Intro To Histo Flashcards
Function of digestive system
The molecules are easily absorbed through the lining of the digestive tract mostly in the ______
Water, vitamins and minerals from ingested foods are also absorbed
small intestine
The entire gastrointestinal tract has certain common structural characteristics
It is a hollow tube with a lumen of (constant or variable?) diameter and a wall made up of four main layers:
The ____
The _____
The ____
The ____
Variable
mucosa
submucosa
muscularis
serosa
The mucosa
Comprises an _____ layer and an underlying ______ of loose connective tissue rich in:
____
_____
_____
____
(Always or Sometimes?) also containing ___ and a (thin or thick?) layer of smooth muscle called the ____
epithelial
lamina propria
Blood vessels
Lymphatics
Lymphocytes
Smooth muscles
Sometimes; glands; thin; muscularis mucosae (MM)
The muscularis mucosae usually separates mucosa from ____
submucosa
The mucosa is frequently called a mucous membrane
T/F
T
The submucosa
contains (more or less?) dense connective tissue with many blood and lymph vessels and the _____ plexus of ______ nerves
It may also contain ____ and lymphoid tissue
More
submucosal; autonomic
glands
The muscularis
Is (thin or thick?) and is composed of smooth muscle cells that are ___ arranged into 2 layers:
The inner ____ layer
The outer _____ layer
In the connective tissue between the 2 layers are:
Blood and lymph vessels
________ plexus
Thick ; spirally
circular; longitudinal
Myenteric nerve
The myenteric nerve plexus and the submucosal plexus together comprise the _______ nervous system of the digestive tract
They largely contain _____ neurons that function (dependently or independently?) of the CNS
local enteric
autonomic
independently
The serosa
Is a (thin or thick?) layer of loose connective tissue rich in:
Blood vessels
Lymphatics and
_________
With a ______ covering epithelium- called the ______
Thin
Adipose tissue
simple squamous; Mesothelium
In the abdominal cavity the serosa is continuous with the ______ which support the intestines, and with the ________
mesenteries
peritoneum
Mesentery= (thin or thick?) membrane covered by ______ on (one or both?) sides
Thin
mesothelium
Both
Peritoneum= ____ membrane that ______
serous
lines the cavity
In places where the digestive tract is not suspended in a cavity but is bound to other structures, such as in the ______ , the serosa is replaced by a (thin or thick?) ______
esophagus
Thick
adventitia
The adventitia consists of connective tissue containing vessels and nerves, lacking ____
mesothelium
Difference between serosa and adventitia
Serosa has mesothelium
Functions of the digestive tract’s epithelial lining
Provide a ______ barrier between the contents of the tract and the tissues of the body
Produce mucus for ______ and ____
selectively permeable
lubrication and protection
Immunologic support of the gastrointestinal tract
The abundant ______ in the _______ and the _______ layer, in association with the epithelium, provides protection for the GI tract
lymphoid nodules
lamina propria and the submucosal
The entire digestive tract, with the exception of the ___,____, and ____ is lined by a simple (thin or thick?) vulnerable epithelium
oral cavity, esophagus and anal canal
Thin
The lamina propria located just below the epithelium is a zone rich in ______ and lymphocytes some of which actively produce _____
macrophages
antibodies
These antibodies produced by the lamina PROPRIA are mainly immunoglobulin ____ and are secreted into the intestinal lumen bound to a ______ produced by the _____ cells
This complex protects against ____ and ____ invasion
A (IgA)
secretory protein
epithelial
viral and bacterial
IgA is resistant to _____ enzymes and can therefore coexist with the ______ present in the lumen
proteolytic
proteases
These plexuses are composed mainly of nerve cell aggregates that form small (sympathetic or parasympathetic?) ganglia
The number of ganglia along the digestive tract is variable- most numerous in the regions of ________
Parasympathetic
greatest motility
In Hirschsprung disease (______) or Chagas disease (________ infection) the plexuses in the digestive tract are severely injured and most of their neurons are destroyed
This results in disturbances of digestive tract ____, with frequent ______ in some areas
congenital megacolon
Trypanosoma cruzi
motility
dilatations
The abundant innervation from the autonomic nervous system that the digestive tract receives provides an anatomic explanation of the widely observed action of ________ on this tract
emotional stress
