Anatomy Pelvis, femoral triangle and inguinal canal Flashcards
What makes up the pelvic floor?
Levator Ani + coccygeus
What does Levator ani consist off?
Puborectalis
Pubococcygeus
Illeococcygeus
What are the attachments of coccygeus? Which ligament does it follow?
From coccyx to Ischial spines
Sacrospinous.
What is the ovarian pedicle?
The ovarian pedicle is made up part of the fallopian tube, mesovarium, ovarian ligament, and ovarian blood vessels
What landmark of USS marks the fixation of the ovarian pedicle?
Origins of internal iliac vessels, as they pass into the true pelvis and run medial to obturator interns.
Where does the ureter run in relation to
1) Ovary/ligament of ovary
2) Internal iliac vessels
1) Posterior
2) Anterior
For USS why should a patient drink 1 litre of water 2 hours before the scan?
A full bladder displaces small bowel loops and straightens the uterus in comparison to the cervix (no longer anteverted).
On USS what colour/form does the endometrium and myometrium appear.
1) Endometrium - bright, centrally, thickness changes depending on menstrual cycle
2) Myometrium - uniform low echogenicity
What are the 3 ligaments suspending the ovary?
- Suspensory ligament (to lateral wall, containing ovarian vessels)
- Broad ligament by the mesovarium
- Ovarian ligament (from uterus)
What 3 bones make up the hip bone?
Ilium, ischium & pubis
The pelvic inlet marks the boundary between the greater pelvis and lesser pelvis.
What are the boundaries of the pelvic inlet?
Posterior – sacral promontory (the superior portion of the sacrum) and sacral wings (ala).
Lateral – arcuate line on the inner surface of the ilium, and the pectineal line on the superior pubic ramus.
Anterior – pubic symphysis.
What marks the boundaries of pelvic outlet (the inferior boarder of the lesser (true) pelvis?
Posterior: The tip of the coccyx
Lateral: The ischial tuberosities and the inferior margin of the sacrotuberous ligament
Anterior: The pubic arch (the inferior border of the ischiopubic rami).
Gives a diamond shape.
During labour, how does the fetal head move to compromise the change in oval shape of the pelvic inlet and rhomboid pelvic outlet?
Fetal head (A-P) enters pelvic inlet transverse and then as it enters the pelvic outlet changes to anteroposteriorly.
Which ligaments convert the sciatic notches into foramen. What are they called and what are their attachments?
Sacrotuberous ligament: Fan like sacrum to ischial tuberosity
Sacrospinous ligament: outer edge of the sacrum and coccyx, and the tip of the ligament attaches to the spine of the ischium
Where does the rectus muscles run in relation to the aponeurosis of external oblique, internal oblique and transverse abdominis? Where does this arrangement change and what to?
Above midway between pubic symphysis and umbilicus
- Rectus muscles run in a split int the apeunorsis of internal oblique, with ap, external oblique and 1/2 ap internal oblique anterior and, 1/2 ap internal oblique and transverse abdominus posterior
Above midway between pubic symphysis and umbilicus
- Rectus muscle run posterior to all 3 apeurosis of the 3 anterior abdominal wall muscles. On the transversalis fascia runs posterior.
What is the line name of the point the transverse abdominis apeurnosis changes from posterior to anterior of rectus muscles?
What vessel gains access to rectus sheets at this point?
Arcuate line
Inferior epigastric artery gains access to the anterior abdominal wall.
The inferior epigastric artery is a branch of which artery?
Which arteries does it anastomose with?
External iliac artery. Inclines medially & passes through the transvarlis fascia.
Anastomosis with superior epigastric artery above umbilicus and lower posterior intercostal arteries.
Where does the inferior epigastric vessels (artery & vein) pass in relation to the inguinal canal?
Medial margin of deep inguinal ring
During laparoscopic surgery how to you avoid inserting the lateral ports into the epigastric vessels (causing major haemorrhage)
Identify the medial umbilical ligament (clearly seen at laparoscopy). The vessels run lateral to this.
