Exam 2 - Abdomen Flashcards
what is the boundaries of the abdomen?
diaphragm -> pubic ramus
- includes part of rib cage
what are the three openings in the diaphragm, what things go through them into the abdomen?
caval -> IVC, right phrenic
esophageal -> esophagus, vagal trunks, lymphatics
aortic -> aorta, thoracic duct, azygos vein (sometimes)
what are other things that go through the diaphragm that aren’t in the three openings?
central tendon (location of muscle connections)
intercostal nerves
median, medial, and lateral arcuate ligaments
what is the pelvic inlet?
top of sacrum -> pubic symphysis (big hole in pelvis)
whats the location of the intertubercular plane?
L5
- tubercle of crest of ilium
whats the location of the supracristal plane?
L4
- top of iliac crest, below umbilicus
whats the location of the subcostal plane?
L3
- above umbilicus
whats the location of the transypyloric plane?
L1/2
- end of 9th costal cartilage
what important structures are at the transpyloric plane?
pyloris sphincter
kidneys
spleen
gallbladder
pancreas
origin of SMA & portal vein
what are the three regions of the abdomen? what regions are to the side of each region?
epigastric (L & R hypochondrium)
umbilical (L & R flank)
pubic (L & R groin)
what is the location of each of the regions in the abdomen? what referred pain goes to each?
epi = above subcostal plane, referred from foregut
umb = above intertubercular, referred from midgut
pubic = below intertubercular, referred from hindgut
what major organs are in the epigastric region?
esophagus
stomach
duodenum
liver
gallbladder
pancreas
what major organs are in the umbilical region?
jejunum
what major organs are in the pubic region?
ileum
cecum
appendix
sigmoid colon
what regions are the ascending colon, transverse colon, and descending colon in?
ascending = epigastric, umbilical
transverse = ALL THREE
descending = ALL THREE
what things branch off the gut tube?
liver
gallbladder
pancreas
what organs are in the abdomen but do NOT branch off the gut tube?
kidneys
suprarenal gland
spleen
what are the two layers of smooth muscle?
longitudinal
circular (circumferential)
what are the four functions of the muscle in the gut tube? where in the gut tube does these functions occur?
propulsion (all parts)
trituration / crushing (stomach)
mixing (small intestine)
reservoir (stomach, colon)
what is the INN of the enteric NS?
mainly parasympathetic (visceral nonsensory)
- some symp
where do the nerves run in the abdomen?
between the mesentery!
what are the two nerve plexuses in the abdomen? where are they? whats their main function?
myenteric plexus (circular muscle) = muscle contraction
meissner plexus (submucosa) = secretion of gut fluids
what is peristalsis initiated by?
distention of gut tube or brushing of vili
what muscles are relaxed and contracted in front of the moving bolus?
longitudinal contract
circular relax
what muscles are relaxed and contracted behind the moving bolus?
longitudinal relax
circular contract
* default myogenic state *
what is a physiological ileus?
no motility in small or large intestine
what organs are supplied by the celiac trunk?
liver
stomach
pancreas
spleen
gallbladder
part of duodenum
what organs are supplied by the superior mesenteric artery?
dudenum
jejunum
ileum
as. colon
trans. colon
what organs are supplied by the inferior mesenteric artery?
desc. colon
sigmoid
rectum
what are the five main sphincters? what is the sixth one that isn’t technically a sphincter, but acts like one?
lower esophageal
pyloric
sphincter of oddi
ileocolic
internal anal
diaphragm
what is achalasia?
failure to open sphincter
what is the peritoneum derived from?
celom
what is the periotneum? list the two types and then describe
parietal peritoneum: on body wall, INN VISCERAL
visceral peritoneum: closed bag incasing abdominal organs
what is intraperiotneal? retroperiotoneal? what are the retro organs?
intra = incased organs
retro = push periotoneum from behind
*aorta, esophagus, kidneys, parts of intestine
what is the mesentery?
double layer of peritoneum that attaches the organs to the abdominal wall
- attaches vessels, nerves, lymphatics to organs
- INN vsiceral!
