anatomy BSC Flashcards
hx: male with painless rectal bleeding. protuberant abdomen, no hernias or masses palpable in rectum. history of colon CA.
- must do colonoscopy, probably thinking internal hemorrhoids as well
what is dividing line b/w internal/external hemorrhoids?
pectinate line/dividing line
Pain with hemorrhoids?
- internal hemorrhoid: superior anal canal is visceral and will be painless upon ligation (endodermal tissue)
- external hemorrhoid: below pectinate line is somatic fibers (ectodermal tissue) - will be painful
hx: rectal bleeding, tenesumus (urgency in stooling), increased stool thickness, sibling had colon polyps, and father had colonoscopy.
- has palpable mass with BRB in wall of rectum
working diagnosis: cancer of rectum - masses in rectum are usually cancer until proven otherwise. Could also be Crohn’s disease or tumor coming from outside and eroding into rectum from prostate.
- check CBC’s, XRay and Colonoscopy
- Lab: anemic, normal function of liver values, colonscopy revels large mass in middle of rectum
- endorectal ultrasound: good means for confirming the cancer
venous drainage of rectum?
drainage around pectinate line: superior rectal drainage goes via inferior mesenteric v. to portal system. Below the dentate line drains via the external pudendal v to the internal iliac v.
- if portal system is hypertensive, then the superior superior rectal area will be used as means of getting back to mesenteric v.
blood supply/peritoneal covering and lymphatic drainage throughout rectum?
upper 1/3: superior rectal aa. (from inferior mesenteric), anterior and lateral portions are peritonealized,
middle 1/3: middle rectal aa. (anterior division of internal iliac), anterior portion is peritonealized, posterior aspect is attached to sacrum
lower 1/3: inferior rectal aa. (from pudendal a.), extraperitoneal and out of view
All three go through the middle and upper vv.
Lymphatic drainage: most will go to internal iliac nodes or to periaortic nodes
what muscle is most responsible for continence?
puborectalis: attaches to pubis anteriorly, slings around rectum and inserts on itself. when sling contracts the rectum is pulled anteriorly, and the rectum is pulled forward creating an acute angle that allows for continence.
- puborectalis is part of the external sphincter
- the internal sphincter has little to do with continence
what nerves must you be careful of in rectal resection? where are the urethral sphincters innervated? where are they located?
- Pelvic splanchnic nn: allow for urination and erection.
- internal sphincter is sympathetically innervated
- ejaculation is a sympathetic response, thus internal sphincter must be contracted so that ejaculation does not move into the bladder
- external urethral sphincter; somatically innervated
- The internal sphincter muscle of urethra: located at the bladder’s inferior end. The internal sphincter is a continuation of the detrusor muscle and is made of smooth muscle, therefore it is under involuntary or autonomic control. This is the primary muscle for prohibiting the release of urine.
- The external sphincter muscle of urethra (sphincter urethrae): located at the bladder’s distal inferior end in females and inferior to the prostate (at the level of the membranous urethra) in males is a secondary sphincter to control the flow of urine through the urethra. Unlike the internal sphincter muscle, the external sphincter is made of skeletal muscle, therefore it is under voluntary control of the somatic nervous system.
how do you locate the ureter?
- ureters are under the uterine aa. or vas deferens and over the iliac bifurcation
- ureters run over the iliac right where it bifurcates, they can be located at the bifurcation
hx: male in accident with high riding prostate. he is neurologically intact. What anatomical structures could have been involved in the accident?
- worried of urethral injury, do a retrograde urethral stain, hope that it goes only into the urethra. If it shows up in pelvic diaphragm, in male know that there is an injury in the intramembranous urethra (goes through UG diaphragm). Ripped from membranous urethra
- also worried about bleeding in pelvis, should be taken in for interventional arteriography to see the artery
hx: “pain in lower right side” 23 y/o female, 2-3 day h/o crampy sharp pain right lower abdomen/upper pelvis. nausea. no vomitting. no fever or chills, hurts to move around. has had chlamydia. last MP was 6 weeks ago, normal. tachycardic and increased BP. Has rebound tenderness in right lower quadrant, goes to hypogastric. +Rovsings (pain occurs in opposite quadrant) +obturator sign. Mass in right adnexa
assesment: ectopic pregnancy, acute appendicitis, PID
why ectopic pregnancy?
- implantation occurs in ampulla or other portion of the uterine tube wall, often due to damage/scarring of STD. adhesions due to prior STD’s can cause occlusion of the tube, and preventing the fertilized egg from moving.
