Chapter 30 - Esophagus Flashcards
The esophagus of the horse:
● varies between 125 - 200 cm
● varies between 150-225 cm
● consists of dorsal, cervical and abdominal part
● consists of dorsa, thoracic and abdominal part
varies between 125 - 200 cm
As the esophagus courses caudad:
deviates from a position dorsal to the trachea in the cranial third of the neck to the left side of the medial plane in the middle third of the neck
In a small percentage of horses esophagus courses to the right side of the median plane. True?
Yes, esophagus courses to the right side of the median plane
How many layers has the esophagus. Name them.
4 layers, from the outside to the lumen
fibrous layer (tunica adventitia)
muscular layer (tunica muscularis)
submucosal layer (tela submucosa)
mucous membrane ( tunica mucosa)
On surgical incision, the esophageal wall
separates easily into two distinct layers. Name them
The elastic inner layer,
composed of mucosa and submucosa, is freely movable within
the relatively inelastic outer muscular layer and adventitia
The muscular layers of the esophagus are striated from the _______to the base of the heart where they gradually blend into ____________muscle
The muscular layer of the esopahgus are striated from the pharynx to the base of the heart, where they gradually blend into smooth muscle
As the esophagus courses caudad:
● its mucosal layers increase in thickness, whereas the lumen diminishes
● its muscular layers increase in thickness, whereas the lumen increases
● its muscular layers increase in thickness, whereas the lumen diminishes
● its muscular layers increase in thickness, whereas the lumen increases
● its muscular layers increase in thickness, whereas the lumen diminishes
Considering the muscle fiber orientation in the esophagus: At mid-cervical esophagus the bands of muscle form intercrossing__________, in the caudal portion the outer muscle fibers become more ___________oriented, while the inner muscle layer is thicker and more circular
At mid-cervical esophagus the bands of muscle form intercrossing spirals, in the caudal portion the outer muscle fibers become more longitudinally oriented, while the inner muscle layer is thicker and more circular
What is the primary source of arterial supply to the cervical part of the esophagus?
A) Bronchoesophageal arteries
B) Gastric arteries
C) Carotid arteries
D) Mesenteric arteries
C) Carotid arteries
Which arteries supply the thoracic and abdominal esophagus?
B) Bronchoesophageal and gastric arteries
What is the nature of the vascular pattern of the esophagus?
A) Linear and continuous
B) Radial and segmented
C) Arcuate and segmental
D) Circular and unbroken
C) Arcuate and segmental
Why is careful preservation of vessels necessary during esophageal surgery?
C) Because the esophagus lacks generous collateral circulation
Which cranial nerves are involved in the innervation of the esophagus?
A) Eighth and ninth cranial nerves
B) Ninth and tenth cranial nerves
C) Tenth and eleventh cranial nerves
D) Eighth and tenth cranial nerves
B) Ninth and tenth cranial nerves
Besides the cranial nerves, which other structure contributes to the innervation of the esophagus?
A) Parasympathetic ganglia
B) Spinal cord
C) Sympathetic trunk
D) Autonomic plexus
C) Sympathetic trunk
Where are the mesenteric ganglion cells, which contribute to the innervation of the esophagus, located?
A) In the mucosa
B) In the submucosa
C) In the muscularis
D) In the serosa
C) In the muscularis
What symptom often follows attempts at ingestion in a horse with choke?
A) Anorexia
B) Odynophagia (painful swallowing)
C) Weight gain
D) Decreased thirst
B) Odynophagia (painful swallowing)
How soon after swallowing do signs of choke appear with a distal esophagus obstruction?
A) Immediately
B) 1-2 seconds
C) 10-12 seconds
D) 20-25 seconds
C) 10-12 seconds
What is the propagation speed of the equine esophagus in the proximal two-thirds?
A) 2.3 cm/second
B) 4.6 cm/second
C) 7.1 cm/second
D) 9.4 cm/second
D) 9.4 cm/second
Which condition often accompanies long-duration choke cases?
A) Hypertension
B) Hyperactivity
C) Electrolyte imbalances
D) Weight gain
C) Electrolyte imbalances
What complication frequently follows esophageal obstruction in horses?
B) Aspiration pneumonia
What is recommended during the physical examination of a horse with signs of choke to rule out rabies?
A) Immediate sedation
B) Wearing gloves
C) Administering antibiotics
D) Isolating the animal
B) Wearing gloves
What may be indicated by crepitation of a diffuse, firm enlargement in the cervical esophagus?
Loss of integrity of the esophageal wall
What diagnostic procedure can confirm luminal obstruction in a horse with choke?
Passage of a nasogastric tube
What medication is used to sedate a horse with choke during treatment to prevent further aspiration?
Sedation of the animal with xylazine (1.1 mg/kg IV) lowers the horse’s head and prevents further aspiration