9.1: Abdominal Viscera

Question 1

outline the primary and secondary organs

Answer 1

The primary organs are the stomach, small intestine, and large intestine; the accessory organs are the liver, gallbladder, pancreas, and spleen

he kid neys, proximal ureters, and suprarenal glands are found outside the peritoneal cavity within the retroperitoneum on the posterior abdominal wall

Question 2

Answer 2

Question 3

which organs are part of the foregut, midgut and hindgut

Answer 3

Foregut, esophagus, stomach, 2/3ds of duodenum, liver, gall bladder and the superior part of the pancreas;

the midgut, which includes the distal half of the duodenum, the jejunum, ileum, cecum, and appendix, and the ascending and proximal two thirds of the transverse colon; and

the hindgut, which includes the distal third of the transverse colon, the descending and sigmoid colons, the rectum, and the upper part of the anal canal.

Question 4

outline the localization of pain from the foregut, midgut and hindgut derivatives

Answer 4

LOCALIZATION OF PAIN FROM FOREGUT, MIDGUT, AND HINDGUT DERIVATIVES

Pain from gastrointestinal organs follows pathways determined by embryologic origin. Pain from foregut structures is localized to the epigastric region, pain from structures of the midgut localizes in the periumbilical region, and pain arising from structures of the hindgut localizes in the hypogastric region.

Question 5

Answer 5

Question 6

Draw a stomach and label it

Answer 6

Question 8

Outline the 4 main parts of the stomach

Answer 8

The cardia, which surrounds the opening to the esophagus

The fundus, the superior portion that rises above and to the left of the opening between the esophagus and stomach (cardiac orifice)

The body, the large expanded portion below the fundus

The pyloric part, which is the outflow channel made up of the wide pyloric antrum, a narrow pyloric canal, and the pyloris or sphincteric region, which contains a muscular pyloric sphincter that surrounds the pyloric orifice into the first part of the duodenum.

Question 9

The layers of peritoneum on the stomach’s anterior and posterior surfaces unite along the lesser curvature to form the ____ ____; along the greater curvature they unite to form the ____ ___

Answer 9

The layers of peritoneum on the stomach’s anterior and posterior surfaces unite along the lesser curvature to form the lesser omentum; along the greater curvature they unite to form the greater omentum

Question 10

whatis the stomach in contact with on the anterior side? posterior side?

Answer 10

anterior: abdominal wall, diaphragm, left lobe of the liver
posteriorly: anterior wall of the omental bursa

Question 11

when the body is supine, the sotmach rests on the:

Answer 11

pancreas, the spleen, the left kidney, the left suprarenal gland, and the transverse colon and its mesentery.

Question 12

which arteries supply the stomach?

Answer 12

Right and left gastric arteries

right and left gastro-omental arteries

short gastric arteries

All are derived from the branches of celiac trunk)

Veins that accompany the arteries of the staomch drain to the hepatic portal venous system

Question 14

Lymph vessels (supplying the stomach) drain to ___ and ___-____ nodes, which drain to the ____ lymph nodes

Answer 14

Lymph vessels drain to gastric and gastro-omental nodes, which drain to the celiac lymph nodes

Question 15

which nerve innervates the stomach?

Answer 15

the celiac nerve plexus innervates the stoamch.

• sympathetic nerves promote vasoconstriction and inhibit peristalsis
• parasympathetic nerves stimulate gastric secretion

Question 16

most retroperitoneal part of the small intestine

Answer 16

duodenum is the most retroperitoneal, but all are suspended by the mesentery of the small intestine.

Question 17

4 parts of the duodenum and where they are located in relation to the vertebra

Answer 17

1. The superior (first) part is at the level of the L1 vertebra.
   - The proximal 2-cm segment, called the duodenal bulb or ampulla, is suspended from a mesentery.
2. The descending (second) part extends along the right side of the L1–L3 vertebral bodies.

This is the site of the junction of the foregut and midgut.

• The hepatopancreatic duct, formed by the common bile duct and main pancreatic duct, enters the duodenum through the major duodenal papilla on the posteromedial wall. Superior to that, the accessory pancreatic duct enters through the minor duodenal papilla.
  3. The horizontal (third) part crosses to the left, anterior to the inferior vena cava, the aorta, and the L3 vertebra, along the inferior border of the pancreas.

