the gastrointestinal system Flashcards
1
Q
what makes up the structure of the upper gastrointestinal (GI)
A
- mouth
- pharynx
- esophagus
- stomach
- duodenum (first part of small intestine)
2
Q
what makes up the structure of the lower GI
A
- jejunum (middle part of the small intestine)
- ileum (lower part of the small intestine)
- colon (large intestine)
- anus
3
Q
what is the function of the gastrointestinal system
A
- intake (eating)
- secretion (enzymes and mucus)
- mixing and propulsion (peristalsis)
- digestion (mechanical and chemical)
- absorption
- excretion (defecation)
4
Q
what is the function of digestion
A
to turn macro molecules into micro molecules
5
Q
can absorption occur without digestion
A
no. when the macro molecules are digested they turn into micro molecules and are now small enough to be absorbed
6
Q
what happens in excretion
A
the macro nutrients that weren’t digested or absorbed will end up in stool
7
Q
what are the layers that make up the gastrointestinal wall
A
- serosa (outer layer)
- longitudinal smooth muscle layer
- circular smooth muscle layer
- sub-mucosa
- mucosa (inner layer)
8
Q
what are the two types of waves in smooth muscle electrical activity
A
- slow waves
- spike potentials
9
Q
what are slow waves
A
- they occur in a rhythmic pattern
- their intensity varies between 5-15 mV and the frequency changes in different parts of tract (3= stomach, 12= duodenum, 8-9=ileum)
*slow waves don’t cause muscle contractions but they excite the appearance of spike potentials which cause them
9
Q
what do interstitial cells of Cajal act as
A
an electrical pacemaker
10
Q
A
