (L4-5)
Path of lumbo sacral trunk
Medial to psoas
Crosses pelvic brim anterior to SIJ
Joins ventral primary ramus of S1
Which nerves form sacral plexus?
Lumbo sacral trunk
Anterior primary rami S1-4
Location of sacral plexus
On piriformis behind internal iliacs, ureter and gut
Structure formed by upper group of sacral plexus
Roots
Sciatic nerve
L4-S2 and part of S3
Structure formed by lower group of sacral plexus
Roots
Pudendal nerve
Mainly S3-4 (small contribution S2)
Nerve supply of piriformis
Sacral plexus
Via nerve that exits at S1-2 and enters anterior surface
Nerve supply of levator ani
Sacral plexus
Through branches derived from S4
Pudendal nerve roots
Path of pudendal nerve
S2,3,4
Leaves pelvis through GSF
Winds around ischial spine medial to IPA just deep to sacrospinous ligament and close to ischial spine
Enters perineum through LSF into pudendal (Alcock’s) canal
Structures supplied by pudendal nerve
Vulva
Perineum
Branches and supply of pudendal nerve
Inferior rectal nerve –> EAS, lining of distal anal canal, perineal skin, sensory fibres to lower part of vagina
Terminal branches
Perineal nerve –> posterior labial branches
Dorsal nerve of clitoris
Which structure is the pudendal needle passed through for nerve block?
Sacrospinous ligament
Sympathetic supply of pelvis
Thoracolumbar
Thoracic via greater and lesser splanchnic nerves - preganglionic arise in thorax but synapse in ganglia related to aortic branches
Greater splanchnic nerve components and path
Preganglionic sympathetics from T5-9(10), also visceral afferents
Passes through diaphragm
Contributes to coeliac ganglion
Lesser splanchnic nerve components and path
T9-10(11) sympathetic ganglia
Passes to aorticorenalganglion
How many ganglia does sympathetic chain consist of in lumbar region?
4
Lie on lateral aspect of lumbar vertebrae
Sympathetic fibres distribute to pelvis via superior hypo gastric plexus (pre sacral nerves)
Location of superior hypo gastric plexus
2 main trunks carrying symp fibres
Relation of trunks to internal iliacs
Origin of parasympathetic fibres in the plexus
Anterior to aortic bifurcation
Right and left hypo gastric nerves
Medial
Pelvic splanchnic nerves S2-4, ascend from inferior hypogastric plexus, usually to L side of plexus
Where do the hypogastric nerves send sympathetic fibres to?
Where do these fibres originate?
Ovarian and ureteric plexuses
Renal and aortic sympathetic plexuses
Another name for inferior hypogastric plexus
Structure
Origin of parasympathetic fibres
Pelvis plexus
Continuation of R and L hypogastric nerves
Pelvic splanchnic nerves S2-4 of sacral plexus
Which structures do pelvic splanchnic nerves supply?
What type of innervation?
Pelvic viscera and hindgut
Parasympathetic
Location if inferior hypogastric plexus
Within fascia surrounding rectum
Fibres lie on either side of rectum, cervical and vaginal fornices and posterior aspect bladder
Which structures does the inferior hypogastric plexus supply?
Where are the fibres from?
Pelvic viscera
Broad ligament –> uterovaginal plexus
T10-L2 of cord
Preganglionic PS fibres if pelvic splanchnic nerves
Origin of fibres of uterovaginal plexus
Destination of fibres from uterovaginal plexus
Inferior hypogastric/pelvis plexus
Some travel with uterine and vaginal arteries, others directly to cervix
Fibres travelling with uterine arteries supply body of uterus, upper broad ligament and tubes
Fibres with vaginal supply walls if vagina and erectile tissue
Action if sympathetic fibres within pelvic plexus
Uterine contraction
Vasoconstriction
Pathetic of afferents fibres from
- Uterus
- Cervix and upper vagina
- Lower vagina
- Back to hypogastric plexus and lumbar splanchnic nerves to lower T and upper L levels of cord
- Via pelvic splanchnics
- Pelvic splanchnics
Position of empty urinary bladder
When full
Lesser pelvis
Abdominal cavity
Shape of fundus of bladder
Posterior relation
Triangular outline
Anterior vaginal wall
Peritoneal covering of bladder fundus
Superior surface
Parietal peritoneum reflected from anterior abdominal wall
Incomplete covering - thin layer reflexes to form vesico-uterine pouch
Direction if bladder apex
Position of bladder neck
Towards pubic symphysis
On pelvic floor within fascia surrounding the urethra
Reflection of peritoneum and pouches in pelvis
Superior surface of bladder –> shallow vesicouterine pouch
From this pouch peritoneum covers uterus and posterior fornix
Uterus to middle part of rectum –> deep rectouterine pouch
Bladder ligaments
Laterally pelvic fascia thickened and condensed to form lateral true ligaments
Lateral ligaments of bladder form two thickened bands called
Pubovesical ligaments
Medial pubovesical ligament attachment and role
What other structure does it form?
