Ch. 56 Intro to GI System

Question 1

Swallowing

Answer 1

stimulated when a food bolus stimulates pressure receptors in the back of the throat and pharynx

Question 2

what happens when the receptors send impulses to the medulla during swallowing

Answer 2

• soft palate elevates
• seals off nasal cavity
• respiration cease ( protect the lungs)
• larynx rises and glottis closes
• pharyngeal constrictor muscles contract = force food bolus into the top of esophagus

Question 3

Vomiting

Answer 3

stimulated when protecting the body from unwanted stimulants

two centers:

• primitive = emetic zone
• mature = CTZ

Question 4

CTZ is stimulated by…

Answer 4

• tactile stimulation of the back of the throat
• excessive stomach distention
• increasing intracranial pressure by direct stimulation
• stimulation of the vestibular receptors (motion sickness)
• stimulation of stretch receptors in the uterus and bladder ( seen in pregnant ppl and before delivery)
• intense pain fiber stimulation
• direct stimulation by various chemicals ( fumes, certain drugs, debris from cellular death chemotherapy)

Question 5

Food travels down the ______ and ends at the ____.

Answer 5

mouth
esophagus
stomach
small intestine
large intestine 
rectum