LESSON 2 - DIGESTIVE SYSTEM

Identify the organ

Esophagus

Identify the layers

Layers of Esophagus

A. Mucosa

B. Submucosa

C. Tunica muscularis

D. Tunica adventita

The projected sublayers are sublayers of the ______?

Mucosa (A)

Identify the sublayers

A. Lining Epithelium

B. Lamina Propria

C. Muscularis mucosa

Lining Epithelium of the organ

Stratified squamous non-keratinized epithelium

Lamina Propia of the organ

Loose Connective tissue with scattered lymphocytes

Muscularis mucosa of the organ

Single layer of smooth muscles

Identify the encircled structure

Superficial Esophageal glands

Identify the morphology of the encircled structure

Branched coiled glands

Identify the location of the encircled structure

Lower end of esophagus

Identify the fundamental type of tissue of B

Connective Tissue

Identify the subtype of B

Lymphatic Tissue or Connective Tissue Proper

Identify the specific subtype of B

Loose Lymphatic Tissue or Loose Connective Tissue

Divides the lamina propria from the submucosa

Muscularis mucosa (C)

Identify the pointed layer

Submucosa

Specific subtype of the pointed layer

Dense Irregular Connective Tissue

Secretes mucus in the submucosa for lubrication to facilitate the passage of food

Meissner’s plexus

What is the encircled structure?

Deep Esophageal glands

Function of the encircled structure

Mucus Secretion

What nerves plexuses are found in this area?

Meissner’s plexus

Identify the Layer

Tunica Muscularis (C)

How is this layer arranged?

Inner Circular and Outer Longitudinal (ICOL)

What is the upper third of this layer composed of?

Skeletal Muscles

What is the middle third of this layer composed of?

Skeletal and Smooth Muscles

What is the lower third of this layer composed of?

Smooth Muscles

What is the name of the nerve plexuses found in this area?

Auerbach’s/ Myenteric plexus

What is the function of the nerve plexuses found in this area?

Promotes motor/ peristaltic movement

Identify the layer

Tunica Adventita (D)

What is this structure composed of?

Loose Connective Tissue

What is present in this structure?

Blood and lymphatic vessels

Identify the pointed structure

Gastroesophageal Junction

What is the junction between the esophagus and the stomach?

Gastroesophageal Junction

Lining epithelium of the left side of this structure

Simple Columnar non-cornified epithelium

Lining epithelium of the right side of this structure

Stratified squamous non-cornified epithelium

Identify the Organ

Stomach

What does this organ produce to aid digestion

Digestive Enzymes

Label the layers of the organ

Layers of Stomach:

A. Mucosa

B. Submucosa

C. Tunica muscularis

D. Tunica serosa

Where layer are the gastric organs of the stomach located

Mucosa; specifically the lamina propia

Label

Where does the secretions of gastric glands come out?

Gastric Pits

Identify the layer

Mucosa (A)

Identify the first two structures (A and encircled) of the mucosa

A: Lining Epithelium

Encircled: Mucous Neck Cells

What is the lining epithelium of the organ?

Simple columnar epithelium without goblet cells

What is the encircled structure?

Mucous Neck Cells

What is the function of the encircled structure?

Produce a thick coating of mucus that protects the gastric mucosa from acid and enzyme secretion

Identify

Lamina Propia

The shown layer produces _______ occupying the entire thickness which opens into the bases of the gastric pits.

Gastric glands

Glands that are responsible for the synthesis and secretion of gastric juice

Gastric glands

What are the two major cell types in the stomach?

LEFT: Parietal/ Oxyntic Cell

RIGHT: CHIEF/ PEPTIC/ ZYMOGENIC CELL

Identify the structure

Parietal/ Oxyntic Cell

What does this structure secrete?

1. Hydrochloric acid

2. Intrinsic factor

Identify the structure

Chief/ Peptic/ Zymogenic Cell

What does this structure secrete?

