Exam 4: Lecture 52: AI Questions Flashcards
What is the main function of the GIT?
Digestion and absorption
What are the four main activities of digestion?
Motility, secretions, digestion, absorption
What are the sections of the GIT in sequence?
Mouth to anus
What organ performs first-pass metabolism?
Liver
Where does most nutrient absorption occur?
Small intestine
What is the main role of the stomach?
Protein digestion
What substance is crucial for protein unfolding in the stomach?
Hydrochloric acid (HCl)
Where does water reabsorption primarily occur?
Large intestine
What GIT layer faces the lumen?
Mucosal layer
What GIT layer faces the blood?
Serosal layer
What cells line the mucosal layer?
Epithelial cells
What muscle layer is responsible for peristalsis?
Circular muscle
What is the last layer of the GIT wall?
Serosal layer
What nervous component innervates the GIT extrinsically?
Autonomic nervous system
Where does the enteric nervous system begin?
Esophagus
Can the enteric nervous system operate independently?
Yes
What plexuses are part of the enteric nervous system?
Myenteric and submucosal
What are the main sensory inputs for the enteric nervous system?
Receptors in mucosa
What are the two neurotransmitter classifications in the ENS?
Cholinergic and peptidergic
Which nerve supplies parasympathetic innervation to the GIT?
Vagus nerve
What type of fibers are in the vagus nerve?
Afferent and efferent
Where does the vagus nerve innervate in the GIT?
Upper GIT
What neurotransmitter is released by cholinergic neurons?
Acetylcholine (Ach)
What do peptidergic neurons release?
Substance P and VIP