Pelvis Flashcards
How long are the ureters
25cm
The point where the renal pelvis narrows to form the ureter is known as what
Ureteropelvic junction
The ureters cross the bifurcation of which main arteries
Common iliac arteries
Which arteries does the ureters run under in the pelvis
Ovarian arteries in females
In men what structure crosses the ureters anteriorly
Vas deferens
Which embryological structure does the ureter develop from
The ureteric bud from the mesonephric duct
What is the blood supply to the abdominal ureter
renal artery, testicular/ovarian artery, and ureteral branches directly from the abdominal aorta
What is the blood supply to the pelvic ureter
Superior and inferior vesical arteries
Where are the 3 narrowings of the ureter
Uretopelvic junction
Pelvic brim
Where the ureter enters the bladder
What connects the bladder to the umbilicus
Median umbilical ligament - connects the apex of the bladder to the umbilicus
It is a remnant of the urachus
What is the trigone of the bladder
A triangular area located at the fundus of the bladder
Marks the orifices where the left and right ureter enter the bladder
What is the specialised smooth muscle that the bladder is composed of
Detrusor muscle
Describe the internal urethral sphincter in men
Smooth muscle fibres under autonomic control, prevents seminal regurgitation during ejaculation
Describe the internal urethral sphincter in women
Functional sphincter
Formed by the anatomy of the bladder neck and the proximal urethra
Describe the external urethral sphincter
Composed of skeletal muscle
Under voluntary control
What is the arterial supply of the bladder
Superior vesical artery - branch of the internal iliac artery
Supplemented in males - inferior vesical artery
Supplemented in females - vaginal arteries
What is the lymphatic drainage of the bladder
Superolateral aspect - external iliac lymph nodes
Neck and fundus - internal iliac, sacral, common iliac nodes
What is the sympathetic supply of the bladder and what is its action
Hypogastric nerve
Relaxation of the detrusor muscle, allowing urinary retention
What is the parasympathetic supply of the bladder and what is its action
Pelvic nerve
Contraction of the detrusor muscle, allowing micturition
What is the somatic innervation of the bladder and what is its action
Pudendal nerve
Innervates the external urethral sphincter, allowing control over micturition
Describe the bladder stretch reflex
Primitive reflex
Bladder wall stretch results in micutration - this is overridden in toilet training
What is the epithelial lining of the urethra
Stratified columnar epithelium
How long is the male urethra
15-20cm
What are the 3 sections of the male urethra
Prostatic
Membranous
Penile
The prostatic urethra has what 2 ducts opening into it
Ejaculatory ducts
Prostatic ducts
Which is the widest part of the male urethra
Prostatic urethra
In which part of the male urethra is the external urethral sphincter found
Membranous urethra
What ducts open into the penile urethra
Bulbourethral glands
What is the arterial supply of the prostatic urethra
Inferior vesical artery (branch of the internal iliac artery)
What is the arterial supply of the membranous urethra
Bulbourethral artery (branch of internal pudendal artery)
What is the arterial supply of the penile urethra
Branches of the internal pudendal artery
What is the lymphatic drainage of the penile urethra
Prostatic and membranous portions - drain to the obturator and internal iliac nodes
Penile portion - inguinal nodes
How long is the female urethra
4cm
Which glands mark the distal end of the female urethra
Skene’s glands
What is the arterial supply of the female urethra
Internal pudendal arteries
Vaginal arteries
Inferior vesical branches of the vaginal arteries
What is lymphatic drainage of the female urethra
Proximal urethra - Internal iliac nodes
Distal urethra - superficial inguinal lymph nodes
What are the 3 paired muscles that make up levator ani muscles
Pubococcygeus
Puborectalis
Iliococcygeus.
Which muscle is the most important in maintaining faecal incontinence
Puborectalis
How does puborectalis maintain faecal incontinence
Creates the anorectal angle which contributes to faecal continence
It is voluntarily inhibited during defecation.
What is the nerve supply to levator ani muscle group
Nerve to levator ani
Pudendal nerve
Which muscle creates the bulk of the levator ani
Pubococcygeus
Which muscle form the posterolateral part of the levator ani
Iliococcygeus
What is the action of pubococcygeus
Stability and support of abdominal and pelvic organs
What is the action of iliococcygeus
Elevates the pelvic floor and anorectal canal
Where is coccygeus located
Posterior to the levator ani muscle group
A small triangular muscle
What is the function of the pelvic floor
Support of abdominopelvic viscera
Resistance to increase intra-pelvic/abdominal pressure
Urinary and faecal incontinence
What are the 2 holes in pelvic floor
Urogenital sinus
Rectal hiatus
What are the anatomical borders of the perineum
Anterior - pubic symphysis
Posterior - tip of coccyx
Lateral - inferior pubic rami and inferior ischial rami
Roof - pelvic floor
Base - skin and fascia
The perineum is split into which two spaces
Anterior urogenital triangle
Posterior anal triangle
What are the boundaries of the anal triangle
Coccyx
Sacrotuberous ligaments
A theoretical line between the ischial tuberosities
What are the contents of the anal triangle
Anal arpeture - opening of the anus
External anal sphincter
Ischioanal fossae (2, located either side of the anus)
What do the ischioanal fossa allow
Allow for expansion of the anal canal during defecation
Which nerve is found in the anal triangle
Pudendal nerve
What are the boundaries of the urogenital triangle
Pubic symphysis
Ischiopubic rami
A theorectical line between the two ischial tuberosities.