what is the greater omentum?
big layer of fat that runs from the stomach to the transverse colon (created by the mesentery folding)
what is the lesser omentum?
space under the liver and above the lesser curve of stomach
what is the lesser peritoneal sac? greater peritoneal sac?
lesser = area behind stomach, liver, and their connecting mesentery
greater = everything else!
what is the inferior recess?
behind greater omentum
what is the superior recess?
behind liver and stomach
- used to communicate to abdomen
in development, what does the cephalic limb of the primary intestinal loop turn into?
upper midgut
- distal duodenum
- jejunum
- part of ileum
in development, what does the caudal limb of the primary intestinal loop turn into?
lower midgut
- distal ileum
- cecum
- appendix
- as. colon
- 2/3 trans. colon
describe the rotation of the gut?
- caudal end twists upward, now caudal is on top & cephalic is on bottom
- cephalic limb starts to get wiggly & herniation reduces
- cecum descends & final form starts
what supplies the foregut, midgut, and hindgut of the developing embryo at 4 weeks?
celiac a = foregut
SMA = midgut
IMA = hindgut
what are the layers of the abdominal wall in order?
skin
campers fascia (fatty layer)
scarpa’s fascia
ex. oblique
int. oblique
transversus abdominalis
transversalis fascia
extraperitoneal fascia (fatty layer)
parietal peritoneum
what is the insertion and origin of the external oblique?
rib 5-12
iliac crest
what is the insertion and origin of the internal oblique?
ribs 10-12
iliac crest
what is the insertion and origin of the transversus abdominalis?
ribs 6-12
pubic bone
what is the insertion and origin of the rectus abdominalis?
xiphoid
pubic bone
what is the line called where the rectus sheath ends?
accuate line
what symp. intercostal nerve supplies organs int he umbilicus region?
T10
what intercostal region is at the top of the iliac crest?
T11
what region includes the last rib?
T9
what is the blood route of the abdomen starting at the aorta?
- aorta
- subclavian
- internal thoracic a -> musclophrenic, superior epigastric a
- sup. epigastric anastimosis w/ inferior epigastric a
- external iliac a. -> deep circumflex iliac, femoral a
- femoral a. -> superficial circumflex iliac, superficial epigastric a.
what are the trunk flexors?
erector spinae
obliques
psoas (when thigh is fixed)
what are the trunk extensors?
erector spinae
why are the erector spinae muscles and rectus abdominus enclosed in a tight sheath? what is those tight sheaths called?
restricts lateral expansion of muscle and increases axial force
- waste energy for muscle to bulge outwards
- thorcolumbar fasic, erector sheath
what allows for lateral flexion?
quadratus lumborum
ipsilateral obliques
psoas
what allows for rotation?
external obliques (front to opposite)
internal obliques (front to same)
psoas
what creates the intrabdominal pressure? what does this pressure help with?
contraction of anterior wall muscles, sucking in
- aids in micturation (urination), defecation (shitting), respiration, childbirth, coughing
what does the psoas connect to on the vertebrae?
T12-L4
when do the testes descend into the scrotum?
26 weeks of development on the 2-3rd day
- 3% do not have descended testes
what is the area of weakened transversalis fascia called?
Hesselbach’s triangle
what two ligaments is the hesselbach’s triangle b/w?
medial and lateral umbilical ligament
what are the two rings for teste descent? where are they?
deep inguinal ring
superficial inguinal ring
* above inguinal lig & below apopneurosis of ex oblique
what layers is pinched off when the testes descend? what new layer does this create?
parietal peritoneum is pinched off to create the tunica vaginalis
what are the layers of the spermatic cord?
skin
dartos fascia
external spermatic fascia
cremaster muscle & fascia
internal spermatic fascia
loose fascia (surround vessels, nerves, ductus deferens)
what are the layers of the scrotum?
skin dartos fascia
external spermatic fascia
cremaster muscle & fascia
internal spermatic fascia
loose fascia (surround vessels, nerves, ductus deferens)
tunica vaginalis testis *
what is an indirect inguinal hernia?
