HAD Unit III ReviewTom Eck ecktw@umdnj.edu

Unit III Exam•A ton of material, but questions tend to be

a bit more targeted—be sure to use the TBL as a guide

•Lab: review the prosections, especially the pelvis ones

•Abdominal Wall•Perineum•Gastrointestinal Tract•Genitourinary•Lower Limb•Lymphatics•Embryology•Shelf

Abdominal Wall•Fascia Layers• Innervation – intercostals, iliohypogastric,

ilioinguinal•Musculature – rectus abd., obliques, quad.

lumborum •Vessels – inferior and superior epigastric•Hernias – inguinal, femoral, congenital•Abdominal folds

▫Median = urachus▫Medial = umbilical arteries (deoxygenated)▫Lateral = inferior epigastric vessels

1. When surgeons cut through the anterior abdominal wall below the arcuate line, which of the following do they NOT encounter?

Camper’s fa

scia

Scarp

a’s fasci

a

Anterio

r laye

r of r

ectus .

..

Posterio

r layer o

f rectu

s...

Transversa

lis fa

scia

13% 13%

20%

43%

10%

1. Camper’s fascia2. Scarpa’s fascia3. Anterior layer of

rectus sheath4. Posterior layer of

rectus sheath5. Transversalis

fascia

Layers of Anterior Abdominal Wall1. Skin2. Camper (fatty)3. Scarpa (fibrous)4. Muscles

-External Oblique -Internal Oblique -Transversus Abdominus

5. Transversalis Fascia (fibrous)6. Extraperitoneal Fat7. Parietal Peritoneum- Above the arcuate line, the aponeuroses of

the abdominal muscles ensheath the rectus abdominus

- Below the arcuate line, they pass in front of it

2. What would likely result from a vertical incision through the right semilunar line superior to the umbilicus?

Paralys

is of t

he right r

ec...

Isch

emia of t

he right r

ec...

Paralys

is of t

he right e

x...

Isch

emia of t

he right e

x...

23% 23%20%

34%1. Paralysis of the right

rectus abdominis2. Ischemia of the right

rectus abdominis3. Paralysis of the right

external oblique4. Ischemia of the right

external oblique

Innervation and Blood Supply to Rectus Abdominus

Semilunar Line

Innervation via Intercostals

Blood Supply via Superior Epigastric

Blood Supply via Inferior Epigastric

3. You palpate a mass lateral to the inferior epigastric artery and superior to the inguinal ligament. What is true of this hernia?

It alw

ays passe

s thro

ugh...

It is

encase

d in sp

ermatic..

.

It does n

ot pass

thro

ugh...

It passe

s medial to

femor..

66%

0%

22%13%

1. It always passes through the superficial inguinal ring

2. It is encased in spermatic fascia

3. It does not pass through the deep inguinal ring

4. It passes medial to femoral vein

Hernias of the Myopectineal Orifice•Superior to Inguinal Ligament = Inguinal

▫Direct: between medial and lateral umbilical folds (in Hesselbach’s Triangle) medial fold = obliterated umbilical artery lateral fold = inferior epigastric vessels

▫Indirect: lateral to lateral umbilical fold; may be congenital, due to failure of processus vaginalis to close

•Inferior to the Inguinal Ligament = Femoral▫Passes through the femoral canal medial to

the femoral veins

4. Which nerve supplies the efferent limb of the cremasteric reflex?

Iliohypoga

stric

nerve

anterio

r scro

tal nerv

e

Ilioingu

inal nerve

genita

l bra

nch of g

enit...

femora

l bra

nch of g

eni...

