Anatomy 30 Online
Lab Exercise 25 – Digestive System
I. Lab Objectives
A. Dissect the digestive system of a fetal pig
B. Identify the organs of the digestive system
C. Identify the serous membranes of the digestive system
D. Identify the 4 tissue layers of the G. I. tract
E. View, draw, and label microscope slides of major digestive organs
II. Dissection of the fetal pig digestive system – follow my directions to dissect the fetal pig.
Label the digestive organs listed in this exercise on the model pictures on the following pages.
III. Use the models to identify the following organs of the digestive system.
A. Head models – hard & soft palates, tongue, teeth, uvula, Eustachian tube opening,
nasopharynx, oropharynx, laryngopharynx, epiglottis, esophagus, palatine tonsil, pharyngeal
tonsil, salivary glands (parotid, submandibular, sublingual).
B. Tooth models – incisors, canines, bicuspids, molars, crown, neck, root, enamel, cementum,
dentin, pulp cavity, root canal, periodontal ligament
C. Torso and digestive organ models
1. Stomach – gastroesophageal (cardiac) sphincter, cardiac region, fundus, body, rugae,
pylorus, pyloric sphincter, greater and lesser curvatures (greater omentum attached to
greater curvature and lesser omentum attached to lesser curvature).
2. Small intestines – duodenum, jejunum, ileum, ileocecal valve, hepatopancreatic ampulla
(of Vater), duodenal papilla, hepatopancreatic sphincter (of Oddi), mesentery interconnects
intestines.
3. Large intestine – ileocecal valve, cecum, appendix, colon (ascending, transverse,
descending, sigmoid), rectum, anal canal, anus (with external and internal sphincters),
teniae coli, haustra.
4. Pancreas – head (next to duodenum), body (behind stomach), tail (next to spleen),
pancreatic duct, hepatopancreatic ampulla
5. Liver – R. lobe, L. lobe, quadrate lobe, caudate lobe, falciform ligament, ligamentum teres,
L. & R. hepatic ducts, common hepatic duct, bile duct, hepatic portal vein, hepatic veins,
hepatic artery
6. Gall bladder with cystic duct
D. Small intestine villi model – villi, microvilli, plicae circularis, capillaries, venules,
arterioles, lacteal, duodenal (Brunner’s) glands. Also identify the following tissue layers.
1. Mucosa – simple columnar epithelium, lamina propria (CT), muscularis mucosa (smooth
muscle).
2. Submucosa – dense CT with blood and lymphatic vessels and nerves.
3. Muscularis externa – circular and longitudinal smooth muscle
4. Serosa – areolar CT and visceral peritoneum (simple squamous epithelium)
IV. Draw and label the following microscope slides (see the histology atlas in the lab manual)
A. Stomach – simple columnar epithelium and mucous cells, gastric pits, gastric glands
B. Small intestine – villi, simple columnar epithelium, duodenal (Brunner’s) glands
C. Pancreas – pancreatic islets (of Langerhans), acini cells
D. Liver – liver lobule, central vein, hepatic triad (branches of hepatic artery, hepatic portal
vein, bile duct), hepatocytes
Label the digestive organs visible on the torso models below.
Superficial organs
Deep organs
Label the digestive structures on the midsagittal head model below.
Label the structures of the pancreas and liver models below.
Posterior, internal Liver
Anterior Pancreas & associated structures
Label the structures of the small intestine and large intestine models below.
Large Intestine
Small Intestine wall
Label the parts of the stomach model below.
External Stomach
Internal Stomach
Lab 25 Review Assignment: answer the questions on pp. 325-328 in the lab manual.