The root of the mesentery of the small intestine (mesenteric root) and superior mesenteric vessels cross anteriorly (see Fig. 8.3).

4. The ascending (fourth) part ascends along the left side of the aorta to the level of the L2 vertebra at the inferior border of the pancreas.
   - It joins the jejunum at the duodenojejunal flexure, which is suspended from the posterior abdominal wall by the suspensory ligament (of Treitz).

Question 18

what quadrant is the jejnum primarily located in

Answer 18

proximal two fifths of the intraperitoneal portion of the small intestine, is suspended by the small bowel mesentery and is located predominantly in the left upper quadran

Question 19

which is thicker, jejnum or ileum

Answer 19

the jejunum is thicker and larger in diameter than the ileum

Question 20

characteristic circular folds of the inner surface of the jejnum is called:

Answer 20

plicae circulares

Question 21

in the jejnum, widely spaced arterial arcades within its mesentery give rise to long, straight arteries called the ___ ___

Answer 21

vasa recta

Question 22

T/F ileum is longer than the jejnum

Answer 22

true

Question 23

characteristic lymphoid nodules of the ileum are called:

Answer 23

peyers patches. they buldge outward from the connective tissue layer underlying the epithelium, and in the ileum, the plicae circulares are low and sparce. tehre is more fat, denser arterial arcades, and a shorter vasa recta in its mesentery than the jejunum

Question 24

compare and contrast the ileum with the jejunum

Answer 24

the ileum has peyers patches. they buldge outward from the connective tissue layer underlying the epithelium, and in the ileum, the plicae circulares are low and sparce (compared to them in the jejnum). there is more fat in the ileum, denser arterial arcades, and a shorter vasa recta in its mesentery than the jejunum

Question 25

outline the blood supply of the small intestine

Answer 25

• The section that extends from the pyloric sphincter to below the major duodenal papilla (foregut) is supplied by the superior pancreaticoduodenal branch of the gastroduodenal artery (supplied through the celiac trunk).

The midgut (distal part of the descending duodenum, the jejunum, and the ileum) is supplied by the inferiorpancreaticoduodenal, jejunal, and ileal arteries, branches of the superior mesenteric artery.

Veins of similar names accompany the arteries and terminate in the hepatic portal system.

Lymph vessels from the small intestine follow the course of the arteries and drain into the celiac and superior mesenteric nodes.

Question 26

which plexuses innervate the small intestine

Answer 26

The celiac (to foregut) and superior mesenteric (to midgut) plexuses innervate the small intestine (see Fig. 8.25A,B).

Sympathetic innervation inhibits intestinal mobility, secretion, and vasodilation.

Parasympathetic innervation restores normal digestive activity following sympathetic stimulation.

Visceral sensory fibers transmit feelings of distension (often perceived as cramping), but the intestine is insensitive to most pain stimuli.

Question 27

What is a Meckel’s diverticulum?

Answer 27

an outpouching of the ileum that is a remnant of the omphalomesenteric duct (yolk stalk) that fails to resorb. The diverticulum may be unattached distally or connect to the umbilicus via a fibrous cord or fistula. They are present in ~ 2% of the population, are located ~ 2 feet proximal to the ileocecal junction, and often contain two or more types of mucosa. The diverticulum can contain gastric, pancreatic, jejunal, or colonic tissue. An ileal diverticulum is usually asymptomatic but when inflamed may mimic acute appendicitis.

Question 28

Answer 28

Question 29

Answer 29

Question 30

Answer 30

Question 31

Answer 31

Question 32

Answer 32

Question 33

Answer 33

Question 35

large intestine extends from the ___ to the ___ ___. Function?

Answer 35

cecum to the anal canal.

It converts liquid feces to a semisolid state through the absorption of water, electrolytes, and salts. It also stores and lubricates fecal matter. Although it consists of five parts, only the cecum, appendix, and colon reside in the abdo men. The rectum and anal canal are described in Chapter 11, Pelvic Viscera.

Question 36

outline the structures of the large colon (9.12)

Answer 36

Question 37

review figure 9.13

Question 38

Does the cecum have mesentery?

