Intro Flashcards
what is the general structure of the alimentary canal (in terms of organisation of layers)?
> mucosa (epithelium, lamina propria, muscularic mucosa)
sub-mucosa
muscularis externa
serosa (below diaphragm)
what are the three components of the mucosa?
> epithelium
lamina propria
muscularis mucosae
what is the submucosa composed of?
> thick irregular connective tissue
glands
lymphatic network
nuerons
what glands are found in the duodenum?
bicarbonate
describe the two layers of muscle in the muscularis externa
two concentric layers of thick muscle
> outer layer is longitudinal (shortens tube)
> inner layer is circular (constricts lumen)
what nerve plexus is found in the muscularis externa?
> myenteric nerve plexus
what nerve plexus is found in the sub-mucosal layer?
> submucosal plexus (parasympathetic)
what does the enteric nerve plexus allow for?
independent control of gut function
Describe the autonomic control of the alimentary system
> long: parasympathetic
> short: ENS reflexes
describe parasympathetic control of the alimentary system
vagus nerve, facial and glossopharyngeal increase secretion and motility
describe the sympathetic control of the alimentary system
> splanchnic nerve decrease secretion and motility
> EXCEPT SALIVATION: increase secretion and motility
what three arteries supply the GI tract?
> celiac trunk
superior mesenteric
inferior mesenteric
what does the celiac trunk supply?
> stomach
small intestine
pancreas
liver
what does the superior mesenteric artery supply?
> small intestine
caecum
ascending colon
transverse colon
what does the inferior mesenteric artery supply?
> descending colon
sigmoid colon
rectum
