exam 3 Flashcards
(29 cards)
from esophagus to anal canal, walls of organs in alimentary canal are made up of 4 basic layers, arrange them from the lumen outwards
mucosa, submucosa, muscularis externa, serosa
swallowing (deglutition)
voluntary portion takes place in mouth; mouth, pharynx, esophagus take part; involuntary portion takes place in pharynx
why are protease enzymes secreted in inactive forms
cells prod inactive enzymes are protected from enzymes until safely in lumen of GI
secretin and cholecystokinin which are released by duodenal enteroendocrine cells will
slow activities of stomach
events of quiet expiration:
phrenic and interc nerves __ sending signals
diaphragm and external interc __
thoracic and lung vol __
intrap pressure __
air moves __ of lungs
stop and dec
relax
decrease
increase
out
what stimulates inc in rate and depth of breathing
dec in CSF ph
inc in arterial PC02
dec in arterial P02 below 60mmHg
a dec in plasma pH
absorptive effectiveness of small intestine is enhances by inc surface area of mucosal lining, which will accomplish this task
pilcae circularis, vili, microvili
HCI made by which cells
parietal cells
C02
concentrations are greater in venous than in arterial blood
its concentration on blood is dec by hyperv
its accumulation in blood is assoc w dec in pH
least involved in mechanical breakdown of food, digestion, absorption
esophagus
cephalic
gastric
intestinal
enterogastric
stimulated by sight, thought, smell
stimulated by stretch recp due to presence of food
briefly stimulates gastric secretions when chyme is first delivered
inhibits gastric secretions thru closing of plyoric sphincter
characteristics of large intestine
exhibits ext muscular bands, doesnt contain villi, pocket like sacs
gastric secretion can be stimulated
before entering mouth
essential role played by larg intestine bacteria
synthesis of some vitamins
hepatocytes do not
produce digestive enzymes
sight of food can trigger events in release of gastric juice
prepares stomach for arrival, cerebral c, hypothalamus and medulla ob are involved in processing of stimulatory info, example of long reflexive pathway
6 essential processes of digestive system
ingestion: food into Gi tract mouth
mechanical digestion: chewing, grinding, churning mouth, stomach
chemical digestion: enzymes break down macrom into smaller components, mouth, stomach, sm intestine
Absorption: of nutrients in blood, sm intestine
Defecation: elim of wastes, large intestine
function of hepatic portal circulation
collect absorbed nutrients for metabolic processing in liver
accessory structure of digestive system
gallbladder, tongue, teeth
order chyme moves thru sm intestine
duodenum, jejunum, ileum
what stomach secretion is necessary for nl hemoglobin production in RBCS
intrinsic factor
list major salivary glands, how much produced in a day
1.5 liters
1 parotid gland
2 submandibular gland’3 sublingual gland
organ involved in propulsion, mech digestion, chem digestion
stomach
bile contains
enzyme for digestion