pushed over inguinal ligament and gets stuck in deep inguinal ring, pushed through spermatocord
what is a direct inguinal hernia?
pushed over inguinal lig and through hesselbach’s triangle
what is a femoral hernia?
pushed through femoral canal under the inguinal lig
what are the four mucosa types? which organs have them?
protective (esophagus, anal canal)
secretory (stomach)
absorptive (small intestine)
absorptive / protective (colon)
what is the muscle like in the esophagus?
upper 1/3 is striated muscle
lower 2/3 is smooth muscle
what is the INN of the esophagus?
vagus
symp T1-5
what is the blood supply of esophagus?
branches of left gastric a
what is the function of the esophagus?
transport food, prevent emesis, peristalsis
what are the two types of peristalsis in the esophagus? describe them
primary = initiated by swallowing
secondary = if food doesn’t go down, mechanoreceptors initiate another round
what is GERD?
stomach acid flowing upwards into the esophagus
what is Barret’s esophagus?
since the stomach and esophagus are genetically the same (just have different genes active) the stomach acid converts the cells in the esophagus due to GERD
- leads ot adenocarcinoma (cancer)
what are the two sphincters of the esophagus? what are their INN?
lower esophageal (vagus) -> smooth muscle
diaphragm (phrenic) -> striated muscle
what is the structure of the lower esophageal sphincter?
incomplete muscle ring that makes clasp fibers
- these fibers convert to sling fibers and fuse w/ the deepest layer of the stomach, oblique
what are the three muscle layers of the stomach?
longitudinal, circular, oblique
what is the INN of the stomach? referred pain?
vagus
symp T5-7
- referred to epigastric & left hypochondriac
what is the blood supply of the stomach?
L & R gastric a
gastroepipolic a
short gastric
what are the branches off of the celiac trunk?
left gastric
hepatic
splenic
what branches off of the hepatic a?
hepatic prosper -> left & right liver lobes
right gastric
gastroduodenal -> gastroepipolic, superior pancreaticoduodneal
what branches off the splenic a?
left gastropipolic
short gastric
what are the two main functions of the stomach? describe them
proximal / upper stomach (reservoir)
- tonic contractions (slow, sustained)
- maintains constant pressure on contents
antral region (muscle contractions)
- phasic contractions (rapid, drastic)
- if stomach is closed, retropulsion back into stomach
what is the migrating motor complex? (MMC)
interdigestive mechanism in the small intestine
- moves food & clears contents very slowly
- moves bile through, preventing concentration of bile
- prevents bacterial growth
what INN is involved with the initiation of mixing in the small intestine?
vagus efferents
what are the four parts of the duodenum, in order?
superior, descending, inferior, ascending
what is the function of the duodenum?
mixes chyme with bile & pancreatic secretions
what is the INN of the duodenum? referred pain?
vagus
symp T7-9
- referred to epigastric & right shoulder
what is the blood supply of the duodenum?
supraduodenal a
gastroduodenal a
pancreaticoduodenal a (sup, inf)
where on the duodenum is the foregut-midgut transition?
ampula of vater
- area for bile & pancreatic secretions
what are the branches off of the SMA? what do they supply blood to?
jejunal branches -> ileum branches, ileocolic (cecum, lower part of as. colon)
right colic (upper part of as. colon)
middle colic (majority of trans. colon)
what are the branches off of the IMA? what do they supply blood to?
left colic (desc. colon, part of trans. colon) -> sigmoid branches
superior rectal
what runs through the root of mesentery?
SMA, SMV along with other veins, nerves, and lymphatics
- at the 4th part of duodenum -> ileocostal junction)
where is the jejunum mostly?
umbilical region
- 2/5 of small intestine
- wrinkled apperance in xrays
where is the ileum mostly?
pubic region
- 3/5 of small intestine
what supplies blood to the jejunum and ileum?
j = jejunal branches of SMA
i = ileal branches of SMA
what does the lymphatics of the gut do?
collect extracellular fluid in the vascular capillary beds
- including pathogens, lymphocytes, cell debris
- have tight junctions to ensure only the right things pass thru
what is an important structure of the small intestine lymphatic system? describe them
lacteals
- drain chylomicrons to lymph system
- major route for the transport of fat from intestine to bloodstream
- important clinically, because this bypasses the liver, making the concentration of materials higher in blood (DRUGS!)
what two types of cells are involved with things such as Peyer’s Patches?