- simple columnar lines the oviduct: formed of ciliated and secretory cells.
- simple columnar cells ALSO line the uterine wall - it is the same type of epithelium, thus implantation can occur in the oviduct as well.
ectopic pregnancy risk factors:
salpingitis, prior ectopic pregnancy, IUD, tubal ligation, tubal reconstructive surgery, ovulation induction
- due to altered tubal transport secondary to damage to ciliated surfaces of endosalpinx
culdocentesis:
checks for abnormal fluid in abdominal cavity behind the uterus: rectouterine pouch
hx: postmenopausal vaginal bleeding for 3 weeks. menopause age 52. estrogen window was 39 years. type II DM. taking oral premarin for post-menopausal symptoms. obese. blood at cervical os, no adnexal masses are palpable. palpable fundus over the pubis.
- palpable fundus over pubis, indicates that it is quite large.
menopause symtpoms:
hot flashes sleep disturbances depression vaginal dryness and atrophy sexual function change cognitive changes joint pain
caused by loss of estrogen
risk factors for endometrial cancer
increased age
estrogen therapy
tamoxifen therapy (estrogen r antagonist)
late menopause
nulliparity (no pregnancy, no interruptions in estrogen synthesis)
polycystic ovary syndrome
Dieabetes mellitus
obesity (adipose tissues express aromatase- peripheral conversion of androgens to estrogens)
what do you do if ultrasound is irregular?
endometrial sampling (in the case see endometrial hyperplasia with atypia = abnormal cells)
what causes uterine cycling?
- increased FSH, with ovarian follcicle development, will have estrogen to build up the endometrial lining
- in menopause, if women take estrogen, they will have endometrial build up
- normal thickness is 2-3 mm, during secretory phase we see an increase in 4-6 mm. This woman had 12 mm of build up
- in proliferative, see long smooth endometrial glands
- in secretory phase: see scalloped and serated endometrial glands
interstitial glands:
left over in the ovary, used to be the corpus luteum theca cells. Theca lutean cells produce the precursors of estrogen. Producing andrestenodione. Her obesity is providing the aromatase, to convert her andrestenodione to estrogen.
hx: vague abdominal pain and HTN. gets headaches, and headaches correspond to spikes in blood pressure. no palpable masses, organomegaly or striae
pheochromocytoma : elevated VMA and catecholamine levels
Endocrine causes of hypertension:
- cushings: over secretion of cortisol, hypertension, moon face, increased central fat disposition, striae, increased weight gain
- primary hyperaldosteronism: caused by aldo secreting tumor in adrenal cortex, would see low potassium levels (hypokalemia)
- pheochromocytoma: tumor of adrenal gland in chromaffin tissue - oversecretion of epinephrine
- hyperthyroidism: would expect weight loss, increased basal metabolism, exopthalmos
- hypothyroidism: weight gain, lowered basal metabolism, sunken eyes, cold intolerance
- if suspect pheochromocytoma: look for VMA, NMET in urine : breakdown products found in urine
pheochromocytoma
tumor of chromaffin tissue, due to excessc atecholamines
- sporadic release, causing spikes in blood pressure
- hypertension
- 3 main presentation: headache, sweating, diaphoresis (sweating)
- other presentations: anxiety, chest pain, palpitations
how do you check for pheochromocytoma?
check Metanephrine, VMA and normetanephrine levels in the urine. These are the degredation prodcuts.
histology of pheochromocytoma?
located in medulla of adrenal gland. tumor of chromaffin cells.
chromaffin cells are postganglionic sympathetic cells that secrete NE and epi
what catecholamine receptors are stimulated with pheochromocytoma?
Alpha 1 = vascular smooth muscle constriction, increased BP
Beta 1: increased heart rate (causing palpitations), and increased venoconstriction (hypertension)
how do you prepare for surgery of pheochromocytoma removal?
- need to prep them ahead of time
- what to block first? alpha 1 receptors should be blocked first to expand vascular bed. they will probably become hypotensive. (started 3 weks prior to surgery and are instructed to drink water)
- increased alpha blockers are they re-expand vascular system (they are 15% vascular contracted)
- don’t use Beta blockers first because you want to maintain the CO and MAP, if use beta blockers the vasculature won’t be relaxed, it will just slow HR and contractility. will cause hypotension and lack of perfusion. (Beta blockers are introduced after alpha 1 blockers)
know differences between arterial and venous anatomy of adrenal glands right and left!!!!
it will be on the test!!!!