0% 0%

14%

70%

16%

1. Iliohypogastric nerve2. anterior scrotal nerve3. Ilioinguinal nerve4. genital branch of

genitofemoral nerve5. femoral branch of

genitofemoral nerve

Cremasteric Reflex

• Afferent Limb: femoral branch of genitofemoral nerve and ilioinguinal nerve

• Efferent Limb: genital branch of genitofemoral nerve

• Iliohypogastric Nerve (L1): skin above inguinal ligament

• Ilioinguinal Nerve (L1): skin of anterior scrotum and adjacent thigh

• Genitofemoral (L1, L2): skin below inguinal ligament, motor to cremaster

• Note: both the ilioinguinal nerve and the genital branch of the genitofemoral nerve pass through the inguinal canal

• Fascia Layers• Muscles – external urethral sphincter, external

anal sphincter, bulbospongiosus, ischiocavernosus• Innervation – Pudendal Nerve, primarily • Autonomics (i.e. point and shoot)

Perineum

5. When fluid deep to Scarpa’s fascia in the abdominal wall reaches the perineum, where does it accumulate?

just

under the sk

in

the su

perficia

l perin

eal...

the deep perin

eal pouch

the is

chioan

al fossa

6% 3%

46%46%1. just under the skin2. the superficial

perineal pouch3. the deep perineal

pouch4. the ischioanal fossa

Perineal Spaces (of Urogenital Triangle)

Levator Ani (Encased in Fascia)

Deep Perineal Compartment (External Sphincter, etc.)

Superficial Perineal Compartment (Ischiocavernosus, Bulbospongiosus, etc.) Perineal Membrane

Colles Fascia* Scarpa’s Fascia of Abdomen Dartos Fascia of Scrotum

Subcutaneous Fat Camper Fascia on Abdomen

Skin

Deep

Su

perfi

cial

*Note: also continuous with the fascia lata of the thigh, though fluid will not pass laterally

6. When anesthetic is injected near the ischial spine, which of the following areas retains sensation?

anal region

anterio

r labium m

ajora

posterio

r labium m

ajora

anterio

r labium m

inora

posterio

r labium m

inora

36%

24%

6%

15%18%

1. anal region2. anterior labium majora3. posterior labium majora4. anterior labium minora5. posterior labium minora

Pudendal Nerve• S2, S3, S4• the pudendal nerve supplies

ALL of the perineal muscles and ALL of the overlying skin…

• EXCEPT for the anterior scrotum/labium majora, which are supplied by the ilioinguinal nerve

• Path: exits greater sciatic foramen and wraps around the ischial spine to enter the lesser sciatic foramen, extending anteriorly to the perineum

Pudendal Nerve Block

• anesthetized it as it wraps around the ischial spine

• Pudendal Nerve Branches▫ Inferior Anal Nerves:

external anal sphincter, perianal skin

▫ Perineal Nerve: perineal muscles, perineal skin

▫ Dorsal Nerve of the Penis/Clitoris: external urethral sphincter

Block here

• Arterial Supply▫Foregut = Celiac Truck▫Midgut = Superior Mesenteric Artery▫Hindgut = Inferior Mesenteric Artery

• Portal Circulation• Biliary Flow• Innervation (Sympathetic and Parasympathetic)

• major relationships (i.e. superior mesenteric artery passes over the third part of the duodenum)

GI Tract

7. Which artery is in direct danger from an ulcer eroding the posterior wall of the stomach’s body?

common hepatic

left ga

stric

right g

astric

gastr

oduodenal

splenic

0%

11%

51%

30%

8%

1. common hepatic2. left gastric3. right gastric4. gastroduodenal5. splenic

The Celiac Trunk

• artery of the foregut• Three branches:

▫ Splenic ▫ Common hepatic▫ Left gastric

• Artery endangered by ulcer in posterior wall of first part of the duodenum?▫ Gastroduodenal

artery

Splenic Artery

Celiac Trunk

8. Which vessel(s) have reversed flow to permit a collateral circulation in this patient with chronic hepatitis?

periumbilic

al veins

left umbilic

al vein

gastr

ic veins

middle re

ctal v

eins

Infe

rior r

ectal v

eins

95%

3% 0%0%3%

1. periumbilical veins2. left umbilical vein3. gastric veins4. middle rectal veins5. Inferior rectal veins

Porto-Caval Anastamoses

1. Paraumbilical veins superficial veins of abdominal wall Caput medusae

2. Superior rectal veins Middle and Inferior Rectal Veins (Inferior Iliac Vein) Internal hemorrhoids

3. Gastric veins Veins of Lower Esophagus ( Azygous System) Esophageal varices

1,2,3

9. If the left renal vein becomes occluded near its termination, which of the following will result?

caput m

edusae

esophage

al varic

es

inte

rnal h

emorrhoids

left va

ricoce

le

right v

aricoce

le

0%

14%5%

73%

8%

1. caput medusae2. esophageal varices3. internal hemorrhoids4. left varicocele5. right varicocele

Memorize major branches/tributaries of the abdominal aorta and IVC as well as how they relate to each other. Be able to draw this out.

