General arrangement of the abdominal viscera pdf - Abdomen

Basic Anatomy

157

Stomach 171

Small Intestine 172

Large Intestine 180

Blood Supply of the Gastrointestinal

Tract 184

Differences Between the Small and

Large Intestines 196

Accessory Organs of the Gastrointestinal

Tract 196

Liver 196

Bile Ducts of the Liver 198

Pancreas 201

Spleen 203

Retroperitoneal Space 206

Urinary Tract 206

Kidneys 206

Ureter 209

Suprarenal Glands 211

Location and Description 211

Blood Supply 215

Lymph Drainage 215

Nerve Supply 215

Arteries on the Posterior Abdominal

Wall 215

Aorta 215

Common Iliac Arteries 216

External Iliac Artery 216

Internal Iliac Artery 218

Veins on the Posterior Abdominal

Wall 218

Inferior Vena Cava 218

Inferior Mesenteric Vein 219

Splenic Vein 219

Superior Mesenteric Vein 219

Portal Vein 219

Lymphatics on the Posterior Abdominal

Wall 219

Lymph Nodes 219

Lymph Vessels 220

Nerves on the Posterior Abdominal

Wall 221

Lumbar Plexus 221

Sympathetic Trunk (Abdominal Part) 222

Aortic Plexuses 224

Cross-Sectional Anatomy of the

Abdomen 226

Radiographic Anatomy 226

Radiographic Appearances of the

Abdomen 226

Radiographic Appearances of the

Gastrointestinal Tract 231

Stomach 231

Duodenum 233

Jejunum and Ileum 234

Large Intestine 234

Radiographic Appearances of the Biliary

Ducts 235

Radiographic Appearances of the Urinary

Tract 235

Kidneys 235

Calyces, Renal Pelvis, and Ureter 235

Surface Anatomy of the Abdominal

Viscera 239

C H A P T E R

trauma to the abdomen are just some of the problems facing

mation and bleeding, malignant disease, and penetrating

one can easily involve another. Gastrointestinal tract inflam

packed within the abdominal cavity; therefore, disease of

and parts of the urinary system. These structures are closely

the gastrointestinal tract, liver, biliary ducts, pancreas, spleen,

The abdominal cavity contains many vital organs, including

O B J E C T I V E S

■

the physician.

■

Emergency problems involving the urinary system are common

and may present diverse symptoms ranging from excruciating

pain to failure to void urine.

■

Within the abdomen also lie the aorta and its branches, the infe-

rior vena cava and its tributaries, and the important portal vein.

■

The purpose of this chapter is to give the student an under-

standing of the significant anatomy relative to clinical problems.

Examiners can ask many good questions regarding this region.

C H A P T E R O U T L I N E

(continued)

natomy

asic

General Arrangement of the

and 5.2). It occupies the left upper quadrant, epigastric, and

between the esophagus and the small intestine (Figs. 5.1

The stomach is a dilated part of the alimentary canal

(Fig. 5.1).

It is deeply placed, lying behind the left lobe of the liver

about 0.5 in. (1.25 cm) enters the stomach on its right side.

slightly to the left of the midline and after a short course of

ynx to the stomach. The esophagus pierces the diaphragm

The esophagus is a tubular structure that joins the phar

(Figs. 5.1 and 5.2).

or fundus, projects below the inferior border of the liver

undersurface of the right lobe of the liver; its blind end,

The gallbladder is a pear-shaped sac that is adherent to the

across the epigastric region.

under the cover of the ribs and costal cartilages and extends

abdominal cavity (Figs. 5.1 and 5.2). It lies almost entirely

The liver is a large organ that occupies the upper part of the

Abdominal Viscera

Liver

Gallbladder

Esophagus

Stomach

158

CHAPTER 5

dix, ascending colon, transverse colon, descending colon,

The large intestine is divided into the cecum, appen

cavity (Fig. 5.3).

the lower right part of the abdominal cavity and the pelvic

of the abdominal cavity, whereas the ileum tends to occupy

(Fig. 5.1). The coils of jejunum occupy the upper left part

nal junction, and the ileum ends at the ileocecal junction

the jejunum. The jejunum begins at the duodenojeju

(6 m) long; the upper two fifths of this length make up

together measure about 20 ft

ileum

jejunum

The

small intestine receives the bile and the pancreatic ducts.

the jejunum (Fig. 5.1). About halfway down its length, the

from the stomach around the head of the pancreas to join

and umbilical regions. It is a C-shaped tube that extends

the posterior abdominal wall. It is situated in the epigastric

of the small intestine, and most of it is deeply placed on

is the first part

duodenum

num, jejunum, and ileum. The

The small intestine is divided into three regions: duode

and then backward and slightly upward.

ribs. Its long axis passes downward and forward to the right

umbilical regions, and much of it lies under cover of the

The Abdomen: Part II—The Abdominal Cavity

Small Intestine

and

Large Intestine

liver

esophagus

diaphragm

stomach

left colic flexure

descending colon

jejunum

sigmoid colon

anus

anal canal

rectum

ileum

appendix

cecum

ileocecal junction

ascending colon

duodenum

transverse colon

right colic flexure

gallbladder

FIGURE 5.1

General arrangement of abdominal viscera.

small intestine.

intestine (Fig. 5.3) and tends to be more fixed than the

intestine arches around and encloses the coils of the small

sigmoid colon, rectum, and anal canal (Fig. 5.1). The large

liver

stomach

gastroepiploic
vessels

greater
omentum

gallbladder

falciform
ligament

FIGURE 5.2

Abdominal organs in situ. Note that the greater

omentum hangs down in front of the small and large

intestines.

