Anatomy Practical 1 Flashcards
(102 cards)
When the pelvis is correctly positioned where is the ASIS in relation to the pubic symphysis? Where is the inguinal ligament>
Vertical line above
Inguinal ligament perpendicular to floor
What are the 3 apertures in the pelvic wall?
Obturator Canal - artery, vein nerve
Greater Sciatic Foramen - Piriformis, Sciatic nerve, pudendal nerve, sup. and inf. gluteal NAV
Lesser Sciatic Foramen - pudendal and tendon of obturator internus
What makes up the anterior wall of the pelvic inlet?
Pubic bones - pubic symphysis
What makes up the lateral wall of the pelvic inlet?
Sacrospinous ligament - covered by coccygeus and obturator internus muscles (lateral rotator of thigh originating from internal aspect of obturator foramen passing to femur greater trochanter)
What makes up the posterior wall of the pelvic inlet?
Sacrum coccyx, piriformis muscles and covering of fascia
What makes up the inferior wall of the pelvic inlet?
Pelvic floor
Which nerves form the sacral plexus?
S1-S4 join lumbosacral L4,5
Lies on anterior surface of piriformis muscle
What are the branches of the pelvic part of the sympathetic trunk?
- gray rami communicantes (join spinal nerves, distributed to periphery)
- fibres to join hypogastric plexus
Where is the superior hypogastric plexus?
Anterior to sacral promontory
What does the superior hypogastric plexus contain?
Sympathetic, sacral PS and visceral afferent fibres
Forms R. and L. hypogastric nerves
Where does the inferior hypogastric plexus lie?
On either side of the rectum
Formed by hypogastric nerve from superior plexus and pelvic splanchnic nerves
Where does lymph from sigmoidal colon travel?
Inferior mesenteric nodes along IMA
What is the nerve supply of the sigmoid?
Autonomic from hypogastric plexus
What is the blood supply to the sigmoid?
IMA
What is a volvulus?
Sigmoid colon rotate around its mesentery
- may correct spontaneously or rotation may continue until blood supply to sigmoid completely shut off
Where does the rectum begin?
- anterior to S3
- inferiorly passes ending at tip of coccyx pierces pelvic floor and continuous with anal canal
- lower rectum dilated = rectal ampulla
Which parts of the rectum does the peritoneum cover?
Anterior and lateral surfaces of first 1/3
Anterior surface of middle 1/3
Lower devoid
What produces the anorectal angle?
Puborectalis portion of levator ani muscle forms sling at junction of rectum with anal canal pulling this part of bowel forward
What is the blood supply to the rectum?
Superior middle and inferior rectal arteries
What forms the superior rectal artery?
IMA
What forms the middle rectal artery?
IIA (internal iliac artery)
What forms the inferior rectal artery?
Pudendal artery
Anastomoses with middle rectal artery at anorectal junction
Where does the superior rectal vein drain?
Hepatic portal vein
Where do the middle and inferior rectal veins drain?
Caval system - internal iliac