Topography of Abdomen Flashcards
4 quadrants of the abdomen
R and L Cranial
R and L Caudal
3 transverse abdominal regions
Cranial abdominal region: caudal border of costal arch to just cranial of the umbilicus
Middle: umbilicus to wing of ilium
Caudal: cranial to wing of ilium
3 parts of the cranial abdominal region
- xiphoid (epigastric)
2,3. R/L hypochondriac (small)
3 subregions of middle abdominal region
- umbilical
2,3. R/L Lateral (flank)
3 subregions of the caudal abdominal region
- Pubic
2,3. R/L Inguinal
What is the paralumbar fossa? What species is it clinically important in?
-upper part of lateral abdominal region
- triangular depression (last rib, below lumbar vertbrae, cranial to ilium)
Large animals - ruminants/equine - window to listen to rumen and rumenotomy
cranial, caudal, dorsal, and lateral/ventral boundaries of the abdominal cavity
• Cranial:
Diaphragm
• Caudal:
Pelvicinlet(freelycontinuous)
• Dorsal:
Lumbar and sacral vertebrae
Diaphragmatic crura
Hypaxial muscles
Lateral and Ventral:
Abdominal muscles:
3 pairs lateral
One pair ventral
5 layers of the abdominal wall
-Superficial fascia
- wet dog shaking fur not attaches
- only in carnivores
-encloses cutaneous trunci m.
-Deep fascia
• Thoracolumbar fascia
• Tunica flava abdominis (large animals)
-Muscles
-Internal Fascia
-Parietal peritoneum
insertion of abdominal wall muscles and why its important
linea alba and prepubic tendon
During flank incisions (as in spaying (neutering cats) or caeserian sections in cows, the surgeon separates the muscles along the direction of their fibers instead of cutting through them (so there is less bleeding). 13
Nerve supply of abdominal wall muscles
lateral branches of:
• Last several Intercostal nn
• First three lumbar nn.
What does the internal fascia do?
attach parietal layer of pleura/peritoneum to body wall
endothoracic fascia and endo-abdominal fascia
What is the linea alba
white line!
An elongate ventral midline tendinous structure
(xiphoid cartilage to the pubis)
• Common insertion for abdominal mm.
• It separates the right & left rectus abd. mm.
• It contains the umbilicus.
The linea alba is easier to locate near the umbilicus because it becomes thinner near the pubis.
why would you make an incision of linea alba in midline laparotomy (celiotomy)?
No muscles need to be cut
• Not crossed by blood vessels (less bleeding)
• disadvantage: heals slowly (so use strong suture material)
• Less sensory innervation (less post-op pain at incision)
• Fibrous →
• strength to hold sutures (strong closure)
• minimize post-surgical dehiscence
linea alba serves as an attachment site for… (3)?
Ventrolateral abdominal mm.
Falciform ligament
Median ligament of the bladder
What, where, why umbilicus
closed scar in ventral midline - cranial part of umilicus region
landmark in abdominal surgical incsions
vortex of hair grows around in it a whirl
what can happen if umbilical ring does not close?
Umbilical hernia - escape of abdominal contents
Where/Why liver
against diaphragm, In all 3 subregions of the cranial abdominal region (mainly on right side)
Needle biopsy:
R side: 7th ICS
L side: Caudodorsal to xiphoid
3 types of stomachs (and their species)?
simple glandular (man, dog, and cat)
simple, composite (horse and pig)
complex, composite ( ruminants)
composite = has glandular and non-glandular regions
3 parts of the stomach
cardiac, fundus, body
is the stomach freely moveable? can you palpate it?
Yes - but cardiac and pyloric extremities are relatively fixed
No - you cannot
comparing k9 and feline stomach
k9 - U-shaped and pyloric is right of midline
feline- J-shaped (angulated)- pyloric on midline
Empty stomach
- Cannot be palpated
- No contact with abd. Floor
- In the intrathoracic part of the abd. cavity
- The spleen caudal border follows the left costal arch
moderately full stomach
- stomach lies under the last 4 ribs
- Contacts abd. floor
- Part of the spleen protrudes over costal arch
Full stomach
- distended stomach form a uniform ROUND sac
- reaching a level of L2,3,4. and pelvic brim
- reaches from the right to the left body walls
- Extensive contact with abdominal floor and easily palpated
- Displacement of the spleen and left kidney caudally
What is the stomach tube
• Before a stomach tube is passed, the length of tube to be passed is marked by measuring from the nose to the last rib.