10. When the pain of acute appendicitis moves into the right lower quadrant from the periumbilical region, which nerves carry this sensation?

visce

ral a

fferents

from th

...

visce

ral a

fferents

from t..

visce

ral a

fferents

from t..

inte

rcosta

l nerves

5%

23%18%

55%1. visceral afferents from the

foregut2. visceral afferents from the

midgut3. visceral afferents from the

hindgut4. intercostal nerves

Referred Pain in Appendicitis•Initial pain = periumbilical; visceral

afferents from inflamed appendix refer to the T10 dermatome

•Later pain = LRQ; as the parietal peritoneum is irritated, somatic afferents from intercostal nerves (subcostal, iliohypogastric, etc.) transmit well-localized pain

•Arterial Supply•Follow the Urinary Tract•Female Reproductive Tract•Male Reproductive Tract

▫SEVEN UP (Seminiferous Tubules, Epididymus, Vas Deferens, Ejaculatory Duct, (Nothing), Urethra and Penis)

• Innervation (Sympathetic and Parasympathetic)

Genitourinary

11. If a surgeon were to accidentally lacerate one of the following, which would involve the least risk of hemorrhage?

susp

ensory

ligament

meso

variu

m

meso

salpinx

meso

metrium

round lig

ament

card

inal ligament

34%

9%

17%

26%

6%9%

1. suspensory ligament2. mesovarium3. mesosalpinx4. mesometrium5. round ligament6. cardinal ligament

Ligaments of the Female Reproductive Tract

• Broad ligament▫ Mesovarium▫ Mesosalpinx▫ Mesometrium

• Suspensory Ligament: carries ovarian neurovascular bundle

• Cardinal Ligament: carries the uterine artery, situated below the broad ligament

• Round Ligament (and Ovarian ligament): remnant of gubernaculum

12. What does this hysterosalpingogram demonstrate?

uterin

e fistula

endometriosu

s

fallo

pian tu

be obstructi

on

conge

nital o

varian agenesis

normal

anatomy

24%

12% 12%16%

36%1. uterine fistula2. endometriosus3. fallopian tube obstruction4. congenital ovarian

agenesis5. normal anatomy

• the female reproductive tract communicates with the peritoneal cavity via the fallopian tubes

• a major route for spread of infection

• basis for abdominal pregnancy

13. Which of the following is at greatest risk in a hysterectomy?

uterin

e artery

urete

r

urinary

bladder

ureth

ra

rectu

m

12%

79%

0%3%6%

1. uterine artery2. ureter3. urinary bladder4. urethra5. rectum

The Ureter

• Know the path of the ureter

• At risk for damage when the uterine artery is ligated

• Passes along the posterior abdominal cavity

• Crosses the external iliac artery lateral to the internal iliac artery below the pelvic brim

• “water under the bridge” - passes under the uterine artery, lateral to the lateral fornix of the vagina before entering the urinary bladder

14. Along which nerve(s) do fibers carrying pain from the prostate travel?

hypogastri

c nerve

sacra

l splan

chnic

nerves

pelvic sp

lanchnic

nerves

thora

coabdominal s

pla...