M-cells
dendritic cells
what is the INN of the ileocecal junction? referred pain?
vagus
symp 10
- referred to umbilicus
what is the function of the appendix?
hides the good bacteria when power propulsion happens
- makes it so the good bacteria can grow after being striped from lumen
what pathways does referred pain follow?
sympathetic nerve paths
- multiple sensory neurons converge on a single ascending tract
what is the thin tendon that runs through the middle of the large intestine?
taeniae coli
what are the little fat blebs that come off the taeniae coli?
appendices epiploicae
what two things doe the large intestine hit? where?
right colic fissure hits liver
left colic fissure hits spleen
what are the permanent swellings of the large intestine called?
haustrae
what is the INN of the large intestine?
switches from vagus -> pelvic splanchnic at left colic fissure
what is the blood supply of the large intestine?
switches from SMA -> IMA (left colic) at left colic fissure
what is the hepatorenal recess?
below liver, above post. side of kidney
what is the subphrenic recess?
above liver in front
what are some functions of the liver?
produce bile
metabolizes carbs, fats, proteins
filtration of blood from intestines
what is the INN of the liver? referred pain?
vagus
symp T7-9
- referred to epigastric and right hypocondrium
what is the blood supply of the liver?
hepatic prosper a (30%, 50% o2)
portal vein (70%, 50% o2)
where does the portal vein and hepatic prosper a blood mix in the liver?
sinusoids
what carries the blood back to the hear for the liver?
hepatic veins -> IVC -> heart
describe the stages of liver failure
fatty liver -> overproduction of fat stays in liver
liver fibrosis -> fat turns into fibrous connective tissue (scaring)
cirrhosis -> fully scared over
what cells help the liver regenerate?
hepatocytes
how many functional liver segments are there?
8
- each have their own vascular inflow, outflow, and biliary drainage
- veins drain at boarders of segments
where does the bile go if the sphincter of oddi is open?
duodenum -> distal ileum to be absorbed by SMA -> liver
what makes bile? where does this bile go to?
hepatocytes -> canaliculi
what is the function of the gallbladder?
concentrates by absorbing water and storing bile
what is the INN of the gallbladder? what does each contract & relax? referred pain?
vagus (contract GB, relax sphincter)
symp T7-9 (relax GB, contract sphincter)
- goes through phrenic n to right shoulder & C3-4
what is unique about duodenum histology?
short-leaf like vili
brunners glands in submucosa
what do brunner’s glands do?
neutralize acid in stomach
what is unique about jejunum histology?
long club like vili
no glands in submucosa
what is unique about ileum histology?
short slender finger vili
Peyer’s patches in submucosa
more goblet cells
what do peyer’s patches do?
lymaphatics
what is unique about appendix histology?
no vili, only a few crypts
lymphoid follicle in lamina propria
what is unique about colon histology?
no vili, only lots of crypts
lots of goblet cells
no cells at bottom of crypts
what is unique about esophagus histology?
stratified epithelium
glands in submucosa
what is unique about fundus histology?
straight vili
shallow gastric pits
long glands
what types of glands are in the fundus? what are their functions?
parietal cells -> secrete gastric juice
chief cells -> secrete pepsin
neuroendocrine -> hormones
what is unique about pylorus histology?
coiled vili
deep gastric pits
G-cell in lamina propria
what do G-cells do?
secrete gastrin and stimulate fundus
what is unique about cardia histology?
coiled vili
pits are not as deep as pylorus
few glands
what are the layers for histology in this unit?
- epithelium
- lamina propria
- muscularis mucosa (smooth muscle)
- submucosa
- oblique (stomach), circular muscle
- longitudinal muscle
- serosa or adventitia