3 parts of the small intestine
duodenum, jejunum, ileum
3 parts of large intestines
cecum, colon, rectum(and anal canal)
What is the cranial duodenum
Fixed to the liver, but can move up & down with pyloric end
- May be cr. or ca. to pancreas (depends on position of stomach)
- fairly mobile, compared to rest of duodenum
descending duodenum
- Right side
- Bile and pancreatic ducts
- hairpin turn
- “anatomical” retractor to retract the viscera to explore the right lumbar area during celiotomy.
- Identified in ultrasonography … straight course along the Rt. lateral abdominal wall → pancreas
Mesoduodenum (contains right lobe of PANCREAS)
Ascending duodenum
It extends cranially, IN THE MEDIAN PLANE.
• almost reach the greater curvature of the stomach.
- starts at caudal duodenum flexure near right tuber coxae and goes to duodenojejeunal flexure)
Its Mesoduodenum attached to the desc. Mesocolon and called DUODENOCOLIC FOLD
What is the clinical importance of duodenocolic fold
• Do Not confuse it with adhesion.
• It is a landmark used during “running of the bowel” during celiotomy
Jejunum
largest part of SI
lesser (mesenteric(inside)) & greater (antimesenteric(outside )) curvatures
• Mesojejunum attached to the short root of the mesentery
• Enterotomies on greater curvature (preserve blood supply)
What is the vacular pattern of the SI
jejunal arches (arcades)
supply jejnum with blood
Ileum
It ends dorsally on the right side of the body (right to asc. duod.)
• opens into the ascending colon (ileo-colic junction)
- bypass the cecum (L1-L2)
The ileum is identified by
Short mesentery + Ileocecal fold.
Straight vessels + antimesenteric blood supply
most common part of SI involved in intussesception
The ileum is the most common part of the small intestine involved in intussusception (i.e., ileocolic or ileocecocolic intussusception).
Cats have a ileo-__________ junction
The cat has ileo-ceco-colic junction
the pancreas has…
2 lobes and a body - makes a 7 shape on stomach and duodenum
extends transversely across ventral aspect of vertebral column
Cecum
• it is a diverticulum of the colon
• In the right side of the cranial abdomen
• Close to dorsal body wall (L2-L4)
• dorsal to the jejunum.
• Ceco-colic orifice → ascending colon
cecum in dog vs cat
Cat has small cecum, comma shape (lil pouch at the end of ileum)
Dog: S shape against roof of abdomen
4 parts of the colon
ascending, transverse, descending, mesocolon
dorsal body wall
Ascending colon
Short
Right to cr. mesenteric a.
mesocolon
continuous short mesentery, less movable
descending colon continues as…
the rectum, at the pelvic inlet
Physiological “anatomical” retractors (4)
explore the lumbar area “gutters”
adrenal gland, kidneys, ureters, uterus/ovaries
Right lumbar “gutters”
Retract- descending duodenum
- Use the Mesoduodenum to retract the intestine to the left (toward the midline)
- Examine the right “gutter” kidney, adrenal gland, ureter and ovary.
left lumbar “gutters”
Retract- Descending colon
- Use the descending mesocolon to retract the abdominal contents to the right (toward the midline).
- Examine the left kidney, adrenal gland, ureter & ovary.
Deepest layer of abdominal cavity
adrenal glands, kidneys, descending aorta, caudal vena cava, ureter, bladder, uterus
Adrenal gland parts and info
2 parts: Cortex and medulla
• The medulla has abundant nerve supply
• The cortex lacks a nerve supply - but essential for life
• The medulla cells = sympathetic postganglionics.
• The medulla is not essential for life (dogs can live if bilaterally removed)
Adrenal gland and blood supply
• lie close to rich source of arterial supply and venous drainage (2nd (to thyroid gland) richest supply for its size)
• In post-mortum: section it sagittally to evaluate corticomedullary ratio (generally 1:1)
Kidneys info
in the sublumbar region AND Retroperitoneal
• lie on either side of the aorta and caudal vena cava
• The left kidney is less firmly attached to the sublumbar area than the right
Kidneys cat vs dog
• Kidneys of the dog are more cr. than the cat.
• Palpation of both kidneys is easier in cats than in dogs
• In the dog the rt. kidney is often nonpalpable (more cranial
Urinary bladder and its clinical significance
variable size
In midline celiotomy, it is in danger of being accidentally incised if the urine has not been expelled prior to surgery.
• Could be palpated in the ventral caudal abdomen.
