GI 3

Question 1

hormone families

Answer 1

gastrin family
secretin family
“other”

Question 2

gastrin family

Answer 2

gastrin, cholecystokinin

Question 3

secretin family

Answer 3

secretin, vasoactive intestinal peptide, gastric inhibitory peptide, glucagon like peptide

Question 4

other hormone

Answer 4

motilin

Question 5

what are the 3 phases that describe integrated function of digestive system

Answer 5

1. cephalic/oral phase
2. gastric phase
3. intestinal phase

Question 6

cephalic/oral phase

Answer 6

digestive processes occurring before food enters the stomach
- long reflexes beginning in brain

Question 7

gastric phase

Answer 7

digestive processes in the stomach

Question 8

intestinal phase

Answer 8

digestive processes in the intestines (split in small and large)

Question 9

what causes long reflexes beginning in brain known as cephalic phase

Answer 9

sight, thought, smell of food will start long reflexes that start motility and secretions in stomach and mouth

Question 10

what is cephalic phase driven by

Answer 10

increased parasympathetic output from medulla to salivary glands and to ENS (via vagus nerve)

Question 11

where does chemical and mechanical digestion begin

Answer 11

mouth

Question 12

what does mechanical digestion begin with

Answer 12

mastification (chewing) of food by teeth
tongue and lips also manipulate food and saliva joins

Question 13

what type of secretion is saliva

Answer 13

exocrine from epithelial cells

Question 14

how much saliva is secreted per day

Answer 14

1.5 L/day: 99.5% water, 0.5% solutes

Question 15

what is saliva made up of

Answer 15

Na, Cl, K, HCO3, P04
amylase, lysozyme, mucus, immunoglobulin A

Question 16

where are secretory cells found

Answer 16

clusters known as acini

Question 17

what cells exist in the glands

Answer 17

mucous and serous cells

Question 18

what does parotid glands secrete

Answer 18

watery solution with amylase (serous cells)

Question 19

what do submandilbular glands secrete

Answer 19

similar to parotid plus some mucus (serous with some mucous)

Question 20

what do sublingual glands secrete

Answer 20

mainly mucus (mucous)

Question 21

what are glands controlled by

Answer 21

parasympathetic control

Question 22

what is deglutition (swallowing)

Answer 22

reflex that pushes a bolus of food or liquid into esophagus

Question 23

how is deglutition activated

Answer 23

pressure agaisnt soft palate and back of mouth (voluntary) activate sensory neurons going to medulla

Question 24

what is the swallowing center

Answer 24

medulla

Question 25

what does the medulla output after deglutition activated

Answer 25

somatic motor outputs to pharynx and upper esophagus and autonomic outputs to lower esophagus

Question 26

what does soft palate do when bolus of food is moving through

Answer 26

closes off nasopharynx

Question 27

what happens in pharynx as bolus moves down

Answer 27

peristaltic contractions

Question 28

what does contraction do to larynx

Answer 28

moves up and forward

Question 29

what does epiglottis do

Answer 29

closes trachea (covers airway) and upper esophageal sphincter relaxes and opens

Question 30

last step of swallowing

Answer 30

lower esophageal sphincter tension relaxes

Question 31

what causes gastroesophageal reflex disease (heartburn)

Answer 31

• churning action of stomach contraction can cause backflow
• negative intrapleural pressure during inspiration can esophagus to expand drawing gastric acid and pepsin

Question 32

why does heartburn happen

Answer 32

lower esophageal sphincter is not true sphincter
- not thickened, high continuous contraction