Abdomen Lectures Flashcards
what are the walls of the abdomen (divisions and parts within each)
divded into cranial, middle and caudal parts
cranial = xyphoid and hypochondriac (on either side of xyphoid section)
middle = umbilical and flank on either side of that
caudal = inguinal and pubic underneath it
what part of the abdomen is a landmark for surgery
umbilical region
what is the general idea of internal extent of abdomen
multiple layers of muscles to contain the heavy abdominal organs
3 flank/ventral muscles and 1 ventral muscle
superficial abdominal structures
umbilical scar, prepuce (in males) and mammary glands (male and female)
what are three important abdominal landmarks and where are they
linea alba (white line)= aponeuroses of the flank muscles runs from xiphoid cartilage to the cranial end of the pelvic symphysis (via the prepubic tendon)
tunic flava = fascia consists largely of elastic tissue and being yellowish.
prepubic tendon = extends from the bring of the pelvis and joins with the abdominal muscles to support the abdomen and abdominal viscera
what happens if the prepubic tendon ruptures
since the main weight of the abdominal organs is carried by the prepubic tendon, it follows that its rupture has the direct consequences
this is rare but most common in heavily pregnant mares and cows (entire floor of abdomen drops down)
muscles of the abdomen
epaxial, hypaxial/sublumbar, diaphragm, ventrolateral (muscles of flank and abdominal floor)
what abdominal muscles are of high surgical importance
muscles of the flank and abdominal floor
what are the abdominal muscles (4) - what layer and where is it
external abdominal oblique = outer layer, lateral surface of ribs and lumbar fascia to linea alba
internal abdominal oblique = intermediate, tuber coxa to linea alba
transverse abdominis = deepest layer of lateral muscles, transverse process of lumbar vertebrae to linea alba
rectus abdominis = broad band on side of linea alba, six pack muscle, ventral surface of rib to pubic brim by prepubic tendon
what muscle are dermatome nerves in
transverse abdominus
what is the rectus sheath
its a ventral aponeurosis of external abd oblique, internal abd oblique and transverse abd that wraps around the rectus abdominus
why is it important to do sutures at the linea alba
because if you do them here, you can get all three layers of the rectal sheath at once since they all meet up at the linea alba
what forms the iliacopsoas muscle, how do the muscles work
the ilacus and psoas major join to form it.
the psoas is the master muscle of the lower body. its a core muscle that is involved in all lower body movement - jumping, changing directions, laying down, standing up, and forward motion
what is the function of the iliacopsoas muscle
the main function is to flex and externally rotate the hip. think of a male dog trying to urinate
what forms the inguinal canal and for what region
what is included in outpouching of peritoneum
abdominal wall is perforated in the region of the groin by the inguinal canal. before or shortly after birth the testes transmitted through the abdominal wall towards the scrotum
outpouching
-male = cremaster muscle, spermatic cord (ductus deferens, lymphatic vescicles, autonomic nerves, testicular arteries and veins)
-male and female = external pudendal artery and usually vein, efferent vessels from superficial inguinal lymph nodes and genitofemoral nerve
-female = vaginal process which is accompanied by the rough ligament of the uterus
where is the inguinal canal location
its a short fissure with CT between the abdominal muscles
what emerges from the inguinal ring in the male dog
spermatic cord and external pudendal vessels
where do the external pudendal vessels run toward in both male and female
they run toward the superficial inguinal lymph node, where they bifurcate
what spinal nerves run on the transversus abdominus
ventral branches of thoracic and lumbar spinal nerves
what emerges from the inguinal ring in the female dog
vaginal process and external pudendal vessels
what is aponeurosis
thin sheet of CT
what can you see when you reflec the external abdominal oblique aponeurosis
the deep inguinal ring
how is the deep external ring bounded
-cranially by the internal abdominal oblique
-medially by rectur abdominus
-caudally by the inguinal ligament which is the caudal edge of external abdominal oblique aponeurosis
where does the cremaster muscle run
on the spermatic cord
how to differentiate between external ring and inguinal ring
external ring = all white
internal ring = not white, made up of three borders
main blood supply and drainage for abdominal walls
-cranial supply and deep epigastric artery and vein (from internal thoracic artery and vein)
-caudal supply and deep epigastric artery and vein (from external pudendal artery and vein and pudendoepigastric trunk)
