GI - Anatomy (Pectinate line, Liver anatomy, Biliary structures, & Femoral region)

Question 1

What is another name for the pectinate line?

Answer 1

Pectinate (dentate) line

Question 2

How/Where is the pectinate (dentate) line formed?

Answer 2

Formed where endoderm (hindgut) meets ectoderm

Question 3

What 2 pathologies are found above the pectinate line?

Answer 3

Above pectinate line - (1) Internal hemorrhoids (2) Adenocarcinoma

Question 4

What 3 pathologies are found below the pectinate line?

Answer 4

Below pectinate line - (1) external hemorrhoids (2) and fissures (3) squamous cell carcinoma

Question 5

What is the arterial supply to the area above the pectinate line? From what major artery does this branch?

Answer 5

Arterial supply from superior rectal artery (branch of IMA)

Question 6

What is the arterial supply to the area below the pectinate line? From what major artery does this branch?

Answer 6

Arterial supply from inferior rectal artery (branch of internal pudenal artery)

Question 7

What is the venous drainage of the area above the pectinate line?

Answer 7

Venous drainage is superior rectal vein –> inferior mesenteric vein –> portal system

Question 8

What is the venous drainage of the area below the pectinate line?

Answer 8

Venous drainage to inferior rectal vein –> internal pudenal vein –> internal iliac vein –> IVC

Question 9

Give and explain the presence of pain in internal versus external hemorrhoids.

Answer 9

Internal hemorrhoids (above the pectinate line) receive visceral innervation and are therefore NOT PAINFUL; External hemorrhoids receive somatic innervation (inferior rectal branch of pudenal nerve) and are therefore PAINFUL

Question 10

What is the lymphatic drainage of the area above the pectinate line?

Answer 10

Lymphatic drainage to deep nodes

Question 11

What is the lymphatic drainage of the area below the pectinate line?

Answer 11

Lymphatic drainage to superficial inguinal nodes

Question 12

What is an anal fissure, and where is it located in reference to the pectinate line?

Answer 12

Anal fissure - tear in the anal mucosa below the Pectinate line

Question 13

What are 2 symptoms of anal fissure? Where is it located, and why?

Answer 13

Anal fissure - tear in the anal mucosa below the Pectinate line. Pain while Pooping; blood on “toilet” Paper. Located Posteriorly since this area is Poorly Perfused.

Question 14

What structure(s) do the apical versus basolateral surface of hepatocytes face?

Answer 14

Apical surface of hepatocytes faces bile canaliculi. Basolateral surface faces sinusoids.

Question 15

How many zones does the liver have, and what are there names?

Answer 15

(1) Zone I: Periportal zone (2) Zone II: Intermediate zone (3) Zone III: Pericentral vein (centrilobular) zone

Question 16

Which zone of the liver is affected first by viral hepatitis? In general, what else affects this zone? Give an example of this.

Answer 16

Zone I: Periportal vein: Affected 1st by viral hepatitis; Ingested toxins (e.g., cocaine)

Question 17

Which zone of the liver is affected first by ischemia? To what else is it most sensitive?

Answer 17

Zone III: Pericentral vein (centrilobular) zone: Affected by ischemia; Most sensitive to metabolic toxins

Question 18

Which zone of the liver contains cytochrome P-450 system? For what clinical condition is this zone also the site?

Answer 18

Zone III: Pericentral vein (centrilobular) zone: Contains cytochrome P-450 system; Site of alcoholic hepatitis

Question 19

Draw a ? view of the liver, including and labeling key anatomy, such as: (1) Bile canaliculus (2) Bile ductule (3) Branch of portal vein (4) Branch of hepatic artery (5) Blood flow (directional arrow) (6) Bile flow (directional arrow) (7) Central vein (to hepatic veins and systemic circulation) (8) Liver cell plates (9) Kupffer cell (10) Portal triad (11) Sinusoids draining to central vein (12) Space of Disease (lymphatic drainage) (13) Zone I (14) Zone II (15) Zone III.

Answer 19

See p. 341 in First Aid for visual at bottom of page

Question 20

What is included in the portal triad?

Answer 20

(1) Bile ductule (2) Branch of portal vein (3) Branch of hepatic artery

Question 21

To what vessel do the liver sinusoids drain? To where does this vessel drain from there?

Answer 21

Sinusoids draining to central vein; Central vein (to hepatic veins and systemic circulation)

Question 22

Draw and label the following biliary structures: (1) Ampulla of Vater (2) Common bile duct (3) Common hepatic duct (4) Duodenum (5) Gallbladder (6) Left hepatic duct (7) Right hepatic duct (8) Cystic duct (9) Main pancreatic duct (10) Sphincter of Oddi (around the duct).

Answer 22

See p. 342 in First Aid 2014 for visual at top of page

Question 23

What is important to know about gallstones and the ampulla at Vater?

Answer 23

Gallstones that reach the common channel at the ampulla of Vater can block both bile and pancreatic ducts

Question 24

What can result from tumors that arise in the head of the pancreas? Where are these tumors located (in reference to another structure besides the pancreas)?

Answer 24

Tumor that arise in the head of the pancreas (near the duodenum) can cause obstruction of the common bile duct

Question 25

What is the organization of the femoral region?

Answer 25

Lateral to medial: Nerve-Artery-Vein-Empty space-Lymphatics; Think: “you go from lateral to medial to find your NAVEL”

Question 26

What is contained in the femoral triangle?

Answer 26

Contains femoral vein, artery, nerve (moving laterally); Think: “Venous near the penis”

Question 27

What structure is used as reference to the local of the femoral sheath fascial tube? How far is the fascial tube from this structure?

Answer 27

Fascial tube 3-4 cm below inguinal ligament

Question 28

What does the femoral sheath include? How is it different from the femoral triangle?

Answer 28

Contains femoral vein, artery, and canal (deep inguinal lymph nodes)… but NOT femoral nerve; Femoral triangle contains femoral vein, artery, nerve

Question 29

Draw the femoral region, including and labeling the following: (1) Femoral Artery (2) Femoral Nerve (3) Femoral Ring - site of femoral hernia (4) Femoral sheath (5) Femoral Vein (6) Inguinal ligament (7) Adductor longus muscle (8) Lymphatics (9) Sartorius muscle.

Answer 29

See p. 342 in First Aid 2014 for visual at bottom of page

Question 30

What is the clinical correlation of the femoral ring?

Answer 30

Femoral ring - site of femoral hernia