Tom Eck ecktw@umdnj.edu HAD Unit III Review Tom 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

Anterior layer of rectus sheath Posterior layer of rectus sheath 1. When surgeons cut through the anterior abdominal wall below the arcuate line, which of the following do they NOT encounter? Camper’s fascia Scarpa’s fascia Anterior layer of rectus sheath Posterior layer of rectus sheath Transversalis fascia

Layers of Anterior Abdominal Wall Skin Camper (fatty) Scarpa (fibrous) Muscles -External Oblique -Internal Oblique -Transversus Abdominus Transversalis Fascia (fibrous) Extraperitoneal Fat 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? Paralysis of the right rectus abdominis Ischemia of the right rectus abdominis Paralysis of the right external oblique Ischemia of the right external oblique

Innervation and Blood Supply to Rectus Abdominus Blood Supply via Superior Epigastric Semilunar Line Innervation via Intercostals 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 always passes through the superficial inguinal ring It is encased in spermatic fascia It does not pass through the deep inguinal ring 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? Iliohypogastric nerve anterior scrotal nerve Ilioinguinal nerve genital branch of genitofemoral nerve 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

Perineum Fascia Layers Muscles – external urethral sphincter, external anal sphincter, bulbospongiosus, ischiocavernosus Innervation – Pudendal Nerve, primarily Autonomics (i.e. point and shoot)

5. When fluid deep to Scarpa’s fascia in the abdominal wall reaches the perineum, where does it accumulate? just under the skin the superficial perineal pouch the deep perineal pouch the ischioanal fossa

Perineal Spaces (of Urogenital Triangle) Skin Subcutaneous Fat  Camper Fascia on Abdomen Colles Fascia*  Scarpa’s Fascia of Abdomen  Dartos Fascia of Scrotum Deep Superficial Superficial Perineal Compartment (Ischiocavernosus, Bulbospongiosus, etc.) Perineal Membrane Deep Perineal Compartment (External Sphincter, etc.) Levator Ani (Encased in Fascia) *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 anterior labium majora posterior labium majora anterior labium minora 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

GI Tract Arterial Supply Portal Circulation Biliary Flow 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)

7. Which artery is in direct danger from an ulcer eroding the posterior wall of the stomach’s body? common hepatic left gastric right gastric gastroduodenal splenic

The Celiac Trunk artery of the foregut Three branches: Splenic Artery 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 Celiac Trunk

8. Which vessel(s) have reversed flow to permit a collateral circulation in this patient with chronic hepatitis? periumbilical veins left umbilical vein gastric veins middle rectal veins Inferior rectal veins

Porto-Caval Anastamoses Paraumbilical veins  superficial veins of abdominal wall Caput medusae Superior rectal veins  Middle and Inferior Rectal Veins (Inferior Iliac Vein) Internal hemorrhoids 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 medusae esophageal varices internal hemorrhoids left varicocele 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? visceral afferents from the foregut visceral afferents from the midgut visceral afferents from the hindgut 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

Genitourinary 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)

11. If a surgeon were to accidentally lacerate one of the following, which would involve the least risk of hemorrhage? suspensory ligament mesovarium mesosalpinx mesometrium round ligament 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? uterine fistula endometriosus fallopian tube obstruction congenital ovarian agenesis 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? uterine artery ureter urinary bladder urethra 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? hypogastric nerve sacral splanchnic nerves pelvic splanchnic nerves 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? obturator umbilical uterine vaginal 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 Foramen Obturator Umbilical ( S. vesicle) Uterine Greater Sciatic Foramen Vaginal Inferior Vesicle (in males) Middle Rectal Internal Pudendal Inferior Gluteal

Lower Limb 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

16. What action at the hip might be lost if the nerve that passes through the obturator foramen were damaged? flexion extension adduction abduction medial rotation 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 extension hip abduction foot eversion posterior thigh sensation 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? extension flexion abduction adduction elevation

Iliopsoas The most powerful flexor of the hip Psoas Major 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 Iliacus Greater Trochanter Lesser 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? anterior cruciate posterior cruciate fibular collateral tibial collateral 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: anterior cruciate posterior cruciate fibular collateral tibial collateral patellar

RIGHT KNEE JOINT FROM ABOVE 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 ACL MEDIAL FEMORAL CONDYLE LATERAL FEMORAL CONDYLE PCL TIBIAL PLATEAU RIGHT KNEE JOINT FROM ABOVE The ligaments become lax upon lateral rotation and taut on medial rotation LATERAL ROTATION

RIGHT KNEE JOINT FROM ABOVE The ACL and PCL ACL MEDIAL FEMORAL CONDYLE LATERAL FEMORAL CONDYLE PCL TIBIAL PLATEAU RIGHT KNEE JOINT FROM ABOVE Only the ACL resists anterior displacement. Likewise, only the PCL resists posterior displacement. ANTERIOR DISPLACEMENT

21. In an individual complaining of “foot drop,” foot inversion is also weakened, but not abolished. Which muscle permits continued functionality? flexor digitorum longus flexor hallucis longus tibialis posterior soleus 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 superficial fibular femoral 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

Lymphatics Memorize the lymph chart!! Also study lower limb drainage When in doubt—which there shouldn’t be any— guess superficial inguinal!

23. To which group of nodes does lymph from the 5th toe reach first? popliteal superficial inguinal deep inguinal external iliac 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

Embryology 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

24. Which of the following is derived from the ventral mesentery of the stomach? Greater omentum Lesser omentum Splenorenal ligament Gastrosplenic ligament Gastrocolic ligament

Stomach Rotation DORSAL VENTRAL 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 DORSAL VENTRAL

25. Which of the following is derived from an embryo kidney structure? uterine tube prostatic utricle suspensory ligament ductus deferens 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? inferior mesenteric vein inferior mesenteric artery fused bladder 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

Shelf Exam 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.

lateral margin of uterine cavity 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? cervical canal lateral margin of uterine cavity subendrometrially in the uterine cavity subperitoneally on the anterior surface of the uterine corpus 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!