Anatomy- Abdominal Pain Flashcards
small intestine
duodenum (short)
jejunum (around 3m)
ileum (around 4m)
large intestine
colon
rectum
anal canal
anus
colon
caecum appendix ascending colon transverse colon descending colon sigmoid colon
abdominal organs
liver oesophagus stomach gall bladder pancreas large intestine small intestine spleen kidneys adrenal glands
foregut
oesophagus to mid-duodenum
liver + gall bladder
spleen
1/2 pancreas
midgut
mid- duodenum to proximal 2/3rds of transverse colon
1/2 pancreas
hindgut
distal 1/3rd of transverse colon to proximal 1/2 anal canal
clinical organisation of organs
quadrants split by horizontal and vertical lines through umbilicus
regions of the abdomen
right hypochondrium epigastric left hypochondrium right lumbar umbilical left lumbar right inguinal pubic left inguinal
which planes divide the regions horizontally?
subcostal plane
transtubecular plane
which planes divide the regions vertically?
mid-clavicular planes
abdominal wall muscles
rectus abdominis
external oblique
internal oblique
transversus abdominis
role of abdominal wall muscles
contract to guard the abdominal organs when injury threatens
peritoneum
thin, transparent, semi-permeable, serous membrane
lines the walls of the abdominopelvic cavity
two layers creates the peritoneal cavity between
parietal
on the body wall
visceral
engulfing the organs
peritoneal cavity
between the 2 layers
contains a small amount of lubricating fluid, as gut moves a lot
peritonitis
blood, pus or faeces within the peritoneal cavity which causes severe and painful inflammation of the peritoneum
intraperitoneal organs
almost completely covered in visceral peritoeneum
minimally mobile
organs with a mesentery (intraperitoneal)
covered in visceral peritoneum
visceral peritoneum wraps behind the organ to form a double layer- mesentery
mesentery suspends the organ from the posterior abdominal wall
very mobile
retroperitoneal organs
only has a visceral peritoneum on its anterior surface
located in the retroperitoneum
intraperitoneal organ egs
liver and gall bladder stomach spleen parts of small intestine transvers colon
retroperitoneal organ egs
kidneys adrenal gland pancreas ascending colon descending colon
peritoneal formations
condensations exist which are double layers of peritoneum which attach organs to each other or to the body wall
types of peritoneal formations
mesentery
omentum
peritoneal ligaments
mesentery
usually connects organ to posterior body wall
omentum
greater and lesser
passes from the stomach to other organs
peritoneal ligaments
connect organs to one another or body wall
types of mesentery
mesentery proper of the small intestine
transverse and sigmoid mesocolon
mesoappendix
greater omentum
four layered
hangs like an apron
attaches the greater curvature of the stomach to the transverse colon
lesser omentum
double layered
runs between lesser curvature of stomach and duodenum to liver
what does the omentum divide the peritoneal cavity into
a greater sac and a lesser sac
how do the greater sac and the lesser sac communicate
omental foramen (foramen of Winslow)
where does the portal triad lie
in the free edge of the lesser omentum
name the three important ligaments formed by the peritoneum
hepatoduodenal ligament which contains the portal triad
hepatogastric ligament
gastrosplenic ligament
splenorenal ligament
name the pouch formed by peritoneum in males
rectovesical pouch
name the pouches formed by peritoneum in females
vesico-uterine pouch
recto-uterine pouch
what is ascites
collection of fluid in the peritoneal cavity
what usually causes ascites
cirrhosis
portal hypertension
how can ascitic fluid be drained from the peritoneal cavity?
paracentesis - abdominocentesis
where must the needle be placed in abdominocentesis and why
lateral to the rectus sheath to avoid the inferior epigastric artery
how do sympathetic nerve fibres get from the CNS to the abdominal organs
leave the spinal cord between levels T5 and L2 and leave the sympathetic chains with abdominopelvic splanchnic nerves
where do abdominopelvic splanchnic nerves synapse?
at prevertebral ganglia at the exit points of the major branches of the abdominal aorta
these pass onto the surface of the arterial branches leaving the abdominal aorta and hitch a ride with arteries
how is the adrenal gland special?
sympathetic nerve fibres leave the spinal cord at T10-L1 and synapse directly onto the cells
how do parasympathetic nerve fibres from the vagus nerve get to the abdominal organs?
presynaptic parasympathetic nerve fibres enter abdominal cavity on surface of the oesophagus (“vagal trunks”)
travel into the periarterial plexuses around the abdominal aorta
carried to the walls of the organs where they synapse in ganglia
supply parasympathetic nerve fibres to the GI tract + abdominal organs up to the distal end of the transverse colon
pelvic splanchnic nerves
S2, 3, 4
Presynaptic parasympathetic nerve fibres
smooth muscle/glands of the descending colon to anal canal
where does pain from the foregut organs tend to be?
epigastric region
where does pain from the midgut organs tend to be?
umbilical region
where does pain from the hindgut organs tend to be?
pubic region
how do visceral afferent nerve fibres get from the abdominal organs to the CNS?
pain fibres from most of the abdominal organs runs alongside sympathetic fibres back to the spinal cord
where do visceral afferent nerve fibres from the foregut organs enter the spinal cord
T6-T9
where do visceral afferent nerve fibres from the midgut organs enter the spinal cord
T8-T12
where do visceral afferent nerve fibres from the hindgut organs enter the spinal cord
T12-L2
where does pain from visceral afferent nerve fibres from abdominal organs tend to be felt
in the dermatomes of the levels at which they enter the spinal cord
