The Equine Abdomen Lecture Flashcards
Stomach
L sided; 9-11 IC spaces dorsally
What separates glandular and non glandular regions of the stomach
margo plicatus
mesenteries of stomach
greater omentum, lesser omentum, gastrospelenic ligament, gastrophrenic ligament
greater omentum
greater curvature of the stomach to ventral body wall
lesser omentum
lesser curvature of the stomach to liver?
gastrosplenic ligament
greater curvature of the stomach to spleen
gastrophrenic ligament
reflection stomach to diaphragm
small intestine
located largely on L side of horse; includes duodenum, jejunum, and ileum
Duodenum
descending duodenum primarily on R; passes idly from R to L cd to root mesentery over base cecum then ascending duodenum passes cr on L side of mesentery to transition to jejunum v to l kidney
duodenum mesentery
medoduodenum
duodenal papilla
major duodenal papilla- opens into bile duct and pancreatic duct
minor duodenal papilla- accessory pancreatic duct
jejunum
transition from duodenum to jejunum v to l kindey
jejunum mesentery
mesojejunum= “the mesentery”
ileum
illeocecal junction and ileocecal fold
ileocecal junction
where ileum drops contents into cecum, important for tape worms -> motility issues -> ileum intercecepting into cecum
ileocecal fold
important sx landmark goes anti mesenteric side of ileum to tenia if can’t find this probably intercecepted
Large intestine
cecum, ascending colon, transverse colon, descending colon
cecum
V large, predominantly R sided; has base body and apex, apex on V body wall
cecocolic orifice
associated with cecal flush
mesenteric of cecum
ileocecal fold and cecocolic fold
ileocecal fold
anti mesenteric surface of ileum to dorsal band of cecum (thin/ fragile)
cecocolic fold
lateral band of cecum to lateral free band of right ventral colon; thicker than ileocecal fold bc 2x connection of mesentery
ascending colon d attachment
no d attachment so can move -> colic
D anv V portions ascending colon connected by
mesocolon
Ascending colon components
RV colon -> sternal flexure -> LV colon -> pelvic flexure -> L D colon -> diaphragmatic flexure -> R D colon
transverse colon
v short, R D colon to transverse colon is cr to root of mesentery
descending colon
small colon; located in L paralumbar fossa
descending colon auscaltation
silent on auscaltation bc contains fecal balls
duodenocolic fold
ascending duodenum to small colon
Liver
mainly located on R side in 7-15th IC spaces
Lobes of liver
R, L, quadrate, caudate; NO GALL BLADDER
R lobe bigger
mesenteric attachments of liver
triangular ligaments, coronary ligaments, falciform ligaments
Right triangular ligament
attaches R lobe of liver to costal pt diaphragm
Left triangular ligament
attaches L lobe of liver to tendinous center diaphragm
coronary ligament
cr reflection at level of diaphrgam
falciform ligament
v full of fat, where umbilical vein headed to liver; runs from umbilical fissure (of liver) to umbilicus
round ligament
is in free margin of falciform ligament, this is where vestige of fetal umbilical vein is located
hepatoduodenal ligament
liver to duodenum; this is cd pt of lesser omentum, helps form cr border epiplic foramen
spleen
located on L side, base last 3-4 ribs
apex of spleen
ventral to 1/3rd of 9-12 IC spaces (b/c this on L do belly taps to R of midline to avoid)
Mesenteric attachments of spleen
gastrospelic ligament, nephrospelic ligament, phrenicosplenic ligament
gastrosplenic ligament
attaches hilus of spleen to greater curvature of stomach, blends with splenic ligaments dorsally and is continuous with greater omentum ventrally
nephrosplenic ligament
spleen connected to L kidney
phrenicosplenic ligament
double fold of peritoneum that connects thoracic diaphragm and spleen
left kidney
left last; V to T 18- L 2/3
Mesenteric attachment- nephrosplenic ligaments (kidney to spleen, can palpate)
right kidney
v to t17/t18 to L1; mesenteric attachments hepatorenal ligament (right)
equine kidney
heart shaped, renal pelvis, terminal recess vs renal crest
Right lobe pancreas
formed within dorsal mesogarsrium and located along descending duodenum
right lobe pancreas duct
pancreatic duct via major duodenal papilla
left lobe pancreas
formed within v mesogastrium and located close to stomach
left lobe pancreas duct
accessory pancreatic duct via minor duodenal papilla
colic and the ascending colon
has no dorsal attachment so it can move leading to colic
- pelvicc flexure and transverse colon both sites of diameter changes which can -> impactions
pelvic flexure and colic
between LV and LD folon intra-luminal diameter changes drastically
Transverse colon and colic
RD colon is short and goes into transverse colon cr to root mesentery which as intraluminal diameter change -> impactions
taenia
longitudinal muscle fibers (bands)
haustra
sacculations which contain circular muscle fibers (sacs)
large colon taenia
cecum -> RVC -> LVC -> LDC -> RDC -> transverse colon -> descending colon (small colon)
444-1322 (Taneia)
+++—+ (Haustra)
Blood supply Cecum
medial and lateral cecal arteries off ileocolic artery) off of cr mesenteric artery
blood supply ventral colon
colic branch ileocolic artery off cr mesenteric artery
blood supply dorsal colon
right colic branch ileocolic artery off cr mesenteric artery
blood supply transverse
middle colic branch ileocolic artery off cr mesenteric artery
