Small Intestine and Large Intestine Flashcards
What regulates and coordinates numerous GI tract activities?
enteric nervous system
What are the activities that the enteric nervous system regulates and controls?
- gastric secretory activity
- GI blood flow
- peristalsis
Where is the ENS located?
between the walls of the GI tract
What is generally independent of CNS and receives input from sympathetic and parasympathetic innervation?
ENS
What is the sympathetic abdominal innervation and associated levels?
- greater splanchnic (T5-T9)
- lesser splanchnic (T10-T11)
- least splanchnic (T12)
- lumbar splanchnic (L1-L2/L3)
The greater splanchnic nerves run to the (1) ganglion which distribute to the (2)
- celiac
- foregut
The lesser and least splanchnic nerves run to the (1) and (2) which distribute to the (3)
- superior mesenteric ganglion
- aorticorenal ganglia
- midgut
The lumbar thoracic splanchnic nerves run to the (1) which distribute to the (2)
- inferior mesenteric ganglion
- hindgut
The celiac, superior mesenteric, aorticorenal, and inferior mesenteric plexus communicate via what?
intermesenteric plexus
What is the parasympathetic abdominal innervation and associated postganglionic distribution?
- vagus n. (CN X) - foregut and midgut
- pelvic splanchnic (S2-S4) - hindgut
Descending sympathetic innervation to the pelvic organs is via what plexuses?
superior hypogastric plexuses
What receives pelvic splanchnic nn. (parasympathetics)?
hypogastric nn (inferior hypogastric plexus)
What are the sympathetic activities of the abdominal organs and what do they go to?
- vasoconstriction
- decreased peristalsis
- decreased hormonal secretion
- goes to smooth muscle and glands
What are the parasympathetic activities of the abdominal organs and what do they go to?
- vasodilation
- increased peristalsis
- increased hormonal secretion
- goes to smooth muscle and glands
Pre-synaptic sympathetic fibers synapse directly into what?
suprarenal gland
What travels with sympathetic fibers (GSA)
pain (GVA)
What is the function of the small intestine?
absorption of nutrients
What are the parts of the small intestine?
- duodenum
- jejunum
- ileum
What does the small intestine extend from?
from pylorus to ileocecal junction
What do the jejunum and ileum contain that increase surface area for absorption?
elaborate folds of mucosa
What part of the small intestine doesn’t absorb any nutrients?
duodenum
What vertebral levels does the duodenum travel from?
L1 to L3
How many parts of the duodenum are there and what are their associated vertebral levels?
- 1st: superior part (L1)
- 2nd: descending part (L2-L3)
- 3rd: horizontal part (L3)
- 4th: ascending part (L3)
What is the most movable part of the duodenum?
superior part (first)