-lateral thoracic artery (minor contribution)
-deep circumflex iliac artery (dorsal flank)
what is the milk vein in cattle
is the superficial abdominal vein which is an anastomosis of cranial and caudal superficial epigastric vein
innervation of the abdominal wall important for cattle
-dorsal branches T13-L5 innervate = epaxial muscles, skin of dorsal flank
-ventral branches innervate = abdominal muscle, skin of ventral flank, udder, scrotum
contribution from lateral thoracic nerve
what are the three nerves to block for flank surgery and what is the block called
T13 (costoabdominal nerve), L1 (iliohypogastric nerve), T2 (ilioinguinal nerve)
paravertebral block
types of superficial inguinal lymph nodes in males vs females
mammary lymph nodes in females
scrotal in males
what is a lymph node only found in large animals
prefemoral lymnode…. or called subiliac lymph node
what does the peritoneum do
provides anchor support (tent guylines) and helps hang abdominal organs from the abdominal rood (shower curtain analogy)
what is the peritoneum
its a serous membrane that lines the walls of abdominal cavity
-visceral peritoneum = around organs
-parietal peritoneum = around ouside
-connecting mesentary = connects bowels to the body wall
what is poorly developed in horses and what does that lead to
omentum is poorly developed. relative susceptibility to peritonitis as a result
types of omentum and what they do
greater omentum = attaches stomach to body wall
lesser omentum = attaches stomach to liver
greater omentum - function
-connects greater curvature of stomach to the spleen and folds on itself
-immune organ as well as protective (against adhesions and infections)
-heat conservation
where is the lesser omentum
present on the lesser curvature of the stomach
specific ligaments and what the connect, location
-coronary ligament = liver to diaphragm, near foramen vena cava, makes liver least mobile
-round ligament (edge contains umbilical cord)
-falciform ligament = attaches to the diaphragm and the ventral abdominal wall as far as the umbilicus
-nephrosplenic ligament = spleen to left kidney
what does the triangular ligament do
attaches liver edges to the diaphragm
what is the gastrosplenic ligament part of and what does it do
part of greater omentum connecting stomach to spleen
keeps spleen anchored and in close proximity with stomach (share blood circulation)
parts of the canine stomach
cardia (where esophagus comes in)
fundus
body
pylorus (where angle changes)
angular incisures (sharp bend)
pylorus (leading into duodenum)
what do rugae gastricae do
increase surface area for acid secretion
where are the cranial and caudal flexures of the stomach
-the duodenum passes caudal to the mesenteric artery (caudal flexure) before passing cranially to join the jejunum
-the colon passes cranial to the mesenteric artery before passing caudally to the rectum (cranial flexure)
where is the prancreas located and where do secretions enter the gut
located at the start of the duodenum
1. pancreatic duct (with bile duct which opens at the sphincter of odie)
2. accessory pancreatic duct
what is the caecum and where is it found
what species is it really big in
its a coma based structure at the beginning of the colon
rabbit and horse
what part of the colon is on the left vs the right
ascending is on the right
descening is on the left
what are the three main branches from the aorta for blood supply to the gut and where does each lead to
-celiac = to liver, spleen, stomach and proximal duodenum and pancreas
-cranial mesenteric = to distal duodenum and pancreas, jejunum, ileum, cecum, ascending and transverse colon
-caudal mesenteric = to descending colon and rectum
what is the iliocecal fold
The ileocecal fold is a mesenteric fold that keeps the ileum attached to the cecum and the ileocolic orifice is the opening of the ileum into the cecum
what is the blood supply to the intestinal tract supplied by
cranial and caudal mesenteric arteries
what is included in the cranial mesenteric artery branching and where do they go
Cranial mesenteric
-Caudal pancreaticoduodenal which goes to the duodenum (remember the cranial pancreaticoduodenal which is off the hepatic which is off the celiac)
-Jejunal arteries to the jejunum
-Ileocecolic branch which gives rise to the following:
- Mesenteric ilial on the mesentery side of the ilium
- Antimesenteric iliac on the lateral side of the ileum
- Cecal to the cecum
- Colic goes to the ascending colon
- Right colic goes to first part of transverse colon
- Middle colic to the rest of the transverse colon
whats included in the caudal mesenteric artery and where do they go
-Left colic which feeds the descending colon
-Cranial rectal to the rectum
what forms the common bile duct
is formed by the hepatic and cystic ducts coming together.
