STRX Week 1 & 2 Flashcards
Which is more likely leukoplakia and which is erythroplakia?
Leukoplakia more likely the right bc leukoplakia is a plaque-like lesion so you would see hyperkeratinized tissue
Erythroplakia is more likely to be malignant so the left is more likely that due to its lack of structure and infiltration of leukocytes
a. HPV is the primary cause of SCC in what anatomical structure?
b. What are the primary causes of SCC in the related structures?
a. Oropharynx - commonly base of tongue and tonsil
b. Oral cavity HCC primary cause is tobacco and alcohol (betal quid in Asia/India)
Lower lip - UV radiation and pipe smoking
Fill in the characteristics of SCC
What are the common driver mutations of P16-negative (non-HPV) HCC?
p53, RB pathways, CDKN2A
Explain what field cancerization is
Because the entire oral cavity/ oropharynx has been exposed to the same carcinogens for the same amount of time, it’s likely that there are multiple mutations within the mucosal cells that could become cancerous at any time
Multiple tumors develop independently (not metastasis) - the second primary tumors often fatal
Differentiate the locations and risk factors of adenocarcinoma vs squamous cell carcinoma in esophageal cancers
Adenocarcinoma:
Lcoation - lower esophagus
Risk factors - Barret’s esophagus, GERD, radiation, tobacco
Squamous Cell Carcinoma
Location - oral cavity to upper esophagus
Risk factors - alcohol, tobacco, achalasia, Plummer Vinson, hot beverages, radiation
Why are SCC and adenocarcinoma of the oropharynx and esophagus so aggressive in terms of spreading quickly to regional lymph nodes?
SCC - in the upper esophagus/oral cavity - surrounded by lymph nodes (tonsillar, submandibular)
Adenocarcinoma - esophagus lacks serosa so it can access lymphatic plexus much more easily
What nerves carry sensory innervation for the upper and lower teeth?
Upper: anterior, middle, and posterior superior alveolar nerves
Lower: Inferior alveolar nerve
What are the differences between tunica adventitia and tunica serosa?
Adventitia is connective tissue contiguous with CT lining and other strctures.
Serosa consists of CT lined by mesothelium (cells that secrete serous fluid to reduce friction caused by movement)
What structures of the oral cavity have lining mucosa?
Vestibular fornix
Sublingual sulcus
Alveolar mucosa
Soft palate
Ventral surface of tongue
What structures of the oral cavity have masticatory mucosa?
Hard palate
Gingiva
What structures of the oral cavity have specialized mucosa?
Dorsum of tongue
Floor of mouth
How can you tell where the oral mucus membrane of the lip stops and the skin begins?
Lip has 3 layers, non-keratinized
Skin has 5 layers, keratinized
Vermilion zone
Presence of hair follicles on the skin
What is the major difference between hard and soft palate?
Presence of bone in hard palate
What type of gland is shown, and what type of excretion would you expect?
Tonsillar gland - mucus
What type of gland is shown, and what type of excretion would you expect?
Palatine gland - mucus
What type of gland is shown, and what type of excretion would you expect?
Lip/Buccal gland - seromucus
What type of gland is shown, and what type of excretion would you expect?
Glands of von Ebner - serous
What type of gland is shown, and what type of excretion would you expect?
Parotid gland - 100% serous
Abundant intercaclated, striated, and excretory ducts
What type of gland is shown, and what type of excretion would you expect?
Submandibular gland - 80% serous, 20% mucus
Rare interacalated ducts, abundant striated and excretory ducts
What type of gland is shown, and what type of excretion would you expect?
Sublingual gland - 40% serous, 60% mucous
No intercalated, rare striated, abundant excretory ducts
Identify the glands
What is the arcuate line?
The transition from bilaminar to a unilaminar sheath approx 2/3 of the way down the anterior wall
What is the order of layers you would encounter cutting into the medial abdomen?
