Chapter 35 - Jejunum and ileum Flashcards
What is the approximate average length of the equine small intestine?
A) 10 meters
B) 20 meters
C) 25 meters
D) 30 meters
C) 25 meters
Where is the duodenojejunal flexure located in the horse?
A) Right side of the ventral abdomen
B) Left side of the dorsal abdomen
C) Right side of the dorsal abdomen
D) Left side of the ventral abdomen
B) Left side of the dorsal abdomen
What is the range of the length of the jejunum in adult horses?
A) 10 to 20 meters
B) 17 to 28 meters
C) 5 to 15 meters
D) 20 to 30 meters
B) 17 to 28 meters
Which artery provides the arterial supply to the jejunum?
A) Caudal mesenteric artery
B) Ileocecocolic artery
C) Cranial mesenteric artery
D) Ileal artery
C) Cranial mesenteric artery
What structure allows the jejunum to have significant mobility?
A) The length of the jejunum
B) The long mesojejunum
C) The ileocecal fold
D) The vasa recta
B) The long mesojejunum
Which of the following structures does NOT form part of the ileal papilla in horses?
A) Inner circular muscle layer
B) Central longitudinal muscle layer
C) Outer layer from the circular muscle of the cecum
D) Inner longitudinal muscle layer
D) Cranial mesenteric artery
What is the length of the ileum in adult horses?
A) 0.5 meters
B) 0.7 meters
C) 1.0 meter
D) 1.5 meters
B) 0.7 meters
Which of the following best describes the role of the venous network at the ileocecal junction?
A) It functions as a true sphincter
B) It contributes to the sphincter mechanism
C) It is most engorged when the ileum is discharging its contents
D) It prevents reflux of cecal contents into the ileum
C) It is most engorged when the ileum is discharging its contents
Which artery branches off to supply the ileum?
A) Jejunal artery
B) Caudal mesenteric artery
C) Cranial mesenteric artery
D) Ileal artery
D) Ileal artery
Which of the following is NOT a component of the vascular arcade in the jejunum?
A) Major jejunal vessel
B) Arcuate vessel
C) Vasa recta
D) Ileal artery
D) Ileal artery
Which statement is correct regarding the ileal orifice?
A) It is located at the cecal base
B) It lacks an annular fold
C) It is surrounded by cecal musculature
D) It has a true sphincter
C) It is surrounded by cecal musculature
What happens to the ileal papilla when the cecum is active?
A) It becomes less prominent
B) It remains unchanged
C) It contracts and closes
D) It becomes more prominent
D) It becomes more prominent
Where does the majority of digestion and nutrient absorption occur in the equine small intestine?
A) In the ileum
B) In the lower half of the small intestine
C) In the upper half of the small intestine
D) In the large intestine
C) In the upper half of the small intestine
What unique feature is found on the epithelial surface of the equine small intestine?
A) Plicae circulares
B) Mucosal folds
C) Villi
D) Rugae
C) Villi
What type of cells makes up the majority of the small intestinal epithelial cells?
A) Paneth cells
B) Enteroendocrine cells
C) Goblet cells
D) Enterocytes
D) Enterocytes
How many crypts of Lieberkühn typically surround each villus in the equine small intestine?
A) 2 to 4
B) 4 to 6
C) 6 to 9
D) 10 to 12
C) 6 to 9
Which statement is TRUE about the turnover time of enterocytes on the villus?
A) They have a turnover time of 1 day
B) They turnover every 2 to 3 days
C) They remain for 7 to 10 days
D) They do not undergo turnover
B) They turnover every 2 to 3 days
Which of the following is NOT a feature of the mature enterocyte’s apical surface?
A) Microvilli
B) Brush border membrane
C) Tight junctions
D) Mucosal folds
D) Mucosal folds
Which type of cells in the small intestine is primarily responsible for surface digestion and active transport of nutrients?
A) Paneth cells
B) Enteroendocrine cells
C) Mature enterocytes
D) Undifferentiated columnar cells
C) Mature enterocytes
What function do tight junctions between enterocytes serve?
A) They allow large molecules to pass through
B) They restrict the transmucosal flux of large molecules
C) They prevent the absorption of water
D) They help in nutrient absorption directly
B) They restrict the transmucosal flux of large molecules
What happens to the intercellular space during water absorption in the small intestine?
A) It shrinks
B) It expands
C) It remains unchanged
D) It becomes impermeable
B) It expands
Where are the enzymes responsible for the final digestion of carbohydrates and proteins located?
A) Within the crypts of Lieberkühn
B) In the brush border membrane of microvilli
C) In the paracellular channel
D) In the intercellular space
B) In the brush border membrane of microvilli
What triggers the release of secretin in the duodenum?
A) Presence of fat
B) Presence of protein
C) Presence of hydrogen ions
D) Presence of carbohydrates
C) Presence of hydrogen ions
What is the primary role of bicarbonate (HCO3−) secreted in the proximal small intestine?
A) To digest carbohydrates
B) To stimulate bile production
C) To neutralize hydrogen ions
D) To activate pancreatic enzymes
C) To neutralize hydrogen ions
Which cells in the duodenal mucosa release cholecystokinin (CCK)?
A) S-cells
B) Parietal cells
C) I-cells
D) G-cells
C) I-cells
Which pancreatic enzyme requires activation by the brush border enzyme enterokinase?
A) Amylase
B) Lipase
C) Trypsinogen
D) Chymotrypsinogen
C) Trypsinogen
Which of the following is a unique feature of the equine pancreatic secretion?
A) High concentration of bicarbonate
B) High enzymatic content
C) Continuous secretion even at rest
D) High concentration of sodium ions
C) Continuous secretion even at rest
How does the concentration of bicarbonate (HCO3−) in equine pancreatic secretion compare to that in other animals?
A) It is higher
B) It is similar
C) It is lower
D) It is negligible
C) It is lower
What is the significance of the chloride ion (Cl−) in equine pancreatic secretion?
A) It is exchanged with HCO3− in the terminal ileum
B) It is a cofactor for enzyme activation
C) It inhibits bile acid secretion
D) It is primarily involved in nutrient absorption
A) It is exchanged with HCO3− in the terminal ileum
Which statement is TRUE regarding nutrient digestion and absorption in horses?
A) It is less efficient than in other species
B) Horses ferment starches only in the large intestine
C) Lipase activity is particularly high compared to other enzymes
D) Starch digestibility is independent of botanical origin
C) Lipase activity is particularly high compared to other enzymes
Which acids combine with glycine and taurine to form conjugated bile salts in the liver?
A) Acetic acid and butyric acid
B) Cholic acid and chenodeoxycholic acid
C) Lactic acid and pyruvic acid
D) Palmitic acid and stearic acid
B) Cholic acid and chenodeoxycholic acid
What percentage of bile salts are reabsorbed by the small intestinal mucosa?
A) 70%
B) 80%
C) 90%
D) 94%
D) 94%
Which process describes the reabsorption and resecretion of bile salts by the liver?
A) Passive diffusion
B) Endocytosis
C) Enterohepatic circulation
D) Osmosis
C) Enterohepatic circulation
Which part of the small intestine is critical for the active transport of bile salts?
A) Duodenum
B) Jejunum
C) Ileum
D) Cecum
C) Ileum
What is the effect of ileal resection on bile salt loss through feces in horses?
A) It significantly increases bile salt loss
B) It decreases bile salt loss
C) It does not increase bile salt loss compared to jejunal resection
D) It stops bile salt loss completely
C) It does not increase bile salt loss compared to jejunal resection
Why can passive absorption in the jejunum preserve enterohepatic circulation of bile salts?
A) Because bile salts are at their highest concentration in the jejunum
B) Because the jejunum has a special enzyme for bile absorption
C) Because the jejunum produces bile salts
D) Because bile salts are not absorbed elsewhere in the intestine
A) Because bile salts are at their highest concentration in the jejunum
Which pancreatic enzyme is NOT directly involved in the digestion of protein?
A) Trypsin
B) Chymotrypsin
C) Carboxypeptidase
D) Amylase
D) Amylase
Where does most water absorption occur in the equine small intestine?
A) Proximal third
B) Middle third
C) Distal third
D) Water is not absorbed in the small intestine
C) Distal third
Which part of the gastrointestinal tract absorbs the bulk of intestinal water?
A) Small intestine
B) Large intestine
C) Stomach
D) Esophagus
B) Large intestine
Which of the following is TRUE about the transcellular movement of Na+ in the small intestine?
A) It is a passive process
B) It involves the Na+/K+–ATPase pump
C) It does not require energy
D) It is driven by water transport
B) It involves the Na+/K+–ATPase pump
What is the main function of the Na+/K+–ATPase pump in the small intestine?
A) To passively transport Na+ into the cell
B) To generate energy for Cl− transport
C) To actively transport Na+ out of the cell
D) To create an osmotic gradient for water absorption
C) To actively transport Na+ out of the cell
How is Cl− transported into the cell across the apical membrane?
A) By passive diffusion
B) By secondary active transport
C) By simple diffusion
D) By primary active transport
B) By secondary active transport
Which process is energized by the Na+ gradient in the small intestine?
