1.
Actin filaments of the microvilli extend from the villin in the tip of the microvillus to what?: They extend down the microvillus where they interact with horizontal actin filaments of the terminal web at the base of the microvillus
2.
Anal Transition zone: Middle 1/3 of Canal
- Layer of stratified columnar epithelium between the simple columnar epithelium and stratified squamous epithelium
3.
Colorectal Zone: Found in the upper 1/3 of the canal
- contains simple columnar epithelium
4.
Describe the changes in the epithelium at the esophagogastric junction.: It transitions from stratified squamous epithelium to columnar epithelium
5.
Describe the two layers of muscularis mucosa.: - Inner circular layer
- Outer longitudinal layer
6.
Does digestion occur in the stomach?: Very limited partial digestion occurs
7.
GALT: - Gut-Associated Lymphatic Tissue
refers to diffuse lymphatic tissue and the lymphatic nodules
8.
IgA is secreted by...: ... plasma cells into the lamina propria
9.
Most substances that enter the body must first cross...: ...the digestive mucosa
10.
Plicae circulares are also known as...: ... Valves of Kerckring
11.
Squamous Zone: Lower 1/3 of Canal
- lined with stratified squamous epithelium that is continuous with the perianal skin
12.
The appendix contains large amounts of...: ...lymphatic nodules
13.
The mucosa of the alimentary tube secretes what antibody?: IgA!
14.
The serosa is equivalent to...: ...visceral peritoneum
15.
What allows lipid digestion?: Pancreatic lipase and bile
16.
What are cardiac glands composed of?: Mainly mucus secreting cells
17.
What are Crypts of Lieberkuhn?: Intestinal glands that help increase the intestinal surface area
18.
What are Haustra?: Large sacculations of the large intestine formed by contractions of the teniae coli
19.
What are lacteals?: Lymphatic vessels that are found at the core of intestinal villi
20.
What are teniae coli?: Three distinct longitudinal muscle bands found on the outer surface of the large intestine
21.
What are the 3 histological regions of the stomach?: - Cardia
- Fundus
- Pylorus
22.
What are the 3 parts of the small intestine?: - Duodenum
- Jejunum
- Ileum
23.
What are the defense mechanisms of the alimentary canal?: - Peyer's patches and associated M cells
- IgA, a product of plasma cells
- Paneth cells
- Acidity of gastric juice
- Peristalsis prevents bacterial colonization
24.
What are the finger like projections of the mucosa?: Intestinal Villi
25.
What are the layers of the alimentary tube?: - Mucosa
- Submucosa
- Muscularis
- Serosa
26.
What are the layers of the appendix?: They are the same 4 layers as the large intestine (mucosa, submucosa, muscularis, serosa)
27.
What are the name of the intestinal glands found in the mucosa of the large intestine?: Crypts of Lieberkuhn
(they extend through the full thickness of the mucosa)
28.
What are the principal functions of the large intestine?: Reabsorption of electrolytes and water as well as the elimination of undigested food and waste (feces)
29.
What are the transversely oriented ridges seen in the mucosal surface of the small intestine?: Plicae circulares
30.
What binds the glycocalyx to the plasma membrane of cells in the intestine?: Microvilli
31.
What causes appendicitis?: Occurs when a fecolith or other foreign object becomes lodged in the lumen of the appendix
32.
What causes Hirschsprung's Disease?: The lack of neural crest migration to a segment of colon results in aganglionosis, in which Meissner's plexus and Auerbach's plexus do NOT form
(segment is permanently contracted)
33.
What causes movement of the mucosa?: Contraction of muscularis mucosa
34.
What causes the damage seen with Crohn's Disease?: Neutrophils, lymphocytes, and macrophages produce cytokines that cause damage to the intestine mucosa
35.
What continuously replaces mucosal cells?: Mitotic activity
36.
What covers the surface of intestinal villi?: Simple Columnar Epithelium
37.
What cross links actin filaments?: Fascin and Fimbrin
(to give rigidity)
38.
What disaccharidases are found in the small intestine?: - Sucrase
- Maltase
- Lactase
39.
What do brunner's glands secrete?: Alkaline secretion to help neutralize acidic chyme
40.
What do cardiac glands secrete?: A neutral mucus
(helps protect esophagus from acid reflux)
41.
What do chief cells secrete?: Pepsinogen and a weak lipase
42.
What do microvilli contain?: They contain actin filaments anchored to villin in the tip of the microvillus
43.
What do submucosal glands of the esophagus secrete?: Slightly acidic mucus
44.
What do the cells of the mucosa of the large intestine consist of?: Absorptive epithelial cells and goblet cells
45.
What do the pyloric glands secrete?: Viscous (probably mucus in nature)
46.
What do the secretory granules of Paneth cells contain?: Lysozme, alpha-defensins, glycoproteins, an arginine-rich protein, and zinc
47.
What does IgA bind to?: Toxins, antigens, and microorganisms in the lumen of the gut
48.
What does the contraction of the terminal web allow?: It allows more surface area exposure for absorption to take place
49.
What does the lamina propria contain?: Glands, vessels, and components of the lymphatic system
50.
What does the mucosa consist of?: - A lining epithelium
- An underlying connective tissue - Lamina Propria
- A layer of smooth muscle - Muscularis Mucosa
51.
What does the pectinate line mark?: The junction between endodermal and ectoderm derivatives
52.
What does the stomach produce?: chyme
53.
What does the submucosa consist of?: A layer of dense irregular connective tissue
54.
What does the terminal web of microvilli contain?: Horizontal actin filaments
55.
What else is found near the pyloric glands?: Enteroendocrine cells
56.