what forms the gallbladder and how is it filled
The cystic duct gives rise to the gall bladder (cyst) that fills up with bile when the sphincter of odie on the bile duct is closed (will open in response to food present).
what are the grooves of the rumen
-left longitudinal groove
-left accessory groove
-cranial groove
-caudal groove
-dorsal coronary groove
-ventral coronary groove
-reticuloruminal groove
-
what are the two blind sacs in the rumen
caudal dorsal blind sac
caudal ventral blind sac
omental layers in ruminants
For the omental layers; we have a deep leaf that goes from the duodenum to the right side of the rumen and a superficial leaf that goes from the duodenum to the left side of the rumen so on the right side of the animal we will have 2 layers of omentum and on the left side only one.
what is the supraomental recess
The supraomental recess is the gap between the walls of the deep leaf where the intestines sit to relax and the space between the two leaves of the omentum is the omental bursa.
rumen papillae - where are they present, function
On the interior surface of the rumen, in the ventral sac we have papillae and in the dorsal sac these papillae are much shorter or even absent since the dorsal sac is mostly just air gap so not in contact with the ruminal contents and thus don’t need the papillae to increase SA for absorption as in the ventral sac
omasum structure
Omasum has a central omasal canal which connects to the abomasum and has long sheets called laminae that are like pages in a book. #1s are the longest and #4s are the shortest and they keep moving and bumping into each other continuing to break down food into smaller particle sizes
regions of the abomasum, where food enters vs exits
true digestive stomach that is the same as the other species in that it has a cardiac, fundus and pyloric region. Food will enter on the left side and exit on the right
celiac artery branches in the ruminant
splenic - splenic, reticular, right ruminal, left ruminal
hepatic - gastroduodinal which leads to right gastric, right gastric epiploic, cranio pancreaticoduodenal
gastric
celiac artery branches in the dog and horse
splenic - splenic, left gastroepiploic
hepatic - gastroduodinal leads to right gastric, right gastric epiploic, cranio pancreaticoduodenal
gastric - left gastric
importance of ansa spiralis
ansa spiralis which is the spiral ascending colon and can look for lesions here in post mortem
ruminal innervations
dorsal trunk - everywhere
ventral trunk - reticulum, omasum, abomasum
what part of the colon has more sacs that the other
the ventral colon has more sacs that the dorsal colon
what are the parts of the ascending colon in horses
right ventral colon, left ventral colon, left dorsal colon, right dorsal colon
what are the three flexures in the horse and where are they
sternal flexure is there the right ventral colon turns to the left ventral colon
pelvic flexure is where the left ventral colon changes to the left dorsal colon
diaphragmatic colon is where left dorsal colon changes to right dorsal colon
what is the most common site for impactions in horses and why
pelvic flexure, narrowest part of large colon
parts of the equine stomach
cardia, nonglandular regoin (fundus), margo plicatus, glandular region (body, pyloric), pylorus
what is the non glandular region of the stomach prone to
grastric ulcer and bot flies
difference between fundus and glandular region
fundus - doesnt produce gastric acid or have protective coating
glandular region - acid production and has a protective coating
what does the margo plicatus
its the line that separates the non-glandular region from the glandular region
what is the ligament called in the spleen and where is it in horses
nephrosplenic ligament. between spleen and kidney
what can happen with the nephrosplenic ligament
can cause splenic entrapment
what does it mean if you feel the jejunum during palpation
Jejunum is rarely felt in rectal palpation but if blockage in duodenum and jejunum is inflamed then tubes with no haustra or sacs can be felt which indicates jejunitis which means problems in cranial tract so maybe pass stomach tube. Remember: there should not be any garden hose at the rectal end of a horse.
cecum in horses, capacity and parts
fermentative vat with about 33-66L of capacity.
there is a base, body and apex. The apex is the cranial side, then we have the body and the base sitting more dorsally
what happens at the iliocecal valve
When the cecum is cut through the base we can appreciate the ileocecal valve which is where the ileum will open and contents dropped into cecum, this is always lower than the cecocolic opening so the food drops into the colon and spends time fermenting
function of cecocolic opening
The cecocolic opening is the exit point of the cecum and has no valve like the ileocecal, it is simply an opening.
path that food passes through starting at the cecum in horses
From the cecum, food will pass into the right ventral colon, around the sternal flexure to the left ventral colon then around the pelvic flexure to the left dorsal colon then the diaphragmatic flexure to the right dorsal colon. From the right dorsal colon we will go into the short transverse colon then to the descending colon.