A) Uptake of water
B) Secretion of digestive enzymes
C) Uptake of glucose and amino acids
D) Release of bicarbonate
C) Uptake of glucose and amino acids
What primarily drives water transport in the small intestine?
A) Active transport
B) Osmotic gradient
C) Electrochemical gradient
D) Chemical gradient
B) Osmotic gradient
Where does water accumulated in the intercellular space move next?
A) Into the lumen
B) Toward the capillary bed
C) Toward the central lacteal
D) Into the cell
B) Toward the capillary bed
What is the effect of the tight junctions between enterocytes in the jejunum?
A) They allow free passage of ions and water
B) They completely block ion and water movement
C) They restrict backflow of absorbed water and electrolytes
D) They facilitate active transport of nutrients
C) They restrict backflow of absorbed water and electrolytes
What is the mechanism called when net water movement from lumen to plasma drags permeant ions and low–molecular weight substances with it?
A) Active transport
B) Solvent drag
C) Facilitated diffusion
D) Osmosis
B) Solvent drag
In which structure does fluid absorbed by the intestinal epithelium initially accumulate?
A) Capillary bed
B) Intercellular space
C) Central lacteal of the villus
D) Crypts of Lieberkühn
C) Central lacteal of the villus
Which factor primarily influences ion and fluid transport in the proximal bowel?
A) Osmotic gradient alone
B) Active Na+ transport only
C) Starling forces
D) Chemical gradients
C) Starling forces
What is the role of solvent drag in the small intestine?
A) It blocks ion movement
B) It enhances nutrient absorption by dragging ions with water
C) It decreases water absorption
D) It prevents water from leaving the lumen
B) It enhances nutrient absorption by dragging ions with water
Which structure is involved in moving absorbed fluid from the villus to deeper lymphatics?
A) Central lacteal
B) Basolateral membrane
C) Tight junction
D) Capillary bed
A) Central lacteal
Which of the following monosaccharides are produced by the hydrolysis of starch digestion products by brush border enzymes in horses?
A) D-ribose, D-mannose, D-glucose
B) D-glucose, D-fructose, D-galactose
C) D-glucose, D-sucrose, D-maltose
D) D-glucose, D-lactose, D-fructose
B) D-glucose, D-fructose, D-galactose
How does sucrase activity in the proximal small intestine of horses on a grass-based diet compare to other nonruminants?
A) It is lower
B) It is higher
C) It is comparable
D) It is absent
C) It is comparable
Which enzyme has a constant distribution along the equine small intestine and higher activity than in other species?
A) Lactase
B) Sucrase
C) Maltase
D) Amylase
C) Maltase
What is TRUE about lactase activity in the equine small intestine?
A) It is highest in the duodenum
B) It increases with maturity
C) It is higher in the jejunum than other parts of the small intestine
D) It remains constant throughout life
C) It is higher in the jejunum than other parts of the small intestine
Which transporter is responsible for the uptake of D-glucose and D-galactose in the small intestine of horses?
A) GLUT5
B) SGLT1
C) GLUT2
D) Na+/K+–ATPase
B) SGLT1
Which part of the equine small intestine is the major site of D-glucose uptake via SGLT1?
A) Ileum
B) Duodenum
C) Jejunum
D) Cecum
B) Duodenum
How does fructose enter enterocytes in the equine small intestine?
A) Via active transport
B) Via facilitated diffusion through GLUT5
C) Via passive diffusion
D) Via SGLT1 cotransport
B) Via facilitated diffusion through GLUT5
Which transporter is responsible for moving monosaccharides out of the enterocytes into the portal venous system?
A) SGLT1
B) GLUT5
C) GLUT2
D) Na+/K+–ATPase
C) GLUT2
How does an increase in soluble carbohydrates (like oats, corn, or barley) in the diet affect glucose transport in the equine small intestine?
A) It decreases glucose transport rates
B) It increases glucose transport rates and SGLT1 expression
C) It increases disaccharidase activity
D) It decreases SGLT1 expression in the duodenum
B) It increases glucose transport rates and SGLT1 expression
What happens to SGLT1 expression in the ileum when a horse’s diet is gradually switched from low to high hydrolyzable carbohydrates?
A) It remains the same
B) It decreases
C) It increases three to five times
D) It decreases in the duodenum
C) It increases three to five times
Which dietary transition can help reduce the risk of diet-induced colic in horses?
A) A sudden increase in hydrolyzable carbohydrates
B) A gradual switch to a high-carbohydrate diet
C) A decrease in fiber intake
D) A switch from grass-based diet to low-carbohydrate feed immediately
B) A gradual switch to a high-carbohydrate diet
Which statement is TRUE about GLUT5 in horses?
A) It is a Na+-dependent transporter
B) It has high affinity but low capacity
C) It is most active in the ileum
D) It facilitates fructose transport
D) It facilitates fructose transport
What is the impact on disaccharidase activity when horses switch from a pasture forage diet to a diet high in soluble carbohydrates?
A) It increases significantly
B) It decreases
C) It remains unaffected
D) It stops altogether
C) It remains unaffected
Which of the following monosaccharides are produced by the hydrolysis of starch digestion products by brush border enzymes in horses?
A) D-ribose, D-mannose, D-glucose
B) D-glucose, D-fructose, D-galactose
C) D-glucose, D-sucrose, D-maltose
D) D-glucose, D-lactose, D-fructose
B) D-glucose, D-fructose, D-galactose
How does sucrase activity in the proximal small intestine of horses on a grass-based diet compare to other nonruminants?
A) It is lower
B) It is higher
C) It is comparable
D) It is absent
C) It is comparable (Correct Answer)
Which enzyme has a constant distribution along the equine small intestine and higher activity than in other species?
A) Lactase
B) Sucrase
C) Maltase
D) Amylase
C) Maltase
What is TRUE about lactase activity in the equine small intestine?
A) It is highest in the duodenum
B) It increases with maturity
C) It is higher in the jejunum than other parts of the small intestine
D) It remains constant throughout life
C) It is higher in the jejunum than other parts of the small intestine
Which transporter is responsible for the uptake of D-glucose and D-galactose in the small intestine of horses?
A) GLUT5
B) SGLT1
C) GLUT2
D) Na+/K+–ATPase
B) SGLT1
Which part of the equine small intestine is the major site of D-glucose uptake via SGLT1?
A) Ileum
B) Duodenum
C) Jejunum
D) Cecum
B) Duodenum
How does fructose enter enterocytes in the equine small intestine?
A) Via active transport
B) Via facilitated diffusion through GLUT5
C) Via passive diffusion
D) Via SGLT1 cotransport
B) Via facilitated diffusion through GLUT5
Which transporter is responsible for moving monosaccharides out of the enterocytes into the portal venous system?
A) SGLT1
B) GLUT5
C) GLUT2
D) Na+/K+–ATPase
C) GLUT2
How does an increase in soluble carbohydrates (like oats, corn, or barley) in the diet affect glucose transport in the equine small intestine?
A) It decreases glucose transport rates
B) It increases glucose transport rates and SGLT1 expression
C) It increases disaccharidase activity
D) It decreases SGLT1 expression in the duodenum
B) It increases glucose transport rates and SGLT1 expression
What happens to SGLT1 expression in the ileum when a horse’s diet is gradually switched from low to high hydrolyzable carbohydrates?
A) It remains the same
B) It decreases
C) It increases three to five times
D) It decreases in the duodenum
C) It increases three to five times
Which dietary transition can help reduce the risk of diet-induced colic in horses?
A) A sudden increase in hydrolyzable carbohydrates
B) A gradual switch to a high-carbohydrate diet
C) A decrease in fiber intake
D) A switch from grass-based diet to low-carbohydrate feed immediately
B) A gradual switch to a high-carbohydrate diet
Which statement is TRUE about GLUT5 in horses?
A) It is a Na+-dependent transporter
B) It has high affinity but low capacity
C) It is most active in the ileum
D) It facilitates fructose transport
D) It facilitates fructose transport
What is the impact on disaccharidase activity when horses switch from a pasture forage diet to a diet high in soluble carbohydrates?
A) It increases significantly
B) It decreases
C) It remains unaffected
D) It stops altogether
C) It remains unaffected
What role do brush border oligopeptidases play in protein digestion in the small intestine of horses?
A) They convert proteins into large peptides
B) They hydrolyze small neutral peptides into dipeptides, tripeptides, or amino acids
C) They activate pancreatic peptidases
D) They transport peptides into the portal blood
B) They hydrolyze small neutral peptides into dipeptides, tripeptides, or amino acids
After peptides are transported into the enterocyte, how are they processed?
A) They are packaged into chylomicrons
B) They are converted into fatty acids
C) They are hydrolyzed into amino acids by cytoplasmic oligopeptidases
D) They are excreted directly into the lumen
C) They are hydrolyzed into amino acids by cytoplasmic oligopeptidases
Which of the following statements about amino acid transport in the equine intestine is TRUE?
A) All amino acids are Na+-dependent for transport
B) Amino acid transport systems are uniform in their specificity
C) Some amino acid transport systems are Na+-dependent while others are not
D) Only dipeptides and tripeptides are Na+-dependent for transport
C) Some amino acid transport systems are Na+-dependent while others are not
What is required for the transport of small peptides in the equine jejunum?
