Gastroenterology

Question 1

Measurement taken with radiographs to assess for constipation

Answer 1

Maximal colon diameter to length of L5 vertebral body ratio is 1.74 (> 1.48 indicates megacolon)

Question 2

Vomiting is coordinated by

Answer 2

The emetic center in the medulla oblongata of the brain stem, which receives efferent from CNS and periphery, especially the GI tract and vestibular apparatus (but can include urinary & repro tracts)

Question 3

The chemoreceptor trigger zone is located in __, and contains ___ receptors that respond to substances circulating in the blood

Answer 3

Medulla oblongata; Dopamine 2 (D2), neurokinin-1 (NK-1), 5-hydroxytryptamine, acetylcholine, and histamine

Question 4

Cats (unlike dogs) have a significant number of __ in the CRTZ, making __ more likely to cause emesis

Answer 4

Alpha-2-adrenergic receptors; alpha-2-adrenergic agonists

Question 5

Peripheral input from the GI tract acts via ___ receptors and transmits signals into the emetic center through ___ and other efferents

Answer 5

NK-1 and serotonin; vagal

Question 6

The vestibular system can induce vomiting through ___ receptors

Answer 6

Histamine and acetylcholine