GI system Flashcards
functions
ingestion
motility
digestion
absorption
secretion
ingestion
food and liquid intake into oral cavity
motility
mechanical processing: swirling, mixing, churning, propulsive motions in tract along entire tube
compaction: dehydration of undigestable material + waste into feces (colon to anus)
digestion
chemical + enzymatic breakdown of sugars, lipids, + proteins into small molecules
secretion
acids, enzymes, + buffers are secreted by accessory organs (liver + pancreas)
help digestion
absorption
movement of molecules, electrolytes, vitamins, + water into ISF β blood vessels
carried from GI tract to liver = distributed to rest of body
excretion
elimination of undigested residue + waste products
GI tract
oral cavity (salivary glands) β pharynx β esophagus β stomach β small intestine (duodenum + jejunum + ileum) β large intestine β anus
accessory organs: liver, gallbladder, pancreas
exocrine tissue
secretions into GI tube (lumen)
endocrine tissue
secretions into surrounding connective tissue β circulation
histology of GI tube
4 layers found along entirety
- mucosa
- submucosa
- muscularis externa
- serosa
mucosa
epithelium (stratified at beginning + end; simple in middle for absorption
lamina propria
muscularis mucosa
lamina propria
connective tissue
has innervation + vasculature to support epithelium
glands + immune cells
muscularis mucosa
propels content of glands (in submucosa) into lumen
submucosa
connective tissue layer
conduit for vasculature, nerves, and lymphatics
immune cells, some exocrine glands, submucosal nerve plexus
muscularis externis
external muscle layer: (skeletal at ends, smooth in the middle)
- inner circular muscle = constriction
- myenteric plexus
- outer longitudinal muscle = propulsion
myenteric plexus
autonomic parasympathetic
innervates both smooth muscle layers
controls GI motility
serosa
simple squamous epithelium + connective tissue
serous membrane = produces watery fluid to lubricate peritoneal surfaces
abdominal quadrants
direct pain
vert + horiz planes intersect at umbilicus
RUQ + RLQ + LUQ + LLQ
RUQ
liver
gall bladder
duodenum
head of pancreas
transverse colon
right kidney
LUQ
stomach
spleen
pancreas (body + tail)
jejunum
transverse colon
left kidney
RLQ
ileum
cecum
appendix
ascending colon
LLQ
ileum
descending + sigmoid colon
abdominal regions
referred pain
two vertical midclavicular planes
horiz. subcostal plane (below ribs, along L1)
horiz. intertubercular plane (tubercles of iliac crests, along L5)
epigastric, umbilical, hypogastric