Histo Flashcards
Organs of the GI tract include:
mouth, most of pharynx, esophagus, stomach, small intestine, large intestine
What are the accessory digestive organs?
Tongue, teeth, salivary glands, pancreas, liver, gallbladder
What accessory digestive organs are associated with physical/mechanical breakdown?
tongue and teeth
What accessory digestive organs are associated with secretions?
salivary glands, pancreas, liver, gallbladder
From the lumen outward what are the four layers of tissue present?
- Mucosa
- Submucosa
- Muscularis externa
- Serosa or adventitia
What are the 3 layers of the mucosal lining of the GI tract?
- Lining epithelium
- Lamina propria
- Muscularis mucosae
What are the two cell types found in the lining epithelium?
- nonkeratinized stratified squamous epitheliium
2. Simple columnar epithelium
The lamina propria is _____ connective tissue.
loose (areolar)
The muscularis mucosae is _____ muscle.
smooth
Smooth muscle tissue of the digestive system wall has two layers. What are they?
- Inner circular layer
2. Outer longitudinal layer
T/F the inner circular layer can be thickened to form sphincters or valves?
True fact of life
Where is the serosa in relation to the other tissues?
It surrounds the smooth muscle layer
The serosa is made up of what two types of tissue?
- Mesothelium
2. Loose (areolar) connective tissue
What type of tissue is the adventitia made up of?
Loose (areolar) connective tissue
What epithelial tissue lines the esophagus?
Nonkeratinized stratified squamous epithelium
What type of muscle tissue is found in the the esophageal lining?
The muscularis externa has both skeletal (upper 1/3) and smooth muscle tissue (lower 1/3) and a mix of both in the middle 1/3
What are the two types of mucous glands found in the esophagus?
- Esophageal glands (proper)
2. Esophageal cardiac glands
Where are esophageal glands (proper) found?
in the submucosa
Where are esophageal cardiac glands found?
In the lamina propria
What are the four divisions of the stomach?
- Cardia
- Fundus
- Body
- Pylorus
(histologically speaking the body and fundus are combined)
The cardiac glands are primarily _____ glands.
mucous
The gastric/fundic glands secrete what two things?
HCl and pepsin
The pyloric glands are primarily ____ glands.
mucous
The surface mucous cells of the stomach are what kind of cells?
simple columnar epithelium
Gastric pits in the stomach lead to _____ _____.
gastric glands
What are the layers of smooth muscle in the stomach?
outer longitudinal
middle circular
inner oblique
What are the three parts of the small intestine?
Duodenum
Jejunum
Ileum
The small intestine has a large surface area which is important in what?
absorption
What are some examples of absorptive cells in the small intestine?
Vili
Microvili
What kind of epithelial cells line the small intestine?
simple columnar epithelium
absorptive enterocytes
goglet cells
Crypts of Lieberkuhn are what?
Intestinal glands
Where are brunner’s glands found (glands that produce alkaline mucous)?
In the duodenum
Does the large intestine have plicae circulares and villi?
Nope
What type of epithelial cells are found in the colon?
simple columnar epithelium
Are Crypts of Lieberkuhn found in the large intestine?
Yes
What are the absorptive cells of the colon called?
coloncytes
What cells are found in the lamina propria of the large intestine?
lymphoid cells and nodules
The pancreas has three parts. What are they?
head
body
tail
The pancreas functions 98-99% as a ______ gland.
exocrine
What are the two sources of blood for the liver?
- The hepatic artery (oxygenated blood)
- The hepatic portal vein (deoxygenated blood with newly absorbed nutrients, drugs, and possible microbes and toxins from GI tract)
Where are oxygen, most nutrients, and certain toxic substances taken up by the hepatocytes? This is also where the hepatocytes products and stored nutrients are secreted back into the blood.
Liver sinusoids
The liver is composed of structural and functional units called ___ ____.
Hepatic lobules
What do the hepatic lobules surround?
A central vein
What are the largest cells lining the sinusoids of the hepatocytes called and what do they do?
Called Kupffer cells
Phagocytic properties- helps break down damaged/old RBCs that reach the liver from the spleen.
chief cells are also called ______ ____.
Zymogenic cells
Where does most absorption take place?
about 90% in the small intestine
What are plicae circulares and where are they found?
permanent circular folds in the small intestine
What are the absorptive cells of the small intestine called?
enterocytes
Chyme from the stomach goes into the duodenum and it’s very acidic. How does the body regulate the acidity?
Brunner’s glands in the duodenum produce an alkaline mucous to neutralize the pH
Where are teniae coli found?
In the large intestine