Inner aspect pubic bone close to midpoint of PS
Passes down and back to form floor if retro public space
Support bladder neck
Apex of bladder is continuous with which structure?
What does this structure represent?
Urachus
Median umbilical ligament
Fibrous cord in fold of peritoneum
Closure of upper end of vesico-urethral canal
Describe detrusor layers
Which layer gives rise to sphincter vesicae? Where does this lie?
3
Outer longitudinal
Middle circular
Inner longitudinal
Middle layer; internal urethral orifice
Where dies the trigone lie?
What is it derived from?
How does the mucous membrane in this area differ?
Posterior wall of bladder
Fusion of distal ureter ends onto wall
Inferior point from fusion of the two Mesonephric ducts (mesoderm)
More firmly attached to underlying muscle so no folds
Which layer do the ureters derive from?
Mesoderm
Source if efferent parasympathetic supply to bladder
Pelvic splanchnic nerves via pelvic plexus
Convey motor fibres to detrusor and inhibitory fibres to sphincter vesicae
Nerve supply to urethral sphincter?
What structure does this form?
Pudendal nerve
Urogenital diaphragm
Length if urethra in female
Name of start and end
Attachment
4-6cm
Internal urethral orifice to external orifice in the vestibule immediately anterior to vagina
Walls in contact except when urine passed
Urethra firmly attached to anterior vaginal wall
Glands of urethra
Name of largest epithelial fold
Numerous small mucous secreting
At distal end several open into para urethral duct
Duct runs down in submucosal tissue, opens on lateral aspect external urethral orifice
Large posterior fold = crest
Muscle fibre arrangement in urethra
Continuous with bladder smooth muscle
BUT
Inner longitudinal and outer circular (ie no 3rd outer longitudinal)
Structure of urethral epithelium
Proximally transitional
Distally non-keratinised stratified squamous
Below mucous layer thin layer of erectile tissue and plexus of veins
Blood supply to urethra
Internal pudendal
Perineal branches
Innervation of urethra
Autonomic via pelvic plexus
Where does urine escape to in case if urethral rupture?
Below level of urogenital diaphragm deep to membranous layer of superficial fascia
Both layers are attached to ischiopubic rami and continuous around superficial transverse perineal muscles so cannot pass laterally or posteriorly
Via areolar tissue of mons pubis and anterior abdominal wall
Embryonic origin of ureters
Length
Position relative to peritoneum
Distal end mesonephric duct
25cm
Behind parietal peritoneum
Which muscle does ureter descend along?
Which nerve does it cross in front of?
Which vessels cross in front of it?
Psoas major
Genitofemoral
Ovarian
Which vessels are posterior to the ureter as it enters the pelvis?
Which structure is the ureter heading towards at this point?
Which structure is immediately anterior?
End of common iliac or start of internal iliac
Greater sciatic notch along lateral pelvic wall
Ovary
At what level do the uttered turn medially?
Which vessels cross superiorly at this point?
Level with ischial spine
Uterine vessels as they enter broad ligament at level if cervix
What is the relation of the ureter to the supravaginal cervix?
2cm lateral as they pass forward before inclining medially to enter posterior bladder wall related to anterior aspect of vagina
Why does one ureter often have a closer relation to the anterior vagina than the other?
Uterus often to one side of median plane
Describe coats of ureter
3
Outer: fibrous, continuous with kidney capsule, merges into bladder wall
Intermediate: inner longitudinal and outer circular muscle layers in upper 2/3 ureter, further outer longitudinal layer in distal 1/3 but inner layer less developed
Inner: thrown into longitudinal folds and covered in transitional epithelium
Blood supply of ureter
Anastomoses of several arteries
Proximal: renal
Also: ovarian, CIA, superior vesical
Nerve supply of ureter
Branches of renal, aortic, pre sacral and pelvic autonomic plexuses
4 point of perineal diamond
Names of 2 triangles and dividing line
Where do the muscles of these triangles unite?
