guinea pig ileum Flashcards
(25 cards)
second brain
enteric nervous system
What is the structure of the gastrointestinal tract?
continuous tubular
How many layers is the gastrointestinal tract made up of?
4
What layer replaces the serosa layer in the oesophagus?
adventitital
mucosa
intermost layer of the GI tract that contains cells responsible for secretion + absorption
What tissue is the mucosa made up of?
thin epithelial
Where is the lamina propria found?
mucosa
What does the lamina propria contain?
numerous lymph nodules that are important in protecting the intestine against disease
musscularis mucosa
thin muscle layer that is responsible for forming the numerous small folds evident in certain regions of the GI tract
How do goblet cells the GI tract?
lubricate the ingested material + aid the passage from mouth to anus
Is the submucosa thicker or thinner than the mucosa?
thicker
What does the submucosa contain?
large proportion of blood vessels that supply the mucosal layer/glands/nerve plexuses
What does the submucosal plexus supply?
muscularis mucosa with autonomic nerve input
What type of muscle does the muscularis contain?
longitudinal + circular
What are the muscularis muscles responsible for?
moving ingested material through segmental contractions + peristaltic movement
Where is the myenteric plexus located?
between the longitudinal + circular muscles
What does the myenteric plexus do?
provides the major nerve supply to the GI tract and includes fibres + ganglia from both the symapthetic + parasympathetic divisions of the autonomic nervous system / controls += synchronises the contractility of the muscularis propria
serosa/adventitia
outer layer of fibrous connective tissue surrounding the intestine (and 2 serous membranes/mesothelium which secretes serous fluid to lubricate against frictional forces for the serosa)
What is the general organisation of the gastrointestinal tract?
1) mucosa (epithelium/lamina propria/muscularis mucosa)
2) submucosa
3) muscularis propria (circular muscle/Auerbach’s (Myenteric) plexus/longitudinal muscle)
4) serosa/adventitia
How many neurons does the enteric nervous system contain?
approximately one hundred million
What are the 2 discrete, but interconnected layers of the enteric nervous system?
1) myenteric plexus
2) submucosal plexus
Where is the submucosal plexus located?
between the muscularis mucosa + muscularis propria
What does the submucosal plexus do?
1) controls the secretion of digestive peptides/mucus/hormones
2) integrates sensory inputs + signals to the myenteric plexus
What does the enteric nervous system do?
relays information up + down the length of the gastrointestinal tract, resulting in short/intrinsic reflexes
