Blue Boxes IV - pt. 2

Question 1

Accessory renal vessels

Answer 1

During kidney ascent, blood supplied by successively superior arteries w/ degeneration of the inferior arteries (failure to degenerate forms an accessory a./v.)

Polar a. –> accessory renal a. entering a pole of the kidney

Inferior polar a. –> crosses ureter and may obstruct it

Question 2

polar vs. inferior a.

types of accessory renal a.

Answer 2

Polar a. –> accessory renal a. entering a pole of the kidney

Inferior polar a. –> crosses ureter and may obstruct it

Question 3

Bifid Renal Pelvis/Ureter

Answer 3

Due to incomplete division of metanephric diverticulum (ureteric bud)

Question 4

supernumerary kidney

Answer 4

Due to complete division of metanephric diverticulum (ureteric bud)

Question 5

Retrocaval ureter

Answer 5

Ureter leaves passes posterior to IVC; rare

Question 6

horseshoe kidney

Answer 6

Rare inferior pole fusion of kidneys over the aorta/IVC

lying at L3-L5 level

halted beneath the inferior mesenteric artery

Question 7

Ectopic pelvic kidney

Answer 7

Failure of the embryonic metanephros to enter the abd

leaves the kidney anterior to the sacrum with blood supplied by aortic bifurcation/common iliac artery

Question 8

Renal/Ureteric Calculi

Answer 8

pass into renal pelvis and into the ureter, causing distension of the
ureter with severe intermittent pain (ureteric colic; may be referred to lumbar/inguinal/external
genital regions) as it is forced down

Question 9

Nerve fibers responsible for referred pain of kidney stones

Answer 9

usually referred by visceral afferents to T11-T12 level extending to proximal anterior
thigh and scrotum/labia majora (L1, L2) via the genitofemoral nerve as the stone passes downward

(sympathetic least splanchnic n.
via aorticorenal ganglia transmits generalized nausea and cramping)

Question 10

Where might kidney stones be entrapped? (3 places)

Answer 10

• At the point of the renal calyx/renal pelvis.
• As it passes in the ureter over the pelvic brim (over the iliac arteries).
• As it passes into the bladder (ureteric orifice).

Question 11

Referred pain from diaphragm

Answer 11

• Irritation of diaphragmatic pleura or peritoneum referred to C3-C5 dermatomes (shoulder region), w/ ventral rami contributions of these regions to the phrenic nerves
• Irritation of the peripheral diaphragm (innervated by inferior intercostal n.) is localized to skin over costal margin

Question 12

psoas abcess

Answer 12

Spread of lumbar spinal TB into the psoas sheath, producing an abscess that spreads inferiorly over the pelvic brim, deep to the inguinal ligament and out in the superior thigh

Pus may enter underneath the inferior part of the iliac fascia (into the iliacosubfascial fossa), allowing the cecum/appendix or sigmoid colon to trap in the fossa –> pain

Question 13

Abdominal Aortic Aneurysm

Answer 13

Arises from a congenital or acquired weakness of the arterial wall, and can be detected by deep palpation of the midabdomen, w/ aneurysms detected further left of the midline.

Ruptured aneurysm –> severe back/abdominal pain and hemorrhage.

Question 14

What sorts of tumors may appear as aortic aneurysms?

Answer 14

Pancreatic/stomach tumor may transmit aortic pulsations, causing them to appear as aneurysms

Question 15

Gynecoid (pelvic variation)

Answer 15

Normal female type; rounded pelvic inlet with wide transverse diameter

(platypelloid is the other common female type)

Question 16

Android (pelvic variation)

Answer 16

Normal male type, which if present in a female, can pose issues with vaginal delivery of a fetus (craniopelvic mismatch)

Question 17

Anteroposterior compression of pelvis causes fracture of …

Answer 17

pubic rami

Question 18

Lateral compression of pelvis causes fracture of …

Answer 18

acetabula and ilia

Question 19

Fractures of the bony pelvic ring are almost always multiple fractures or a fracture combined with _________.

Answer 19

a joint dislocation

exp. hard to break a pretzel ring at just one point

Question 20

Weak points of pelvis

Answer 20

pubic rami, acetabula, sacroiliac joints and alae of ilium

Question 21

Iatrogenic Injury of ureter during hysterectomy

Answer 21

Ureter passes inferior to uterine a. near the lateral part of the fornix of the vagina

This makes it susceptible to damage during hysterectomy (when uterine a. is ligated and severed)

Question 22

Iatrogenic Injury of ureter during ovariectomy

Answer 22

ureter can be damaged when the ovarian vessels are ligated/severed as they cross over the pelvic brim together

Question 23

Rectal Examination

Structures to palpate?

What might impede scope passage?

Answer 23

• Palpate prostate (L/R lobes), seminal vesicles or cervix.
• Palpate sacrum/coccyx, ischial tuberosities/spines and enlarged iliac lymph nodes, thickening of the ureters, or swellings of the ischioanal fossae (abscesses or abnormal contents of the rectovesical or rectouterine pouches)
• Transverse rectal folds may impede scope passage

Question 24

Prostate Hypertrophy

Answer 24

may distort the prostatic urethra impeding urine flow

usually due to middle lobe enlargement which causes further occlusion with strain

sx: nocturia, dysuria, urgency

inc risk of bladder infection (cystitis) and kidney damage

Question 25

prostate cancer metastasis

Answer 25

can metastasize to internal iliac/sacral lymph nodes or to Batson’s Plexus (internal vertebral plexus) to the brain

Question 26

Vaginal examination

Answer 26

can palpate cervix, ischial spines, sacral promontory and pulsations of the uterine arteries in the lateral parts of the fornix, along with ovarian cysts