what artery supplies the large intestine and what branches from it
its from the ileocolic artery
-Cecal arteries to the cecum; we have medial and lateral cecal branches
-Colic branch to the ascending colon, starting along right ventral colon, all of the blood supply to the ventral colon is from the colic branch of the ileocolic artery
-Right colic travels along right dorsal and will meet the colic branch at the pelvic flexure… all of the dorsal colon is supplied by the right colic
what is present in the cecum and colon and what is the function
taeniae (bands) and haustrae (sacculations)
the sacs allow for stretching during peristalsis
how many taeniae is each part of the horse colon
-There will be 4 bands (taeniae) found on the ‘floor’ which includes cecum (lateral, medial, cranial, caudal), right ventral and left ventral.
-The pelvic flexure will have 1 band, left dorsal 1-3, right dorsal 3 and descending colon 2.
-There are only haustra present in the ventral branches, cecum and descending colon.
what are the dorsal wall muscles
psoas major, psoas minor (with shiny tendon), deep circumflex iliac artery (to flank and mammary gland)
what does the phrenicoabdominal artery supply
supplies adrenals only present in carnivores
what are the paired vessels of the abdominal aorta
what does the suspensory ligament do in dogs and cats
it tethers the ovary to the dorsal abdominal cavity
position, blood supply and capsule of the kidneys
position - dorsal abdomen +/- retroperitoneal. right kidney cranial to left
blood supply - renal artery ~10% cardiac output
capsule - fibrous. in cats, fibrous vessels
what is the building block of the kidneys, parts and organization of it
The renal pyramid is the building block of the kidneys, a renal pyramid is a cone-shaped region of tissue containing both cortex (where filtration takes place) and medulla (where filtrate is processed and concentrated). Collecting ducts exit through openings in tip of pyramid which is called a papilla. An extension of the ureter surrounds the papilla in a cup shape called a calyx
cow kidney appearance
-looks tumor like
-numerous separate pyramids, each with its own branch of the ureter
-calyx is an unexpanded end of the ureter around each papillae
what species is there a renal crest
dog, bagel cut (off centre)
sections of a dog kidney and what happens at each
-renal hilus = is a concave area on the kidneys medial border where the renal atery, vein and ureter enter and exit the kidney
-renal sinus = is a hollow chamber that provides space for the structures entering and leaving the kidneys, for example blood vessels, nerves and fat
-renal pelvis = open space within the kidney whose primary function is to collect uine produced by the kidney
-renal crest = also known as fusion of the renal papilla, refers to the inner medullary part of the kidney where urine is eventually funneled into the renal pelvis
what species has a different shaped kidney and why
The equine kidney has a unique shape in that it looks like our heart emoji as it folds back on itself forming a double medulla since the horse guts are all about conserving space.
what does the terminal recess do
The terminal recesses of the pelvis will form a T like shape with the renal pelvis.
what is the cisterna chyli
is junction where all the lymph from the abdomen will collect and then proceed through the thoracic duct and enter blood stream where it will be mixed back into circulation
what does the portal venous system drain
most abdominal organs - all of the GIT, spleen, pancreas
takes to the liver for processing
what do the hepatic veins drain
liver into caudal vena cava on dorsocranial aspect of the liver
what is the portosystemic shunt
also called a liver shunt. its a bypass of the liver by the bodys circulatory system. it can be either a congenital or acquired condition and several species of animals where portal vein direct connect to hepatic veins and bypass the liver filatration
what does the caudal vena cava drain
drains the caudal rectum non-GI abdominal organs, hindlimbs, pelvis
what does the azygous vein drain
cranial abdominal wall
liver anatomy species differences
in dogs = equally present in left and right
pig = more towards the right
horse = mostly on right side and no gallbladder
cow = completely to right side
what type of innervation is in the viscera and what does it include
Autonomic Innervation of the viscera includes the celiacomesenteric and caudal mesenteric plexus as well as the pelvic plexus
what is both sympathetic and parasympathetic
The celiacomesenteric ganglion and plexus are both sympathetic and parasympathetic
parts of sympathetic innervation
celiacomesenteric ganglion, splanchnic nerve from sympathetic trunk, caudal mesenteric ganglion
parts of parasympathetic innervation
vagus nerve (R+L) - dorsal trunk to stomach, ventral trunk all GI to transverse colon
pelvic nerve - descending colon, urogenital organs, pelvis in general
