EX2 Histology Flashcards
These accessory digestive organs come in direct contact with food and help to physical break it down
tongue and teeth
These accessory digestive organs produce or store secretions that will reach the digestive tract via ducts; never in contact with food directly; chemical breakdown
salivary glands
pancreas
liver
gallbladder
True or False
Anything that is within the GI tract is “outside” of the body
True; it must pass by epithelium to be considered in the body
What are the four layers of the GI tract wall from the lumen outward
muscosa
submucosa
muscularis externa
serosa or adventitia
What are the three layers of the mucosa
lining epithelium
lamina propria
muscularis mucosae
What two types of lining epithelium are there and where are they found
nonkeratinized stratified squamous; found in the mouth, pharynx, esophagus, and anus
simple columnar; found in the stomach, SI, and LI
Which type of lining epithelium is better for serving a protective role/barrier
nonkeratinized stratified squamous
Which type of lining epithelium is better for secretion and absorption
simple columnar
The lamina propria is made up of what
loose (areolar) connective tissues
The muscularis mucosae is what type of muscle tissue
smooth muscle tissue
The submucosa is made up of what type of tissue and its purpose is what
dense irregular connective tissue; collagen
binds mucosa to muscularis externa
lymphoid tissues
The submucosa contains which plexus and what for
Meissner’s plexus providing innervation to secretory cells
The muscularis externa contains what two layers which work together to do what
inner circular layer
outer longitudinal layer
peristalsis
This layer of muscularis externa works to lengthen the GI tract, constricts the lumen, and can be thickened to form sphincters or valves
inner circular layer
This layer of muscularis externa runs along the length of the tract, dilates the lumen, and shortens the GI tract
outer longitudinal layer
This nerve plexus controls the muscularis externa
Myenteric nerve plexus (Auerbach’s plexus)
The serosa is made up of what type of tissues and is found where
mesothelium (simple squamous epithelium)
loose (areolar) connective tissue
found interperitoneal
The adventitia is made up of what tissue and is found where
loose (areolar) connective tissue found retroperitoneal (esophagus)
The esophagus has which type of lining epithelium
nonkeratinized stratified squamous
The esophagus has what type of muscularis externa
proximal 1/3 –> skeletal muscle
middle 1/3 –> mix of smooth and skeletal
distal 1/3 –> smooth muscle
True or False
Serosa is found in the distal esophagus
True; adventita is found proximally
What are the two types of glands found in the esophagus
esophageal glands proper (submucosa)
esophageal cardiac glands (lamina propria)
Which gland is found in the distal esophagus
esophageal cardiac glands; protects against stomach acid
This is where the nonkeratinized stratified squamous epithelium changes to simple columnar
cardioesophageal junction
What are the four subdivisions of the stomach
cardia
fundus
body
pylorus
The stomach is responsible for the digestion of what type of macromolecules and the formation of what
carbs, lipids, and proteins
into chyme
True or False
The rugae allow for increased surface area for absorption
False; while the do increase the surface area, it allows for expansion
In the cardia of the stomach, the cardiac glands produce what
primarily mucous
In the fundus/body of the stomach, the gastric hands (fundic glands) produce what
HCl and pepsin
In the pylorus region of the stomach, the pylori hands produce what
primarily mucous
What type of lining epithelium is found in the stomach; and what is so special about it
simple columnar with surface mucous cells
it can invaginate into the lamina propria forming gastric pits which are the opening for different glands
What is so special about the muscularis externa in the stomach
it contains an additional inner oblique layer which aids in breakdown of the bollus
What are the three parts of the fundic gland
isthmus
neck
base
What are the five different types of cells found in a fundic gland
surface mucous cell mucous neck cell parietal cell (HCl and intrinsic factor) chief cell (pepsingoen and gastric lipase) G cell (gastrin)
True or False
The fundic gland contains stem cells
True; they are located in the isthmus
Where does absorption take place in the GI tract
roughly 10% of absorption is in the large intestine and stomach and the other 90% is in the small intestine
What macromolecule is absorbed in the small intestine and not in the stomach
nucleic acids
These are the circular folds in the small intestine with a submucosa core
plicae circulares
These are the fingerlike projections of mucosa in the small intestine
villi
These are projections of apical membrane of intestinal absorptive cells; striated border
microvilli
What two cell types are found in the epithelium of the small intestine
absorptive cells (enterocytes) goblet cells
These are tubular glands consisting of paneth cells, enteroendocrine cells, and stem cells
crypts of Lieberkühn (intestinal glands)
These cells are found at the base of the crypts of Lieberkühn and produce lysozyme and regulate normal microbiota
paneth cells
The submucosa of the small intestine (specifically the duodenum) contains what specialized gland
Brunner’s glands; it neutralized chyme via an alkaline mucous
True or False
The majority of the stomach contains serosa
True; except for the retroperitoneal duodenum
In the ileum, groups of what are present in the lamina propria and submucosa and are referred to as what
lymphatic nodules
Peyer’s patches
What type of cells overlay Peyer’s patches
M (microfold) cells
involved with antigen presentation
True or False
The large intestine contains plicae circulars and villi
False; it does not contain those
Found in the large intestine, this is an outer muscularis externa layer that is gathered into bands
teniae coli
These are the pouches found in the large intestine
haustra
These are small fatty projection found on the large intestine
omental appendages
The large intestine’s primary function is to what
continued breakdown and resorption via bacteria
synthesize vitamins
What type of epithelial cells lines the small and large intestines
simple columnar
The large intestine contains crypts of Lieberkühn; two main differences between these and those in the small intestine are what
the absorptive cells are called colonocytes
no paneth cells
What are the three parts of the pancreas
head, body, and tail
True or False
The pancreas is mostly an endocrine gland
False; it is 98-99% and exocrine gland (compound acinar gland)
The pancreas as an exocrine gland does what
secretes pancreatic juices (digestion of carbs, proteins, lipids, NAs); neutralizes chyme (bicarb)
The pancreas and an endocrine gland does what
Islets of Langerhans
secretes hormones; glucagon/insulin
The liver receives blood from what two sources
hepatic artery (oxygenatd blood) hepatic portal vein (deoxygenated blood with things to be filtered out such as toxins, microbes, nutrients, etc.)
This is the six-sided structure consisting of specialized cells called hepatocytes in plates surrounding a central vein
hepatic lobulues
The stacks of hepatocytes are one cell thick and surrounded by these
sinusoids; leaky capillaries
These are the largest cells lining the sinusoids and are phagocytotic
Kupffer cells
The microvilli of the hepatocytes extend into this space
space of Disse; space between the endothelial cells and hepatocytes
On each corer of the hexagonal hepatic lobule are what
portal triad; portal vein, hepatic artery, bile duct
This is used for the storage of bile and the release of it when it is needed for fast breakdown
gall bladder
This is very large in the gall bladder
muscularis externa; used for squeezing out bile