Answer 38

no. surrounded by peritoneum and is fairly mobile.

Question 39

The (vermiform) appendix is a blind muscular _____ (outpouching) that opens into the posteromedial wall of the ___ below the ____ orifice.

What do the walls of the appendix contain?

Answer 39

The (vermiform) appendix is a blind muscular diverticulum (outpouching) that opens into the posteromedial wall of the cecum below the ileocecal orifice.

Contains a large amont of lymphoid tissue.

Question 40

The appendix, transverse colon, and sigmoid colon are ____. Each is suspended by its respective ____ (mesentery). The left colic flexure is attached to the ____ by the ____ ligament.

Answer 40

The appendix, transverse colon, and sigmoid colon are intraperitoneal. Each is suspended by its respective mesocolon (mesentery). The left colic flexure is attached to the diaphragm by the phrenicocolic ligament.

Question 41

the ascending and descending colons are ___ ___ and lack mesenteries

Answer 41

SECONDARILY RETROPERITONEAL

Question 42

External features of the colon distinguish it from the small intestine:

Answer 42

External features of the colon distinguish it from the small intestine:

Teniae coli, three longitudinal bands formed by the outer muscular layer

Haustra, outpouchings of the intestinal wall visible between the teniae coli

Epiploic appendices, small sacs of fat aligned along the teniae

Question 43

The ____, ____ colic, and ____ colic branches of the superior mesenteric artery supply the cecum, ascending colon, and proximal two thirds of the transverse colon (midgut)

Answer 43

The ileocolic, right colic, and middle colic branches of the superior mesenteric artery supply the cecum, ascending colon, and proximal two thirds of the transverse colon (midgut)

Question 44

The ____ colic and ______ branches of the inferior mesenteric artery supply the distal third of the transverse colon, and the descending and sigmoid colons (hindgut). A ____ ____ branch supplies the upper rectum in the pelvis.

Answer 44

The LEFT colic and SIGMOID branches of the inferior mesenteric artery supply the distal third of the transverse colon, and the descending and sigmoid colons (hindgut). A superior rectal branch supplies the upper rectum in the pelvis.

Question 45

The ____ artery runs along the mesenteric border of the large intestine, anastomosing branches of the ____ mesenteric artery with those of the _____ ____ artery. In turn, the superior ____ artery anastomoses with middle rectal and inferior rectal branches in the pelvis.

Veins of the colon follow the arteries and drain into the ____ _____ _____.

Lymph vessels follow arterial pathways to drain into _____ or ______ mesenteric nodes.

Answer 45

The marginal artery runs along the mesenteric border of the large intestine, anastomosing branches of the superior mesenteric artery with those of the inferior mesenteric artery. In turn, the superior rectal artery anastomoses with middle rectal and inferior rectal branches in the pelvis.

Veins of the colon follow the arteries and drain into the hepatic portal system.

Lymph vessels follow arterial pathways to drain into superior mesenteric or inferior mesenteric nodes.

Question 46

which nerve plexuses innervate the large intestine

Answer 46

the superior mesenteric (midgut) and inferior mesenteric (hindgut) nerve plexuses innervate the large intestine.

Question 47

explain VOLVULUS OF THE SIGMOID COLON

Answer 47

Rotation and twisting of the sigmoid colon on its mesentery can lead to obstruction of the descending and sigmoid colons. Constipation, the primary symptom, may progress to fecal impaction where the bowel becomes obstructed by hardened feces. This may be accompanied by abdominal pain, distension, and vomiting. The volvulus can become ischemic (have a reduced blood supply) and necrotic (tissue death) if not treated. Surgery is required to untwist the affected segment and resect any necrotic bowel.

Question 48

explain appendicitis and how the pain is transmitted

Answer 48

Inflammation of the appendix is felt initially as vague pain in the periumbilical region, transmitted via visceral fibers from the T10 spinal cord segment. As the inflammation irritates the overlying parietal peritoneum, acute pain is felt in the lower right quadrant and can be elicited by pressure near McBurney’s point (located one third of the distance along a line between the anterior superior iliac spine and the umbilicus). Although the attached part of the appendix usually lies deep to this point, its free end is variable and may lie posterior to the cecum (retrocecal) or drape over the pelvic brim.