Traffic - week 15 Flashcards
function of digestive (amazon)
transfer nutrients, H2O and electrolytes from food to body
food is…(blocks)
an energy source and contains basic building blocks of body tissues
4 digestive processes (DAMS)
motility, secretion, digestion and absorption
motility
muscular contractions that move food through digestive tract (propulsive) and mix food
secretion (BEHM - bile)
digestive juices (enzymes, bile, mucus, hormones)
digestion (catabol)
breaking down large molecules into smaller units
absorption - substances moved from…(nymph)
digestive tract to blood or lymph. major and accessory organs
intrinsic nerve plexuses (stomach - tv wall)
- network of nerves in digestive tract wall (enteric nervous system)
- influence all digestive tract activity a. mainly coordinate activities
- influenced by extrinsic nerves
extrinsic nerves (ANS) (motor bike)
- influences motility and secretion
a. modify activity of intrinsic plexuses
b. act directly on glands and smooth muscle
digestive tract contains (COM - receptors)
a. chemoreceptors
b. mechanoreceptors
c. osmoreceptors
stimulation of receptors initiates reflexes (short - in..long - different)
a. short reflexes - entirely within intrinsic nerves
b. long reflexes - also involve ANS
gastrointestinal hormones (bloody nose-hormones)
produced in mucosa, released to blood in response to local chemical changes or nerve stimulation
mastication
mixes and breaks down food
saliva produced by salivary glands (amyl - kitchen counter)
begins digestion of carbohydrate with salivary amylase
- moistens food with mucus for easy swallowing
- lysozyme lyses bacteria
- produced in response to stimulation from chemoreceptors and pressure receptors in mouth, or seeing/smelling food
Pharynx and Esophagus - pathways to…
stomach
3 major functions of stomach (closet - oates)
store duodenum, Hcl and enzymes, mix to chyme
- store food and release to duodenum at the appropriate rate
- secrete HCl and enzymes to begin protein digestion (continue carbohydrate digestion with salivary enzymes)
- mix food with gastric secretions to make chyme
4 aspects of motility (pie)
gastric filing, gastric storage, gastric mixing, gastric emptying
gastric filling (stretch - stress ball)
a. plasticity-stomach can stretch without
increasing tension
b. receptive relaxation - eating triggers reflex relaxation
gastric storage (body)
food stored mainly in body of stomach
gastric mixing (perry ant)
mostly in antrum (thicker muscle layer) b. peristaltic contractions
gastric emptying - influencing factors (stomach) (chyme full- house - body builder)
amount of chyme - more chyme increases
emptying via direct effect on smooth muscle, intrinsic and extrinsic neurons, hormone gastrin
gastric emptying (perry - wave)
peristaltic waves push some chyme into duodenum
gastric emptying - influencing factors (duodenum) (SNH)
(1) stimuli
(2) neural response
(3) hormonal response
gastric secretions come from…(pit)
gastric pits/gastric glands