ANATOMY OF GASTROINTESTINAL TRACT Consists of  Gastrointestinal (GI) tract  Accessory glandular organs Anatomy and functions of the GI tract  GI tract ◦ mouth, pharynx, esophagus, ◦ stomach, small intestine, ◦ large intestine, anus ◦ Accessory Glandular Organs  salivary glands, liver, gallbladder, pancreas Histology/organization of the Gut Wall  From esophagus to anus, GI tract has the same basic arrangement of tissues.  There are following layers from outer surface to inward.  Serosa  Longitudinal smooth muscle  Circular smooth muscle layer  Submucosa  Mucosa Layers of Alimentary Canal Gastrointestinal Smooth Muscle Functions as a syncytium  The individual smooth muscle fibers in the gastrointestinal tract are 200 to 500 micrometers in length and 2 to 10 micrometers in diameter, and they are arranged in bundles of as many as 100 parallel fibers.  In the LONGITUDINAL MUSCLE LAYER, the bundles extend longitudinally down the intestinal tract.  In the CIRCULAR MUSCLE Layer, they extend around the gut.  Within each bundle, the muscle fibers are electrically connected with one another through large numbers of GAP JUNCTION .  Because of these gap junction electrical signals that initiate muscle contractions can travel readily from one fiber to the next within each bundle but more rapidly along the length of the bundle than sideways.  Each muscle layer functions as a SYNCYTIUM . That is , when an action potential is elicited anywhere within the muscle mass, it generally travels in all directions in the muscle. MAIN FUNCTIONS 1. Ingestion or consumption of food substances. 2. Breaking them in to small particles. 3. Transport of small particles to different areas of the digestive tract. 4. Secretion of necessary enzymes and other substances for digestion.

1. 2020
Maryam Fida (o-1827)
[Type the companyname]
1/1/2020
GGAASSTTRROOIINNTTEESSTTIINNAALL PPHHYYSSIIOOLLOOGGYY

2. ANATOMY OF GASTROINTESTINAL TRACT
Consists of
 Gastrointestinal (GI) tract
 Accessory glandular organs
Anatomy and functions of the GI tract
 GI tract
◦ mouth, pharynx, esophagus,
◦ stomach, small intestine,
◦ large intestine, anus
◦ Accessory Glandular Organs
 salivary glands, liver, gallbladder, pancreas
Histology/organization of the Gut Wall
 From esophagus to anus, GI tract has the same basic arrangement of tissues.
 There are following layers from outer surface to inward.
 Serosa

3.  Longitudinal smooth muscle
 Circular smooth muscle layer
 Submucosa
 Mucosa
Layers of Alimentary Canal

4. Gastrointestinal Smooth Muscle Functions as a syncytium
 The individual smooth muscle fibers in the gastrointestinal tract are 200 to 500
micrometers in length and 2 to 10 micrometers in diameter, and they are arranged in
bundles of as many as 100 parallel fibers.
 In the LONGITUDINAL MUSCLE LAYER, the bundles extend longitudinally down the
intestinal tract.
 In the CIRCULAR MUSCLE Layer, they extend around the gut.
 Within each bundle, the muscle fibers are electrically connected with one another
through large numbers of GAP JUNCTION .
 Because of these gap junction electrical signals that initiate muscle contractions can
travel readily from one fiber to the next within each bundle but more rapidly along the
length of the bundle than sideways.
 Each muscle layer functions as a SYNCYTIUM . That is , when an action potential is
elicited anywhere within the muscle mass, it generally travels in all directions in the
muscle.
MAIN FUNCTIONS
1. Ingestion or consumption of food substances.
2. Breaking them in to small particles.
3. Transport of small particles to different areas of the digestive tract.
4. Secretion of necessary enzymes and other substances for digestion.