From deep to superficial what are the layers of the urogenital triangle
Deep perineal pouch
Perineal pouch
Superficial perineal pouch
Perineal fascia
Skin
What is the deep perineal pouch
A potential space between the deep fascia of the pelvic floor superiorly and the perineal membrane inferiorly
In females what is contained in the deep perineal pouch
Urethral
External urethral sphincter
Vagina
In males what is contained in the deep perineal pouch
Bulbourethral glands
Deep transverse perineal muscles
What is the function of the perineal membrane
Provide attachments for the muscles of the external genitalia
What is the superficial perineal pouch
A potential space between the perineal membrane superiorly and the superficial perineal fascia inferiorly
What is contained in the superficial perineal pouch
Erectile tissues that form the penis and clitoris, and three muscles – the ischiocavernosus, bulbospongiosus and superficial transverse perineal muscles.
What are the two components of the perineal fascia
Deep fascia
Superficial fascia
What does the deep perineal fascia cover
The superficial perineal muscles and protruding structures (penis and clitoris)
How many layers of superficial perineal fascia is there
2
What is the superficial layer of the superficial perineal fascia continuous with
Camper’s fascia of the anterior abdominal wall
What is the deep layer of the superficial perineal fascia continuous with
Scarpa’s fascia of the abdominal wall
What attaches to the perineal body
Levator ani
Bulbospongiosus muscle.
Superficial and deep transverse perineal muscles
External anal sphincter muscle
External urethral sphincter muscle fibres
What is the neurovascular supply to the perineal body
Pudendal nerve
Internal pudendal artery
What travels in Alcock’s canal
Pudendal nerve, artery and vein
What separates the greater and lesser sciatic foramen
Sacrospinous ligament
What are the borders of the greater sciatic foramen
Superior - anterior sacroiliac ligament
Posteromedial - sacrotuberous ligament
Anterolateral - greater sciatic notch of ileum
Inferior - sacrospinous ligament and ischial spine
What passes through the greater sciatic foramen
Superior gluteal artery and vein
Superior gluteal nerve
Sciatic nerve
Pudendal nerve
Inferior gluteal artery and vein
Inferior gluteal nerve
Posterior femoral cutaneous nerve
Nerve to obturator internus
Nerve to quadratus femoris
What are the borders of the lesser sciatic foreman
Superior - sacrospinous ligament and ischial spine
Anterior - ischial spine, lesser sciatic notch and ischial tuberosity
Posterior - sacrotuberous ligament
What passes through the lesser sciatic foramen
Internal pudendal artery and vein
Pudendal nerve
Obturator internus tendon
Nerve to obturator internus
Which nerve leaves the great sciatic Forman and re-enters the lesser sciatic foramen
Pudendal nerve
Which nerve leaves the great sciatic Forman and re-enters the lesser sciatic foramen
Pudendal nerve
Which nerve roots form the sacral plexus
Anterior rami of S1-S4
What are the 5 main main branches of the sacral plexus
Sciatic nerve
Pudendal nerve
Superior gluteal nerve
Inferior gluteal nerve
Posterior femoral cutaneous nerve
What are the nerve roots of the pudendal nerve
S2, S3, S4
What is the sensory function of the pudendal nerve
Innervates the external genitalia of both sexes and the skin around the anus, anal canal and perineum
What is the motor function of the pudendal nerve
Bulbospongiosus
Ischiocavernosus
Levator ani muscles (including the iliococcygeus, pubococcygeus and puborectalis)
External urethral sphincter
external anal sphincter
The inferior rectal nerve is a branch of which nerve and what does it innervate
Branch of pudendal nerve
Innervates the perianal skin and lower third of the anal canal
The perineal nerve is a branch of which nerve and what does it innervate
Branch of pudendal nerve
Inervates the skin of the perineum, labia minora and majora or posterior scrotum.
The dorsal nerve of the penis/ dorsal nerve of the clitoris is a branch of which nerve and what does it innervate
innervates the skin of the penis or clitoris. Thus, responsible for the afferent component of penile and clitoral erection.