What forms gastric pits?: The gastric mucosa invaginates to form gastric pits
57.
What forms the communication between the nasal cavity and the larynx?: The Pharynx
58.
What forms the Crypts of Lieberkuhn?: Invaginations of the mucosa between adjacent intestinal villi
59.
What glands are present in the lower esophagus?: Cardiac glands
60.
What hormones are secreted from the enteroendocrine cells, from the fundus to the colon?: VIP (Vasoactive Intestinal Peptide)
Somatostatin
61.
What indicates contractile ability in microvilli?: The presence of myosin II and tropomyosin
62.
What is a continuation of the jejunum?: The ileum
63.
What is Achlorhydria?: Condition characterized by the absence of parietal cells
64.
What is Crohn's Disease?: A chronic inflammatory process that involves the small intestines, but is also observed in the large intestine
65.
What is pepsin?: A proteolytic enzyme
66.
What is pepsinogen converted to?: Pepsin (when it comes into contact with the acidic gastric juice)
67.
What is responsible for segmentation and peristalsis?: Muscularis (externa)
68.
What is special about IgA?: It is the only immunoglobulin that can be selectively passed across the mucosa to the lumen**
69.
What is the deepest layer of the mucosa and serves as a boundary between the mucosa and the submucosa?: The muscularis mucosa
70.
What is the diagnostic feature of the distal ileum?: Peyer's Patches
71.
What is the diagnostic feature of the duodenum?: Brunner's Glands
72.
What is the diagnostic feature of the ileum?: Peyer's Patches
73.
What is the first and widest part of the small intestine?: The duodenum
74.
What is the function of enteroendocrine cells?: They release hormones into the lamina propria
75.
What is the function of goblet cells?: They produce mucus
76.
What is the function of intestinal villi?: They increase surface area
77.
What is the function of intrinsic factor?: It is a glycoprotein that forms a complex with vitamin B12 and is necessary for the vitamins subsequent absorption in the ileum
78.
What is the function of myosin I in microvilli?: It binds the actin filaments to the plasma membrane of the microvillus
79.
What is the function of Plicae Circulares?: They are permanent transverse folds that increase surface area
80.
What is the function of spectrin in microvilli?: It stabilizes the actin filaments that compose the terminal web
81.
What is the layer of connective tissue that underlies the mucosa?: The lamina propria
82.
What is the lifespan of mucosal cells?: Relatively short - 3 to 5 days
83.
What is the longest component of the digestive tract?: The small intestine
84.
What is the main site for digestion and absorption?: The small intestine
85.
What is the outer layer of the alimentary tube?: The serosa
86.
What is the plexus of the submucosa?: Meissner's Plexus
87.
What is the result of a genetic defect in lactase?: The genetic defect prevents the absorption of lactose, leading to lactose intolerance
88.
What is the role of Paneth Cells?: They play a role in regulating the normal flora of the small intestine
89.
What is the serosa?: It is a serous membrane that consists of simple squamous epithelium (mesothelium)
90.
What is vitamin B12 necessary for?: For red blood cell production and maintenance of the central nervous system
91.
What layer forms sphincters?: The circular inner layer forms sphincters at specific locations (i.e. pyloric sphincter, ileocecal valve. and the internal anal sphincter)
92.
What leads to pernicious anemia?: The absence of parietal cells
93.
What lines the pharynx in the area close to the nasal cavity?: Pseudostratified ciliated columnar epithelium with goblet cells (respiratory epithelium)
94.
What lines the pharynx in the region continuous with the esophagus?: Nonkeratinized stratified squamous epithelium
95.
What lymphatic tissues are within the lamina propria?: - Diffuse lymphatic tissue
- Lymphatic nodules (often with germinal centers)
- Eosinophils, macrophages, and sometimes neutrophils
96.
What makes up the mucosa of the esophagus?: Stratified squamous epithelium
97.
What receptors are found on parietal cells?: - Gastrin
- Histamine H2
- Acetylcholine M
98.
What secretes intrinsic factor?: Parietal Cells
99.
What serves as a reservoir of active proton pumps?: The membrane of the tubulovesicular system
100.
What type of muscle is the lower 1/3 of the esophagus?: Smooth muscle
101.
What type of muscle is the middle 1/3 of the esophagus?: Mixture of both skeletal and smooth muscle
102.
What type of muscle is the upper 1/3 of the esophagus?: Skeletal muscle
103.
Where are Brunner's Glands located?: In the submucosa of the duodenum
104.
Where are cardiac glands located?: They are limited to an area around the opening of the esophagus into the stomach
105.
Where are enzymes in the small intestine located?: They can be found in the glycocalyx of the microvilli of the intestinal absorptive cells (enterocytes)
106.
Where are Paneth cells located?: At the bases of intestinal glands
107.
Where are parietal cells located?: In the neck of fundic glands
108.
Where are Peyer's Patches located?: In the distal portion of the small intestine - the ileum
(they are extensive aggregates of lymphatic nodules)
109.
Where are the pyloric glands located?: Between the fundus and the pylorus
110.
Where does the duodenum begin and end?: It begins at the pylorus and ends at the duodenojejunal junction
111.
Where does the ileum end?: At the ileocecal junction
112.
Where does the majority of lipid digestion occur in humans?: In the duodenum and jejunum
113.
Where is HCL produced?: In the lumen of the intracellular canaliculi of the parietal cells
114.
Where is the Myenteric or Auerbach's plexus?: In a layer of connective tissue between the two muscle layers of muscularis (externa)
115.
Where is the pectinate line located?: Just below the anal columns in the rectum
