Lesson 20: Basic Organs and Structures in the Abdominal and Pelvic Cavity

Caudal border (pelvic inlet from left and right hip bones)

Abdominal cavity boundaries:

Red

Dorsal border (thoracic and lumbar vertebrae)

Abdominal cavity boundaries:

Purple

Cranial border (last ribs, costal arch, and diaphragm)

Abdominal cavity boundaries:

Yellow

Ventral border (lateral and ventral abdominal muscles)

Abdominal cavity boundaries:

Blue

Liver

Left abdominal cavity:

7 and 8

Stomach

Left abdominal cavity:

9

Spleen

Left abdominal cavity:

10

Left kidney

Left abdominal cavity:

11

Jejunal loops

Left abdominal cavity:

12

Bladder

Left abdominal cavity:

14

Liver

Right abdominal cavity:

8, 7, and 5

Right kidney

Right abdominal cavity:

9

Cecum

Right abdominal cavity:

13

Descending duodenum

Right abdominal cavity:

14

Caval foramen

Diaphragm:

1

Aortic hiatus (aorta, azygous vein, thoracic duct)

Diaphragm:

2

Esophageal hiatus

Diaphragm:

3

Visceral peritoneum

Peritoneal lining:

1

Lines organs

Parietal peritoneum

Peritoneal lining:

2

Lines walls

Retroperitoneal right and left kidneys

Peritoneal lining:

4 and 4'

Located behind the peritoneum

External abdominal m.

Abdominal cavity muscles:

Origin: costal arch, thoracolumbar fascia

Insertion: linea alba, prepubic tendon

External abdominal m.

Abdominal cavity muscles:

a

Origin: costal arch, thoracolumbar fascia

Insertion: linea alba, prepubic tendon

Internal abdominal m.

Abdominal cavity muscles:

Origin: tuber coxae, thoracolumbar fascia

Insertion: costal arch, linea alba, prepubic tendon

Internal abdominal m.

Abdominal cavity muscles:

b

Origin: tuber coxae, thoracolumbar fascia

Insertion: costal arch, linea alba, prepubic tendon

Rectus abdominis m.

Abdominal cavity muscles:

Origin: xiphoid process

Insertion: as prepubic tendon on the pecten of the pubis

Rectus abdominis m.

Abdominal cavity muscles:

c

Origin: xiphoid process

Insertion: as prepubic tendon on the pecten of the pubis

Transversus abdominis m.

Abdominal cavity muscles

Origin: transverse process of lumbar vertebrae, last ribs, thoracolumbar fascia (deep)

Insertion: linea alba, prepubic tendon

Transversus abdominis m.

Abdominal cavity muscles:

d

Origin: transverse process of lumbar vertebrae, last ribs, thoracolumbar fascia (deep)

Insertion: linea alba, prepubic tendon

Linea alba (white line)

Rectus sheath

The tendonous wrapping around the rectus abdominis muscle

Heavy abdominal contents need reinforcement

External rectus sheath

Rectus sheath:

1

Internal rectus sheath

Rectus sheath:

2

Caudo-dorsal quadrant

Quadrants of abdominal wall:

1

Cranio-ventral quadrant

Quadrants of abdominal wall:

4

Caudo-ventral quadrant

Quadrants of abdominal wall:

3

Cranio-dorsal quadrant

Quadrants of abdominal wall:

2

Phrenico-abdominal artery (common trunk)

Abdominal wall blood vessels:

1

Branches the cranial abdominal and caudal phrenic arteries

Phrenico-abdominal artery (common trunk)

Abdominal wall blood vessels:

1

Deep circumflex iliac (caudal abdominal artery)

Abdominal wall blood vessels:

2

Caudal superficial epigastric artery

Abdominal wall blood vessels:

7

Caudal epigastric artery

Abdominal wall blood vessels:

6

Cranial epigastric artery

Abdominal wall blood vessels:

5

Cranial superficial epigastric artery

Abdominal wall blood vessels:

5

Cranial superficial epigastric artery

Abdominal wall blood vessels:

1

Cranial epigastric artery

Abdominal wall blood vessels:

4

Caudal epigastric artery

Abdominal wall blood vessels:

3

Internal thoracic artery

Abdominal wall blood vessels:

3

Caudal superficial epigastric artery

Abdominal wall blood vessels:

2

Costo-abdominal n.

DOG Abdominal wall nerves (outer surface):

T13

Costo-abdominal n.

DOG Abdominal wall nerves (outer surface):

T13

Cranial iliohypogastric n.

DOG Abdominal wall nerves (outer surface):

L1

Cranial iliohypogastric n.

DOG Abdominal wall nerves (outer surface):

L1

Caudal iliohypogastric n.

DOG Abdominal wall nerves (outer surface):

L2

Caudal iliohypogastric n.

DOG Abdominal wall nerves (outer surface):

L2

Ilioinguinal n.

DOG Abdominal wall nerves (outer surface):

L3

Ilioinguinal n.

DOG Abdominal wall nerves (outer surface):

L3

Lateral cutaneous femoral n.

DOG Abdominal wall nerves (outer surface):

L4

Paralumbar fossa

Bovine important surgical and clinical area

Boundaries-

Cranially: last rib

Dorsally: transverse processes of lumbar vertebrae

Caudally: craniodorsal edge of the internal abdominal oblique m.

Costoabdominal n.

Bovine nerves of paralumbar fossa:

T13

Iliohypogastric n.

Bovine nerves of paralumbar fossa:

L1

Ilioinguinal n.

Bovine nerves of paralumbar fossa:

L2

Genitofemoral n.

Bovine nerves of paralumbar fossa:

L3

Dorsal border

Pelvic cavity borders:

sacrum, first few caudal vertebrae

Lateral border

Pelvic cavity borders:

pelvic bones (ilium, ischium) and broad sacrotuberous/sacrosciatic ligament

Ventral border

Pelvic cavity borders:

pelvic symphysis, floor of pelvic canal, extends between pelvic inlet and outlet

Caudal border

Pelvic cavity borders:

closed off by muscles that create a pelvic diaphragm and a urogenital diaphragm

Anal triangle

Pelvic cavity boundaries:

Top triangle

Dorsal: caudal vertebrae

Lateral: deeper sacrosciatic ligament

Ventral: line between ischiatic tuberosities/deeper structure will be ischial arch

Pelvic diaphragm

Closes off the anal triangle

Urogenital triangle

Pelvic cavity boundaries:

Bottom triangle

Dorsal: line between ischiatic tuberosities

Ventral: ventral commissure of the vulva

Urogenital diaphragm

Closes off the urogenital triangle

Includes the urogenital muscles

Pararectal fossa

Compartments of the pelvic cavity:

1

the region/space dorsal to the rectum and ventral the sacral/caudal vertebrae

Rectogenital pouch

Compartments of the pelvic cavity:

2

the region/space between the rectum dorsally and the reproductive organs ventrally

Vesicogenital pouch

Compartments of the pelvic cavity:

3

the region/space between the reproductive organs dorsally and the bladder ventrally

Pubovesical pouch

Compartments of the pelvic cavity:

4

the region/space between the bladder dorsally and the pubis or ventral abdominal floor