A) Na+
B) H+
C) K+
D) Cl-
B) H+
How do long-chain fatty acids and 2-monoglycerides reach the enterocyte membrane for absorption?
A) They diffuse directly through the lumen
B) They form mixed micelles with bile acids
C) They are actively transported by GLUT5
D) They bind to amino acids
B) They form mixed micelles with bile acids
What is the fate of long-chain fatty acids and 2-monoglycerides once they enter the mucosal cells?
A) They are broken down into amino acids
B) They are converted into glucose
C) They are reesterified and form chylomicrons
D) They are directly absorbed into the blood
C) They are reesterified and form chylomicrons
How is fat digestion in horses affected by the composition and concentration of dietary fat?
A) Fat digestion is highest in forage-based diets
B) Fat digestion decreases with increasing dietary fat
C) Fat digestion is lowest for forages and highest with added triglycerides
D) Fat digestion is unaffected by dietary composition
C) Fat digestion is lowest for forages and highest with added triglycerides
How can the lipolytic activity in horses be upregulated?
A) By decreasing dietary fat intake
B) By gradually increasing dietary fat through supplementation
C) By increasing fiber intake
D) By reducing dietary triglycerides
B) By gradually increasing dietary fat through supplementation
Why might horses require greater supplementation with fat-soluble vitamins during growth and pregnancy?
A) They have reduced fat digestion during these periods
B) They have increased demand for energy
C) Lipolytic activity increases with dietary fat, necessitating higher intake of fat-soluble vitamins
D) They lose fat-soluble vitamins in the feces
C) Lipolytic activity increases with dietary fat, necessitating higher intake of fat-soluble vitamins
What effect does adding fat to the diet of horses have on fat digestion?
A) It decreases the residence time of fat in the small intestine
B) It reduces the digestibility of fat
C) It increases fat digestibility through delayed gastric emptying
D) It inhibits fiber digestion in the large intestine
C) It increases fat digestibility through delayed gastric emptying
What does the term “micellar solubilization” refer to in the context of fat digestion?
A) The breakdown of fats into amino acids
B) The formation of mixed micelles that facilitate lipid absorption
C) The conversion of triglycerides into monosaccharides
D) The passive diffusion of fatty acids across the brush border
B) The formation of mixed micelles that facilitate lipid absorption
What happens to absorbed ferrous iron in the enterocyte if iron stores in the body are low?
A) It binds to apoferritin and is stored
B) It is released into the circulation via transferrin receptors
C) It is excreted into the intestinal lumen
D) It is converted to ferritin and stored in the liver
B) It is released into the circulation via transferrin receptors
What is the role of apoferritin in iron regulation within the enterocyte?
A) It transports iron across the basolateral membrane
B) It binds to absorbed ferrous iron to form ferritin
C) It activates transferrin receptors
D) It facilitates iron absorption from the lumen
B) It binds to absorbed ferrous iron to form ferritin
Where is the highest flux of calcium absorption in the horse’s small intestine?
A) Jejunum
B) Duodenum
C) Ileum
D) Colon
B) Duodenum
What effect does a high concentration of dietary magnesium have on calcium absorption?
A) It enhances calcium absorption
B) It decreases calcium absorption through competition
C) It has no effect on calcium absorption
D) It increases calcium-binding protein activity
B) It decreases calcium absorption through competition
Which vitamin regulates the specific calcium-binding protein that facilitates calcium transport in enterocytes?
A) Vitamin A
B) Vitamin D
C) Vitamin E
D) Vitamin K
B) Vitamin D
Where does magnesium absorption primarily occur in the equine digestive tract?
A) Stomach
B) Proximal small intestine
C) Distal small intestine
D) Large intestine
B) Proximal small intestine
What is the primary determinant of intestinal water and electrolyte secretion in horses?
A) Na+ absorption by crypt cells
B) K+ secretion by villi
C) Cl− secretion by crypt cells
D) Mg2+ absorption by enterocytes
C) Cl− secretion by crypt cells
Which cells are thought to act as pacemakers for generating electrical slow waves in the equine small intestine?
A) Enterocytes
B) Myenteric plexus neurons
C) Interstitial cells of Cajal (iCC)
D) Crypt cells
C) Interstitial cells of Cajal (iCC)
What is the function of mucus secreted by Brunner glands in the equine small intestine?
A) To aid in the absorption of nutrients
B) To neutralize acidic chyme
C) To protect the duodenal wall from gastric secretions
D) To stimulate peristalsis
C) To protect the duodenal wall from gastric secretions
In horses, where is the density of interstitial cells of Cajal (iCC) highest?
A) In the duodenum
B) In the jejunum
C) In the ileocecal junction
D) In the colon
C) In the ileocecal junction
Which phase of the migrating motor complex (MMC) is characterized by no action potentials and slow waves only?
A) Phase I
B) Phase II
C) Phase III
D) Phase IV
A) Phase I
What is the primary role of the migrating motor complex (MMC) during the interdigestive state?
A) To enhance nutrient absorption
B) To increase gastric emptying
C) To reduce bacterial colonization in the small intestine
D) To slow down peristalsis
C) To reduce bacterial colonization in the small intestine
What neural components are involved in the control of motor events in the small intestine?
A) Vagus nerve and sympathetic nervous system
B) Enteric nervous system
C) Both A and B
D) None of the above
C) Both A and B
Which plexus in the enteric nervous system is primarily responsible for innervating the longitudinal muscle and the outer lamella of circular muscle?
A) Submucosal (Meissner) plexus
B) Myenteric (Auerbach) plexus
C) Intrinsic plexus
D) Sympathetic plexus
B) Myenteric (Auerbach) plexus
What role does motilin play in the gastrointestinal system?
A) Stimulates the release of digestive enzymes
B) Regulates the interdigestive migrating motor complex (MMC)
C) Inhibits intestinal contractions
D) Promotes absorption of nutrients
B) Regulates the interdigestive migrating motor complex (MMC)
Where can the migrating action potential complex (mAPC) be recorded in ponies?
A) Jejunum only
B) Ileum only
C) Both jejunum and ileum
D) Neither jejunum nor ileum
B) Ileum only
What is the effect of withholding food for 24 hours on the ileal migrating action potential complex (mAPC) in ponies?
A) Increases frequency of mAPC
B) Decreases frequency of mAPC
C) Increases slow-wave frequency
D) Decreases conduction velocity of spike bursts
B) Decreases frequency of mAPC
Which neurotransmitter decreases ileal and cecal activity but increases ileal sphincter tone?
A) Serotonin
B) Epinephrine
C) Acetylcholine
D) Dopamine
B) Epinephrine
Which drug does NOT significantly affect duodenal motility in horses?
A) Xylazine
B) Butorphanol
C) Acepromazine
D) Detomidine
C) Acepromazine
What happens to myoelectric activity in the horse’s ileum after small intestinal resection and anastomosis?
A) Increases in frequency
B) Stops aboral progression of the MMC
C) Enhances motility
D) Remains unaffected
B) Stops aboral progression of the MMC
Which neurotransmitter receptor type is responsible for increasing ileal sphincter tone?
A) β-adrenergic receptors
B) α1-adrenergic receptors
C) H1 receptors
D) M3 muscarinic receptors
B) α1-adrenergic receptors
How does fasting affect motility in the equine jejunum and large intestine?
A) Increases motility
B) Decreases motility
C) Has no effect on motility
D) Increases sensitivity to acetylcholine
B) Decreases motility
What is the primary function of the ileal papilla in the horse?
A) To increase nutrient absorption
B) To prevent reflux of cecal contents
C) To stimulate bile secretion
D) To enhance peristalsis in the ileum
B) To prevent reflux of cecal contents
Which substance increases ileal peristalsis in ponies?
A) Bile acids
B) Luminal fatty acids
C) Lipids
D) Intraluminal short-chain fatty acids
B) Luminal fatty acids
What percentage range of all colic cases treated at veterinary hospitals is attributed to small intestinal diseases?
A) 10% to 20%
B) 25% to 64%
C) 70% to 90%
D) Less than 10%
B) 25% to 64%
What is the median percentage of colic cases due to small intestinal diseases in veterinary hospitals?
A) 10%
B) 25%
C) 34%
D) 50%
C) 34%
In what percentage of small intestinal obstructions is the ileum involved?
A) 10% to 20%
B) 25% to 30%
C) 41% to 46%
D) 50% to 60%
C) 41% to 46%
What percentage range of small intestinal colics are caused by strangulating lesions?
A) 10% to 30%
B) 31% to 50%
C) 58% to 85%
D) 90% to 100%
C) 58% to 85%
What is the remaining percentage of small intestinal colics caused by nonstrangulating obstructions?
A) 10% to 30%
B) 15% to 42%
C) 50% to 70%
D) 85% to 100%
B) 15% to 42%
What is the most common cause of nonstrangulating obstruction of the equine small intestine?
A) Strangulating obstruction
B) Ileal impaction
C) Gastric rupture
D) Cecal impaction
B) Ileal impaction
In which region of the United States is ileal impaction most frequently diagnosed?