What is the major artery of the pelvis
Internal iliac artery
Where does the internal iliac artery divide into anterior and posterior trunks
At the superior border of the greater sciatic foramen
What are the branches of the internal iliac artery
Obturator artery
Umbilical artery
Inferior vesical artery
Vaginal artery
Uterine artery
Middle rectal artery
What are the branches of the anterior trunk of the internal iliac artery
Obturator artery
Umbilical artery
Inferior vesical artery
Vaginal artery
Uterine artery
Middle rectal artery
Internal pudendal artery
Inferior gluteal artery
What are the branches of the posterior trunk of the internal iliac artery
Iliolumbar artery
Lateral sacral arteries
Superior gluteal artery
What are the minor arteries of the pelvis
Gonoadal arteries
Median sacral arteru
Superior rectal artery
The external iliac vein is a continuation of which vein, and what veins drain into it
Continuation of the femoral vein - from the point of the inguinal ligament
Receives the inferior epigastric and the deep circumflex iliac veins
Which veins drain into the internal iliac veins
Superior and inferior gluteal veins
Internal pudendal vein
Obturator vein
Lateral sacral veins
Middle rectal vein
Vesical veins
Uterine and vaginal veins
Which vessels drain directly into the common iliac vein
Iliolumbar veins
Middle sacral vein
At what level do the common iliacs combine to form the IVC
L5
What is pelvic congestion syndrome
Intense pain in the pelvis secondary to venous congestion following valve failure, usually occurs in ovarian veins
What 3 bones make up the hip
Ilium
Pubis
Ischium
What forms the pelvic girdle
The 2 hip bones
Sacrum
Coccyx
What are the 4 articulations of the pelvis
Sacroiliac joints
Sacrococcygeal symphysis
Pubic symphysis
What are the functions of the pelvis
Transfer weight from axial skeleton
Provides attachment for muscles and ligaments
Contains and protects the abdominopelvic viscera
What is the greater pelvis
Also known as the false pelvis
Located superiorly
Gives support to the lower abdominal viscera - the sigmoid and the ileum
What is the lesser pelvis
Also known as the true pelvis
Located inferiorly
Forms the pelvic cavity and holds the pelvic viscera
What is the pelvic inlet
The junction between the greater and lesser pelvis
What is the pelvic brim
The outer bony edges of the pelvic inlet
What are the borders of the pelvic inlet
Posterior - sacral promontory and sacral wings (ala)
Lateral - arcuate line on the inner surface of the ileum and the pectineal line on the superior pubic ramis
Anterior - pubic symphysis
What is the linea terminalis of the pelvis
The combined pectineal line, arcuate line and sacral promontory
What does the iliopectineal line represent
This represents the lateral border of the pelvic inlet.
What is the iliopectineal line
The combined arcuate and pectineal lines
What are the borders of the pelvic outlet
Posterior - tip of the coccyx
Lateral - The ischial tuberosities and inferior margin of the sacrotuberous ligament
Anterior - the pubic arch
How is the gynaeoid pelvis different from the android pelvis
Wider and broader structure, with an oval shaped inlet - compared to a heart shaped inlet
A greater angled sub-pubic arch
What are the 6 surfaces of the sacrum
Base - articulates with L5
Apex - articulates with the coccyx
2 x Auricular surfaces - lateral surfaces which articulate with the posterior surface of the ilium
Anterior and posterior surfaces
How many crests are found on the dorsal surface of the sacrum
Median sacral crest
2 x intermediate sacral crest
2 x lateral sacral crest
What attaches to the median sacral crest of the sacrum
Supraspinous ligament
What forms the median sacral crest of the sacrum
Formed by the fusion of the spinous processes of the first 3 sacral vertebrae
What attaches to the intermediate sacral crest
Posterior sacroiliac ligaments
What attaches to the lateral sacral crest
Posterior sacroiliac ligaments
Sacrotuberous ligament
At what age does fusion of the sacral vertebrae begin
20
In which sex is the sacral promontory less prominent
Females
Which muscles attach to the anterior surface of the sacrum
Piriformis
Coccygeus
Iliacus
Which muscles attach to the posterior surface of the sacrum
Multifidus lumborum
Erector spinae
At what level does the dural sac terminate
S2
What is the blood supply to the sacrum
Median sacral artery - posterior branch of the aorta
Lateral sacral arteries - bilateral vessels from the internal iliacds
What embryological structure does the coccyx arise from
Caudal eminence
What is the sacrococcygeal symphysis
The fibrocartilaginous joint where the coccyx articulates with the sacrum
Which 5 ligaments support the sacrococcygeal symphysis
Anterior sacrococcygeal ligament
Deep posterior sacrococcygeal ligament
Superficial posterior sacrococcygeal ligament
Lateral sacroccygeal ligament
Interarticular ligaments
The anterior sarcococcygeal ligament is a continuation of which ligament
Anterior longitudinal ligament of the spine
Connects the anterior aspect of the vertebral bodies
Which muscles attach to the coccyx
Gluteus maximus
Levator ani muscle
Anococcygeal raphe
What is a sacrococcygeal teratoma
Tumour of the coccyx
most common presenting tumour of a newborn
What type of joint is the sacroiliac joint
Synovial
Which 3 main ligaments reinforced
Interosseous sacroiliac ligament
Posterior sacroiliac ligament
Anterior sacroiliac ligament
Which is the strongest of the sacroiliac ligaments
Interosseous sacroiliac ligament
What is the arterial supply of the sacroiliac joint
Iliolumbar arteries
Median and lateral sacral arteries
What is the nervous innervation of the sacroiliac joint
Sacral spinal nerves