Pubic symphysis
Coccyx
Ischial tuberosities
Arbitrary line between tuberosities divides into triangles
Urogenital
Anal
Perineal body
Superficial muscles of urogenital region
Bulbospongiosus
Ischiocavernosus (R,L)
Transverse perineal (R,L)
Deep muscles of urogenital region
Urethral sphincter
Deep transverse perineal
Occupy deep perineal pouch and collectively form urogenital diaphragm
Describe the urogenital diaphragm
Deep muscles of perineum - urethral sphincter and deep transverse perineal muscles - between 2 layers of fascia (superior fascia of UGD and thicker inferior fascia if UGD also called perineal membrane)
Which nerve roots form sacral plexus?
Lumbo sacral trunk L4-5
Anterior primary rami S1-4
Where does the sacral plexus lie?
On piriformis
Behind internal iliac vessels, ureter and gut
How do the sciatic plexus nerves exit the greater sciatic foramen?
In 2 groups
Upper form sciatic L4-S2,part S3
Lower form pudendal partS2, S3-4
Which muscles does the sacral plexus supply within the pelvis?
Piriformis S1-2 enters anterior surface
Levator ani S4
Where does pudendal nerve lie in relation to internal pudendal artery?
Which foramen does it gain entry to pelvis through?
Medial
Lesser sciatic to enter pudendal canal innervating perineum and vuvla
What is the space between the two layers of fascia of the urogenital diaphragm called?
Deep perineal pouch
Muscles - deep group urethral sphincter, deep transverse perineal Urethra Urethral gland Vessels an nerves
Which structure pierce the perineal membrane?
Vagina - outer coat fuses with perineal membrane - transverse perineal ligament
Urethra
Blood vessels
Nerves
What is the transverse perineal ligament?
As outer coat if vagina fuses with perineal membrane it stretches horizontally across public arch with a thickened apex, this thickened part is the TPL
Which ligaments does the deep dorsal vein and dorsal nerve of the clitoris clitoris pass between?
Transverse perineal ligament
Arcuate pubic ligament
Blood supply of perineum
Internal pudendal
Terminal branch of anterior division of internal iliac
How does internal pudendal artery exit the pelvis?
Which structure accompanies it medially?
Via GSF to enter gluteal region
Pudendal nerve
What are the boundaries of the pudendal canal?
Fascial compartment related to deep surface of ischial tuberosity and ischiopubic rami
Forms lateral boundary of ischioanal fossa (bounded medially by EAS and inferior fascia of pelvic diaphragm)
Roof and lateral wall - lower obturator externus fascia extending upwards to blend with inferior fascia of PD and down to become sacrotuberous ligament
Which artery leaves proximal end of pudendal canal?
Inferior rectal
Traverses medially across ischioanal fossa to supply anal canal and skin
Where does perineal artery branch from internal pudendal?
What does this artery supply?
Near the anterior end of pudendal canal
Branches to skin and muscle both deep and superficial to perineal membrane
Branches and supply of perineal artery
Posterior labial - labia
Artery to bulb of vestibule - erectile tissue
Deep artery of clitoris - corpus cavernosum
Dorsal artery of clitoris - dorsum, glans, prepuce
What does inferior rectal nerve supply?
What is this a branch of?
EAS
Lower anal canal and perinatal skin
Pudendal nerve (accompanies inferior rectal artery)
Branches if the perineal nerve and supply
- Posterior labial - usually pass anterior to perineal membrane
- Deep branches that supply ishiocavernosus
- Dorsal nerve of clitoris deep to perineal membrane
Which branches of pudendal nerve supply sensory supply to vagina?