A) Northeast
B) Midwest
C) Southeast
D) Northwest
C) Southeast
Which type of hay is associated with an increased risk of ileal impaction in horses?
A) Alfalfa hay
B) Timothy hay
C) Coastal Bermuda grass hay
D) Orchard grass hay
C) Coastal Bermuda grass hay
What is a significant risk factor for ileal impaction in the United Kingdom?
A) Feeding poor-quality hay
B) Tapeworm infection
C) Lack of exercise
D) High grain diet
B) Tapeworm infection
What is the primary initial cause of pain in ileal impaction?
A) Mucosal ulceration
B) Spasmodic contraction of the bowel around the impaction
C) Gastric rupture
D) Severe infection
B) Spasmodic contraction of the bowel around the impaction
What percentage of cases allows the impacted ileum to be palpated per rectum early in the disease?
A) 10% to 39%
B) 40% to 60%
C) 61% to 80%
D) 81% to 100%
A) 10% to 39%
Which diagnostic method can detect small intestinal distention in 99% of ileal impaction cases?
A) Radiography
B) Ultrasonography
C) Endoscopy
D) MRI
B) Ultrasonography
What complication is common if the diagnosis of ileal impaction is delayed?
A) Dehydration
B) Laminitis
C) Heart failure
D) Skin infection
B) Laminitis
What is the 1-year survival rate for horses treated for ileal impaction, whether surgically or medically?
A) 50%
B) 60%
C) 75%
D) Over 90%
D) Over 90% (Correct Answer)
What is the typical physical characteristic of an ileal impaction in horses?
A) A soft, pliable mass
B) A doughy to solid tubular mass up to 90 cm long
C) A liquid-filled obstruction
D) A hardened, rock-like mass
B) A doughy to solid tubular mass up to 90 cm long
What is a recommended treatment for tapeworms in horses to reduce the risk of ileal impaction?
A) Antibiotics
B) Pyrantel pamoate
C) Anti-inflammatory drugs
D) Antifungal medication
B) Pyrantel pamoate
What factor is associated with an increased risk of ileal impaction in horses fed coastal Bermuda grass hay?
A) Feeding a mixed diet with alfalfa
B) Recent introduction or feeding of poor-quality hay
C) Feeding only high-quality hay
D) Supplementing with a mineral block
B) Recent introduction or feeding of poor-quality hay
What is a significant factor contributing to ileal impaction in the United Kingdom, where coastal Bermuda grass hay is not fed?
A) Poor water quality
B) Lack of exercise
C) Tapeworm infection
D) Overfeeding of grain
C) Tapeworm infection
Which diagnostic method can detect small intestinal distention in nearly all cases of ileal impaction?
A) Endoscopy
B) Radiography
C) Ultrasonography
D) CT scan
C) Ultrasonography
Which season shows a higher occurrence of ileal impaction in the United States, though not consistently?
A) Winter
B) Spring
C) Summer
D) Fall
D) Fall
What is the success rate of medical management for early-detected ileal impaction compared to surgical treatment?
A) Significantly lower than surgery
B) Slightly lower than surgery
C) Comparable to surgery
D) Higher than surgery
C) Comparable to surgery
What is the most common complication if ileal impaction treatment is delayed?
A) Dehydration
B) Gastric rupture
C) Chronic diarrhea
D) Hair loss
B) Gastric rupture
What is the recommendation for horses that have had ileal impaction related to tapeworms?
A) Regular exercise
B) A specialized diet
C) Administer anthelmintics such as pyrantel pamoate
D) Frequent surgical check-ups
C) Administer anthelmintics such as pyrantel pamoate
What type of surgical treatment is generally is recommended for stubborn ileal impactions in horses?
A) Enterotomy
B) Jejunocecostomy
C) Manual massage with fluid infusion
D) Distal jejunal enterotomy with warm water lavage
A) enterotomy
What is a common outcome of muscular hypertrophy of the ileum in horses?
A) Acute ileal impaction
B) Recurrent colic
C) Rapid weight gain
D) Chronic diarrhea
B) Recurrent colic
What is the most likely cause of muscular hypertrophy of the ileum in horses?
A) Chronic obstruction
B) Idiopathic (unknown cause)
C) Genetic predisposition
D) High-fiber diet
B) Idiopathic (unknown cause)
In the passage, pseudodiverticula are most commonly found on which side of the intestine?
A) Anterior side
B) Posterior side
C) Mesenteric side
D) Antimesenteric side
C) Mesenteric side
What is a common clinical history for horses with ileal hypertrophy?
A) Sudden onset of severe colic
B) Recurrent, low-grade colic of variable duration
C) Immediate and severe weight loss
D) Diarrhea and fever
B) Recurrent, low-grade colic of variable duration
Which of the following is true about the thickened wall in ileal hypertrophy?
A) It affects only the circular muscle layer
B) It typically leads to a dilated lumen
C) It involves both circular and longitudinal muscle layers
D) It always results in full-thickness rupture
C) It involves both circular and longitudinal muscle layers
In which part of the gastrointestinal tract are hypertrophic changes usually spared in horses with muscular hypertrophy of the ileum?
A) Proximal jejunum
B) Terminal ileum and ileocecal junction
C) Ascending colon
D) Descending colon
B) Terminal ileum and ileocecal junction
Which diagnostic tool is helpful in identifying severe annular thickening of the muscle wall and lumen collapse in affected ileal segments?
A) Endoscopy
B) Radiography
C) Ultrasonography
D) CT scan
C) Ultrasonography
What surgical procedure is commonly used to manage muscular hypertrophy of the ileum in horses?
A) End-to-end ileocecostomy
B) Side-to-side ileocecostomy
C) Resection of the entire ileum
D) Colostomy
B) Side-to-side ileocecostomy
Which of the following is a typical sonographic finding in horses with ileal hypertrophy?
A) Decreased wall thickness
B) Lumen dilation
C) Preferential thickening of the muscularis layer
D) Uniform thickening of all layers
C) Preferential thickening of the muscularis layer
What is a rare but serious complication of muscular hypertrophy of the ileum in horses?
A) Bowel strangulation
B) Full-thickness rupture
C) Intestinal volvulus
D) Hemorrhagic colitis
B) Full-thickness rupture
What age group is primarily affected by intestinal stages of Parascaris equorum?
A) Newborn foals
B) Foals and weanlings (median age of 5 months)
C) Mature horses over 3 years old
D) Elderly horses
B) Foals and weanlings (median age of 5 months)
What condition often precedes ascarid impaction in foals?
A) Dehydration
B) Overeating
C) Anthelmintic treatment
D) Stressful events
C) Anthelmintic treatment
What is the typical prognosis for foals with ascarid impactions treated surgically?
A) Excellent, with full recovery
B) Poor, with high postoperative mortality
C) Average, with 90% survival rate
D) Guarded, with most foals surviving long-term
B) Poor, with high postoperative mortality
Which of the following is NOT a recommended strategy for preventing ascarid impaction?
A) Administering anthelmintics as soon as possible
B) Using only anthelmintics known to be effective against local populations
C) Collecting fecal samples 14-21 days after treatment
D) Initiating anthelmintic treatment no sooner than 60 days of age
D) Initiating anthelmintic treatment no sooner than 60 days of age
Which anthelmintic has shown no effect against P. equorum in foals according to a 2007 study?
A) Fenbendazole
B) Pyrantel pamoate
C) Ivermectin
D) Oxibendazole
C) Ivermectin
What is a common complication of ascarid impaction in foals?
A) Diarrhea
B) Small intestinal obstruction
C) Hepatitis
D) Chronic cough
B) Small intestinal obstruction
What percentage of foals affected by ascarid impaction experience postoperative mortality?
A) 20%
B) 40%
C) Up to 92%
D) 10%
C) Up to 92%
Which method offers the best prognosis for resolving ascarid impaction during surgery?
A) Jejunostomy
B) Enterotomy
C) Massaging the worm impaction into the cecum
D) Resection of the small intestine
C) Massaging the worm impaction into the cecum
Why might mature horses occasionally have ascarid infections?
A) They have a different diet
B) Some isolates of the parasite might be less immunogenic
C) They have stronger immune systems
D) They are more resistant to anthelmintics
B) Some isolates of the parasite might be less immunogenic
Which anthelmintic is NOT recommended for use in foals less than 6 months old?
A) Moxidectin
B) Fenbendazole
C) Oxibendazole
D) Pyrantel pamoate
A) Moxidectin
Which of the following best describes Duodenitis-Proximal Jejunitis (DPJ)?
A) Inflammation of the distal part of the small intestine
B) Inflammation of the proximal part of the small intestine, fluid accumulation, and endotoxemia
C) A form of colitis affecting the large intestine
D) A parasitic infection of the small intestine
B) Inflammation of the proximal part of the small intestine, fluid accumulation, and endotoxemia
Which organism is associated with the induction of DPJ-like symptoms in healthy horses?
A) Escherichia coli
B) Clostridium difficile
C) Salmonella enterica
D) Streptococcus equi
B) Clostridium difficile
What is a clinical hallmark of DPJ in affected horses?
A) Absence of gastric reflux
B) Nasogastric reflux of a large volume of fluid
C) Severe diarrhea
D) Excessive sweating without gastric reflux
B) Nasogastric reflux of a large volume of fluid
How can DPJ be distinguished from a strangulating small intestinal lesion?
