Emesis Physio

Question 1

Peripheral receptors

Central receptors

Answer 1

P- intestinal (chemo/osmo/mechano), vistublar and visual matching, olfactory/taste, gag

C- psychogenic, AP, pregnancy

Question 2

Efferents result in

Chronic vomiting causes loss of

Answer 2

SM in sphincters relaxing

Skeletal muscle for respiraton generates force

H+ and K+ (met alk, dehydr, hypokalemia)

Question 3

Area postrema location

function

affected by

Answer 3

caudal end of 4th ventricle

Poor BBB- inc permeability

nicotine, dopamine

Question 4

Emesis

Peripheral affernts

chemoreceptors sens

Answer 4

Mechanoreceptors sense gastric/intestinal overdistenion

duodenal irritation, molecules

Question 5

Central afferents (CTZ)

location

stimulated by

antiemetics effect

Answer 5

AP

DA, nicotine

suppress CTZ and NTS

Question 6

Vesitubular visual mismatch leads to

Vomiting center

Efferents involve

Answer 6

motion sickness

NTS

somatic NS, ANS
insp/exp muslce
costal diaphragm contraction, crus relaxation
sphincter relaxation by ANS

Question 7

Retching process

Duodenal spasm result in

Vomiting

Projectile vomiting

Answer 7

LES relaxes and inc intraab pressure causes reflux but UES stays closed

duodenal contents entering stomach

UES opens w high pressure

usually brainstem trauma/NTS stimulation

Question 8

Neurokinin

Serotonin

Ach

Dopamine

Histamine

Vasopressin

Receptors

Antagonists result in

Cannabinoids

Answer 8

NK1

5HT3

M1

D2

H1

dehydration/exercise

anti-emesis

CB1 in cortex (antiemetic)