GIT Physiology Flashcards
(19 cards)
State the major activities of the GIT.
Motility, Secretion, Digestion and Absorption
The GIT is arranged in a linear sequence of the order…
Mouth -> esophagus-> stomach-> small intestines -> large intestines -> anus.
The alimentary canal has
4 layers
Mention the layers of the gastrointestinal tract.
Mucosa, submucosa, muscularis propria and Serosa/adventitia
The GI tract is innervated by
Extrinsic and intrinsic nerves
The extrinsic nervous system comprises of
Parasympathetic and sympathetic nerves
The intrinsic nervous innervation is from the
Enteric nervous system
The enteric nervous system communicates with the extrinsic component through
Extrinsic components
Which of the following statements is true about the GI tract.
A. The intrinsic nervous innervation of the GI can function in absence of extrinsic innervation
B. The enteric nervous system controls contractile, secretory and endocrine functions of GI tract.
C. The intrinsic nervous innervation receives input from mechanoreceptors and chemoreceptors in the mucosa and both parasympathetic and sympathetic nervous systems
D. All of the above are true
D
Parasympathetic fibers arr supplied by the
Vagus nerve and the pelvic nerves
The extrinsic fibers that provide excitatory action are
Parasympathetic nerves
Parasympathetic nerves
- Increase activity
- Increase smooth muscle activity
- Promote gastric motility
- Promote secretion of GI secretions
- Reduce the constriction of sphincters
Parasympathetic nerves promote digestion and absorption of nutrients. (T/F)
T
The proximal half of the GI is innervated by
Vagus nerve
Distal half of the GI is innervated by the
Pelvic nerves(Sacral nerves)
Which of the following statements is false?
A. The sacral nerves control defalcation reflex.
B. Vagus nerve controls the swallowing reflex.
C. Both A and B are False
D. Both A and B are true
D
Which statement is false?
A. The sympathetic nerve fibers originate from the sympathetic ganglia of T5 to L2 and terminate on the enteric plexus.
B. The sympathetic innervation is noradrenergic postganglionic.
C. In order to inhibit GI motility the sympathetic nerves are stimulated.
D. The autonomic nerves that regulate the GI can function independently from stimulation from the CNS
D
Increases sympathetic activity causes
- Decreased acetylcholine secretion
- Vasoconstriction
- Decreased GI motility and secretion
- Increased constriction of sphincters
The GI reflexes are categorized into
Local reflexes, regional reflexes and systemic reflexes