A) DPJ is associated with a higher incidence of severe pain and no response to gastric decompression
B) DPJ shows significant relief after gastric decompression and often presents with fever and leukocytosis
C) DPJ is characterized by serosanguinous peritoneal fluid
D) DPJ is diagnosed exclusively through abdominal surgery
B) DPJ shows significant relief after gastric decompression and often presents with fever and leukocytosis
Which treatment option is controversial in managing DPJ?
A) Frequent gastric decompression
B) Fluid and electrolyte correction
C) Use of antibiotics
D) Prophylaxis against laminitis
C) Use of antibiotics
What is the prognosis for horses with DPJ that undergo surgical treatment?
A) Surgery significantly improves survival rates
B) Surgery is associated with lower survival rates and a greater likelihood of diarrhea
C) Surgery always hastens resolution of reflux
D) Horses treated surgically have a higher rate of incisional infection
B) Surgery is associated with lower survival rates and a greater likelihood of diarrhea
What is a significant complication associated with DPJ that can be life-threatening?
A) Colic recurrence
B) Laminitis
C) Liver failure
D) Severe weight loss
B) Laminitis
Which of the following is NOT a histopathological finding in DPJ?
A) Hyperemia and edema of the mucosa
B) Severe villus atrophy without inflammation
C) Neutrophil infiltration of the lamina propria and submucosa
D) Hemorrhagic and necrotic patches in the mucosa
B) Severe villus atrophy without inflammation
What is one of the potential causes of liver damage in horses with DPJ?
A) Direct parasitic invasion of the liver
B) Reflux of duodenal contents and ascending infection through the common bile duct
C) Vitamin E deficiency
D) Overuse of NSAIDs
B) Reflux of duodenal contents and ascending infection through the common bile duct
Which laboratory finding is associated with a poor prognosis in horses with DPJ?
A) Low serum calcium levels
B) High anion gap
C) Normal electrolyte levels
D) Low gastric reflux volume in the first 24 hours
B) High anion gap
Which of the following is the most common type of intestinal neoplasm causing obstruction in horses?
A) Adenocarcinoma
B) Alimentary lymphoma
C) Ganglioneuroma
D) Intestinal carcinoid
B) Alimentary lymphoma
Which breed of horse is at a higher risk of developing intestinal neoplasia?
A) Thoroughbred
B) Quarter Horse
C) Arabian
D) Standardbred
C) Arabian
What is the most common segment of the intestine affected by neoplasms in horses?
A) Large intestine
B) Cecum
C) Small intestine
D) Rectum
C) Small intestine
Which of the following clinical signs is NOT commonly associated with intestinal neoplasia in horses?
A) Poor body condition
B) Tachycardia
C) Diarrhea
D) Hemorrhagic nasal discharge
D) Hemorrhagic nasal discharge
Which diagnostic method is mentioned as part of the antemortem diagnosis of intestinal neoplasia in horses?
A) Endoscopy
B) Abdominocentesis
C) MRI
D) CT scan
B) Abdominocentesis
Which type of tumor resection has the best prognosis for survival in horses?
A) Lymphosarcoma
B) Ganglioneuroma
C) Adenocarcinoma
D) Intestinal carcinoid
C) Adenocarcinoma
What is the prognosis for horses with resected lymphosarcoma lesions?
A) Excellent, with full recovery expected
B) Good, if the lesion is isolated and no metastasis is present
C) Guarded, as this is generally a multiorgan disease with a grave prognosis
D) Poor, even with early surgical intervention
C) Guarded, as this is generally a multiorgan disease with a grave prognosis
Which of the following neoplasms is NOT mentioned as causing small intestinal obstruction in horses?
A) Smooth muscle tumors
B) Ganglioneuroma
C) Hemangiosarcoma
D) Intestinal carcinoid
C) Hemangiosarcoma
Which of the following diseases is associated with inflammation or fibrosis in the small intestinal wall?
A) Equine proliferative enteropathy
B) Pythiosis
C) Intestinal fibrosis
D) All of the above
C) Intestinal fibrosis
Where was intestinal fibrosis originally reported as a cause of colic and weight loss in horses?
A) Florida
B) California
C) Colorado
D) Kentucky
C) Colorado
What is the causative agent of equine proliferative enteropathy?
A) Clostridium difficile
B) Lawsonia intracellularis
C) Pythium insidiosum
D) Strongylus vulgaris
B) Lawsonia intracellularis
Which clinical signs are characteristic of equine proliferative enteropathy in weanling foals?
A) Coughing and nasal discharge
B) Weight loss, colic, fever, depression, hypoproteinemia, and diarrhea
C) Lameness and joint swelling
D) Skin lesions and pruritus
B) Weight loss, colic, fever, depression, hypoproteinemia, and diarrhea
How is equine proliferative enteropathy diagnosed?
A) Based on clinical signs, exclusion of similar diseases, and fecal PCR analysis
B) Through blood cultures
C) By endoscopic examination
D) Via radiographic imaging
A) Based on clinical signs, exclusion of similar diseases, and fecal PCR analysis
What is the treatment of choice for equine proliferative enteropathy?
A) Antifungal medications
B) Antibiotics such as doxycycline, oxytetracycline, or erythromycin
C) Steroids
D) Anthelmintics
B) Antibiotics such as doxycycline, oxytetracycline, or erythromycin
Pythiosis, caused by Pythium insidiosum, primarily affects which part of the horse?
A) Large intestine
B) Skin and subcutis
C) Jejunum
D) Liver
C) Jejunum
Which geographic regions are commonly associated with Pythiosis in horses?
A) Northeast United States
B) West Coast of the United States
C) Gulf Coast states and Midwest
D) Rocky Mountain region
C) Gulf Coast states and Midwest
What type of lesion is caused by Pythium insidiosum in horses?
A) Neoplastic
B) Granulomatous
C) Ulcerative
D) Necrotizing
B) Granulomatous
What is the typical treatment for jejunal obstruction caused by Pythium insidiosum granulomas?
A) Systemic antifungals
B) Resection of the affected intestine
C) Chemotherapy
D) Antiviral medications
B) Resection of the affected intestine
What is the primary characteristic of idiopathic focal eosinophilic enteritis (iFee)?
A) Systemic eosinophilic disease
B) Circumferential mural bands (CmBs) in the small intestine that cause obstruction
C) Mucosal ulceration
D) Granulomatous lesions in the colon
B) Circumferential mural bands (CmBs) in the small intestine that cause obstruction
Which group of idiopathic diseases does iFee belong to?
A) Multisystemic eosinophilic epitheliotropic disease (MEE)D
B) Eosinophilic diseases confined to the intestine (EDCI)
C) Segmental eosinophilic colitis (SEC)
D) Idiopathic fibrosing enteritis
B) Eosinophilic diseases confined to the intestine (EDCI)
What differentiates idiopathic focal eosinophilic enteritis (iFee) from segmental eosinophilic colitis (SEC)?
A) iFee involves the colon, whereas SEC involves the small intestine
B) SEC can progress to necrosis of the affected segment
C) iFee is related to intestinal parasitism
D) iFee shows mucosal ulceration, whereas SEC does not
B) SEC can progress to necrosis of the affected segment
What is the typical seasonal occurrence of iFee in horses according to studies in the United Kingdom?
A) Spring to summer
B) Autumn to winter
C) July to November
D) Winter to spring
C) July to November
What histologic features are associated with idiopathic focal eosinophilic enteritis (iFee)?
A) Granulomatous inflammation and mucosal ulceration
B) Intense eosinophilic, lymphocytic, and plasmacytic infiltration in the submucosa, muscularis, and serosa
C) Neoplastic lesions and necrosis
D) Non-inflammatory fibrous bands without eosinophils
B) Intense eosinophilic, lymphocytic, and plasmacytic infiltration in the submucosa, muscularis, and serosa
What is a common treatment approach for iFee?
A) Surgical resection of the affected segment
B) Dietary restrictions alone
C) Antifungal medications
D) Chemotherapy
A) Surgical resection of the affected segment
What is the recommended approach if multiple circumferential mural bands (CmBs) are present in iFee?
A) Immediate surgical resection of all bands
B) Decompress the affected small intestine into the cecum without resection
C) Long-term corticosteroid therapy only
D) Biopsy of the lesions
B) Decompress the affected small intestine into the cecum without resection
Why is resection not always preferred in the treatment of iFee?
A) It leads to high recurrence rates and complications
B) It has no effect on the gross lesions
C) Non-resected lesions may not cause obstruction
D) Most cases can be managed without resection with fewer complications and better survival rates
D) Most cases can be managed without resection with fewer complications and better survival rates
What are the main goals in the management of iFee after surgery?
A) Immediate resection of all lesions
B) Antifungal treatment and prolonged hospitalization
C) Antiinflammatory therapy, usually with corticosteroids
D) High-dose antibiotics and supportive care
C) Antiinflammatory therapy, usually with corticosteroids
What potential issue might arise from corticosteroid use in horses with iFee after surgery?