Question 27

Uterine Examination

Answer 27

Bimanual palpation: Two fingers anteriorly in vagina while other hand presses inferoposteriorly in the pubic region of the anterior abdomen

^can detect whether the uterus is in its normal anteverted position

Question 28

Hegar’s Sign

Answer 28

Softening of the uterine isthmus, causing cervix to feel separated from the body – early pregnancy sign

Question 29

Normal proportion of uterus at birth

Answer 29

body:cervical ratio 2:1

Question 30

Normal proportion of uterus postpartum

Answer 30

shrinks to childhood dimensions (1:1 body:cervical ratio)

Question 31

Normal proportion of uterus during puberty

Answer 31

Uterine body grows, returning to 2:1 size

Question 32

Normal proportion of uterus Postpuberty/Premenopausal

Answer 32

Pear-shaped body, with thick walled ⅔ lying within the pelvic cavity

Question 33

Normal proportion of uterus during pregnancy

Answer 33

Massive expansion and thinning of the walls

after delivery –> thick-walled and edematous, w/ a nodular body extending into the pelvis and causing a protrusion of the inferior abdominal wall

Question 34

Normal proportion of uterus during menopause

Answer 34

Decreased size, involuted and assuming childhood proportions (1:1)

Question 35

Spinal Anesthesia

Answer 35

Anesthetic into subarachnoid space at L3-L4 producing complete anesthesia below waist level

Perineum, pelvic floor, birth canal are anesthetized with loss of motor/sensory function in lower limbs

Question 36

Pudendal Nerve Block

Answer 36

Anesthetic peripherally blocking S2-S4 dermatomes (including most of the perineum and inferior quarter of the vagina).

Pain still felt in the superior birth canal (uterine cervix and superior vagina) and sensation of uterine contractions is maintained.

Readministration can be dangerous for pregnancy.

Question 37

Caudal Epidural Block

Answer 37

aka saddle block

Administered in advance of delivery via injection through the sacral hiatus.

Blocks S2-S4 nerve roots, including afferent pudendal nerve fibers and pain fibers of the cervix/superior vagina.

(anesthetizes sub peritoneal + somatic areas inner. by pudendal n.)

Question 38

Perineal Body Disrupt`

Answer 38

Perineal body=supports muscles that cross the pelvic outlet (insertion point)

May be disrupted during childbirth, causing prolapse of the pelvic viscera (bladder, through urethra), prolapse of uterus/vagina (through vaginal orifice)

Can be caused by trauma,

May result in diastasis (separation) of the puborectalis and pubococcygeus parts of the levator ani

• -> cystoceles, rectoceles, enteroceles
• -> bladder, rectum, or rectovaginal pouch herniations into the vaginal wall

Question 39

Episiotomy

Answer 39

Incision of perineum and inferoposterior vaginal wall enlarges the vaginal orifice during childbirth.

Question 40

Median Episiotomy

Answer 40

Incision through the perineal body, causes scar produced to be similar to the fibrous CT of the perineal body itself

further tearing is toward the anus with risk of anovaginal fistulae or sphincter damage

Question 41

Mediolateral Episiotomy

Answer 41

Lower incidence of damage to anal sphincter

Question 42

Rupture of Male Urethra

via rupture of intermediate part of the urethra

Answer 42

Rupture of intermediate part of the urethra (inferior to prostate) can occur with pelvic girdle fractures (when pubic symphysis and puboprostatic ligaments are separated) causing extravasation of urine/blood into the deep perineal pouch

Question 43

Rupture of Male Urethra

via rupture of corpus spongiosum

Answer 43

Rupture of corpus spongiosum (spongy/penile urethra) at the bulb of the penis often occurring with a straddle injury/false passage of Foley catheter

Causes extravasation of urine into the superficial perineal space, building up in the scrotum, around the penis, or within fascial layers surrounding the tissues

Question 44

Internal hemorrhoids

Answer 44

Prolapsed rectal muscosa containing internal rectal venous plexus veins, w/ breakdown of muscularis mucosa layer

May be compressed by sphincters if near the anal canal

Question 45

External hemorrhoids

Answer 45

Thromboses in the external rectal venous plexuses covered by skin

Question 46

How do anastomoses between superior/middle/inferior rectal veins provide a portovenous shunt

Answer 46

Superior Rectal Vein drains to inferior mesenteric vein.

Middle, Inferior Rectal Veins drain through systemic venous system via internal iliac vein to IVC.

Question 47

How can portal HTN lead to varicosities in the rectal region?

Answer 47

Portal HTN can cause blood to backup through the portal system through the superior rectal vein and out to the systemic venous system via the middle/inferior rectal veins –> varicosities.

Question 48

How is pain superior to pectinate line transmitted?

Answer 48

via visceral fibers, making it virtually insensitive

Question 49

How is pain inferior to pectinate line transmitted?

Answer 49

via somatic fibers of the inferior anal/rectal nerves, making it highly sensitive

Question 50

Urethral Catheterization

Answer 50

Intermediate part of the urethra just past the corpus spongiosum flexes anteriorly and is vulnerable to puncture along the bulb of the penis, at the point where it passes through the external urethral sphincter

Question 51

Pudendal Block

Answer 51

Injection made where pudendal n. crosses the lateral aspect of the sacrospinous ligament near attachment to the ischial spine

Question 52

Ilioinguinal Block

Answer 52

Abolishes sensation in anterior perineum

Question 53

Urethral stricture

Answer 53

may result from external trauma of the penis or infection of the urethra.

Urethral sounds are used to dilate the constricted urethra in such cases (spongy urethra will expand enough to permit passage of an instrument ~8 mm in diameter)

Question 54

narrowest and least distensible part of the male urethra

Answer 54

external urethral orifice