3% 3%

67%

28%

1. hypogastric nerve

2. sacral splanchnic nerves

3. pelvic splanchnic nerves

4. thoracoabdominal splanchnic nerves

Visceral Pain

• pain line = lower limit of peritoneum • above the pelvic pain line, visceral afferents

follow sympathetic fibers• below the pain line, visceral afferents follow

parasympathetic fibers• Pelvic splanchnic nerves carry

Parasympathetic fibers• Sacral splanchnic nerves carry Sympathetic

fibers (as do all other splanchnic nerves)• Don’t get hung up on pathways for autonomics

(i.e. greater splanchnic celiac ganglion, etc.; straight from Dr. Vasan); symptoms are more important

15. Which branch of the internal iliac artery supplies the superior portion of the bladder?

obtura

tor

umbilical

uterin

e

vaginal

superio

r vesic

le

6%

42% 42%

0%

9%

1. obturator2. umbilical3. uterine4. vaginal5. superior vesicle

The Internal Iliac Artery

•posterior division: superior gluteal, iliolumbar, lateral sacral

•anterior division: supplies the viscera of the pelvis from anterosuperior to posteroinferior

The Anterior Division

Obturator

Umbilical ( S. vesicle)

Vaginal

Middle Rectal

Internal Pudenda

l

Inferior

Gluteal

Uterine

Obturator Foramen

Greater Sciatic

Foramen Inferior Vesicle (in

males)

•Muscles, Actions, and Innervations•Same kinds of things as upper limb, except…

▫ligaments are stressed a bit more▫the foot matters <<< the hand▫In general, somewhat less detail required—

knowing muscle compartment often enough to define action and innervation

▫know all major nerve deficits, how to recognize them, and what structures are involved

Lower Limb

16. What action at the hip might be lost if the nerve that passes through the obturator foramen were damaged?

flexion

extensio

n

adduction

abduction

medial ro

tation

late

ral ro

tation

8%5% 5%

8%5%

68%1. flexion2. extension3. adduction4. abduction5. medial rotation6. lateral rotation

Medial Compartment of Thigh

• Innervation: obturator nerve• Receives blood supply, in part, from the

obturator artery• Muscles: adductors longus, brevis, and

magnus; gracilis, obturator externis*

• For most muscles, simply knowing the compartment will tell you its primary action

*The pectineus is the only muscle that contributes to adduction, but is not innervated by the obturator nerve.

17. If a tumor were to compress the structures that exit the greater sciatic foramen superior to the piriformis, which of the following might be lost?

thigh

extensio

n

hip abduction

foot e

version

posterio

r thigh se

nsation

urinary

continence

36%

28%

3%

25%

8%

1. thigh extension2. hip abduction3. foot eversion4. posterior thigh

sensation5. urinary continence

Greater Sciatic Foramen• formed from greater sciatic

notch, closed off inferiorly by the sacrospinous ligament and posteromedially by the sacrotuberous ligament

• the superior gluteal nerve innervates the gluteus medius, gluteus minimus, and tensor of the fascia lata all three provide hip abduction (and medial rotation); loss = “hip drop”

• thigh extension = tibial, inferior gluteal; • foot eversion = peroneal (superficial); • posterior thigh sensation = post. femoral cutaneous• urinary continence = pudendal (external urethral

sphincter)

18. What action at the hip would be most weakened by avulsion of the lesser trochanter of the femur?

extensio

n

flexion

abduction

adduction

elevation

5%

39%

5%

37%

13%

1. extension2. flexion3. abduction4. adduction5. elevation

Iliopsoas• The most powerful flexor of

the hip• Three muscles: psoas major,

psoas minor, iliacus• Psoas major and iliacus are

the only muscles that insert at the lesser trochanter

• Psoas major significant for signaling apendicitis, route for spread of infection to/from thigh

• Greater trochanter: most of the gluteal muscles; gluteus medius, minimus, gemelli, obturator internis, piriformis Lesser

Trochanter

Iliacus

Psoas Major

Greater Trochanter

Important Attachment Sites• Greater trochanter• Lesser trochanter• Tibial tuberosity = quadriceps femoris• Ischial tuberosity = hamstrings (except short head

of biceps femoris)• Base of 5th metatarsal = fibularis brevis• Base of 1st metatarsal = fibularis longus

• For most of the rest, simply knowing the bone (or general region) should suffice

19. Following injury, if you note ease in abducting the tibia, causing visual deformity (genu valgum), which ligament may have been damaged?

anterio

r cru

ciate

posterio

r cru

ciate

fibular colla

teral

tibial colla

teral

patella

r

16% 16%

6%

39%

23%

1. anterior cruciate2. posterior cruciate3. fibular collateral4. tibial collateral5. patellar

Ligaments of the Knee• The knee is the largest and least stable joint of the

body; know the deficits

• ACL = laxity in anterior displacement of tibia; connects lateral femoral condyle to anterior tibia

• PCL = laxity in posterior displacement of tibia; connects medial femoral condyle to posterior tibia

• FCL (lateral) = genu varum• TCL (medial) = genu valgum

• vaLgum = Lateral displacement of distal component• varum = medial displacement of distal component

• Coxa = hip; genu = knee; hallux = big toe

20. ID this ligament:

anterio

r cru

ciate

posterio

r cru

ciate

fibular colla

teral

tibial colla

teral

patella

r

50%

31%

19%

0%0%

1. anterior cruciate2. posterior cruciate3. fibular collateral4. tibial collateral5. patellar

The ACL and PCL

• The attachments of the ACL and PCL are important to know; they also explain why lateral rotation of the tibia—when the knee is bent—is greater than medial rotation

MEDIAL FEMORAL CONDYLE

LATERAL FEMORAL CONDYLE

ACL

PCL TIBIAL

PLATEAU

RIGHT KNEE JOINT FROM

ABOVE LATERAL ROTATION

The ligaments become lax upon lateral rotation and taut on medial rotation

The ACL and PCL

MEDIAL FEMORAL CONDYLE

LATERAL FEMORAL CONDYLE

ACL

PCL TIBIAL

PLATEAU

RIGHT KNEE JOINT FROM

ABOVEANTERIOR DISPLACEMENT

Only the ACL resists anterior displacement. Likewise, only the PCL resists posterior displacement.

21. In an individual complaining of “foot drop,” foot inversion is also weakened, but not abolished. Which muscle permits continued functionality?

flexor d

igito

rum lo

ngus

flexor h

allucis

longu

s

tibialis poste

rior

soleus

gastr

ocnemius

10%

27%

17%

7%

40%

1. flexor digitorum longus2. flexor hallucis longus3. tibialis posterior4. soleus5. gastrocnemius

Ankle Joint Movements

• “foot drop”: loss of deep fibular nerve, specifically, but most common injury occurs to the common fibular nerve as it winds around the neck of the fibula

• Inversion: tibialis anterior and posterior • Eversion: lateral compartment muscles• Plantar flexion: posterior compartment muscles• Dorsiflexion: anterior compartment muscles

22. Which nerve, when damaged, leads to anesthesia over the plantar surface of the foot?

tibial

deep fibular

superfi

cial fi

bular

femora

l

obtura

tor

50%

11%

0%

14%

25%

1. tibial2. deep fibular3. superficial fibular4. femoral5. obturator

Cutaneous Nerves of the Lower Limbs• Fairly important to know• Generally, knowing the

name of the cutaneous nerve is less important than knowing the major nerve it is derived from

• Tibial medial/lateral plantar

• Femoral saphenous• Know cutaneous

distribution of obturator, superficial peroneal, deep peroneal

•Memorize the lymph chart!!•Also study lower limb drainage•When in doubt—which there shouldn’t be

any—guess superficial inguinal!

Lymphatics

23. To which group of nodes does lymph from the 5th toe reach first?

popliteal

superfi

cial in

guinal

deep inguinal

extern

al iliac

inte

rnal il

iac

66%

26%

3%0%6%

1. popliteal2. superficial inguinal3. deep inguinal4. external iliac5. internal iliac

Lymphatics of the Lower Limbs

• Lymph following the drainage of the small saphenous vein popliteal ( deep inguinal)

• Lymph following the drainage of the great saphenous vein superficial inguinal

• Lymph following the deep veins of the legs deep inguinal

•Gastrointestinal – know foregut, midgut, hindgut derivatives; rotation

•Urinary – three stages of kidney development

•Reproductive – know the precursors to each adult structure; know the male/female homologs