Skin –> Camper’s fascia –> Scarpa fascia –> External oblique aponeuorosis –> internal oblique aponeurosis –> transversalis abdominis aponeurosis –> transversalis fascia –> extraperitoneal fat –> parietal peritoneum
What’s the difference between the layers of the rectus sheath above and below the arcuate line?
Above the arcuate line - the rectus sheath is bilaminar:
external and internal oblique aponeurosis contributing to the anterior lamina
internal oblique and** transversalis abdominis** aponeurosis contributing to posterior lamina
Below the arcuate line - rectus sheath is unilaminar:
Anterior lamina is made of all three muscle fascia (ext, int, transversalis)
Posterior lamina no longer exists and is simply transversalis fascia
What is the blood supply of the abdominal wall?
Superior epigastric a. from Internal Thoracic
Descending Aorta
Inferior Epigastric a and Deep Circumflex a from External Iliac
Superficial Epigastric a and Superficial Circumflex a from Femoral
What is the significance of portal veins that anastomose with caval veins?
When there is portal hypertension, blood can flow retrograde due to an absence of valves in the portal system –> back to the anastamoses with the caval veins to drain from there
This locations are the esophageal veins, superficial epigastric veins, and rectal veins
What nerve passes through the superficial ring and what level does it originate?
Ilioinguinal n from L1
What are the routes of lymphatic drainage of the anterior abdominal wall?
Superior to transumbilical plane:
Axillary LN
Parasternal LN
Inferior to transumbilical plane:
Superficial inguinal LN
What forms the inguinal ligament?
Inferior portion of the external oblique aponeurosis extending from ASIS to pubic tubercle
What forms the Lacunar and Pectineal ligaments?
Lacunar: deeper fibers of inguinal ligament that attach to superior pubic ramus
Pectineal: lateral fibers that run along pecten pubis
What layers make up the inguinal canal?
Superficial to deep:
Transversalis fascia
Internal Oblique muscle (Cremaster muscle)
External Oblique aponeurosis
What does the inguinal canal contain?
Blood vessels
Lymphatic vessels
Ilioingional n (L1)
Genital branch of genitofemoral n
Males: spermatic cord
Females: round ligament of uterus
What is the first structure crossed by any abdominal hernia?
Transversalis fascia
What are the walls of the inguinal canal?
MALT
Roof - Muscles - Internal Obl and Transv Abdom
Anterior -Aponeurosis - Ext Obl and Int Obl
Floor - Ligaments - Lacunar and Inguinal
Posterior - 2T’s - Transv fascia and conjoint Tendon
Compare and contrast Direct vs Indirect hernias
Direct:
composes 15% of all hernias
abdominal contents protrude through weak area in ab wall through superficial ring
medial to inferior epigastric vessels
Indirect:
most common form of hernia
passes through deep ring, inguinal canal, superficial ring into the scrotum
lateral to inferior epigastric vessels
What is the significance of the omental foramen?
It’s created by the hepatoduodenal ligament, which houses the portal triad, extending from the liver to duodenum
What does the portal triad entail?
Portal vein
Hepatic artery
Bile duct
What level is the bifurcation of the aorta?
What level is the union that begins the IVC?
L4 into the left and right common iliac arteries
Union of the common iliac veins is at L5
Outline the pathway of visceral pain from the gallbladder to the vertebrae
What is the peri-arterial plexus that the right and left lobes of the liver would follow back for pain response?
Right: Right hepatic –> proper hepatic –> common hepatic –> celiac trunk –> celiac ganglion –> greater splanchnic n –> etc.
Left: Left hepatic –> proper hepatic –> common hepatic –> celiac trunk –> celiac ganglion –> greater splanchnic n –> etc.
What is the origin of the artery that must be ligated in a cholecystectomy?