What is the median (middle) umbilical ligament a remnant off?
Foetal urachus
What is the medial (just lateral to median) umbilical ligament a remnant off?
Umbilical arteries
What is the ligamentum teres a remnant off?
Where does it run
Umbilical vein
Ascends from umbilicus to the liver between the two layers of the falciform ligament.
If haemostasis of the inferior epigastric muscles if not achieved in caesarean section what complication can occur?
Rectus sheath haematoma
In which neurovascular plain do the lower six intercostal nerves supplying the muscles of the abdomdinal wall and skin (dermatome) run?
Between transversus and internal oblique
Where does the round ligament uterus run?
Starts at uterine horn, exists pelvis and deep inguinal ring, passes through the inguinal canal and exists throughout the superficial inguinal ring to attach to the labia majora where it forms fibres with the mons pubis.
What is the anterior boarder of the inguinal canal?
Apoeunrosis of external oblique.
In lateral 1/3 - muscles fbres of internal oblique (specifically opposite deep inguinal ring)
Medial 1/3 Superficial inguinal ring
What is the superior boarder of the inguinal canal
Musculoaponeurotic arches of internal oblique and transverse abdominal Transversalis fascia (Medial crus of aponeurosis of external oblique)
What is the posterior boarder of the inguinal canal?
Transvarlis facia Conjoint tendon (common aponeurosis of internal oblique and transvarlis abdominus that inserts into the crest of pubis and pectineal line, immediately behind the superficial ring. Lateral 1/3 deep inguinal ring
The inferior boarder of the inguinal ring
Inguinal ligament
Medial 1/3 pectinal ligament
What is the location of the deep inguinal ring
Midway between anterior superior iliac spine and pubic symphysis is an opening in the trasversalis facia
Where to the inferior epigastric vessels run in relation to the deep inguinal ring?
Immediately medial.
How is the deep inguinal ring closed in pregnancy
Increased intraabdominal pressure contracts the internal oblique fibres.
What is the location of the superficial inguinal ring?
Above the inguinal ligament just lateral to the pubic tubercle. Made in opening of aponeurosis of external oblique/
What structures run in the inguinal canal in females
Round ligament
Ilioinguinal nerve
What does the ilioinguinal nerve supply?
Damage to the ilioinguinal nerve can increase risk of which condition?
Skin of medial aspect of thigh, skin over mons pubis, and labia majora.
Supplies muscle fibres of internal oblique and transversus abdominis.
Increased risk of direct hernia due to damages conjoint tendon.
What are the medial, lateral, superior, roof and floor of the femoral triangle.
Medial boarder: Lateral boarder of abductor longus
Lateral boarder: Medial boarder of sartorus
Superior: Inguinal ligament
Roof: Facia lata
Floor: Ileopsoas (lateral), pectineus (medial)
What are the contents of the femoral triangle
Femoral nerve artery and vein
Deep inguinal ligaments
What vein joins with the femoral vein at an opening in the fascia late?
Great saphenous vein. Saphenous opening
What is the retro-inguinal space.
What runs within this compartment
Passage between trunk and and the lower limb. Below the inguinal ligament
Lateral: Ileopsoas & femoral nerve
Medial: Femoral artery, vein and lymphatic vessels
What are femoral hernias are why are they more common in females.
Hernation of abdominal contents through the retro-inguinal space. The femoral ring is larger in females because of great width of the female pelvis and smaller femoral vessels.
What is pubovaginalis
Fibres meeting from the 2 levator muscles, running A-P from body of pubis to anterior surface of the coccyx. Around the vagina acts as a supplementary sphincter.
At which level does the abdominal aorta split into right and left common iliac arteries?
L4/L5
At what level does the right or left common iliac divide into an internal and external branch?
What structure runs anteriorly to the internal iliac artery just after point of bifurcation.
