Carnivore Anatomy Lab 17 Introduction

CONTENTS:

Lab Objectives
Anatomical Terms
Instructor Commentary
Dissection Steps
Dissection Videos
Dissection Images

Lab Objectives:

• Examine abdominal viscera:
      - pancreas (pancreatic lobes, pancreatic ducts, and duodenal papillae)
      - adrenal glands
      - kidneys (renal hilus; renal cortex and medulla)
            -- ureter (renal pelvis & pelvic recesses)

• Examine female internal genitalia:
      - ovary ( and proper ligament of ovary)
      - uterine tube (and infundibulum)
      - broad ligament of the uterus (connecting peritoneum):
            mesovarium & suspensory ligament of ovary
            mesosalpinx & ovarian bursa
            mesometrium & round ligament of the uterus

• Identify "mesenteries" of the alimentary tract:
      - greater and lesser omentum and omental bursa
      - mesoduodenum
      - mesentery (mesojejunum, mesoileum, & root of mesentery)
      - mesocolon
      - mesorectum
      also, liver ligaments (falciform ligament, coronary, & triangular)

• Identify autonomic nerves and sympathetic ganglia:
      - vagus nerve, vagal branches and vagal nerve trunks
      - sympathetic trunk and splanchnic nerves
      - celiac plexus and cranial mesenteric plexus (celiacomesenteric plexus)
            -- celiac ganglia & cranial mesenteric ganglion
      - caudal mesenteric plexus & ganglion
      - right/left hypogastric nerves

CONTENTS

Anatomical Terms:

Abdominal viscera - (continued)
        pancreas (left lobe, body, & right lobe)
                pancreatic duct
                accessory pancreatic duct
        major and minor duodenal papillae
        adrenal glands (right & left)
        kidneys (right & left [palpate] )
                hilus
                renal cortex
                renal medulla
                        pyramids
                        renal crest
                arcuate branches (of renal vessels)
                renal sinus
        ureter
                renal pelvis
                        pelvic recesses

        ovary
                proper ligament of the ovary
        uterine tube
                infundibulum
                        abdominal ostium (not easily seen)
                tuberouterine junction
        uterus (cervix, body, uterine horns)
        broad ligament of the uterus
                mesovarium
                        suspensory ligament of the ovary
                mesosalpinx
                        ovarian bursa
                mesometrium
                        round ligament of the uterus

Peritoneum
        parietal & visceral peritoneum
        connecting peritoneum:
                lesser omentum
                        hepatoduodenal ligament
                greater omentum
                        omental bursa
                                epiploic foramen
                mesoduodenum
                        duodenocolic fold
                mesentery (mesojejunoileum)
                        root of the mesentery
                mesocolon
                        (ascending, transverse, descending)
                ligaments of the liver:
                        right triangular ligament
                        left triangular ligament
                        coronary ligament
                        falciform ligament
                                umbilical vein remnant (round ligament of the liver)

Abdominal viscera: nerves
        vagus nerve (right & left )
                dorsal & ventral branches
                        dorsal & ventral vagal trunks
                                branch to celiacomesenteric plexus (celiac br.)
        sympathetic trunk (right & left )
                major splanchnic n.
                minor splanchnic n.
                lumbar splanchnic nerves
        celiacomesenteric plexus & ganglia:
                celiac plexus
                        right & left celiac ganglia
                cranial mesenteric plexus
                        cranial mesenteric ganglion
        caudal mesenteric plexus & ganglion
                right & left hypogastric nerves

        Note:
             omentum [Latin] = fatty skin
             epiploic [Greek: epiploon] = omentum
             peritoneum [Latin] from per = around & teinien = to stretch
             falciform [Latin] from falx = sickle and forma = form

CONTENTS

Instructor Commentary:

The major duodenal papilla, which receives both the bile duct and the pancreatic duct, is always present cranially in the duodenum. The minor duodenal papilla, which receives the accessory pancreatic duct, is generally present in the dog but present in only a minority (20%) of cats. The minor papilla is absent when the accessory pancreatic duct has atrophied.

The suspensory ligament of the ovary tethers the ovary to the dorsal abdominal wall. During a spay operation (ovariohysterectomy), the suspensory ligament must be manually disrupted in order to bring the ovary to the incision site where ovarian vessels are accessible for ligation.

The evolutionary value of an extensive greater omentum probably relates to limiting peritonitis. The peritoneal cavity offers invading bacteria a good location to reproduce and to spread throughout the abdomen. An infection (abscess) that results from puncture through the abdominal wall or through the gut wall would tend to spread throughout the abdomen unless it is encapsulated. The encapsulation process is greatly facilitated by adhesion of greater omentum to the inflamed surface, bringing leukocytes and fibroblasts to an otherwise exposed surface.

CONTENTS

Dissection Steps:

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Show List of Dissection Steps (PDF)

Dissection Videos:

CONTENTS

Dissection Images:

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