Chapter 24 [ EXAM #4 ] Flashcards
what is catabolism
Larger molecules broken down into smaller
what anabolism
Smaller molecules used to make larger essential molecules
what is peristalsis
involuntary, ADJACENT alternating STRONG waves of contraction and relaxation of smooth muscle to move food along
what is secretion
release of enzymes, acids, buffers, bile into GI tract
what is mastication
breaking up food into smaller pieces with teeth
incisors bite into
canines tear into
premolars chew and grind
molars chew and grind
what is absorption
passive movement of nutrients to blood or lymph
what is excretion/defection
waste, indigestible
what parts consist of the GI tract
Mouth
Pharynx
Esophagus
Stomach
Small intestines
Large intestines
what is the submucousal plexus
sensory and motor neurons, regulates activity of glands and smooth muscle in mucosa and submucosa
what is the myenteric nerve plexus
controls GI tract motility
what is the enteric nerve plexus
submucosal and myenteric nerve plexus
what are the accessory organs in the digestive system
Teeth and tongue, gallbladder
salivary glands, liver, pancreas
how does motility work in the muscularis externa
through peristalsis and segmentation
what is segmentation
NON-ADJACENT
mixes food back and forth with digestive juices / enzymes
what’s the diff between serosa and adventitia
serosa is serous membrane in peritoneal cavity
adventitia is fibrous attachment in oral cavity, pharynx, esophagus, and rectum
what are the two kinds of sensory receptors in digestive system
mechanoreceptors: stretch and pressure
chemoreceptors: chemical content, osmolarity, pH
what nervous system will enhance secretory activity and GI motility
parasympathetic NS
what’s the diff between mechanical digestion and chem digestion
mechanical = physical change through mastication and tongue movement
chemical = chemical bonds broken in mouth, stomach, and small intestines
where is MALT located and what does it do
lamina propria and protects
what is the submucousal plexus
vs.
what is the myenteric nerve plexus
submucousal plexus = regulates activity of glands and smooth muscle in mucosa and submucosa
myenteric nerve plexus = controls GI tract motility
what dat sphincter do
forward movement, prevents backflow
what do enteroendocrine cells do
produce 3 hormones
Gastrin: stomach
Secretin: small intestines
CCK: small intestines
what are the three main hormones of digestive system
where are they from and what do they do
gastrin from G cells
↑ gastric juice (pepsinogen, HCl ) and stomach motility
secretin and CCK from enteroendocrine cells
Inhibit gastrin release, ↓ gastric secretion and motility, ↑ bile pancreas
what is the function of salivary amylase
starts carb/strach breakdown