BOK380

The Abdomen and Mammary Gland

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GNK313: Abdomen and abdominal complaints

Part 1:
Mouth, Esophagus and Salivary glands

All the tubular organs of the GI tract consist of the following layers from inside to outside:
Mucosa Epithelium  
Lamina propria
Muscularis mucosa
Submucosa  
Muscularis externa
Adventitia or serosa

The structure of the layers varies with location.

For example, the epithelial lining of the oesophagus is unkeratinised, stratified squamous, while the more distal parts of the GI tract usually display simple columnar epithelium.

Fig 10.24 Stevens & Lowe

        Oral cavity

Lip Slide 51
Fig 51-001 Fig 51-002
Lip

        Tongue
The tongue is a mass of skeletal muscle covered by a mucous membrane. The V-shaped sulcus terminalis divides the dorsal surface into an anterior oral region and a posterior pharyngeal or follicular region. The oral region contains two types of papillae:
  • papillae filiformis
  • papillae fungiformis
The posterior part of the tongue is known as the follicular part. Circumvallate papillae (7-12) are distributed in the V of the pharyngeal region.

Fig 10.1 Stevens & Lowe

Tongue Slides 7K, 53, & 33
Fig 7-001 Fig 53-001 Fig 53-002
Fig 33-001    
Tongue
Tongue
Tongue

        Salivary Glands
Three paired salivary glands are found, the parotid, sublingual and submandibular glands. The salivary glands are compound tubulo-acinar glands and are distinguished by the number of serous, mucous and combined secretory units. The glands differ further in terms of type and number of ducts.

Differences between mucous and serous units
Serous Mucous
Staining Dark, prominent Light, "washed out"
Shape of unit Round Tubular
Lumen Not visible with LM Visible with LM
Nuclei of secretory cells Round, prominent Flattened in base of cell

Structure of a secretory unit


Fig 13.17 Wheater

        Salivary glands

Salivary glands Slides 85K, 35 & 107
Fig 85-002 Fig 85-003 Fig 35-004
Fig 35-005 Fig 107-001 Fig 107-002
Parotid salivary gland

Submandibulary salivary gland

Sublingual salivary gland

        Oesophagus
The oesophagus is a hollow muscular tube consisting of the above mentioned layers.
Mucosa Thick unkeratinised stratified squamous epithelium  
Lamina propria contains tubular mucous glands
Muscularis mucosa consists of two layers
Submukosa Contains oesophageal glands
Muscularis externa
  • The inner layer is circularly arranged while the outer layer is longitudinally arranged
  • The upper third contains skeletal muscle and the bottom third smooth muscle, while the middle third contains both skeletal and smooth muscle
Adventitia Connects the oesophagus to the environment

Esophagus Slide 31K
Fig 31-001 Fig 31-002
Esophagus

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