Level of sacroiliac joint.
Ureters as they enter the pelvis, ovarian artery + veins, fimbriated end of uterine tube + ovary.
What is the course of the external iliac artery
Continues towards thigh, on medial aspect of psoas major and passed into the thigh under the inguinal ligament midway between the ACIS and pubic symphysis.
At what level does the internal iliac artery branch into and anterior and posterior division
Upper margin of greater sciatic notch
What are the terminal branches of the poster branch of the internal iliac artery?
Superior gluteal artery
Lateral sacral artery
Iliolumbar artery
How does the superior gluteal artery leave the pelvis?
Via the greater sciatic foreman above piriformis.
Where do the internal iliac veins run in relation to the internal iliac arteries
Posterior
How does the obturator artery & vein gain access to the anterior compartment of the thigh
Via the obturator canal a foramen in the obturator membrane
How are the obliterated umbilical artery and the superior vesicle arteries related?
The umbilical artery remains patent and gives rise to the superior vesicle artery supply the superior aspect of the bladder. The distal end has become fibrous and as it runs on either side of the inner surface towards the umbilicus forms the medial umbilical ligament.
What is the course of the uterine artery
A branch of the anterior branch of the internal iliac artery. It runs medially on fascia overlaying the levator ani, reaching the junction with the cervix.
In its course turning medially in crosses the ureter (giving it some blood supply). It ascends in the broad ligament of the uterus (very tortuous) until the uterine tube where it turns laterally and courses in the mesovsrium to anastomose with branches of the ovarian artery.
What does the uterine artery supply
Uterine muscle, cervix, round ligament of uterus, vagina (through vaginal arteries), related bladder & rectum.
What does the middle rectal artery (branch on anterior division) supply? Is it always present
Muscle wall of lower part of rectum
Elusive present roughly 60%
What does the inferior vesical artery (branch on anterior division) supply?
Fundus of bladder, distal part of ureter
What is the course of the internal pudendal artery (branch on anterior division)? What does it supply?
Leaves the pelvis in greater sciatic foramen below piriformis (above coccyges), then hooks around the ischial spine and enters the perineum via the lesser sciatic foramen to enter the pudendal canal.
Where does the pudendal canal run?
Lateral wall of the ischioanal fossa.
When is contained within the pudendal canal
Pudendal artery and 2 veins - gives off inferior rectal artery & perineal artery Pudendal nerve (which splits into the dorsal nerve of clitoris and perineal nerve)
What does the inferior gluteal artery (branch on anterior internal iliac artery) supply & what route does it take?
(Note difference from superior gluteal artery which is branch of the external branch).
Supplies Gluteal region and posterior aspect of thigh.
Pass out of greater sciatic foremen below piriformis.
What is the general lymph drainage from lymph with the pelvis.
Either from intestinal lymphatic trunk or lumbar lymphatic trunk which feeds into the cisterna chyli which feeds into the thoracic duct which feed into the internal jugular vein
What 2 major plexus provide innervation to the pelvis
Lumbar Plexus and Sacral Plexus
What are the nerve roots of the lumbar plexus
T12/L1-L4
Name as many arteries form from the lumbar plexus
Iliohypogastric nerve Ilioinguinal nerve Genitofemoral nerve Lateral femoral cutaneous nerve Femoral nerve Obturator nerve
What muscle does the femoral nerve run along?
Between psoas major and iliacus until it reaches the inguinal ligament where it is related to anterior surface of iliopsoas
Why can ovarian pain be referred to the medial aspect of the thigh?
As the obturator nerve supplies the parietal perineum near the ovary, as it passed medially and out of the obturator canal to supply the medial aspect of the thigh.
When using a large pfannenstiel incision which nerve do you risk damage and what symptoms does it cause?
Gentiofemoral nerve - paresthesia over anterior thigh and groin.
What units the lumbar and sacral plexus, what is its nerve roots
Lumbosacral trunk L4-L5
What is nerve roots of the sacral plexus
Lumbosacral trunk L4-L5 and S1-S4
Names as many nerves formed by the sacral plexus
superior and inferior gluteal nerve Sciatic nerve (L4-S2) Pudendal nerve (S3-S4)
Contents of greater sciatic foramen above piriformis
Superior gluteal vessels & nerve
Contents of greater sciatic foramen below piriformis
Inferior gluteal vessels Internal pudendal vessels Inferior gluteal nerve pudendal nerve Sciatic nerve posterior femoral cutaneous nerve
What muscles does the sacral plexus supply in the pelvis
Piriformis and levator ani
What is the nerve root of the pudenal nerve?
What is its route?
What does it supply?
What branches does it give off & what is its supply and what is its route
S2-S4
Leaves greater sciatic foreamen, hooks around ischial spine (deep to sacrospinous ligament), enters lesser sciatic foreamen enters pudenal canal.
Innervates vulva and perineum
Gives off inferior rectal nerve which crosses sischioanal fossa to supply the external anal sphincter & perianal skin.
Pudendal nerve splits into perineal nerve and dorsal nerve of clitoris.
How is a pudendal nerve block achieved and what is it used for.
VE palpate ischial spine, inject through sacrospinous ligament.
For instrumental deliveries.
What are the 2 main types of autonomic ganglia?
Pre-veterbral (aortic) associated with each unpaid branches of the aorta e.g. celiac ganglion.
Para-veterbral (aortic)- connect series of ganglion either side of the spinal column. Sympathetic chain.
Receive pre-ganglionic fibres from the autonomic nervous system.
What does splanchnic mean?
An autonomic fibre passing to organs of the trunk- can be para or sympathetic in nature
What is an autonomic plexus
A collection of autonomic fibres
Describe the sympathetic pre-ganglionic fibres contributing to the abdomen? Where do they synapse. Is this the same as the thorax?
The sympathetic fibres from the thoroco/lumbar nerve fibres (cell body in grey horn within spinal cord), sends pre ganglionic fibres towards the autonomic ganglia.
Thorax - autonomic ganglia in sympathetic chain.
Abdomen - pass through sympathetic chain to pre-veterbral ganglia (celiac, superior mesenteric or inferior mesenteric or superior hypogastric plexus)
Where do the parasympathetic pre-ganglionic fibres synapse?
Comes down via vagus nerve, but does not synapse until the target organ.
Where is the superior hypogastric plexus located?
What does it split into?
Bifurcation of the aorta, contains para + sympathetic fibres.
The superior hypogastric plexus splits into 2 (right and left) hypogastric nerves.
What are the nerve root of the pelvic splanchnic nerve? What type of nerve fibres does it contain>
S2-S4
Parasympathetic
As the splanchnic nerves and the fibres from the hypogastric nerve meet - what do they form?
The inferior hypogastric plexus.
Summarise the autonomic nerve supply to the anal canal. What are the nerve roots.
Sympathetic - from the lumbar (L1-L3) splanchnic nerves, via the superior hypogastric plexus, which communicates with the inferior hypogastric plexus via the hypogastric nerve.
Parasympathetic from pelvic splanchnic nerves (S2-S4) via the right and left inferior hypogastric plexus.
Described the somatic innervation to the external anal sphincter (below the pectinate line)
Inferior rectal nerve (a branch from the pudendal nerve) S2-S4 (autonomic fibres)
Where does the uterovaginal plexus run?
Along the uterine artery. It is an extension of the inferior hypogastric plexus which also supplies the ovarian plexus.
Explain all the autonomic fibres within the inferior hypogastric plexus and their nerve roots
Post-ganglionic sympathetic fibres T10-L2, of thoracolumbar spinal cord.
Pre-ganglionic parasympathetic fibres from the pelvic splanchnic nerve S2-S4