Blood supply to small colon
L colic artery off of cd mesenteric artery
blood supply to liver
fx- portal vein
structural- hepatic artery
blood supply to spleen
splenic artery (branch off celiac artery)
blood supply to kindey
renal artery (branch off aorta)
epiploic foramen
allows for communication between peritoneal space and omental bursa; can end up with intestinal entrapment (generally jejunum)
epiploic foramen boudnaries
Dorsal- cd vena cava and caudate process of caudate liver lobe
Cranial- hepatoduodenal ligament (lesser omentum)
Ventral- portal vein
Caudal- hepatic artery/ mesoduodenum
Rectal palpation general
Moving clockwise starting L dorsal abdominal quadrant: cd border spleen in L dorsal abdominal quadrant, md to spleen, neophrosplenic ligament coursing from spleen to cd pole L kidney medially, aorta palpable D body wall, root mesentery and short portion of duodenum may be palpable, base cecum and some of medial cecal tenia (bands) palpable in R dorsal abdominal quadrant, pelvic flexure palpable in pelvic canal or just over bulimic brim, small colon palpable in L V and dorsal abdominal quadrant, SI usually only palpable in abdominal conditions but occasionally normally palpable
Rectal palpation on L
- spleen
- cd pole L kidney
- L D/V colon
- Small colon
- +/- cd edge nephrosplenic ligament
- Jejunum
Rectal palpation dorsally
- aorta
- iliacs
- +/- LNs
- Root mesentery
- Ovaries (female)
Rectal palpation Right
- Cecum (base)
2. Descending duodenum
Rectal palpation ventrally
- Uterus (female)
- Bladder
- Vaginal rings (male)
- Pelvic flexure
- Pelvic brim
Common GI cases of colic Ascending (Large) colon
large colon impaction, large colon Volvos, nephrosplenic entrapment/ Left dorsal displacement, right dorsal displacement
Small intestine
Epiploic entrapment, strangulating lipoma, mesenteric rent
Large colon impaction
impaction bc accumulation dehydrated ingest; most common sites pelvic flexure (luminal diameter change and 180 degree turn) and transverse colon (not palpable on rectal bc cr to root mesentery)
can often treat with medical management
Large colon volvus
aka large colon torsion; twist involves mesentery btwn D and V colons (mesocolon) (essentially D and V colons twist on themselves along mesocolon); twist usually at level cecocolic ligament disrupting blood flow to D and V colons; RDC moves towards body wall and V; RVC usually moves axially and dorsally; if viewed from back of horse colon moves clockwise
large colon volvus steps and presentation
Volvos obstructs blood flow -> inability of ingest to move -> gas build up; fast onset uncotrlable pain; rectally may only get in a few inches and may feel gas and tight bands; sx is a must before colon dies from lack blood supply or gut ruptures; can be prone to twisting again bc things stretch
large colon volvus causes
common after partition, rapid changes in feed, forage increases concentrate, impaction
Nephrospleic entrapment/ Left dorsal displcement
L V and L D colons migrate dorsally and medially to become entrapped in space btwn spleen and L kidney in nephrosplenic space; colon rotates 180 degrees and moves so LV colon becomes dorsal to LD colon
what happens in Left Dorsal Displacement aka nephrosplenic entraptment
weight of colon occludes blood flow to spleen via splenic vein -> engorvment of spleen; on rectal feel kidney, band of colon, spleen my displace dorsally
treatment left dorsal displacement aka nephrosplenic entrapemtnet
Can treat with phenylephrine to cause vasoconstriction -> shrinkage in size of spleen and horse lunged vigorously to try to free colon from nephrosplenic space, but sx may ne necisary; may reoccur bc nephrosplenic ligament can stretch in which case can do sx to put mesh in space btwn spleen and cd pole l kidney and eliminate space where things get stuck (ablasian of nephrosplenic space)
right dorsal displacement
colon displaced between cecum and body wall; pelvic flexure can move more cr and sternal and diaphragmatic flexures move cd and lie cd to cecum; pelvic flexure may move fly and to R then laterally around base of cecum; rectally feel bands going R -> L
right dorsal displacement treatment
may resolve with medical tx, bumpy trailer ride, holding off feed ect, may require sx
right dorsal displacement can lead to
pinching off SI -> reflux
what can lead to right dorsal displacement
impaction -> displacement
small intestine strangulation
strangulation of bowl results when blood supply to region of bowel is impaired; many causes including epiploic entrapment, strangulating lipoma, mesenteric rent
epiploic entraptment
strangulation of loop of jejunum after it has passed through epiploic foramen, usually loop passes L to R and often -> greater omentum being torn; occasionally loop passes R -> L; entrapped loop swells with gas and becomes thickened due to vessel and lymphatic obstruction; clinical signs vary bc strangulated bowel remains in somewhat enclosed space
strangulating lipoma
lipomas form in mesentery and can stretch mesentery to form long pedicle, pedunculate lipoma can wrap around piece SI or descending colon (less common) -> occlusion blood supply
mesenteric rent
similar to epiploic entrapment in principle, piece jejunum may pass through rent (tear) in mesentery become gas distended and then ischemic as blood supply is compromised; requires sx to repair
