Pelvis & perineum Flashcards
What does the external iliac artery give rise to?
inferior epigastric artery immediately above the inguinal ligament and deep iliac circumflex (behind inguinal ligament) and anastomosasing with lateral femoral circumflex
What are the branches of the inferior epigastric artery?
external spermatic (cremasteric), pubic (anastamose with obturator), and muscular (ab muscles, + anastomoses with superficial epigastric)
What does the femoral artery give rise to?
superficial epigastric artery to anastamose with inferior epigastric and superficial external pudendal (skin of lower abdomen, penis, scrotum, labium majorus)
What is the venous drainage of the pelvic area?
lumbar veins -> IVC
deep circumflex -> external iliac
inferior epi, superficial epi, superficial external pudendal drain into great saphenous vein
What’s the inguinal canal?
4 cm long, parallel to inguinal ligament that has a multitude of things that travel through the canal (testis, ductus deferens, blood, lymph, nerves)
How is the inguinal canal formed?
aponeuroses of 3 ab muscles - external oblique, internal oblique, tranversus abdominis/ tranversilas fascia that begins at deep (internal) inguinal ring and ends at superficial (external) ring
What does the inguinal canal transmit?
spermatic cord, round ligament of uterus, ilioinguinal nerve
What is the superficial ring mostly made of?
external oblique
What is the internal ring mostly made of?
transversalis fascia
What is the inguinal ligment?
thick enrolled lower border of external oblique muscle
What is the inguinal region?
area between anterior superior iliac spine and pubic tubercle Between ASIS and pubic tubercle
What is the deep (internal) inguinal ring?
where the transversalis fascia pouches out creating an opening above the inguinal ligament, lateral to inferior epigastric artery
What’s the floor of the internal inguinal ring?
lower margin of the inguinal ligament
What’s the roof of the inguinal ring?
internal oblique and transversus
Where is the superficial (external) inguinal ring?
above pubic tubercle, lateral crus attaches there and medial crus attaches to rectus sheath
What is processus vaginalis?
outpouching of peritoneum in fetus at 12 weeks, passing through fascia and adding layers of ext, oblique to scrotum
When do the testes start to move behind processus vaginalis in the embryo?
7th month
How are testes formed?
posterior wall deep to transversalis fascia and peritonium where they migrate to inguinal region, pass through wall and to scrotum
What is the gubernaculum?
what becomes the scrotal ligament
Do the ductus deferens/testis and processus vaginalis have the same coverings?
yes, all the way to the scrotum
What is an ovary in embryo?
never leaving the abdomen, the round ligament passes through inguinal canal behind processus vaginalis to end in labium majus
What happens if part of the processus vaginalis fails to obliterate at birth?
more likely to have a congenital inguinal hernia
What are the layers that make up the testes?
inner to outer: tunica vaginalis (visceral and parietal), internal spermadic fascia, cremaster muscle, external spermadic fascia, dartos muscle
What are the layers that form to make the layers of the testes?
inner to outer: peritoneum, transversalis fascia, internal oblique, external oblique, scarpa’s fascia
What does the camper’s fascia (protective fat) of the abdomen turn into in the peritoneum?
dartos smooth muscle (cold)
What does the Scarpa’s fascia (deep to camper’s) in the abdomen turn into in the peritoneum?
colle’s fascia (membranous)
What does the spermatic cord consist of?
ductus deferens, testicular artery, pampiniform plexus, testicular lymphatics, genital branch of genitofemoral nerve, artery of the ductus deferens, sympathetic nerves
What layers does the spermatic cord pick up as it travels?
internal spermatic fascia from transversalis fascia, mantle of looped muscle fibers from the internal oblique, cremaster muscle/fascia, and external spermatic fascia from external oblique
What does the cremastic reflex do?
elicited by stroking the skin of medial thigh (if genitofemoral nerve is intact = retraction)
What is an inguinal hernia?
pressure and weak point in wall leading to protrusion
When is a hernia sac formed?
when hernia goes through the abdominal wall and has peritoneum holding it (often bringing abdominal content)
What happens if the hernia passes through the external ring?
travel down to scrotum or labium majus
How is the inguinal canal structured to prevent hernias?
oblique pushes posterior abdominal wall against anterior muscle which reduces the capacity of canal and protected by pressure of conjoint tendon and rectus abdominus pressing against the canal
How can you check for a hernia?
finger over internal ring (a bit above femoral artery palpation), have patient cough and a direct hernia will pop out
What types of inguinal hernias are there?
indirect (lateral to inferior epigastric arteries and through ring, common on right side)
and direct (defect in wall, medial/inferior to epigastric, common in old man with weak muscle)
What does the transversalis fascia in the abdomen become in the pelvis?
internal spermatic fascia
What does the internal oblique become in the pelvis?
cremasteric fascia
What does the external oblique become in the pelvis?
external spermatic fascia
How is the inguinal triangle defined?
RIP
rectus abdominis
inferior epigastric vessels
Poupart’s ligament (inguinal ligament)
What are the layers of the scrotum?
skin, superficial fascia (continuous with membranous layer), smooth muscle (dartos)
spermatic cord is deep to superficial fascia from testes
What is the accumulation of fluid from inflammation or trauma that may fill the space in the scrotum?
hydrocele
What do the seminiferous tubules do?
produce sperm
What are the inner/peritoneal layers of the testis?
covered by tunica vaginalis (except postmedial) and tunica albuginea is deep to vaginalis
What produces testosterone?
interstitial cells
What is the coiled structure that receives the efferent ductules?
epididymis – mature sperm are stored here until ejaculated
Where does testicular cancer spread?
abdomen - can produce large abdominal wall mass if spread to aortic lymphnodes
What is an undescended testicle?
failure of migrating; may be fixed by surgical means, no spermatagenesis will not occur, but needs to be taken care of young (3-4), “empty, cold, frightened”
Why does the testis need to be 2-3 degrees cooler?
normal spermatogenesis
