Hs: Week 4: Small And Large Intestines

Front 1

Name 4 arteries that supply the duodenum.

Back 1

Proximal part:
1. Supraduodenal A
2. Gastroduodenal A
3. Superior pancreaticoduodenal AA

Distal part:
4. Inferior pancreaticoduodenal AA

Front 2

List 4 factors that distinguish the jejunum from the ileum.

Back 2

1. Larger diameter
2. Thicker walls
3. Emptier
4. No fat (has "windows" between arterial arcades)

Front 3

Arterial arcades are less prominent in which part of the small intestine?

Back 3

Jejunum

Front 4

Arterial arcades are more prominent in which part of the small intestine?

Back 4

Ileum

Front 5

Vasa recta are longer when traveling to which part of the small intestine?

Back 5

Jejunum

Front 6

Vasa recta are shorter when traveling to which part of the small intestine?

Back 6

Ileum

Front 7

T or F.

Most of the duodenum is retroperitoneal.

Back 7

TRUE.

Only the first part of the duodenum is intraperitoneal (surrounded by peritoneum). The beginning of the first part is connected to the liver by the hepatoduodenal L of the lesser omentum.

Front 8

The major duodenal papilla represents the junction of _______ and ______.

Back 8

Foregut and midgut

(This is why duodenum receives blood supply from the Celiac trunk (foregut arteries) and the Superior Mesenteric A (midgut arterties).

Front 9

Name the surgical landmark of the duodenum

Back 9

Duodenojejunal junction
(fixed in position by the Suspensory L--aka "Ligament of Treitz")

Front 10

Name the arterial anastomoses that indicates the junction b/w the foregut and the midgut.

Back 10

Superior pancreaticoduodenal A (from the Gastroduodenal A) and the Inferior pancreaticoduodenal A (from the Superior Mesenteric A)

Front 11

Name the anastomoses that indicates the junction b/w the midgut and hindgut.

Back 11

Marginal branches of the Middle Colic A and the Left Colic A.

Front 12

Encroaching fat is found on what part of the small intestines?

Back 12

Ileum

Front 13

Name the 5 layers of the small intestine.

Back 13

1. Serosa (visceral peritoneum)
2. Longitudinal M layer
3. Circular M layer
4. Submucosa
4. Mucosa w/ circular folds

(Layers are same in jejunum and ileum, except the circular folds are not as close together in the ileum and lymphoid tissue is present in the mucosa).

Front 14

What are "Peyer's patches" and where are they found?

Back 14

Lymphoid tissue patches found in the ileum, particularly in the lower part.

Front 15

What is Meckel's diverticulum?

Back 15

Outpouching (finger-like pouch) of the ileum derived from an unobliterated yolk stalk.

Front 16

Name the anastomoses that indicates the junction b/w the midgut and hindgut.

Back 16

Marginal branches of the Middle Colic A and the Left Colic A.

Front 17

Encroaching fat is found on what part of the small intestines?

Back 17

Ileum

Front 18

Name the 5 layers of the small intestine.

Back 18

1. Serosa (visceral peritoneum)
2. Longitudinal M layer
3. Circular M layer
4. Submucosa
4. Mucosa w/ circular folds

(Layers are same in jejunum and ileum, except the circular folds are not as close together in the ileum and lymphoid tissue is present in the mucosa).

Front 19

What are "Peyer's patches" and where are they found?

Back 19

Lymphoid tissue patches found in the ileum, particularly in the lower part.

Front 20

What is a Meckel's diverticulum?

Back 20

Outpouching (finger-like pouch) of the ileum derived from an unobliterated yolk stalk (vitelline or omphalo-mesenteric duct)

Front 21

Where are Meckel's diverticulums typically located?
How long are they?
In what percent of the population do they generally occur?

Back 21

1. Located 2 feet proximal to the ileocecal junction on the antimesenteric side.
2. About 2 inches long.
3. 2% of the population

Front 22

What types of ectopic tissues can be found in Meckel's diverticulums?
Describe the symptoms.

Back 22

1. Gastric cells
2. Pancreatic cells

SYMPTOMS:
1. Abdominal pain
2. Vomiting
3. Fever
4. Constipation

Front 23

What is volvulus?

Back 23

Twisting of the intestine.

Front 24

What things can cause small bowel obstruction?

Back 24

1. Postoperative adhesions
2. Tumors
3. Gallstones
4. Volvulus
5. Congenital malrotation
6. Chron's disease (inflammatory bowel disease)
7. Hernias
8. Peritonitis

Front 25

Describe some symptoms of small bowel obstruction.

Back 25

1. Colicky abdominal pain and cramping
2. Nausea and vomiting
3. Constipation
4. Abdominal distension

Front 26

Name 3 distinguishing characteristics of the large intestine.

Back 26

1. Tenia coli
2. Haustrations
3. Epiploic appendages

Front 27

Describe the functions of the large intestine.

Back 27

Absorbs electrolytes, minerals, water, and salt in order to concentrate waste and form feces.

