Chapter 41 Flashcards
What is the gastrointestinal tract?
A continuous tube that is specialized along its length for sequential processing
Ingested foods undergo what two processes in the GI tract?
Digestion and absorption
Digestion requires the actions of?
Enzymes
Where are enzymes secreted for digestion in the GI tract?
Mouth, stomach, pancreas, and small intestine
As soon as you ingest food, what happens?
Endocrine, neural, and paracrine processes are activated
What are some other functions besides nutritional digestion and absorption of nutrients by the GI tract?
Roles in excretion, electrolyte balance, and immunity
The enteric nervous systems is considered a “minibrain” in that it contains what components similar to the CNS and PNS?
Sensory neurons, interneurons, and motor neurons
What are the neurotransmitters of the enteric nervous system (ENS)?
Acetylcholine, peptides, and bioactive amines
How is the brain-gut axis a bi-directional system that controls GI function?
Because it acts through the autonomic nervous system, gastrointestinal hormones, and the immune system to commnicate with each other
Tonic and rhythmic contractions of smooth muscle in the GI tract has what function?
Churning of food, peristalsis, and reservoir action
Sphincters are composed on what type of muscle?
Specialized circular muscles
Segments of the GI tract are composed of arrays of what type of muscles, excluding sphincter muscle?
Longitudinal and circular
What are the 6 sphincters of the GI tract?
- Upper esophageal sphincter
- Lower esophageal sphincter
- Pyloric sphincter
- Ileocecal sphincter
- Internal anal sphincter
- External anal sphincter
The temporal pattern of what segment of the GI tract differs between fed and fasting states?
The small intestinal segment of the GI tract
What are the 2 movements of the small intestine?
Churning and propulsive movements
What are the 2 movements of the large intestine?
Propulsive and reservoir movements
