Gastrointestinal physiology Flashcards
Seizing food and conveying into the mouth.
prehension
Mechanical breakdown of food in the mouth.
mastication
Swallowing or conveying the food from the mouth to the stomach.
deglutition
What are the three stages of deglutition?
mouth (voluntary)
pharynx (reflex)
esophagus (reflex)
The back and forth mixing due to intermittent contraction of circular smooth muscle, promotes digestion and absorption.
segmentation
The unidirectional, usually aboral waves of contraction.
peristalsis
What is propulsive motility?
moving aboral
What is retentive motility?
material is retained longer
What is mixing motility?
material within the lumen is churned
The timing of material getting from one are to another.
Transit time
What is the goal of digestion?
to reduce food to molecules small enough to be absorbed
What methods does digestion use to breakdown food?
physical, chemical, enzymatic
The simple decrease in size of food particles caused by a mechanical action. (chewing, tearing food apart)
mechanical digestion
Hydrolysis of chemical bonds accomplished by the action of hydrochloric acid.
chemical digestion
Hydrolysis of chemical bonds via enzymes produced by various regions of the alimentary tract or by hasten microbes.
enzymatic digestion
In all species the major digestive enzyme produced by the salivary glands is _________.
amylase
What solution helps support rumen microbes and buffer acid produced in the fermentation process?
ruminant saliva
Transport of nutrient particles into vascular system.
absorbtion
What is integral in detoxifying many substances?
liver
True of false: all species must keep colonic bacteria out of small intestine.
true
What controls majority of GI functions including regulation of digestion, independent of the CNS?
enteric nervous system
What kinds of influences to hormones MADE BY the alimentary tract have?
both local and systemic because they are secreted into systemic circulation
What is the only extrinsic gut hormone currently identified, which helps regulate water absorption from the GI tract?
aldosterone
Which nerves in the parasympathetic and sympathetic nervous systems have extrinsic control on the GI tract?
vagus nerve and pelvic nerve (parasympathetic)
splanchnic nerve and hypogastric nerve (sympathetic)
