Digestive Histo I Flashcards
(21 cards)
Name the associated/accessory digestive organs and whether they are responsible for physical breakdown (PB) or secretions (S).
Tongue (PB), teeth (PB), salivary glands (S), Pancreas (S), liver (S), and gallbladder (S)
What percentage of absorption occurs in the SI?
90%
What is the skeletal muscle that surrounds the opening of the oral cavity?
Orbicularis oris
What is the term for the opening of the oral cavity into the oropharynx?
Fauces
What is the vestibule?
The area between the lips/teeth and the cheeks/teeth; oral cavity proper is the rest of the area of the oral cavity before the fauces
What type of cells line the oropharynx and laryngopharynx?
Nonneratinized stratified squamous
What are the layers of the alimentary canal going from the lumen outward?
1.Mucosa 2.Submucose 3.Muscularis externa 4.Serosa/Adventitia
What are the layers of the mucosa from lumen outward?
1.Lining epithelium 2.Lamina propria 3.Muscularis Mucosae
What are the layers of the Muscularis externa?
1.(Inner) circular muscle 2.(External) Longitudinal muscle
What are the serosa/adventitia layers?
1.Areolar CT (inner) 2. Epithelium (outer)
Which organs are highly associated with having simple columnar lining epithelium?
Stomach, SI, and most of LI
Which layer of the mucosa contains blood vessels?
The lamina propria
What is GALT and where is it located?
Gut-Associated Lymphatic Tissue; lamina propria
Which of the alimentary canal layers contains glands, some lymphoid tissue, and Meissner’s plexus?
Submucosa
What is responsible for controlling the secretion of lining epithelium?
Meissner’s plexus
Which smooth muscle layer can be thickened to form sphincters or valves?
The inner circular layer of the muscularis externa
Contraction of this muscle constricts the lumen and lengthens the organ?
Inner circular smooth muscle; outer longitudinal does the opposite
What is responsible for the alternating contraction of inner circular and outer longitudinal layers?
The myenteric (Auerbach’s) plexus; this plexus is located between inner circular and outer longitudinal layers
What kind of CT makes up the submucosa?
Dense irregular CT
Describe the difference in type of muscle (skeletal or smooth) of the muscularis externa of the esophagus.
Upper 1/3 = skeletal, middle 1/3 = mixed skeletal and smooth, lower 1/3 = smooth
Which type of esophageal glands are found in the submucosa closer to the stomach and what do they produce?
Esophageal cardiac glands; mucous, important to protect esophagus from acid reflux from the stomach