Cystic a is ligated so Right Hepatic a
What symptoms might you see in an infant with:
Esophageal atresia
Esophageal atresiaDrools
Substantial mucus
Appears to choke or difficulty maintaining airway when suckling at breast or bottle
Significant respiratory distress
What symptoms might you see in an infant with:
Pyloric stenosis
Non-bilious vomiting or regurgitation, which may become projectile -after which the infant is still hungry
1/3 of cases are congenital in such disorders as VATER or VACTERL
Ultrasound detection of intestines outside of abdominal cavity covered with a membrane
Ompholocele
Ultrasound detection of uncovered intestines outside of abdominal cavity
Gastroschisis
Most patients live their entire lives without any symptoms
Complications are the result of bowel obstrcution, ectopic tissue, or inflammation
Meckel’s diverticulum
A loop of intestine twists around itself and the mesentery that supports it, resulting in bowel obstruction
Volvulus
Failure of the cloacal membrane to break down
Imperforate anus
Rectum ends as a blind sac above the puborectalis muscle.
Usually due to abnormal formation of the urorectal septum
Anorectal agenesis usually with one of three fistulas
Anal canal ends as a blind sac below the puborectalis muscle
Anal agenesis
Unconnected rectal and anal canal
Rectal atresia
An invagination of surface ectoderm that forms the lower anal canal
Imperforate anus
What is the origin of the liver, gallbladder, and biliary apparatus?
Hepatic diverticulum
What sheet of the splanchnic mesoderm forms the central tendon of the diaphragm?
Septum transversum
What process begins in the liver by the 6th week?
Hematopoesis
What comes from the stalk of th ehepatic diverticulum?
Cycstic and bile ducts
What is the most common form of extra-biliary atresia?
Obliteration of the bile ducts
What forms most of the head and uncinate process of the pancreas?
Ventral pancreatic bud
What mutation can lead to esophageal atresia?
7q35 deletion encompassing SHH
GLI3 mutation
What findings would you see in infantile pyloric stenosis?
Seen 2-6 weeks after birth
Non-bilious vomiting –> hypokalemic hypochloremic metabolic acidosis from loss of HCl and fluids
Imaging shows elongated pyloric channel with thickened muscle wall, “olive-like mass”
What do 7, 8, and 9 depict?
7: Cloaca
8: Allantois
9: Vitelline duct
What is the most common type of esophageal atresia?
Estophageal Atresia with Distal Tracheoesophageal Fistula - upper and lower esophagus separated with lower esophagus connected to trachea
What disorder might you expect with polyhydramnios in utero (fetus can’t swallow amniotic fluid), choking, drooling, vomiting, unable to pass NG tube, prominent gastric bubble on imaging
Esophageal Atresia with Distal Tracheoesophageal Fistula (TEF) - upper and lower esophagus separated, lower esophagus connected to trachea
What disorder might you expect with vomiting, a gasless stomach and no lung congestion
Pure Esophageal Atresia - upper and lower esophagus separated with no connections to trachea
What disorder might you expect with aspiration pneumonia and a prominent gas bubble, but no vomiting?
Pure TEF “H type” - esophagus in tact with connection to trachea
Explain the difference between omphalocele and gastroschisis
Omphalocele - hernation through midline umbilical cord with intestines encased in peritoneal sac
Associated with Trisomy 13, 18, and Beckwith Wiedemann syndrome
Labs show increased materal AFP
Gastroschisis - herniation through paraumbilical abdominal folds with no peritoneal sac protecting intestines - surgical emergency
10x increased materal AFP
Characterize Meckel’s Diverticulum
Partial closer of vitelline duct connecting ileum to umbilicus –> outpouching of muscosa, submucosa, and muscularis layers inside the ileum (true diverticulum)
Presents with:
RLQ pain, Intussusception, Volvulus, Obstruction
Hematochezia, melena
What part of the pancreas is formed from the vental bud?
Pancreas head and duct
What part of the pancreas is formed from the dorsal bud?
Pancreas body, tail, pancreatic and accessory pancreatic duct
Where does the esophagus transition from cervical to thoracic to abdominal?
Cervical to thoracic: superior thoracic aperture
Thoracic to abdominal: esophageal hiatus (T10)
Label A, B, C
A = cervical constriction (UES) formed by cricopharyngeaus m.
B = Thoracic constriction formed by arch of aorta
C = diaphragmatic constriction by esophageal hiatus of diaphragm
