3

14

15

16

16

309

Liver and gall bladder

Inferior view, posterior at top

Besides pancreatic juice, the other secretory product emptied into the duodenum is bile. The biliary system, which

Liver and Gallbladder

also develops as an embryonic outgrowth of the duodenum, includes the liver, the gallbladder, and

associated ducts. The rounded, wedge-shaped liver, the largest organ of the abdomen, occupies a

major portion of the upper right peritoneal cavity. The gallbladder is a pear-shaped, saccular organ situated in a depression on the inferior surface of the right lobe of the liver where it is a storage organ of the

bile that is produced in the liver. Connecting the gallbladder to the common hepatic bile duct is the cystic

bile duct. The junction of these ducts forms the main bile duct that drains into the duodenum. The liver

is the largest and most important metabolic organ in the body, which in addition to producing the important bile salts associated with digestion, performs a myriad of metabolic functions.

 1 Right lobe of liver

 2 Left lobe of liver

 3 Caudate lobe of liver

 4 Quadrate lobe of liver

 5 Gallbladder

 6 Cystic bile duct

 7 Hepatic artery

 8 Hepatic portal vein

 9 Round ligament

10 Inferior vena cava

 11 Hepatocytes

12 Central vein

13 Hepatic sinusoid

14 Branch of hepatic artery

15 Bile duct

16 Branch of hepatic portal vein

Photomicrograph of liver lobule

50x

Photomicrograph of portal triad

150x

Photomicrograph of central vein

100x

1

2

3

4

5

6 7

8

9

10

11

11

11

11

12

12

13

14

15

16

1

2

3

4

5

6 7

8

9

10

11

11

11

11

13

14

15

16

310

 1 Cecum

 2 Vermiform appendix

 3 Ascending colon

 4 Right colic (hepatic) flexure

 5 Transverse colon

 6 Left colic (splenic) flexure

 7 Descending colon

 8 Sigmoid colon

The large intestine is much shorter than the small intestine,

averaging about 1.5 meters in length, but typically has a greater

diameter, therefore the name. The large intestine consists of

Large Intestine

 9 Rectum

10 Omental or fatty appendices

 11 Haustra

12 Taeniae coli

13 Absorptive cells

14 Goblet cells

15 Intestinal glands

16 Muscularis mucosae

the cecum, appendix, colon, and rectum. The cecum receives indigestible material from the small intestine and

then moves it through the subdivisions of the colon — the ascending colon, transverse colon, descending

colon, and sigmoid colon — before it enters the terminal portion of the gut tube, the rectum. The large intestine

is primarily a drying and storage organ of indigestible plant fi bers. Minimal absorption of fl uids occurs in the

large intestine as the fecal contents are stored prior to evacuation.

17 Lamina propria

18 Tela submucosa

19 Ileum (cut)

20 Duodenal-jejunal junction (cut)

21 Stomach

22 Root of the mesentery (cut)

Portion of descending colon

Anterior view

Dissection of abdominal cavity with jejunum and ileum removed

Anterior view

Photomicrograph of of large

intestine mucosa

100x

1

2

3

4

5

6

7

8

9

10

12

11

13 13

14

15

15

15

16

17

17

18

19

20

21

22

1

2

3

4

5

6

7

8

9

10

12

11

13 13

14

15

15

15

16 17

19

20

21

22

311

Sagittal section of head and trunk

Medial view

Dissection of the mesentery with jejunum and ileum removed

Anterior view

 1 Transverse mesocolon

 2 The mesentery partially dissected to reveal vessels

 3 Greater omentum

 4 Superior mesenteric vein and tributaries

 5 Branches of superior mesenteric artery

 6 Cecum

 7 Ascending colon

 8 Transverse colon

 9 Gallbladder

10 Cystic bile duct

 11 Common hepatic bile duct

12 Common bile duct

13 Omental or fatty appendices

14 Stomach

15 Small intestine

16 Aorta

Mesenteries are refl ections of the serous peritoneal membrane from the parietal layer

lining the posterior abdominal wall to the visceral layer covering the peritoneal abdominal

organs. The mesenteries not only support the digestive organs and help anchor them in

Mesenteries

the abdominal cavity, but also are the pathways for the vessels and nerves that supply the peritoneal organs.

