Clinical Anatomy

Question 1

Name the 3 sections of the esophagus and what causes a stricture in each

Answer 1

1. Cervical portion: stricture can be caused by cricopharyngeus muscle
2. Thoracic portion (bulk): stricture can be caused by bronchi-aortic arch
3. Abdominal portion: stricture caused by esophageal hiatus of diaphragm

Question 2

What ligament allows for movement between the esophagus and the stomach?

Answer 2

Phreno-esophageal igament

Question 3

What is an esophageal hernia? Describe the two types

Answer 3

When the stomach escapes above the diaphragm into the thorax:

1. Sliding hiatal hernia: failure of the phreno-esophageal ligament to keep the stomach in place
2. Rolling (paraesophageal) hernia: fundus of stomach sticks out of the diaphragm and forms a pouch

Question 4

Which type of esophageal hernia is more urgent and why?

Answer 4

Rolling: the fundus of the stomach can become tightly constricted -> leading to a part of the stomach becoming necrotic

Question 5

List two things that a sliding esophageal hernia can cause

Answer 5

Heartburn, indigestion

Question 6

What are the pathways of venous drainage for the esophagus?

Answer 6

1. Most drain through systemic veins: esophageal v -> azygous v -> SVC
2. Veins lower down drain through the portal system; esophageal v -> L gastric v -> portal v -> liver -> hepatic v -> IVC

Question 7

What is the primary cause of esophageal varicies and why?

Answer 7

Portal hypertension: The esophagus has a portal-systemic anastomoses (so both portal and systemic systems meet to drain the same structure). If the liver is blocked (e.g; cirrhosis), the liver becomes too hard for venous drainage to exit via the hepatic vein: causing portal hypertension that builds up. Venous blood coming from the esophagus is forced to push more volume through the systemic circulation, (blood may also become turbulent due to incompetent valves) = causing venous dilation

Question 8

Name 5 factors that contribute to continous hepatocyte damage

Answer 8

1. Alcohol
2. Hep B, C, D
3. Excess iron in the liver
4. Autoimmune liver disease
5. Obesity

Question 9

Name two other locations besides the esophagus where portal-systemic anastomoses exist. Name a condition that can arise from each of these anastomoses

Answer 9

1. Around the rectum: rectal varicies/hemorrhoids
2. Around the umbilicus: if blood cannot drain into the liver more drains through the systemic circulation into the abdomen: caput medusae

Question 10

How can you predict the origin of a tumour based on it’s location in the liver?

Answer 10

Hepatic drainage is so slow that blood in the portal vein (going to the liver) tends to stick to the side (R or L) that it entered from. Therefore one can predict that tumours on the L side of the liver entered via the L portal vein and came through the inferior mesenteric vein -> likely originating from the hindgut

Tumours on the R side of the liver entered via the R portal vein and drained from the superior mesenteric vein -> likely originating in the midgut

Question 11

What other vein does the superior mesenteric vein combine with to form the portal vein?

Answer 11

Splenic vein

Question 12

Which regions does the spleen tend to enlarge into in splenomegaly?

Answer 12

Travels downwards and medial: from the Left hypochondrium towards the R iliac fossa

Question 13

What happens if the spleen ruptures?

Answer 13

Since the spleen is highly vascular a rupture may lead to lots of blood loss

Question 14

What is a common complication of cancer in the pancreatic head region?

Name 3 symptoms of cancer in this region

Answer 14

Since the head region of the pancreas has its own pancreatic duct that drains into the duodenum at the same place as the bile duct, cancer can block this drainage so bile never enters the GI tract and overflows in the liver and boodstream.

Symptoms: jaundice, pale stools, dark urine (excessive bile being excreted)

Question 15

What connects the duodenum to the liver?

Answer 15

The Hepatoduodenal ligament

Question 16

Which region of the duodenum are duodenal ulcers most likely to occur

Answer 16

The Superior part/ “Duodenal cap”

Question 17

Which section of the duodenum do bile and pancreatic juices enter?

Answer 17

The descending part

Question 18

Where and what is the ligament of treitz?

Answer 18

Double fold of peritoneum suspending the duodenojejunal flexure from the posterior abdominal wall. When this suspensory muscle contracts the angle of the duodenojejunal flexure expands, enhancing motion of the intestinal tract contents.

Question 19

What symptom can be observed ‘lower down’ as a result of nutcracker syndrome?

What else can happen in the GI tract as a result of this condition and how might you surgically treat this?

Answer 19

An aneurysm of the SMA can put pressure on the L renal vein which drains the L gonad. This causes a back-pressure tracing back to the testis: presenting with varicosities down to the scrotum.

This can also obstruct the duodenum, and be treated by cutting out the ligament of treitz

Question 20

What is intussusception? Where does it commonly occur?

Answer 20

When part of the intestine folds into the section immediately in front of it, commonly happens at the ileocolic junction (ileum and proximal colon)

Question 21

Name 3 things that intussusception can cause.

Which age group is it more common in and which age group is it more serious?

Answer 21

1. Abdominal cramping
2. Currant jelly stools: dark red and mucoid
3. Possible necrosis and bowel perforation

More common in infants, more serious in adults

Question 22

What is diverticulosis? Which age group and location is it most common?

Name 2 symptoms diverticulosis can cause

Answer 22

Multiple outpocketings of mucosa, commonly in the sigmoid colon in middle aged-elderly

Results in diarrhea and cramping

Question 23

Which investigation can be done if GI polyps or tumours are suspected?

Answer 23

Colonoscopy

Question 24

What is the significance of the ‘apple core sign’ on an x-ray?

Answer 24

Indicates colonic narrowing: could be caused by an annular (ring-like) colorectal carcinoma causing a stenosis.

Question 25

Define volvulus, what are the possible consequences?

Answer 25

When a loop of intestine twists around itself and the mesentery supporting it, resulting in bowel obstruction, perforation and necrosis

Question 26

Where does volvulus of the colon most commonly occur?

Answer 26

In the sigmoid colon

Question 27

Where in the GI tract is most commonly affected by Crohn's disease? What can happen to the affected region?

Answer 27

Most commonly the distal ileum or colon are affected, although it can affect any part of the GI tract. The inflammation can become transmural and lead to deep ulceration, even breaching the muscle and forming a fistula. Granulomas are also common as the macrophages try to wall off the destructive pathogens (and an accumulation of neutrophils)

Question 28

What causes Crohn's disease?

Answer 28

Unknown, thought of as autoimmune but research may suggest it is the immune system attacking a harmless pathogen or food in the gut