Inferior rectal
Posterior labial branches
Boundaries of anal triangle
Posterior aspect of perineal membrane
Ischial tuberosities and sacrotuberous ligament
Relation of ischioanal fosse to anal canal
Laterally
Anal canal length
3-4cm
Describe mucosa of upper part of anal canal
Lined by mucous membrane thrown into folds - anal columns with valves and sinuses at distal end
Relation if anal sphincter muscles to anal canal
IAS surrounds upper 75% with white line at lower extremity
EAS surrounds lower part, overlapping IAS and inserting into skin at lower end of canal
Describe parts of EAS
- Deep region - fibres interdigitate with puborectalis and muscles of deep perineal ouch via perineal body
- Superficial fibres insert into coccyx and contribute to ani coccygeal ligament (separates anus from coccyx)
- Subcutaneous - thin horizontal band around distal canal below IAS, some fibres attach to anococcygeal ligament and perineal body - no bony attachments
Uterus Type of muscle Normal and pregnant weight Location Number if ligaments
Smooth 40g 800g both hypertrophy and hyperplasia Between bladder and rectum 4
Cervix:
Type of tissue
Dense connective
Point if reflection off uterovesical peritoneal fold
Junction between cervix and uterine body
Nature if rectovaginal fold
Boundaries if rectouterine pouch
Reflection from posterior fornix of vagina onto surface of rectum forming floor of rectouterine pouch
Anterior: posterior wall if uterine body
Posterior: rectum
Laterally: peritoneal folds from cervix to posterior walls if lesser pelvis
Uterosacral ligament boundaries
Extend posteriorly from cervix to attach to anterior sacrum
Contain smooth muscle and fibrous tissue
Contents if broad ligament
Tubes
Round ligament
Ligament of ovary
How does ovary attach to broad ligament?
Attaches to posterior layer via mesovarium
Where does the broad ligament run?
Side wall of uterus to lateral wall of pelvis creating septum between anterior pelvis containing bladder and posterior region if rectum
Extent of suspensory ligament if ovary
Contents
Part of broad ligament from infundibulum of tube and upper pole of ovary to lateral pelvic wall
Ovarian vessels and lymphatic continues over external iliacs as a distinct fold
What is the mesometrium?
Part of broad ligament extending from pelvic floor upwards to ovary and ligament if ovary
Uterine artery is a branch of__?
Position
Internal iliac
From origin travels within transverse cervical (cardinal) ligament
Crosses above ureter inclining medially
Passes 1.5cm medially to cervix
Then travels superiorly within substance if broad ligament to anastomose with ovarian artery
Name of folds within cervical canal
Palmate
Nature of transverse cervical ligament
Not truly ligamentous
Dense condensation of connective tissue around neurovascular structures from lateral walls pelvis to pelvic viscera
Passes backwards and upwards to root of internal iliacs
Role of transverse cervical ligament
Supports cervix and upper vagina
Helps to maintain angle between axis of vagina and anteverted uterus
(round ligament may also have this role)
Continuous inferiorly with superior fascia of pelvic diaphragm
Cervix as a proportion of uterus
Cylindrical lower third
Communicates with body via internal os
Changes of cervical mucosa with endometrial cycle
Very little
Cervical changes in pregnancy
Increases in vascularity
Mucous secretion thickens
Dense collagen loosens due to fluid uptake by mucopolysaccharides - allows lower section to shorten as upper expands
Extent of vagina
Muscular tube between cervix and vestibule, opens onto perineum
Which fornix is closely related to the peritoneal cavity?
Posterior
Covered in peritoneum
Blood supply of uterus
Mainly uterine arteries
But rich azygous system with contribution from uterine, vaginal and internal pudendal
Lymphatic drainage of uterus
Mainly internal iliac nodes
Some communication with superficial inguinal via round ligaments so malignant cells can track this way
Length of uterine tube
Name if different parts of tube
10cm
Fimbriae - Infundibulum - ampulla - isthmus
How are ovaries attached to broad ligament?
Attached at posterosuperior aspect by short pedicle of peritoneum, the mesovarium
Ovary orientation in nullipatius woman
Vertical
Medial and lateral surfaces
Tubal and uterine extremities
Location of ovary
Ovarian fossa on lateral pelvic wall
Lined by parietal peritoneum, separates ovary on lateral surface from extra peritoneal tissue, obturator vessels and nerves
Bounded by obliterated umbilical artery anteriorly, internal iliac posteriorly, tubal extremity is related to external iliac vein
What is the mesosalpinx?
Mesentery of Fallopian tube
What covers medial surface if ovary?
Uterine tube
What is the ovarian bursa?