1. Pepsinogen

2. Gastric lipase

A secretion of this structure that is activated into pepsin when it comes in contact with gastric acid

Pepsinogen

Lipase found in the stomach which also aids in the digestion of lipids

Gastric lipase

Which among the two cells is the parenchyma of the stomach?

Parietal/ Oxyntic Cell

Which among the two cells is more numerous in the stomach?

Chief/ Peptic/ Zymogenic Cell

Which among the two cells is basophilic in staining?

Chief/ Peptic/ Zymogenic Cell

Which among the two cells has a large round nucleus with eosinophilic cytoplasm

Parietal/ Oxyntic Cell

Identify the layer

Submucosa (B)

This layer is composed of?

Dense Irregular Connective Tissue

T OR F:

The layer has:

• Meissner’s plexus

• blood and lymphatic vessels

• gastric glands

FALSE

There are no gastric glands present in this layer.

Identify the layer

Tunica Muscularis (C)

Arrangements of the layer

Smooth muscle arranged in 3 LAYERS:

1. Outer Longitudinal

2. Middle Circular

3. Inner Oblique

T OR F:

From the esophagus down to large intestine, except the stomach, the arrangement of tunica muscularis is ICOL

TRUE

The arrangement for the stomach is:

1. Outer Longitudinal

2. Middle Circular

3. Inner Oblique

What plexus is present

Myenteric/ Auerbach’s plexus

Identify the Main Organ

Small Intestine

Identify the three segments of the small intestine

Layers of the Wall of the Intestines (same for small and large)

1. Mucosa

2. Submucosa

3. Tunica Muscularis

4. Tunica Adventitia

Sublayers of the Mucosa (same for small and large)

1. Lining epithelium

2. Lamina propria

3. Muscularis mucosa

Lining Epithelium (same for small and large)

Simple columnar with goblet cells

Lamina propia (same for small and large)

Loose connective tissue

Muscularis mucosa (same for small and large)

2 thin layers of smooth muscle

Composition of the submucosa (same for small and large)

Dense connective tissue with BV, LV, and Meissner’s plexus

Nerve Plexus present in submucosa (same for small and large)

Meissner’s plexus

Arrangement of Tunica Muscularis (same for small and large)

Inner Circular Outer Longitudinal (ICOL)

Nerve Plexus present in Tunica Muscularis (same for small and large)

Auerbach’s plexus

Composition of Tunica Adventitia (same for small and large)

Loose connective with BV, LV, and nerve

Identify the encircled structure

NOTE: present in both small and large intestine

Intestinal Gland(s)

Label

NOTE: present in both small and large intestine

Another term for the encircled structure

Crypts of Lieberkuhn

What specific layer are these structures found

Lamina Propia

Four Cells of Intestines/ Intestinal Gland

1. Columnar cells (enterocytes)

2. Goblet cell

3. Paneth cell

4. Argentaffin cell/ Enteroendocrine cell (not seen in staining)

Which cell is the parenchyma

Columnar cells (enterocytes)

Which cell is the most numerous

Columnar cells (enterocytes)

Mucin producing epithelial cells

Goblet Cell

Which cell is pyramidal in shape

Paneth Cell

Which cell is found at the base of the glands

Paneth Cell

Which cell is highly acidophilic

Paneth Cell

Which cell precipitate silver salts

Argentaffin cell/ Enteroendocrine cell

Which layer are these cells found

Mucosa; specifically Lamina Propia

Identify the Segment

Duodenum

Identify the encircled structure

Brunner’s/ Duodenal Gland

Where is the encircled structure found

Submucosa

Function of the encircled structure

produces an alkaline fluid composed of mucin, protecting it from the acidic chyme of the stomach

Identify the segment

Jejunum

Characteristic feature of the segment

prominent and numerous plicae circularis

Identify the encircled structure

plicae circularis

Function of the encircled structure

To increase the amount of surface area available for nutrient absorption

Identify the segment

Ileum