•congenital abnormalities

Embryology

24. Which of the following is derived from the ventral mesentery of the stomach?

Gre

ater o

mentum

Lesse

r omentu

m

Splenore

nal liga

ment

Gastr

osplenic

ligament

Gastr

ocolic

ligament

50%

33%

6%11%

0%

1. Greater omentum2. Lesser omentum3. Splenorenal ligament4. Gastrosplenic ligament5. Gastrocolic ligament

Stomach Rotation

VEN

TRAL

DO

RSA

L

• The stomach rotates clockwise 90° during development

• Ventral mesentery lesser omentum

• Dorsal mesentery greater omentum

• The greater omentum can be divided into gastrocolic, gastrosplenic, gastrophrenic, and occasionally, splenorenal ligaments

25. Which of the following is derived from an embryo kidney structure?

uterin

e tube

prosta

tic utri

cle

susp

ensory

ligament

ductus d

eferens

round lig

ament

36%39%

0%

9%

15%

1. uterine tube2. prostatic utricle3. suspensory ligament4. ductus deferens5. round ligament

Urogenital Development

• The urinary tract and reproductive tract develop in close association with each other

• Much of the male reproductive tract is derived from the mesonephric duct of the second set of kidneys (mesonephros), including the ductus deferens

• Remember: Male = Mesonephric duct = Medulla-Derived Testis

• Female = Paramesonephric duct = Cortex-Derived Ovary

26. What restricts the normal ascent of a horseshoe kidney?

inferio

r mese

nteric

vein

inferio

r mese

nteric

artery

fuse

d bladder

shorte

ned ureters

6%

35%

15%

44%1. inferior mesenteric

vein2. inferior mesenteric

artery3. fused bladder4. shortened ureters

Horseshoe Kidney

• Because the IMA is the inferiormost vessel that branches off the aorta anteriorly, it will block the ascent of a horseshoe kidney

• This condition is asymptomatic

•The Bad News: cumulative final; limited study time

•The Good News: you’ve been preparing all along! The clinical approach the course directors employ is a good representation of what you’ll see. Also, questions tend to be less detail-oriented on the Shelf.

Shelf Exam

27. A 45-year-old woman has a uterine leiomyoma that is 5 cm in diameter and is pressing on the urinary bladder, causing urinary frequency. Which of the following is the most likely location of the leiomyoma?

cerv

ical c

anal

late

ral m

argin of u

terin

e...

subendro

metrially

in th

e...

subperit

oneally on th

e ...

subperit

oneally on th

e ...

3%6%

36%

42%

12%

1. cervical canal2. lateral margin of uterine cavity3. subendrometrially in the

uterine cavity4. subperitoneally on the anterior

surface of the uterine corpus5. subperitoneally on the posterior

surface of the uterine fundus

•First, don’t let the details of the clinical scenario intimidate you

•Who knows what a leiomyoma is?! Who cares!

•All we need to know is that its pushing on the bladder and causing increased urinary frequency

•You are well equipped to handle most questions; don’t assume anything is over your head

• The question is really just a convoluted way to test our understanding of how the uterus relates to the bladder

• Process of elimination • Cervical canal and

subendometrial are both inside the uterus

• Lateral margin – too far away

• Subperitoneally – good – on surface of uterus; anterior or posterior? anterior – uterus lies behind the bladder (this is what they were testing!)

What’s on the Test?

• Go to nbme.org and look for “Basic Science Subject Examinations” “Content Outline”

• You will find a breakdown of the topics and their representation; 20 sample questions – do them

• Last year’s exam• A ton of GI questions• Very little head and neck – if you dissect the content

outline, this is plausible• From asking around about previous years, I found

this to be a common observation

Study Suggestions

• My number one suggestion: make learning this unit your number one priority, since GI and pelvis tend to be strongly represented

• If you do that, you will leave yourself a day and a half to go over the first two units (especially unit I)

• Review Books: • BRS Gross Anatomy: detail can be a bit

overwhelming; focus on the pink boxes; comprehensive exam at end is fairly representative; chapter exams are somewhat detail-oriented (also try RoadMap, PreTest)

• High-Yield Embryology: embryo is 25 of 150 questions; high-yield has a reasonable level of detail, no questions

Study Suggestions

• Another good approach: review your TBL’s; the questions tend to cover the most clinically relevant material

• If you’re really ambitious, you might even consider reading through the Big Moore Blue Boxes (depending on how comfortable you are with the basic anatomy)

You’re almost there! Good luck!