17 Heart

18 Vertebral column

19 Trachea

20 Aortic arch

21 Pulmonary trunk

22 Brain

23 Tongue

24 Sternum

25 Rectum

26 Bladder

27 Prostate

28 Testis

29 Penis

30 Pubic symphysis

31 Diaphragm

32 Esophagus

1

2

2

3

4

5

5

6

7

8

8

9

10

11

12

13

13

14

14

15

15

15

16

17 18

19

20

21

22

23

24

25 26

27

28

29

30

31

32

1

2

2

3

4

5

5

6

7

8

8

9

10

11

12

13

13

14

14

15

15

15

16

17 18

19

20

21

22

23

24

25 26

27

28

29

30

31

32

312

Omenta are mesenteric structures that unite two digestive organs. These refl ections of the peritoneal membrane course from one abdominal digestive organ to another abdominal digestive organ,

rather than from organ to body wall. There are two omenta in the abdominal cavity. The greater

Omenta

Superfi cial dissection of abdominal cavity with liver elevated

Antero-inferior view

omentum is a peritoneal refl ection between the greater curvature of the stomach and the transverse colon. The lesser

omentum is a peritoneal refl ection between the lesser curvature of the stomach and the liver.

 1 Greater omentum

 2 Lesser omentum

 3 Hepatogastric ligament of lesser omentum

 4 Hepatoduodenal ligament of lesser omentum

 5 Hepatorenal part of coronary ligament

 6 Falciform ligament

 7 Transverse mesocolon

 8 Liver

 9 Stomach

10 Duodenum

 11 Transverse colon

12 Fossa for removed gallbladder

13 Gallbladder

14 Common hepatic bile duct

15 Common bile duct

16 Caudate lobe of liver

17 Lung

18 Heart

19 Breast

20 Diaphragm

21 Epiploic foramen

22 Spleen

Dissection of abdominal cavity with

anterior aspect of liver removed

Antero-inferior view

Dissection of abdominal cavity with

Anterior body wall removed exposing body cavity

Anterior view

1

1

2

4 3

5

6

6

7

8

8

8

9

9

9

10

11

12

13

13

14

15 16

17

18

18

18

19

19

20

20

22

21

1

1

2

4 3

5

6

6

7

8

8

8

9

9

9

10

11

12

13

13

14

15 16

17

18

18

18

19

19

20

20

22

21

REAL ANATOMY

313

Like the respiratory and digestive systems, the urinary system is an environmental

 exchange system. Like all the exchange systems of the body, the urinary system forms an immense interface with the cardiovascular system for the single purpose of regulating the homeostatic balance of the water environment (extracellular matrix)

that surrounds every cell in the body. To make this exchange possible a

large network of microscopic urinary tubes form an intimate

 interface with an equally large network of cardiovascular

capillaries. Th e urinary system consists of two

blood processing centers called the kidneys, two

transport tubes called the ureters, a storage

 organ called the bladder, and a drain called the

urethra. Th e kidneys continually produce

urine, which is then moved via the

 ureters to the storage organ, the bladder.

When it is convenient to remove the

urine from the body, contractions in

the wall of the bladder expell the

urine through the urethra.

In order to survive, every

body cell requires a water environment that is similar to the composition of the oceans in which

 cellular life fi rst arose. Th e kidneys

help maintain this intercellular

 water environment by fi ltering the

blood and regulating its contents

so the blood can help maintain

the correct composition of the

 extracellular fl uid that bathes every

cell. By adjusting the amount of

water in the plasma and the various

plasma constituents, which are

 either conserved for the body or

eliminated in the urine, the kidneys

are able to maintain water and

electrolyte balance within the very

narrow range compatible with life,

despite wide variations in intake

and losses of these constituents

through other avenues.

Find more infomation

about the urinary

system in

19 Urinary System

314

retroperitoneal and subperitoneal spaces in the abdominopelvic cavity, where they are

surrounded by a large amount of adipose tissue and some areolar connective tissue. The

dissection images on this and the facing page depict the organs of the urinary system

and their relations to other organs in the abdominopelvic cavity.

The organs of the urinary system include

the paired kidneys, paired ureters, bladder,

and urethra. The urinary organs occupy the

Urinary Organs

 1 Kidney

 2 Renal pelvis

 3 Ureter

 4 Bladder

 5 Renal vein

 6 Renal artery

Dissection of the retroperitoneal space of the abdominal cavity

Anterior view

 7 Adrenal gland

 8 Aorta

 9 Inferior vena cava

10 Diaphragm

 11 Common iliac artery

12 Psoas major muscle

13 Liver

14 Lumbar vertebra

15 Hilum

16 Perirenal fat

17 Intestines

18 Mesenteric fat

1

2

3

4

5 6

7

8

11 12

10

1

3

5

6

7

10

12

9

11

1

2

3

4

5 6

7

8

11 12

10

1

3

5

6

7

10

12

9

11

315

Transverse section of abdomen at level of fi rst lumbar vertebra

Inferior view

Dissection of abdomen showing perirenal fat

Anterior view

Level of section

Transverse section of abdomen through kidneys

Inferior view

9

18 17

16

14 15

13

1 1

16

8

5

6

17

17

17

17

9

18 17