Anatomy to Biostats Flashcards
(13 cards)
What is the cause of direct hernias? Where are they located in respect to the inferior epigastric veins? What demographic do they occur in? What ring do they protrude through? What fascia are they covered by?
Cause: weakness of the transversalis fascia (acquired or chronic injury)
Location: medial
Demographic: older men
Protrude through: external (superficial) inguinal ring ONLY
Covered by: external spermatic fascia ONLY
What is the cause of indirect hernias? Where are they located in respect to the inferior epigastric veins? What demographic do they occur in? What ring do they protrude through? What fascia are they covered by?
Cause: persistent processus vaginalis and failure of internal inguinal ring to close
Location: lateral
Demographic: infant males
Protrude through: external (superficial) AND internal (deep) inguinal rings
Covered by: all THREE layers of spermatic fascia (external spermatic, cremasteric, internal spermatic)
Hawthorne effect? Pygmalion effect? Berkson bias?
Hawthorne - groups know they’re being studied and act differently
Pygmalion - self-fulfilling prophecy - belief in efficacy by researcher changes outcome
Berkson - bias from studying only hospital pts as the control group
What does the left gonadal (testicular/ovarian) vein drain directly into? The right?
Left gonadal vein -> left renal vein -> IVC
(obstruction of left renal vein leads to varicocele in men)
Right gonadal vein -> IVC
What is a hydrocele and where is the fluid confined? How does it form?
serous fluid that collects in the tunica vaginalis
occurs when communication between processus vaginalis and peritoneum (normally obliterated) remains patent – allows fluid from peritoneum to accumulate in scrotum
What ligament must be ligated during oophorectomy or removal of ovarian mass to avoid excessive bleeding during surgery?
suspensory ligament (infundibulopelvic ligament) contains the ovarian vessels
What region of the urethra is most at risk in pelvic fracture? In saddle injuries?
Pelvic fracture – injury to posterior urethra
(membranous segment most at risk - weakest segment vs. prostatic)
Saddle injury – injury to anterior urethra
Presents with full bladder sensation, inability to void, high-riding boggy prostate, blood at urethral meatus.
What vessels will best aid surgeon in distinguishing indirect from direct hernia?
inferior epigastric vessels
medial - direct
lateral - indirect
“MDs don’t LIe”
Enlarged lymph nodes in the inguinal area – what do they drain?
all skin from the umbilicus down drains to superficial inguinal lymph nodes
(including anus up to dentate/pectinate line, but excluding posterior calf)
Which LNs do lymph from the testes drain to?
abdominal aortic lymph nodes
What drugs can be used in treatment of BPH?
alpha-1 adrenergic blockers (relax smooth muscle in bladder neck)
5alpha reductase inhibitors (prevent conversion of testosterone to DHT)
Difference in stratified analysis with confounding vs. effect modification scenario?
Confounding:
stratified analysis looking at external variable will give large, nonsignficant P values (suggesting effect was due to confounding variable)
Effect modification:
stratified analysis looking at external variable will still give a significant effect for risk between stratified groups (suggests external variable modifies the effect of a real relationship)
LN drainage of a superficial scrotal mass? A testicular mass?
scrotum drains to superficial inguinal lymph nodes
testes drain to the para-aortic lymph nodes