Digestive System Physiology

Basic functions

motility

propulsive movements

mixing movements

secretion

digestion:  chemical processes

carbohydrates ¹ and sugars ²

monosaccharides

polysaccharides

proteins and amino acids ³

fats ⁴

triglycerides

hydrolysis

absorption

The digestive tube

anatomic components

structure of the wall ⁵

mucosa

submucosa

muscularis externa

serosa or adventitia

Regulation of digestive function

autonomous smooth-muscle function

slow-wave potentials

intrinsic nerve plexuses ⁶

myenteric plexus  (Auerbach’s plexus)

submucosal plexus  (Meissner’s plexus)

extrinsic nerves

vagus n

gastrointestinal hormones ⁷

gastrin

stimulus:  protein-rich chyme in stomach

gastro-colic reflex

secretin

stimulus:  acidic chyme in duodenum

cholecystokinin

stimulus:  fatty and protein-rich chyme in duodenum

receptor activation

chemoreceptors

mechanoreceptors

osmoreceptors

Go to beginning

Links

• Referenced sites


• ¹ Digestion of dietary carbohydrates



• ² Fructose metabolism



• ³ Amino acid metabolism



• ⁴ Various aspects of fat metabolism and ketogenesis



• ⁵ Microscopic anatomy of the various organs is portrayed elegantly in The Virtual Labguide by Christopher Brandon, Ph.D., and Douglas S. Mehr, M.D.



• ⁶ Michael D. Gershon’s article on the enteric nervous system



• ⁷ Extensive documentation of the motilides as motilin agonists



• Other sites


• An interesting analysis of what our anatomy tells us about what we should eat