Basic Anatomy

the inferior surface of the right lobe of the liver, occupying

extends upward from the cecum to

ascending colon

The

that arises from its medial side (Fig. 5.1).

is a worm-shaped tube

appendix

(Figs. 5.1 and 5.3). The

ward in the right iliac region below the ileocecal junction

is a blind-ended sac that projects down

cecum

The

159

greater omentum

coils of
jejunum

descending
colon

coils of ileum

cecum

appendix

ascending
colon

transverse
colon

FIGURE 5.3

Abdominal contents after the greater omentum

the left upper part of the abdomen between the stomach

The spleen is a soft mass of lymphatic tissue that occupies

and extends from the duodenum to the spleen.

gastric region (Fig. 5.4). It is situated behind the stomach

obliquely across the posterior abdominal wall in the epi

The pancreas is a soft, lobulated organ that stretches

with the anal canal in the perineum.

vis by piercing the pelvic floor. Here, it becomes continuous

colon and descends in front of the sacrum to leave the pel

cavity (Fig. 5.1). It is continuous above with the sigmoid

occupies the posterior part of the pelvic

rectum

The

the rectum in front of the sacrum.

down into the pelvic cavity in the form of a loop. It joins

a continuation of the descending colon (Fig. 5.1). It hangs

begins at the pelvic inlet, where it is

sigmoid colon

The

upper and lower quadrants.

to the pelvis below (Figs. 5.1 and 5.3). It occupies the left

extends from the left colic flexure

descending colon

The

ure to become the descending colon.

of the spleen, bends downward, forming the left colic flex

into the pelvis. The transverse colon, on reaching the region

the erect position, the lower part of the U may extend down

ure (Figs. 5.1 and 5.3). It forms a wide U-shaped curve. In

ical region from the right colic flexure to the left colic flex

crosses the abdomen in the umbil

transverse colon

The

flexure.

reaching the liver, it bends to the left, forming the right colic

the right lower and upper quadrants (Figs. 5.1 and 5.3). On

the periphery.

transverse, and descending parts of the colon are located at

the central part of the abdominal cavity, whereas ascending,

has been reflected upward. Coils of small intestine occupy

-
-

Pancreas

Spleen

central tendon of diaphragm

phrenic artery

inferior vena cava

portal vein

right kidney

bile duct

hepatic artery

ascending colon

superior pancreaticoduodenal artery

transverse colon

descending colon

splenic artery

pancreas

phrenicocolic

ligament

left kidney

spleen

left suprarenal gland

gastroduodenal artery

right suprarenal gland

FIGURE 5.4

Structures situated on the posterior abdominal wall behind the stomach.

160

CHAPTER 5

between the viscera.

surfaces of the peritoneum and allows free movement

which lubricates the

peritoneal fluid,

serous fluid, the

and 5.7). The peritoneum secretes a small amount of

(Figs. 5.5

epiploic foramen

or the

ing of the lesser sac,

open

with one another through an oval window called the

ach. The greater and lesser sacs are in free communication

is smaller and lies behind the stom

lesser sac

pelvis. The

partment and extends from the diaphragm down into the

is the main com

greater sac

sac (Figs. 5.5 and 5.6). The

and the lesser

greater sac

and is divided into two parts: the

The peritoneal cavity is the largest cavity in the body

supports the kidneys.

kidneys, this tissue contains a large amount of fat, which

in the area of the

extraperitoneal tissue;

tissue called the

of the abdominal and pelvic walls is a layer of connective

Between the parietal peritoneum and the fascial lining

the uterus, and the vagina.

munication with the exterior through the uterine tubes,

males, this is a closed cavity, but in females, there is com

peritoneal cavity.

space of the balloon, is called the

the parietal and visceral layers, which is in effect the inside

covers the organs. The potential space between

toneum

visceral peri

the abdominal and pelvic cavities, and the

lines the walls of

parietal peritoneum

from outside. The

regarded as a balloon against which organs are pressed

the viscera (Figs. 5.5 and 5.6). The peritoneum can be

walls of the abdominal and pelvic cavities and clothes

The peritoneum is a thin serous membrane that lines the

abdominal wall.

the upper poles of the kidneys (Fig. 5.4) on the posterior

The suprarenal glands are two yellowish organs that lie on

muscle.

that runs vertically downward on the psoas

ureter

to a

the liver is smaller than the right). Each kidney gives rise

slightly higher than the right (because the left lobe of

of the vertebral column (Fig. 5.4). The left kidney lies

up on the posterior abdominal wall, one on each side

The kidneys are two reddish brown organs situated high

the 10th left rib.

and the diaphragm (Fig. 5.4). It lies along the long axis of

The Abdomen: Part II—The Abdominal Cavity

Kidneys

Suprarenal Glands

Peritoneum

General Arrangement

lesser sac

ileum

greater sac

inferior vena
cava

ascending colon

paracolic gutters

descending colon

aorta

mesentery

coils of ileum

greater omentum

hepatic
artery

portal vein

bile duct

free margin of
lesser omentum

inferior vena
cava

right kidney

left kidney

splenicorenal ligament

gastrosplenic
omentum (ligament)

aorta

stomach

lesser sac

greater sac

falciform ligament

liver

spleen

right

left

T12

median
umbilical
ligament

lateral umbilical ligament

FIGURE 5.5

Transverse sections of the abdomen showing the arrangement of the peritoneum. The

position of the opening of the lesser sac. These sections are viewed from below.

arrow in B indicates the