2. Anatomy Pt. II Flashcards
(21 cards)
Hindgut derivatives
Distal 1/3 transverse colon, descending colon, sigmoid, rectum
Receive blood supply from the ____ and its branches
Receive preganglionic sympathetic innervation from ____ nerves
Receive preganglionic parasympathetic innvervation from the ____
inferior mesenteric artery
lumbar splanchnic
pelvic splanchnics (S2-4)
Cannon’s Ring is the name for the junction between the ____ and ____ derivatives. It’s essentially a constriction in the ____ colon. It is hard to find anatomically and more easily seen in radiographic studies of the colon than in a gross anatomical one.
The splenic (left colic) flexure is always going to be found significantly more ____ located in the upper left quadrant than the hepatic flexure was in the upper right quadrant
midgut
hindgut
superiorly
IMA
- ____ artery
- ____ artery
- ____ branches
Additional rectal arteries are derived from the ____ arteries in the pelvis.
superior rectal
left colic
sigmoidal
iliac
Anastomoses exist between the three arteries supplying the abdominal gut
1 Around the ____ and pancreatic head
2 Around the ____ flexure
3- IMA-Iliac anastomoses occur along the ____
duodenum left colic (splenic) rectum
The RECTUM is ____, lying anterior to the sacrum and differing in aspects of its ____ from the rest of the colon
secondarily retroperitoneal
structure
Internally, the rectum features three ____ rectal folds
The terminal rectum is distended to form the ____ just prior to penetrating the ____
transverse
ampulla
pelvic diaphragm
The terminal rectum turns posteroinferiorly as it prepares to penetrate the pelvic diaphragm to become continuous with the ____
anal canal
Tonic contraction of a ____ helps to maintain fecal continence at the anorectal flexure…
…along with the ____, an involuntary sphincter formed by the circular muscle layer of the upper anal canal
puborectal sling
internal anal sphincter
The ____ marks the caudal boundary between the gut and the body wall
The smooth muscle of the
____
plays a role in maintaining fecal continence
pectinate line
internal anal sphincter
Recall that bundles of
____ sympathetic axons that pass through the paravertebral chain ganglia without synapsing are called
____
preganglionic
splanchnic nerves
Recall too that these fibers synapse in ____ ganglia located anterior to the spine…
and are thus referred to as ____ or…
…____
GANGLIA as they are clustered on the anterior surface of the ____ aorta
collateral
prevertebral
preaortic
abdominal
Associated with these
____ ganglia
are similarly named autonomic plexuses that
also contain ____ fibers
sympathetic
preganglionic parasympathetic
Both ____ and ____ parasympathetics contribute to the innervation of the abdominal GI organs
cranial
sacral
CN X -
VAGUS NERVES
provide parasympathetic innervation to derivatives of the embryonic foregut and midgut via the ____
PELVIC SPLANCHNICS
supply the hindgut from
____
anterior and posterior vagal trunks
S2-4
Postganglionic sympathetics and preganglionic parasympathetics form a dense, mixed \_\_\_\_ around the branches of the \_\_\_\_, \_\_\_\_ and \_\_\_\_ arteries as they course toward their targets
periarterial plexus
celiac
superior mesenteric
inferior mesenteric
These extrinsic inputs modulate the function of the ____, in principle an independent network of neurons that provide the foundation for autonomic GI reflexes
enteric nervous system
Parasympathetic stimuli
• promote ____
• promote ____
Sympathetic stimuli: • facilitate contraction of \_\_\_\_ sphincters • inhibit both \_\_\_\_ and glandular \_\_\_\_
peristalsis secretion smooth muscle peristalsis secretion
In the abdomen, visceral afferents accompanying sympathetic nerves also transmit ____ from…
- ____ stimulated by excessive ____ of GI viscera
- Strong contractions of ____ in visceral walls
pain
nociceptors
distension
smooth muscle
VISCERAL AFFERENTS fibers, also course along with ____ nerves
Some of these convey ____ sensations
arising from ____ responding to distension in the walls of the GI tract
Others convey inputs from ____ e.g. those sensitive to the concentration
of ____ ions in the stomach
parasympathetic physiologic mechanoreceptors chemoreceptors hydrogen
Splanchnics convey these ____ fibers from viscera
to the ____ of spinal nerves ____ via the ____
These pain afferents may stimulate ____ fibers in the dorsal roots of these nerves and produce abdominopelvic
“____”
GVA
dorsal roots
T5-L2
white communicating rami
GSA
Pain from pathological ____ is also consistently
referred to specific regions of the body wall
abdominopelvic viscera
