Lecture 4 - Lower Abdomen Flashcards
entrance into stomach from esophagus
cardiac oriface
exit to duodenum from stomach
pyloric sphincter
stomach is lined with___,temporary folds within the body of the stomach
rugae
rugae are a result of___
result of Muscularis Externa; churning movement
acts as a food blender and a reservoir
stomach
primary function of the stomach is
enzymatic digestion
gastric juices concery mass of food to a semiliquid mixture
chyme
Gastric folds = rugae; mostly longitudinal, contraction, reduces volume of stomach – controlled by
Auerbach’s plexus (myenteric plexus) – ANS, enteric NS
3 areas of the small intestine
duodenum
jejunum
ileum
small intestine; fixed and relatively immobile
duodenum
small intestine; tethered, but very mobile. combined length of 3 segments~20ft
jejunum and ileum
permanent folds within small intestine, become more diffuse distally
plicae circularis
__ empties into cecum at ileocecal junction
ileum
first part of the small intestine; widest portion, fixed and retroperitoneal except for superior part which is connected to the liver by
duodenum
connected to liver by hepatodoudenal ligament
arterial supply of the duodenum of the small intestine
arterial supply from gastroduodenal br. (common hepatic a - celiac) & br. of SMA
( clinical note)
remnant of embryonic yolk stalk
appears as a finger like pouch
located ~1 m proximal to ileocecal valve
May become inflamed & mimic appendicitis
Meckel”s (ileal) diverticulum
5 segments & 2 flexures
‘Frames’ small intestines
{Cecum, Ascending, Transverse, Descending, Sigmoid}
Terminates into Rectum
[R. colic (hepatic) & L. colic (splenic) flexures]
large intestine (colon)
opens into cecum inferior to ileocecal oriface; triangular mesentary =___.
commonly retrocecal, but varies considerably
veriform appendix
mesoappendix
(clinical note)
Vague pain begins in the periumbilical region
from afferent pain referred to T10 level
Severe pain later from R. lower quadrant
from irritation of peritoneum of posterior abdominal wall
Pain most severe over spinoumbilical point between the ASIS & umbilicus
appendicitis
umbilicus is are which vertebral level
L4
divides the abdominal cavity into two compartments
transverse mesocolon
compartment of the abdominal cavity separated by transverse mesocolon that contains stomach, liver, and spleen
supracolic compartment
compartment of the abdominal cavity separated by transverse mesocolon that contains small intestine and ascending/descending colon
infracolic compartment
Colon Specializations; 3 smooth muscle bands paralleling length of colon
teniae coli
Colon Specializations; outpouchings produced by teniae coli
haustra coli
Colon Specializations; fat tags found along the colon
epiploic appendages
Arterial Supply of lower Abdomen
superior mesenteric artery (SMA)
second major branch of the abdominal aorta; 1cm inferior of celiac: sends 15-18 intestinal artery’s to small intestine
superior mesenteric a.
SMA supplies up to ____, via ileocolic, right colic and middle colic, inferior pancreaticoduodenal
up to proximal 2/3 of transverse colon
Third major branch of the abdominal aorta; 5cm superior to aortic bifurcation
Inferior mesenteric a. (IMA)
Inferior mesenteric artery supplies ____, via left colic, sigmoid and superior rectal
colon from distal 1/3 of transverse colon
Anastomoses exist between colic branches of SMA & IMA for _____ circulation
collateral
SMA and IMA form a consistent vascular arc around colon via
marginal a. of Drummond
Pancreatic Arteries anastomoses;
Gastroduodenal a. gives off ____
SMA gives off ____
Gastroduodenal a. gives off Superior pancreaticoduodenal aa.
SMA gives off Inferior pancreaticoduodenal aa.
lateral branches of abdominal aorta (lateral to SMA)
Enter hilum of each kidney to supply it
sends off brs. to adrenal glands and ureters
other adrenal branches from inferior phrenic aa & aorta
renal aa
lateral branches of abdominal aorta (inf. to renal aa.) Ovarian aa (♀)-crosses over ureters & iliac vessels descends to pelvis to supply ovaries
Testicular aa. (♂)
crosses over ureters & enters inguinal canal
descends into scrotum to supply testes
gonadal a.
portal venous system means that is must pass through __ via __before entering inferior vena cava
pass through liver via the hepatic v.
largest vein in body;
begins at ___level
at union of common iliac vv.
returns poorly oxygenated blood from LL, most of the back, abdominal wall, & abdominopelvic viscera
to the RA of heart
Inferior vena cava
L5
Formed by union of splenic and superior mesenteric vv. (L2)
portal vein
Returns nutrient rich, poorly oxygenated blood to the liver
Then via IVC to the RA of heart
portal vein
Venous return from: Spleen Pancreas Gall bladder Abdominal gastrointestinal tract
portal vein
4 anastomoses: portal & caval vv
gastric vv & esophageal vv (1)
paraumbilical vv & epigastric vv (3)
superior rectal vv & middle/inferior rectal vv (2)
colic vv & retroperitoneal vv (4)
__system has no valves
Portal venous system
reversal of blood flow into ____ is possible
caval vv
distended and engorged paraumbilical vv. (often resulting from cirrhosis)
Caput medusae
Dilated espophageal vv produce
esophageal varices
Dilated ____produce caput medusae
epigastric vv.
Dilated infr. & mid. rectal vv produce
hemorrhoids
Innervation to abdomen viscera is via
autonomic n. plexus
___ fibers originate from T5-T12_L2 (thoracolumbar
sympathetic fibers
__ fibers originate from CN X and S2-4 (craniosacral)
Parasympathetic fibers
(vertebral level) esophageal and cardiac stomach that start in abdominal cavity
T5
sympathetics of abdomen;
preganglionic splanchnic n. synapse in
collateral ganglia
sympathetics of abdomen;
postganglionic fibers leave ganglia to
reach effector organs
post-synaptic fibers travel on
all main arterial branches.
celiac trunk, SMA, renal aa, IMA and all their branches
4 options once sympathetic presynaptic fiber enters the chain:
Ascend then synapse Synapse at level of exit Descend then synapse Pass through without synapsing Splanchnic nerves
preganglionic sympathetics:
____communicates to anterior and posterior rami of all spinal nerves for distribution to body walls and limbs (vasomotion, sudomotion, and pilomotion)
gray rami
where does the greater splanchnic nerve synapse?
celiac ganglion
where is the celiac ganglion (greater splanchnic nerve synapses at the celiac ganglion)
T5-T9
where does the lesser splanchnic nerve synapse
SMA ganglion (T10 and T11)
where does the least splanchnic nerve synapse
aorticorenal ganglion(T12)
where does lumbar splanchnic nerve synapse
IMA ganglion(L1 and L2)
what is a plexus
lots of nerve fibers/axons coming together
another name for parasympathetics
craniosacral
what does vagus nerve supply
foregut and midgut derivatives
where does the vagus nerve stop innervating
proximal 2/3 of transverse colon (end of midgut)
where do you find parasympathetics postganglionic fibers
in the walls of the organs they innervate
autonomic ganglia; receive thoracic splanchnic nn & CN X brs
celiac ganglion
SMA ganglion
Aorticorenal ganglion
receives lumbar splanchnic n. and S2-S4 brs
IMA ganglion