A) Increased risk of bacterial infection
B) Adverse effect on abdominal wound healing
C) Enhanced risk of intestinal rupture
D) Development of parasitic infections
B) Adverse effect on abdominal wound healing
Where is Equine Grass Sickness (EGS) most frequently reported?
A) Ireland
B) United States
C) Northeast Scotland
D) Chile
C) Northeast Scotland
What are the three forms of Equine Grass Sickness (EGS)?
A) Acute, Subacute, Chronic
B) Mild, Moderate, Severe
C) Early, Intermediate, Late
D) Sudden, Progressive, Terminal
A) Acute, Subacute, Chronic
Which form of Equine Grass Sickness (EGS) is most relevant to colic diagnosis?
A) Chronic
B) Subacute
C) Acute
D) Mild
C) Acute
What risk factors are consistently reported for Equine Grass Sickness (EGS)?
A) Advanced age and winter season
B) Young age, recent movement to new pasture, and spring/summer season
C) Heavy rainfall and increased humidity
D) Lack of exercise and low-quality feed
B) Young age, recent movement to new pasture, and spring/summer season
What percentage of all colic cases does Equine Grass Sickness (EGS) account for?
A) 1.3%
B) 4%
C) 10%
D) 15%
B) 4%
What is a common presentation of acute Equine Grass Sickness (EGS)?
A) High fever and severe colic
B) Inappetence, profound depression, gastrointestinal stasis, dysphagia, and large volumes of nasogastric reflux
C) Persistent cough and nasal discharge
D) Chronic diarrhea and weight loss
B) Inappetence, profound depression, gastrointestinal stasis, dysphagia, and large volumes of nasogastric reflux
How is Equine Grass Sickness (EGS) definitively diagnosed?
A) Clinical signs and response to treatment
B) Histologic examination of an ileal biopsy
C) Blood tests and fecal analysis
D) Ultrasound examination
B) Histologic examination of an ileal biopsy
What histologic findings are characteristic of Equine Grass Sickness (EGS)?
A) Neuronal degeneration and loss of enteric neurons in the myenteric and submucous plexuses
B) Granulomatous inflammation and mucosal ulceration
C) Eosinophilic infiltration and fibrosis
D) Neoplastic lesions and necrosis
A) Neuronal degeneration and loss of enteric neurons in the myenteric and submucous plexuses
What is the recommended action if acute Equine Grass Sickness (EGS) is diagnosed?
A) Immediate surgical intervention
B) Long-term medical management
C) Euthanasia
D) Symptomatic treatment and observation
C) Euthanasia
What percentage of horses with Equine Grass Sickness (EGS) that undergo small intestinal surgery in UK hospitals are affected by this condition?
A) 1.3%
B) 3.2% to 14%
C) 20%
D) 25%
B) 3.2% to 14%
What is a common cause of jejunal impaction in horses?
A) Impacted feed material
B) Cracked corn
C) Persimmon fruit
D) All of the above
D) All of the above
What can cause an impaction of the jejunum during fall and winter in the South?
A) Ripe persimmon fruits
B) Molasses-based stable treats
C) Compact wood fragments
D) Choleliths
A) Ripe persimmon fruits
What is the primary concern when persimmon seeds cause small intestinal impactions?
A) Response to medical treatment is usually successful
B) High risk of gastrointestinal tract rupture
C) Spontaneous resolution without treatment
D) Minimal risk of complications
B) High risk of gastrointestinal tract rupture
Which object is known to cause perforation of the jejunum leading to peritonitis or localized intestinal necrosis?
A) Wire
B) Baling twine
C) Choleliths
D) Trichophytobezoar
A) Wire
What can wire perforation of the jejunum lead to if it migrates?
A) Ascitic fluid accumulation
B) Splenomegaly and splenic abscessation
C) Renal failure
D) Intestinal necrosis
B) Splenomegaly and splenic abscessation
Which condition is characterized by congenital segmental aplasia of jejunal lymphatics causing chyloperitoneum?
A) Idiopathic perforating ulcers
B) Extraluminal obstruction
C) Congenital segmental aplasia of jejunal lymphatics
D) Gastric and small intestinal ileus
C) Congenital segmental aplasia of jejunal lymphatics
How can congenital segmental aplasia of jejunal lymphatics be diagnosed?
A) Abdominal radiography
B) Fecal analysis
C) Ultrasonographic findings of thick-walled small intestine and anechoic peritoneal fluid
D) Blood tests
C) Ultrasonographic findings of thick-walled small intestine and anechoic peritoneal fluid
What can ruptured lymphatics and chyloperitoneum develop secondary to?
A) Idiopathic perforating ulcers
B) Tearing of postsurgical mesenteric adhesions
C) Consumption of persimmon fruit
D) Wire ingestion
B) Tearing of postsurgical mesenteric adhesions
Which of the following is a rare cause of recurrent small intestinal obstruction in horses?
A) Ileal diverticulum not related to omphalomesenteric remnants
B) Intraabdominal abscesses
C) Intestinal malformation
D) Choleliths
A) Ileal diverticulum not related to omphalomesenteric remnants
What is a common presenting sign of gastric and small intestinal ileus in postparturient thoroughbred mares?
A) Mild colic
B) Elevated heart rates, abdominal distention, and nasogastric reflux
C) Chronic diarrhea
D) Normal wall thickness of distended small intestine
B) Elevated heart rates, abdominal distention, and nasogastric reflux
What is a pedunculated lipoma?
A) A malignant tumor with multiple attachments
B) A benign, smooth-walled fat tumor suspended by a thin mesenteric pedicle
C) A fibrous growth on the intestinal wall
D) An abnormal growth in the liver
B) A benign, smooth-walled fat tumor suspended by a thin mesenteric pedicle
Where are pedunculated lipomas most commonly found in horses?
A) Small colon
B) Omentum
C) Small intestine
D) Large intestine
C) Small intestine
What is the primary mechanism by which a pedunculated lipoma causes colic in horses?
A) Direct obstruction of the intestinal lumen
B) Strangulation of the intestine by wrapping of the pedicle around the intestine and mesentery
C) Compression of the abdominal wall
D) Formation of a gastric ulcer
B) Strangulation of the intestine by wrapping of the pedicle around the intestine and mesentery
In which age group is intestinal strangulation by a mesenteric lipoma most commonly diagnosed?
A) Foals
B) Young horses (2–5 years)
C) Middle-aged horses (6–10 years)
D) Older horses (mean age 14 to 19.2 years)
D) Older horses (mean age 14 to 19.2 years)
Which breeds of horses are reported to be at higher risk for intestinal strangulation by pedunculated lipomas?
A) Thoroughbreds and Warmbloods
B) Ponies, Arabian horses, Saddlebreds, Quarter Horses, and geldings
C) Draft horses and Shetland ponies
D) Standardbreds and Appaloosas
B) Ponies, Arabian horses, Saddlebreds, Quarter Horses, and geldings
What is the general risk factor for pedunculated lipomas causing strangulation?
A) Size of the lipoma
B) Length of the pedicle
C) Location of the lipoma
D) Color of the lipoma
B) Length of the pedicle
Which of the following can be a complication when performing surgery to remove a pedunculated lipoma?
A) Formation of an abdominal abscess
B) Mesenteric rent and mesenteric bleeding
C) Complete resolution without surgical intervention
D) Perforation of the stomach
B) Mesenteric rent and mesenteric bleeding
What are the published short-term survival rates for horses undergoing surgery for strangulation by pedunculated lipomas?
A) 20% to 40%
B) 40% to 60%
C) 48% to 84%
D) 85% to 95%
C) 48% to 84%
Which condition can be confused with pedunculated lipoma due to similar clinical signs?
A) Colonic impaction
B) Duodenitis–proximal jejunitis (DPJ)
C) Gastric ulcer
D) Pythiosis
B) Duodenitis–proximal jejunitis (DPJ)
What surgical approach is often necessary for dealing with a pedunculated lipoma?
A) Conservative management with medication
B) Complete resection of the lipoma and involved intestine
C) Blind resection of the pedicle
D) Application of bandages to reduce strangulation
C) Blind resection of the pedicle
What is the epiploic foramen (eF)?
A) An anatomical structure found in the large intestine
B) The entry into the vestibule of the omental bursa from the peritoneal cavity
C) A type of intestinal malformation
D) A space between the liver and the gallbladder
B) The entry into the vestibule of the omental bursa from the peritoneal cavity
Which of the following is NOT a possible variant of incarceration in the epiploic foramen (eF)?
A) Strangulation of the cecum by the involved small intestine
B) Incarceration of a Meckel diverticulum (Littre hernia)
C) Simultaneous incarceration of the stomach and duodenum
D) Simultaneous strangulation of two loops of small intestine
C) Simultaneous incarceration of the stomach and duodenum
What is the most common segment of intestine involved in eF incarceration?
A) Duodenum
B) Cecum
C) Jejunum
D) Ileum
D) Ileum
Which factor is associated with an increased risk of developing eF in horses?
A) Increased age of the horse
B) Being a thoroughbred
C) Cribbing behavior
D) High grain diet
C) Cribbing behavior
What is a common predisposing factor to eF in horses that is related to their behavior?
A) Excessive exercise
B) Cribbing
C) Infrequent feeding
D) Regular deworming
B) Cribbing
Which method is used during surgery to correct eF incarceration if the intestine cannot be drawn back through the foramen?
A) Complete resection of the involved segment
B) Enterotomy or transection of the jejunum
C) Manual reduction without surgical intervention
D) Application of an external compression bandage
B) Enterotomy or transection of the jejunum
What is a significant complication that may occur during surgery for eF incarceration?
A) Rupture of the small intestine
B) Portal vein injury leading to fatal hemorrhage
C) Pancreatic necrosis
D) Colonic volvulus
B) Portal vein injury leading to fatal hemorrhage
What is the reported range of short-term survival rates after surgery for eF?
A) 10% to 30%
B) 30% to 50%
C) 60% to 80%
D) 18% to 95%
D) 18% to 95%
Which recent method has been developed to prevent recurrence of EF?
A) Laparoscopic closure of the eF with an expandable mesh implant
B) Medications to reduce intraabdominal pressure
C) Dietary changes to prevent colic
D) Routine use of anti-cribbing devices
A) Laparoscopic closure of the eF with an expandable mesh implant
What is the definition of volvulus in horses?
A) A condition where the intestine becomes obstructed due to an external band
B) Rotation of a segment of jejunum or jejunum and ileum about the mesentery, forming distinct spirals
C) An inflammation of the mesenteric tissue
D) A hernia involving the cecum and colon
B) Rotation of a segment of jejunum or jejunum and ileum about the mesentery, forming distinct spirals (Correct
Which of the following is a potential secondary cause of volvulus?
A) Gastric reflux
B) Preexisting lesions such as acquired inguinal hernia or mesodiverticular band
C) Excessive fluid intake
D) Simple intestinal impaction
B) Preexisting lesions such as acquired inguinal hernia or mesodiverticular band
What is a notable form of volvulus that involves a mesenteric pouch and can resemble a mesenteric hernia?
A) Volvulus nodosus
B) Mesenteric volvulus
C) Cecal volvulus
D) Epiploic foramen volvulus
A) Volvulus nodosus
In which age group are volvulus nodosus and other types of volvulus most commonly seen?
A) Foals aged 2 to 7 months
B) Adult horses aged 10 to 15 years
C) Horses aged 3 to 5 years
D) Senior horses older than 20 years
A) Foals aged 2 to 7 months
Which clinical sign is commonly associated with small intestinal volvulus in foals?
A) Severe pain alternating with periods of depression
B) Chronic diarrhea
C) Weight gain
D) Constant mild colic
A) Severe pain alternating with periods of depression
What is a common diagnostic finding in cases of small intestinal volvulus?
A) Gastric reflux
B) Stacks of tightly distended small intestine palpated per rectum
C) Large volume of nasogastric reflux
D) Normal-sized bowel loops
B) Stacks of tightly distended small intestine palpated per rectum
What is the primary treatment approach for volvulus?
A) Conservative management with diet changes
B) Correction of the volvulus, followed by resection and anastomosis
C) Medical management with anti-inflammatory drugs
D) Use of endoscopic techniques for bowel decompression
B) Correction of the volvulus, followed by resection and anastomosis
What is the general prognosis for survival to hospital discharge after treatment for volvulus?
A) Poor, with a survival rate of 20%
B) Favorable, with a survival rate of approximately 80%
C) Moderate, with a survival rate of 50%
D) Uncertain, with variable outcomes
B) Favorable, with a survival rate of approximately 80%
How can volvulus nodosus be corrected if the bowel involved is necrotic?
A) By massaging the contents of the entrapped loop into the proximal segment
B) By resection of the entire lesion without reduction, followed by a jejunocecostomy
C) By conservative management and monitoring
D) By inserting a mesh implant to support the bowel
B) By resection of the entire lesion without reduction, followed by a jejunocecostomy
Which procedure may be used to correct volvulus nodosus in foals and adults?
A) Manual decompression and reduction
B) Massaging the contents into the proximal segment
C) Endoscopic removal of the involved bowel
D) Laparoscopic banding of the volvulus
B) Massaging the contents into the proximal segment
What is the most common form of inguinal hernia in horses?
A) Direct inguinal hernia
B) Congenital indirect inguinal hernia
C) Acquired indirect inguinal hernia
D) Direct scrotal hernia
C) Acquired indirect inguinal hernia
Which type of inguinal hernia involves the small intestine passing through the vaginal ring into the vaginal tunic?
A) Direct inguinal hernia
B) Congenital indirect inguinal hernia
C) Acquired indirect inguinal hernia
D) Direct scrotal hernia
C) Acquired indirect inguinal hernia
In which age group are direct inguinal hernias more commonly seen?
A) Foals
B) Adult horses
C) Both foals and adults equally
D) Yearlings
D) Yearlings
What is a notable difference in hernia characteristics between foals and adult horses?
A) Foals have longer segments of intestine involved compared to adults.
B) Adults have a longer, wider inguinal canal than foals.
C) Foals with congenital indirect hernias have a shorter, more direct inguinal canal, which allows for longer segments of intestine to remain viable.
D) Adult hernias are always reducible, while foal hernias are not.
C) Foals with congenital indirect hernias have a shorter, more direct inguinal canal, which allows for longer segments of intestine to remain viable.
What is the role of the vaginal ring in the development of an inguinal hernia?
A) It is the primary site where the intestine becomes strangulated.
B) It is a structure the intestine must pass through, but strangulation occurs distal to it.
C) It prevents any hernia from occurring.
D) It is irrelevant in hernia formation.
B) It is a structure the intestine must pass through, but strangulation occurs distal to it.
What are common predisposing factors for acquired inguinal hernias in horses?
A) Genetic predisposition and breed-specific tendencies
B) Recent strenuous exercise, recent breeding, and trauma
C) Age and body condition score
D) Seasonal changes and stabling conditions
B) Recent strenuous exercise, recent breeding, and trauma
What is a common clinical presentation of congenital indirect scrotal hernias in foals?
A) Severe abdominal distention and fever
B) Easily reducible hernia shortly after birth, resolving spontaneously within 3 to 6 months
C) Persistent and painful swelling of the testicle
D) Intermittent colic and severe scrotal swelling
B) Easily reducible hernia shortly after birth, resolving spontaneously within 3 to 6 months
Which breed has been reported to have a higher prevalence of inguinal/scrotal hernias?
A) Thoroughbreds
B) Arabians
C) Standardbreds
D) Warmbloods
C) Standardbreds, followed by Tenessee walkng horses, american saddlebreds
What is the typical treatment for direct or ruptured inguinal hernias in foals?
A) Conservative management and monitoring
B) Immediate surgical intervention due to the risk of strangulation
C) Use of a supportive bandage
D) Reduction and application of a mesh implant
B) Immediate surgical intervention due to the risk of strangulation
What diagnostic tool is especially useful if rectal palpation is not possible in cases of inguinal hernia?
A) Endoscopy
B) Ultrasonography
C) Laparoscopy
D) Gastroscopy
B) Ultrasonography
Which type of intussusception is most commonly reported in horses?
A) Jejunojejunal
B) Ileocecal
C) Ileoileal
D) Cecocecal
B) Ileocecal
Which of the following is NOT considered a suspected predisposing factor for intussusception in horses?
A) Enteritis
B) Heavy ascarid burden
C) Mesenteric arteritis
D) Volvulus
D) Volvulus
Chronic intussusceptions often lead to which of the following changes in the jejunum?
A) Jejunal atrophy
B) Jejunal dilation and thickening of the muscular coat
C) Jejunal shortening
D) Jejunal ulceration
B) Jejunal dilation and thickening of the muscular coat
Which parasite is typically implicated in ileocecal intussusception in horses?
A) Anoplocephala perfoliata
B) Strongylus vulgaris
C) Parascaris equorum
D) Giardia lamblia
A) Anoplocephala perfoliata
What is the most common type of intussusception in horses, causing 74% of all small intestinal cases?
A) Jejunojejunal
B) Ileocecal
C) Ileoileal
D) Cecocecal
B) Ileocecal
What percentage of chronic ileocecal intussusceptions causes intermittent colic?
A) 50%
B) 27%
C) 74%
D) 10%
B) 27%
In cases of chronic intussusception, what is the typical characteristic of the intussusceptum?
A) Strangulated and causing complete obstruction
B) Non-strangulated and causing incomplete obstruction
C) Non-strangulated and causing total necrosis
D) Strangulated but causing no obstruction
B) Non-strangulated and causing incomplete obstruction
Which of the following age groups in horses is most commonly affected by ileocecal intussusception?
A) 1-3 years
B) 4-7 years
C) 3-12 months
D) Foals under 6 months
C) 3-12 months
Which breed of horse was reported to have a higher risk for developing intussusception in one study?
A) Arabian
B) Thoroughbred
C) Standardbred
D) Quarter Horse
B) Thoroughbred
What type of intussusception is described with a secondary partial invagination of the jejunum into the ileum?
A) Jejunojejunal
B) Ileocecal
C) Ileoileal
D) Cecocecal
B) Ileocecal
In one study, what percentage of horses had asymptomatic intussusceptions as detected by ultrasonography?
A) 15%
B) 30%
C) 56%
D) 70%
C) 56%
Which type of intussusception is more commonly associated with recurrent colic in horses?
A) Short jejunojejunal intussusceptions
B) Short ileocecal intussusceptions
C) Long ileocecal intussusceptions
D) Long jejunojejunal intussusceptions
A) Short jejunojejunal intussusceptions
Which clinical sign is typically observed in a horse with a short intussusception?
A) Severe abdominal pain
B) Mild, intermittent postprandial colic
C) Vomiting
D) Severe weight gain
B) Mild, intermittent postprandial colic
Where can an ileocecal intussusception often be palpated in horses during a rectal examination?
A) Right ventral quadrant of the abdomen
B) Left dorsal quadrant of the abdomen
C) Right dorsal quadrant of the abdomen
D) Left ventral quadrant of the abdomen
C) Right dorsal quadrant of the abdomen
In acute small intestinal intussusceptions, which change is usually characteristic of the peritoneal fluid?
A) Decreased WBC counts
B) Increased WBC counts and protein
C) Low protein concentration
D) No changes in peritoneal fluid
B) Increased WBC counts and protein
Which of the following is more likely in horses with acute ileocecal intussusceptions?
A) Serosanguineous abdominal fluid
B) Clear abdominal fluid
C) Fibrinous abdominal fluid
D) Purulent abdominal fluid
A) Serosanguineous abdominal fluid
In horses under 3 years of age, which type of intussusception is more likely to cause recurrent colic?
A) Jejunojejunal
B) Ileoileal
C) Cecocecal
D) Colocolic
B) Ileoileal
What is a likely clinical suspicion in a horse between weaning and 3 years of age with a history of recurrent mild colic and unthrifty appearance?
A) Gastric ulceration
B) Ileocecal intussusception
C) Colonic torsion
D) Cecal impaction
B) Ileocecal intussusception
acquired hernia can be corrected with 5 types of laparoscopic surgical techniques, name them
1) mesh on lay graft
2) cylindrical mesh plug
3) transposition peritoneal flap over vaginal ring
4) cyanoacrylate glue closure of the vaginal ring
5) closure of vaginal ring with barbed suture
Which type of hernia is common in horses?
Horses is indirect and humans is direct and foals (4 to 48h postpartum)
What are the predisposition factors?
1 - Size of vaginal ring
2 - Congenital in foals (spontaneous reduction by 12 months)
3 - Breed warmblood and andalusian more predisposed than ST
What are the advantages of doing standing laparo in hernial correction nstead of GA? Disadvantage?
Reduce costs
Reduce risk GA
Can be done early after laparotomy correction
Immediate view of flap with gravity
Disadvantage is that difficult horse might be dangerous
General anesthesia laparo for correction of hernia ring disadvantages?
You have to wait 6 weeks post surgical castration and correction
Risk of GA
What are the laparoscopic tx?
Polypropylene mesh placement under periotoneal flap close vaginal ring (TAP fischer)
Polypropylene rolled into cylinder mesh within vaginal canal standing (Marien)
Peritoneal flap hernioplasty (PFH) under GA (Rossignol)
Peritoneal flap hernioplasty (PFH) under sedation (Hans)
Cyanoacrylate herniolasty standing
Direct laparoscopy suturing of the vaginal ring
What is the major consequence if the mesh is in contact with spermatic cord?
Sterility
Describe PFH under GA
incision 1 cm caudal to umbilicus
Peritoneum blunted perforated with 15 to 20 mm cannula into abdomen
Introduce 30degrees 57 cm laparoscope
Trendelenburg position
Insuflatte co2 to 15 mmHg and check vaginal ring
Portals 2 and 3 created 12 cm craniolaterally to each inguinal ring under laparo guidance
Elevate ventrolat to internal ring the peritoneum with laparo scissors in ipsilat site and with Babcock on contralateral cut 3 sites and separate from underlying muscle (internal obq) and the flap is inverted down dorsomed and fixed laterally to parietal wall and medially 2cm dorsal to the ring
Use laparoscopic helicoidal staples or simple interrupted intracorporeal sutures usp 3 vicryl
If you use helicoidal staples which extra step you have to perform?
Do 2 extraports perpendicular to the tissue
Advantages of the peritoneal flap hernioplasty? Disadvantages?
No recurrence
Normal fertility
Reduced inflammation if spermatic cord
Return high level
Disadvantage is that the caudomedial portion of the flap is difficult to close
Tx is difficult if performed for the 2nd time
Which cases are indicated the placement of mesh?
Direct hernia
How to perform placement of mesh?
Mesh is positioned under peritoneal flap, collapsing neck of vaginal tunic and diminish the size of vaginal ring and you secure the mesh with staples
Tissue ingrowth into mesh led to scar tissue
What are disadvantages of mesh placement?
Time consuming
Difficult to totally cover
Adhesion
Very close to spermatic cord
Polypropylene mesh rolled in cylinder and maintained with 2 sutures can cause what?
Infertility and adhesions
Describe the tx for placement of cyanoacrylate
Laparoscope between paralombar fossa
2 extra portals : one 7 cm ventral and other 2 cm caudal to this one
Trocar 10 mm inserted
The ductus diferens is displaced caudomedially with babcock and with 2 mm polyethylene extension tube, 2 ml of cyanoacrylate is injected with compression of 30 sec
Postop management of cyanoacrylate?
24 h peni/genta
3 day Pbz
Discharge 48 h with handwalk twice daily
2 w box rest
2 w handwalk
Reavaluation through rectal palpation 4- 6 weeks
Diagram of peritoneal flap
image intraop peritoneal flap
Portals of GA laparo for inguinal hernia
stab incision is
created 1 cm caudal to the umbilicus, the peritoneum is bluntly perforated, and a 15- to 20-mm
cannula with a blunt trocar is introduced into the abdomen. When the surgeon senses that the cannula is in the abdomen (free movements and contact with intestines), a 30° 57-cm laparoscope
(Optomed, Les Ulis Cedex, France) is introduced. The horse is positioned in a 30° Trendelenburg position. The abdomen is insufflated with CO2 until the vaginal rings are visible, which generally corresponds to ≤15 mmHg intra-abdominal
ressureInsufflation is continued until the vaginal rings can be observed. Portals 2
and 3 are created about 12 cm craniolaterally to each external inguinal ring (Figure 27.2) under laparoscopic guidance. The peritoneum ventrolateral to the internal inguinal ring is elevated and
cut on three sides, then separated from the underlying muscle using laparoscopic scissors (Optomed) to form a flap of 8 × 5 cm
Limitations of deep or internal inguinal ring
The base of the triangle (i.e., the medial border of the ring, closest to ventral midline) is formed by the lateral margin of the rectus abdominis muscle at its insertion on the pubic bone (referred to as the prepubic tendon at this location). The cranial
border of the triangle is the fleshy, slightly oblique caudal margin of the internal abdominal oblique muscle. The caudal
border of the triangle is formed by the curved, thickened, caudal margin of the aponeurosis of the external abdominal
oblique muscle (referred to as the “inguinal ligament”). The cranial and caudal borders converge dorsally on the
abdominal wall to form the apex of the triangular space, approximately 10–15 cm from the base
Limitations of superficial or external inguinal ring
The superficial (or external) inguinal ring is an elongate oval formed by a division in the aponeurosis of the
external abdominal oblique muscle . The split is created by the separation of the aponeurosis into 2 broad tendons of insertion, the abdominal and pelvic tendons. The abdominal tendon inserts on the linea alba and the prepubic tendon and its edge provides the medial crus (border) of the superficial inguinal ring. The edge of the pelvic tendon forms the lateral crus of the superficial inguinal ring and this part of the aponeurosis of the external abdominal oblique muscle inserts on the tuber coxae and prepubic tendon and terminates as the inguinal ligament. The pelvic tendon is the portion of the external abdominal oblique aponeurosis described previously that also limits the lateral surface of the deep inguinal ring, and in doing so, it is forming the lateral wall of the inguinal canal. The long axis
of the superficial inguinal ring runs caudomedial to
craniolateral. The caudomedial angle is closely related to the
underlying deep inguinal ring, resulting in the inguinal canal being short in this region and longer (see Fig. 13.9-6)
at the craniolateral angle (up to 15 cm (equine comparitive book)
Portals for standing laparoscopy and introduction of cyanoacrylate (Ragle book)?
The first portal is
located in the paralumbar fossa, 15 cm ventral to
the transverse processes of the lumbar vertebra,
midway between the last rib and the tuber coxae.
The other two portals are located about 7 cm ventrally
and 1–2 cm caudally to the previous portal
while introducing cyanoacrylate the cord is pulled in which direction? caudomedial or caudolateral?
Babcock forceps pulling the cord caudomedially
how many ml of metyl-cyanoacrylate is introduced? how much time you have to wait?
Then 2 mL of methyl-cyanoacrylate or n-butyl-
2-cyano-acrylate are injected with 2mm diameter polyethylene extension tube into the inguinal
canal, including its margins, taking care to avoid
the viscera, especially the bladder and the bowel.
The lateral parts of the vaginal ring are compressed
for 30 seconds using the Babcock forceps,
taking special care not to get any glue on the
forceps.