Front 28

The arterial supply to the appendix comes from where?

Back 28

Appendicular A
(branch of the ileal branch of the Ileocolic A (Superior mesenteric A))

Front 29

T or F.

The cecum is surrounding by peritoneum, but has no associated mesentery.

Back 29

TRUE.

Front 30

T or F.

Lymphoid tissue is located within the appendix.

Back 30

TRUE.

Front 31

Where is the typical location of the appendix?

Back 31

"McBurney's point"
Draw a line from umbilicus to the ASIS. The lateral 1/3 of line is this point.

Front 32

What are diverticula?

Back 32

External evaginations or small mucosal herniations

Front 33

Why do diverticula develop and what are the factors put a person at risk?
How can it be treated?

Back 33

Diverticula develop as a result of high pressure within the colon.
Risk factors include older age and a low-fiber diet.
Can be treated with rest, high-fiber diet, and antibiotics (for the case of diverticulitis).

Front 34

Diverticulits occurs most often where?

Back 34

Sigmoid colon.

Front 35

If a patient experiences right lower quadrant pain, what should you immediately consider?

Back 35

Acute appendicitis

Front 36

If a patient is experiencing left lower abdominal pain, what should you consider?

Back 36

Diverticulitis
(occurs most often in sigmoid colon).

Front 37

Which organs are supplied by the Superior Mesenteric A?

Back 37

(midgut organs)
1. Cecum
2. Appendix
3. Ascending colon
4. Transverse colon
5. Distal portion of duodenum
6. Jejunum and Ileum

Front 38

Which organs are supplied by the Inferior mesenteric A?

Back 38

1. Descending colon.
2. Sigmoid colon
3. Rectum

Front 39

Which portions of the colon are retroperitoneal?

Back 39

Ascending and descending portions

Front 40

Name 3 mesenteries of the colon.

Back 40

1. Mesoappendix
2. Transverse mesocolon
3. Sigmoid mesocolon

(the cecum is covered by peritoneum, but has no mesentery)

Front 41

In the case of portal hypertension, which vein becomes functional that is normally not functional?

Back 41

Paraumbilical V

Connects Portal V to Superficial and Inferior epigastric VV.

Front 42

Name 4 important Portacaval anastomoses.

Why are these regions important?

Back 42

1. Left Gastric V with Esophageal V of azygous venous system.
2. Superior rectal V with Middle and Inferior Rectal VV
3. Paraumbilical VV with radicles of the Epigastric (superficial and inferior) VV.
4. Retroperitoneal VV draining the colon and twigs of the renal, suprarenal, and gonadal VV.

*In the case of portal hypertension, these regions will become distended.

Front 43

Internal hemorrhoids present _____ pain, while external hemorrhoids present _______ pain.

Back 43

Internal hemorrhoids = DULL pain (autonomic nerves)
External hemorrhoids = SHARP pain (somatic nerves)

Front 44

What are some causes of portal hypertension?

Back 44

1. Thrombosis of Portal V
2. Liver cirrhosis

Front 45

Caput medusa, hemorrhoids, and esophageal varices can all be caused by _________?

Back 45

Portal hypertension

Front 46

How can portal hypertension be reduced?

Back 46

Diverting blood from the portal to the caval system:
1. Anastomosing the Splenic V to the Left Renal V
2. Creating communication bw/ the Portal V and the IVC.
3. TIPS (transjugular intrahepatic portosystemic shunt) procedure.

Front 47

What is a TIPS procedure?

Back 47

Transjugular Intrahepatic Portosystemic Shunt

1. Nonsurgical, invasive radiologic procedure
2. Cather is placed in the right Internal jugular V through which an intrahepatic shunt is created b/w a Heptic V and a branch of the Portal V. Then an extendable stent is placed to created a channel.

Front 48

Preganglionic sympathetic fibers in the Greater splanchnic N synapse with postganglionic fibers where?

Back 48

Celiac ganglion

Front 49

What plexus is b/w Longitudinal and Circular muscles of the intestine?

Back 49

Myenteric plexus

Front 50

What plexus is found in the submucosa of the intestine?

Back 50

Submucosal plexus

Front 51

What causes Hirschsprung's disease?

Back 51

Absense of enteric ganglia (post-ganglionic parasympathetic ganglia) in the lower part of the colon.
Leads to dilation of the colon PROXIMAL to the inactive segment.

Front 52

A failure of neural crest cells to form the myenteric plexus will result in what disease?

Back 52

Hirschprung's disease

Front 53

Pelvic splanchnic nerves consist of what types of fibers?

Which organs do these nerves supply?

Back 53

Preganglionic parasympathetic fibers coming from S2, S3, S4.

Supply descending colon, sigmoid colon, and ALL pelvic organs.

Front 54

Which parasympathetic nerve supplies all thoracic and abdominal viscera down to the transverse colon?

Back 54

Vagus N.

(pelvic splanchnic nerves supply parasympathetic fibers to rest of abdomen and pelvis).