Peritoneal recess between medial ovary and mesosalpinx
Path of sensory fibres from uterine body and fundus
Travel with sympathetics via hypogastric plexus to T11-12
Path of sensory fibres from cervix and upper vagina
Via pelvic splanchnics to S2,3,4
Path of sensory fibres from lower vagina and perineum
Via pudenadal nerve to S2,3,4
Origin of motor fibres to uterine body and fundus
Sympathetic from superior hypogastric plexus
Origin of motor fibres to lower segment of uterus and upper vagina
Parasympathetic origin via pelvic splanchnics
Origin of motor fibres to lower vagina and perineum
Somatic via pudendal nerve
Position of base of breast
Number of lobules
Rib 2-6 overlying investing fascia of pec major
20, each with a lactiferous duct in radial arrangement opening around nipple
Breast composition
Non pregnant
Pregnant
Fat
Increased glandular tissue
Sacrum is made of _ vertebrae
5
Pudendal nerve roots
Regions traversed by perineal nerve
Branches
S2-4
Sacral, Gluteal, pudendal canal, deep perineal space, superficial perineal space
Dorsal nerve of penis/clitoris, perineal nerve, inferior rectal nerve
Extent of pudendal canal
Begins at posterior edge of ischiorectal fossa
Ends at posterior edge of urogenital diaphragm
Borders of deep perineal space
Fascial plane between superior and inferior fasciae of UGD
Sacrum contains _ foramen
4
Female urethra length
5cm
Hip bone is made of _ bones
3
There are _ tendinous insertions of rectus abdominis
3
External oblique arises from lower _ ribs
8
Rectus sheath has _ vessels
4
Origin of pelvic splanchnic nerves
S2-4
Innervation of piriformis
S1-2
Sciatic nerve originates from
L4-S3
Pudendal nerve originates from
Same as which other nerves
S2-4
Pelvic splanchnic
Are pelvic nerves autonomic?
Yes
Does sacral plexus give off pudendal nerve
Yes
Obturator nerve roots
L2-4
Lymphatic drainage of ureters
Internal iliacs
How does obturator nerve exit pelvis?
Obturator canal
Which vessel supplies pelvic ureters?
Superior vesical artery
Which structure do ureters cross on entering pelvis
Bifurcation of common iliacs
Which muscle compresses the vagina?
Bulbospongiosus
Sympathetic innervation to vagina is from?
Lumbar splanchnics
Lymphatic drainage of cervix
Internal iliacs
Which ligaments provide major support for uterus?
Cardinal
Which wall of vagina is longer?
Posterior by 3cm
Which muscle constricts lower part of vagina?
Levator ani
Vaginal length
7-10cm
Support of lower third of vagina
Levator fibres and pubococcygeous (fibres of Luschka)
Support of middle third of vagina
Fibrous attachment to arcuate line
Support of upper third of vagina
Cardinal and utero sacral ligaments as endo pelvic fascia is continuous with them
Nerve supply to lower 2/3 vagina
Mainly somatic
Pudendal nerve to skin and subcutaneous tissue
Nerve supply to upper vagina
Mainly visceral from inferior hypogastric plexus
Location of Bartholin’s glands
Vestibule 5 + 7 o’clock position
Location of Skenes’s glands
Peri urethral
Peritoneal covering of rectum
Anterior and lateral in upper third
Anterior in middle third
None in lower third
Rectal blood supply
Superior middle and inferior rectal arteries
Superior pierces muscular wall and continues in submucosa to anastomose with inferior
Middle supplies posterior rectum
Shape of obturator foramen in female
Triangular
cf ovoid in male
T/F iliac blades more vertical in male
F
Supra public arch angle in male
50-60 deg
Supra public arch angle in female
80-85 deg
Which sex has narrower greater sciatic notch
Male
Peritoneum of Fallopian tube
Completely covered except narrow inferior strip - upper part of broad ligament or mesosalpinx
Fallopian tube lining
Ciliated cells interspersed with secretory (peg) cells
Part of Fallopian tube with thickest muscle layer
Isthmus
Part of Fallopian tube with thinnest muscle layer
Infundibulum
Relation of round ligament to tube
Commences in front and below
T/F Ovarian ligament attaches lateral to pelvic wall
F
Lies beneath posterior layer of broad ligament
Passes from medial pole of ovary to uterus just below tube entry point
Path of ovarian artery
Aorta just below renals
Down on anterior surface of psoas to pelvic brim
Crosses in front of ureter
Passes into infundibulopelvic fold of broad ligament
How do ovarian vessels enter hilum?
Through mesovarium
Which structures in female are homologous to gubernaculum testis
Ovarian and round ligament together
Which structure dies ureter lie in front of at pelvic brim
Bifurcation of common iliac