Pretend you are a teacher preparing a quiz for the text I will provide. 
            Each quiz question should follow the format below. 
            Ensure that you carefully recheck the questions and answers for accuracy. 
            The output should be a ready-to-use list of dictionaries for the Python eval function:

            [

                    "question": "WRITE THE QUESTION HERE",
                    "options": ["A) OPTION_1", "B) OPTION_2", "C) OPTION_3", "D) OPTION_4"],
                    "answer": INDEX_OF_CORRECT_ANSWER_IN_OPTIONS_LIST,
                    "explanation": "EXPLAIN WHY THE ANSWER IS CORRECT"

            ]

            Text:
            fied squamous non keratinized 
epithelium. In addition, we find labial vessels, nerves, 
and labial salivary glands. 
The vermilion border (red margin) is an  area of 
transition from the skin to the oral mucosa. It is covered 
with partially keratinized epithelium. Numerous 
connective tissue papilla extend deep into the 
epithelium, are rich in sensory nerve ending and are 
heavily vascularized.  
The proximity of these vessels to the surface of the epithelium gives the vermilion its 
red 
appearance. It contains few sebaceous glands. It has no hair follicles or sweet glands.
 
GIT 2025                                                                                                                                          Histology 
46 
 
Salivary glands 
 
Types of salivary glands: - 
A. Major salivary glands: 
Parotid 
Sublingual 
Submandibular   
 
 
B. Minor salivary glands:  
Scattered under oral mucosa. Saliva is produced by 
secretory units and is conducted to the oral cavity by short ducts. 
 
They include 
buccal, labial, palatal and lingual glands.
 
General Histological structure of the digestive 
 (Alimentary) tract 
 
The wall of the alimentary canal has the same basic structure 
throughout its length. 
It consists of four basic layers. 
 
1) Mucosa 
2) Submucosa 
3) Musculosa  
4) Serosa/adventitia. 
1. Mucosa (tunica mucosa): innermost 3 layers 
surrounding lumen: 
Epithelium: may be a stratified squamous 
epithelium or simple columnar epithelium.  
Lamina propria: loose CT rich in blood and 
lymph vessels.
 glands as in fundus, pylorus, and intestinal  
crypts. 
 
Muscularis mucosa: thin layer smooth 
muscle. Formed of  
inner circular and outer longitudinal helps movement in 
mucosa.  
 
GIT 2025                                                                                                                                          Histology 
47 
 
2. Submucosa: loose CT, may contain glands (as esophagus & 
duodenum) and 
 
 
 
 
 
Meissner's nervous plexuses. 
 
3. Musculosa: two or more muscle layers: inner circular may be 
modified in sphincters and outer longitudinal. Auerbach's plexus 
between muscle layers helps  
independent peristaltic action. 
 
4. Serosa (Adventitia): irregular dense CT surrounded by 
mesothelium (serosa) or bound to body wall (adventitia). 
 
 
esophagus 
It extends from the cricoid cartilage through diaphragm to 
opening of stomach. The 
wall is formed of: 
1. Mucosa: 
▪ Epithelium: 
stratified 
squamous 
non 
keratinized epithelium for protection. 
 
▪ Lamina propria: esophageal 
cardiac glands (mucus), two 
clusters. one near pharynx, 
other 
near 
junction 
with 
stomach 
 
▪ Muscularis mucosa: unusual formed 
of single longitudinal layer  
In the lower part it differentiates into inner 
circular  
and outer longitudinal 
 
2. Submucosa: 
          CT containing esophageal mucous glands. 
 
3. Musculosa: 
A. In the upper third, muculosa is formed of skeletal muscle. 
B. In the middle third → mixed.

            Quiz: