Chapter 36 - Cecum Flashcards
Approximately how long is the cecum?
A) 0.5 meters
B) 1 meter
C) 1.5 meters
D) 2 meters
B) 1 meter
What is the average capacity of the horse’s cecum?
A) 10 liters
B) 20 liters
C) 30 liters
D) 40 liters
C) 30 liters
What is the only part of the cecum that is secured to the abdominal wall?
A) The apex
B) The base
C) The body
D) The teniae
B) The base
Where is the base of the cecum located?
A) In the dorsal right iliac and paralumbar fossa regions
B) Near the pelvic flexure
C) Along the left ventral colon
D) In the middle abdominal cavity
A) In the dorsal right iliac and paralumbar fossa regions
What structure divides the cranial and caudal aspects of the cecal base?
A) Cecocolic fold
B) Ileal fold
C) Transverse fold
D) Greater curvature
C) Transverse fold
How many teniae (longitudinal bands) course along the cecum?
A) Two
B) Three
C) Four
D) Five
) Four
Which teniae are connected to the antimesenteric border of the ileum by the ileocecal fold?
A) Dorsal teniae
B) Lateral teniae
C) Ventral teniae
D) Medial teniae
A) Dorsal teniae
The lateral cecal tenia is connected to the
lateral free tenia of the right ventral colon by the cecocolic fold
What artery provides the major blood supply to the cecum?
A) Cranial mesenteric artery
B) Caudal mesenteric artery
C) Celiac artery
D) External iliac artery
A) Cranial mesenteric artery
(A) Right lateral view of a cadaver cecum and large colon of a horse. (B) Medial view of a cadaver cecum of a horse. (C) Base of the cecum and the proximal part of the ascending colon (right ventral colon), opened laterally to show the ileal and cecocolic orifices, fixed in situ. a, Ileum; b, base of cecum; c, body of cecum; d, apex of cecum; e, lateral tenia; f, right ventral colon; g, ileocecal orifice;
h, cecocolic orifice; i, dorsal tenia of the cecum; j, cecolic fold; k, ventral tenia of the cecum; l, pelvic flexure; m, right dorsal colon; n, duodenum; o, medial tenia of the cecum; p, ileocecal fold.
a, Ileum; b, base of cecum; c, body of cecum; d, apex of cecum; e, lateral tenia; f, right ventral colon; g, ileocecal orifice;
h, cecocolic orifice; i, dorsal tenia of the cecum; j, cecolic fold; k, ventral tenia of the cecum; l, pelvic flexure; m, right dorsal colon; n, duodenum; o, medial tenia of the cecum; p, ileocecal fold.
Which cecal artery primarily supplies the cecal apex?
A) Lateral cecal artery
B) Ileocolic artery
C) Medial cecal artery
D) Cecocolic artery
C) Medial cecal artery
What is the function of the cecal rete?
A) Facilitates digestion of proteins
B) Provides alternative blood supply in case of a thromboembolus
C) Promotes microbial digestion
D) Enhances motility of the cecum
B) Provides alternative blood supply in case of a thromboembolus
(A) Right lateral view of a cadaver cecum and large colon of a horse. (B) Medial view of a cadaver cecum of a horse. (C) Base of the cecum and the proximal part of the ascending colon (right ventral colon), opened laterally to show the ileal and cecocolic orifices, fixed in situ. a, Ileum; b, base of cecum; c, body of cecum; d, apex of cecum; e, lateral tenia; f, right ventral colon; g, ileocecal orifice;
h, cecocolic orifice; i, dorsal tenia of the cecum; j, cecolic fold; k, ventral tenia of the cecum; l, pelvic flexure; m, right dorsal colon; n, duodenum; o, medial tenia of the cecum; p, ileocecal fold.
Figure 36-2. Schematic diagram of the cecal arterial rete that form a meshlike network around the cecal veins before continuing into the submucosal network plexus. The extensive rete and submucosal network may provide an alternative route for blood flow in the case of an arterial embolus. 1, Marginal artery; 2, marginal vein; 3, secondary arcade;
4, long artery and vein; 5, tenia; 6, branch supplying the tenia; 7, vascular rete; 8, lymph node and lymph vessels (shown only at one place).
What structure prevents the reflux of cecal contents into the ileum?
A) Cecocolic valve
B) Ileocecal orifice
C) Cecal apex
D) Lesser curvature
B) Ileocecal orifice
Which structure allows ingesta to exit the cecum into the right ventral colon?
A) Cecocolic orifice
B) Ileocecal valve
C) Cecal base
D) Transverse fold
A) Cecocolic orifice
What prevents retrograde movement of ingesta at the cecocolic orifice?
A) Presence of a sphincter
B) Constriction at the ileocecal orifice
C) Cecocolic valve
D) Cecal apex orientation
C) Cecocolic valve
What are the main physiologic functions of the cecum?
A) Absorption of water and microbial digestion of carbohydrates
B) Protein digestion and glucose absorption
C) Enzyme secretion and lipid metabolism
D) Electrolyte storage and bile production
A) Absorption of water and microbial digestion of carbohydrates
Which function is the cecum particularly effective at performing?
A) Lipid absorption
B) Reabsorption of water
C) Protein metabolism
D) Digestion of starches
B) Reabsorption of water
In ponies, how much water is absorbed by the cecum per hour between meals?
A) 100-200 mL/h
B) 300-400 mL/h
C) 600-800 mL/h
D) 900-1000 mL/h
C) 600-800 mL/h, 30 L day
What impact does microbial fermentation in the cecum have on a horse’s body temperature?
A) It decreases body temperature
B) It produces heat, which helps maintain body temperature
C) It neutralizes heat produced in other parts of the body
D) It causes excessive heat loss
B) It produces heat, which helps maintain body temperature
Which volatile fatty acids are primarily produced by microbial digestion in the cecum?
A) Acetic, propionic, butyric
B) Lactic, formic, acetic
C) Stearic, butyric, propionic
D) Citric, malic, acetic
A) Acetic, propionic, butyric
What negative effect could the heat produced by microbial fermentation have on a horse?
A) Increase in gastrointestinal motility
B) Disruption of electrolyte balance
C) Increase in body temperature during exercise in high ambient temperatures
D) Decreased microbial fermentation efficiency
C) Increase in body temperature during exercise in high ambient temperatures
Which type of exchange occurs during volatile fatty acid absorption in the cecum?
A) Ionized volatile fatty acid/bicarbonate exchange
B) Glucose/insulin exchange
C) Sodium/potassium exchange
D) Calcium/magnesium exchange
A) Ionized volatile fatty acid/bicarbonate exchange
Which motility pattern in the cecum is associated with emptying of cecal contents?
A) Pattern I
B) Pattern II
C) Pattern III
D) Pattern IV
D) Pattern IV
How often do muscular contractions that cause cecal emptying occur in a normally fed horse?
A) Every 5-10 minutes
B) Every 2-3 minutes
C) Every 10-15 minutes
D) Once per hour
B) Every 2-3 minutes
What anatomical structure is responsible for elevating the cecal base and opening the cecocolic orifice during cecal emptying?
A) Cecocolic fold
B) Cecal apex
C) Cupula of the cecum
D) Transverse fold
C) Cupula of the cecum
What tool or technique is used to investigate cecal motility patterns?
A) Visual inspection through endoscopy
B) Visual inspection through indwelling cannulae
C) Cinefluoroscopy
D) All of the above
D) All of the above
Where does the electrical pacemaker region for cecal motility appear to be located?
A) Near the ileocecal valve
B) At the cecal base
C) Near the cecal apex
D) In the transverse colon
C) Near the cecal apex
Which method directly monitors myoelectric activity of the cecum?
A) Electrointestinography
B) Ultrasonography
C) Radiolabeled markers
D) Endoscopy
A) Electrointestinography
Which part of the cecum has the major vascular supply from the medial cecal artery?
A) Cecal base
B) Cecal body
C) Cecal apex
D) Cecocolic valve
C) Cecal apex
The ileocolic artery branches off from which major artery?
A) External iliac artery
B) Internal iliac artery
C) Cranial mesenteric artery
D) Caudal mesenteric artery
C) Cranial mesenteric artery
What structure connects the lateral cecal tenia to the right ventral colon?
A) Ileocecal fold
B) Cecocolic fold
C) Medial cecal band
D) Cecal apex
B) Cecocolic fold
What role do bacteria, protozoa, and fungi in the cecum play?
A) Enzyme secretion
B) Protein absorption
C) Microbial digestion of carbohydrates
D) Water reabsorption
C) Microbial digestion of carbohydrates
What happens when the smooth muscle around the ileocecal orifice contracts?
A) It opens the orifice to allow ingesta to pass
B) The submucosal vessels become engorged
C) It relaxes to allow for greater blood flow
D) It inhibits the movement of ingesta
B) The submucosal vessels become engorged
Why does microbial fermentation produce volatile fatty acids in the cecum?
A) To aid in protein digestion
B) To provide energy for the horse
C) To produce heat for body temperature regulation
D) To facilitate water absorption
B) To provide energy for the horse
Which nutrient type is primarily digested by microbes in the cecum?
A) Proteins
B) Simple sugars
C) Insoluble carbohydrates
D) Fats
C) Insoluble carbohydrates
What structural feature is found within the annular fold of the ileocecal orifice?
A) A smooth muscle bundle
B) Submucosal venous plexus
C) Pacemaker region
D) Cecal rete
B) Submucosal venous plexus
Which process does not occur at the cecocolic orifice?
A) Sphincter contraction
B) Ingestion exiting into the right ventral colon
C) Movement of ingesta through the cecocolic valve
D) Retrograde movement of ingesta
D) Retrograde movement of ingesta
What happens to the cranial and caudal portions of the cecal base during emptying?
A) They remain separate
B) They fuse
C) They are elevated
D) They collapse
C) They are elevated
What effect does intravenous xylazine hydrochloride have on cecal motility?
A) Increases progressive motility
B) Decreases both mechanical activity and progressive motility
C) Stimulates contractions
D) Has no effect on motility
B) Decreases both mechanical activity and progressive motility
How long does xylazine hydrochloride decrease cecal motility after administration?
A) 10-15 minutes
B) 15-20 minutes
C) 20-30 minutes
D) 30-40 minutes
C) 20-30 minutes
What is the dose of butorphanol tartrate that decreases progressive cecal motility?
A) 0.02 mg/kg IV
B) 0.04 mg/kg IV
C) 0.06 mg/kg IV
D) 0.08 mg/kg IV
B) 0.04 mg/kg IV
What is buthorphanol?
morphinan-type synthetic agonist kappa–antagonist mu opioid receptors
When administered together, how do xylazine and butorphanol affect cecal motility?
A) They counteract each other
B) They synergistically reduce motility
C) They have no effect
D) They increase motility
B) They synergistically reduce motility
What is the dose of detomidine hydrochloride that decreases cecal power ratios?
A) 0.010 mg/kg IV
B) 0.015 mg/kg IV
C) 0.020 mg/kg IV
D) 0.025 mg/kg IV
B) 0.015 mg/kg IV
Which method is used to calculate decreased cecal power ratios with detomidine administration?
A) Electrocardiography
B) Ultrasonography
C) Multichannel electrointestinography
D) Fluoroscopy
C) Multichannel electrointestinography
How does Buscopan Compositum affect cecal contractions?
A) It has no effect on cecal contractions
B) It increases cecal contractions
C) It induces a reduction in contractions
D) It stimulates rapid contractions
C) It induces a reduction in contractions
After administration of Buscopan Compositum, how long does it take for cecal contractions to be restored?
A) 10 minutes
B) 15 minutes
C) 30 minutes
D) 45 minutes
C) 30 minutes
What is the dose of bethanechol chloride that increases cecal myoelectric activity?
A) 0.020 mg/kg IV
B) 0.025 mg/kg IV
C) 0.030 mg/kg IV
D) 0.035 mg/kg IV
B) 0.025 mg/kg IV
What side effects are associated with bethanechol chloride administration?
A) Mild abdominal pain and hypersalivation
B) Increased heart rate and sweating
C) Reduced appetite and weight loss
D) Fever and tachycardia
A) Mild abdominal pain and hypersalivation
What is the main function of neostigmine methylsulfate in cecal motility?
A) It decreases cecal motility
B) It improves cecal emptying
C) It causes cecal atony
D) It reduces myoelectric activity
B) It improves cecal emptying
Which of the following medications is associated with abdominal pain in humans and equids?
A) Yohimbine
B) Bethanechol chloride
C) Neostigmine methylsulfate
D) Buscopan Compositum
C) Neostigmine methylsulfate
What effect does yohimbine have on the cecum of healthy ponies?
A) Decreases myoelectric activity
B) Increases myoelectric activity
C) Decreases cecal emptying time
D) Significantly increases motility
B) Increases myoelectric activity
Does yohimbine significantly affect cecal emptying time?
A) Yes
B) No
B) No
Which medication is recommended at 1.5-2 mg/kg PO to increase cecal motility?
A) Erythromycin lactobionate
B) Mosapride
C) Yohimbine
D) Neostigmine methylsulfate
B) Mosapride
What is the dose of erythromycin lactobionate that increases cecal activity in healthy horses?
A) 0.5 mg/kg IV
B) 1 mg/kg IV
C) 1.5 mg/kg IV
D) 2 mg/kg IV
B) 1 mg/kg IV
When did erythromycin (0.5 mg/kg IV) show an effect on cecal activity after exploratory celiotomy?
A) 12 hours post-surgery
B) 24 hours post-surgery
C) 8 days post-surgery
D) No effect observed
C) 8 days post-surgery
What important factor should be considered when using prokinetic medications in diseased animals?
A) They may cause diarrhea
B) Effects may vary with gastrointestinal disease
C) They work faster in diseased animals
D) They are ineffective in healthy animals
B) Effects may vary with gastrointestinal disease
Which breed is reported to have a predisposition for cecal impaction?
A) Thoroughbred
B) Arabian
C) Quarter Horse
D) Standardbred
B) Arabian
Cecal impactions are more frequently reported in horses of what age?
A) Younger than 5 years
B) 5-10 years
C) 10-15 years
D) Over 15 years
D) Over 15 years
Which type of cecal impaction involves motility dysfunction preventing cecal outflow?
A) Type I
B) Type II
C) Acute impaction
D) Chronic impaction
B) Type II
Which of the following describes a Type I cecal impaction?
A) Firm dry ingesta
B) Gas-filled cecum
C) Motility dysfunction
D) Cecal ulceration
A) Firm dry ingesta
Cecal tympany is most commonly associated with what underlying condition?
A) Colonic displacement
B) Cecal ulceration
C) Inflammation of the colon
D) Dehydration
A) Colonic displacement
What is the primary treatment for cecal tympany?
A) NSAIDs
B) Antibiotics
C) Cecal trocharization
D) Fluid therapy
C) Cecal trocharization
What risk is associated with cecal trocharization?
A) Cecal perforation
B) Gas trapping
C) Abscess formation
D) Over-stimulation of motility
C) Abscess formation
Which anatomical structure is important to avoid during cecal trocharization?
A) Cecal apex
B) Cecal tenia
C) Cecal vasculature
D) Cecocolic fold
C) Cecal vasculature
What percentage of cecal diseases are represented by cecal impaction?
A) 10-15%
B) 20-30%
C) 40-55%
D) 60-75%
C) 40-55%
Which factor is NOT a known risk for cecal impaction?
A) Poor dentition
B) Use of NSAIDs
C) Feeding dry hay
D) Overhydration
D) Overhydration
What clinical sign may indicate impending cecal rupture?
A) Severe tachycardia
B) Increased gut sounds
C) Sudden relief of abdominal pain
D) Fever and sweating
C) Sudden relief of abdominal pain
What is a hallmark of Type II cecal impaction?
A) Soft ingesta buildup
B) Severe pain on palpation
C) Lack of detectable cecal contractions
D) High fecal output
What is the typical treatment protocol for Type I cecal impaction?
A) Surgery
B) Dietary changes
C) Trocharization
D) Fluid therapy and NSAIDs
D) Fluid therapy and NSAIDs
- What is the primary aim of medical therapy for cecal impaction?
A) Eliminate the impaction surgically
B) Soften the impaction for passage and restore motility
C) Stimulate appetite and gastrointestinal activity
D) Prevent electrolyte imbalances
B) Soften the impaction for passage and restore motility
- Why is feed generally withheld from horses with cecal impaction?
A) To improve electrolyte balance
B) To prevent enlargement of the impaction
C) To increase the effectiveness of oral fluids
D) To facilitate surgery
B) To prevent enlargement of the impaction
- What role does hand walking play in the treatment of cecal impaction?
A) Increases fluid absorption
B) Stimulates gastrointestinal motility
C) Prevents electrolyte imbalances
D) Reduces the need for surgery
B) Stimulates gastrointestinal motility
What is a potential risk associated with administering large volumes of oral fluids?
A) Hypoglycemia
B) Cecal rupture
C) Hypertension
D) Hypercalcemia
B) Cecal rupture
Which electrolyte abnormality is NOT a risk associated with large volumes of oral hypotonic fluids?
A) Hypokalemia
B) Hyponatremia
C) Hypocalcemia
D) Hyperkalemia
D) Hyperkalemia
What is the recommended composition of isotonic oral fluids for cecal impaction?
A) 4.9 g NaCl and 0.37 g “Lite salt”
B) 5.0 g KCl and 1.0 g NaCl
C) 2.0 g NaCl and 0.5 g potassium phosphate
D) 6.0 g NaCl and 0.5 g magnesium sulfate
A) 4.9 g NaCl and 0.37 g “Lite salt”
What is the typical tolerance of adult horses for oral fluid administration?
A) 2-4 L/h
B) 4-6 L/h
C) 6-10 L/h
D) 10-12 L/h
C) 6-10 L/h
What is a common side effect of large volume oral fluid administration?
A) Diarrhea
B) Constipation
C) Fever
D) Hypertension
A) Diarrhea
Which laxative agent has limited evidence of effectiveness in resolving cecal impactions?
A) Psyllium
B) Magnesium sulfate
C) Mineral oil
D) Dioctyl sodium sulfosuccinate (DSS)
C) Mineral oil
How is mineral oil most useful in managing cecal impaction?
A) Reducing inflammation
B) As a marker of transit time
C) Hydrating feces
D) Preventing dehydration
B) As a marker of transit time
What could the appearance of mineral oil in feces indicate in horses with cecal impaction?
A) Resolution of the impaction
B) Increased gastrointestinal motility
C) Passage of oil despite impaction
D) Dehydration
C) Passage of oil despite impaction
Which of the following is NOT a potential surgical intervention for cecal impaction?
A) Typhlotomy
B) Ileocecal bypass
C) Gastrectomy
D) Cecocolic anastomosis
C) Gastrectomy
Which factor could influence a surgeon’s decision on cecal bypass?
A) Patient age
B) Likelihood of functional recovery
C) Amount of mineral oil administered
D) Availability of oral fluids
B) Likelihood of functional recovery
What is the difference between Type I and Type II cecal impactions regarding surgery?
A) Type II is more likely to require cecal bypass
B) Type I requires immediate bypass
C) Type II is more responsive to mineral oil
D) Type I requires no surgical intervention
A) Type II is more likely to require cecal bypass
Cecal impaction can be caused by accumulation of dry ingesta (type ___) or abnormal caecal motility resulting in a feed impaction of fluid consistency (type____)
Type I or type II