NPB 101: Final Exam Questions and
Answers Graded A+
What are the layers of the digestive system from most inside to most outside and
what do they do? - Correct answer-Lumen: continuous with the external
environment
Mucosa
Submucosa (enteric nervous system)
Muscularis (smooth muscle)
Serosa
What are the four digestive processes? - Correct answer-1) Motility: muscle
contraction (movement and mixing)
2) Secretion: digestive juices secreted
3) Digestion: breakdown into units
4) Absorption: transfer into blood
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,What are the two types of motility? - Correct answer-1) Propulsive: moves the
content forward
2) Mixing: acid digestion (exposes food to absorbing surfaces)
What do the lips, tongue, palate, and uvula do? - Correct answer-The lips and
tongue contain and guide food.
The palate or roof of your mouth allows for chewing and breathing at the same
time
The uvula seals off the nasal passage during swallowing
What is the cephalic phase response in the mouth? - Correct answer-We salivate
from thinking about food in order to prep the food intake and speed up the
digestive effects. This speed/prepping is crucial for metabolism and homeostasis
What do the three salivary glands in the mouth do and secrete? - Correct answer-
They secrete saliva due to autonomic stimulation. The saliva contains mucus,
lysosomes, bicarbonate buffer, and amylase. Mucus moistens the food, lysosomes
break bacteria, bicarbonate buffer neutralizes acids, and amylase begins digestion
of carbohydrates into sugar.
Saliva also helps facilitate speech
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
,The two parts of the esophagus? - Correct answer-It consists of an upper sphincter
and lower sphincter. The upper sphincter is normally closed to prevent air from
entering the esophagus and the lower one is normally closed to prevent acid reflux
What does the pharynx share? - Correct answer-It is the rear of the mouth and
shares both food and air
How does swallowing work? - Correct answer-It is an all-or-nothing reflex that
starts when food is pushed into the pharynx. Pressure receptors there activate the
swallowing center and the correct muscles are activated
What are the two stages of swallowing? - Correct answer-1) Oropharyngeal stage:
the bolus moves through the pharynx into the esophagus
2) Esophageal stage: esophagus into the stomach through peristaltic waves (push
from the top)
What are the three parts of the stomach? - Correct answer-1) Fundus: the part
above the lower sphincter (gastroesophageal sphincter)
2) Body: middle of the stomach
3) Antrum: bottom section, it is thick and has a lot of contractions
What does the stomach do? - Correct answer-It delivers food into the small
intestine at an appropriate rate. It also secretes HCl to begin protein digestion.
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
, What is chyme? - Correct answer-Ingested food plus gastric secretions. It is a thick
liquid mixture.
Also, the stomach can expand btw and hold 1000mL of chyme
What are the two different types of gastric mucosa? - Correct answer-Oxyntic
mucosa: lines the body and fundus
Pyloric gland area: lines antrum
Oxyntic mucosa cells and purpose - Correct answer-Its goal is to protect us from
injury, self digestion from pepsin, and acid injury.
The main cells present are chief cells, and parietal cells. Chief cells secrete
pepsinogen and parietal cells release HCl and intrinsic factor. There are also cells
that create mucus
How does HCl activate pepsinogen? - Correct answer-Pepsinogen is secreted
inactively. HCl cleaves off a piece of it to form pepsin which works well in acid
and digests proteins.
How do parietal cells release HCl and what does HCl do? - Correct answer-Parietal
cells secrete H+ and Cl- separately through active pumps bc its less dangerous.
HCl activates pepsinogen, breaks connective tissue, and kills microorganisms
©COPYRIGHT 2025, ALL RIGHTS RESERVED 4
Answers Graded A+
What are the layers of the digestive system from most inside to most outside and
what do they do? - Correct answer-Lumen: continuous with the external
environment
Mucosa
Submucosa (enteric nervous system)
Muscularis (smooth muscle)
Serosa
What are the four digestive processes? - Correct answer-1) Motility: muscle
contraction (movement and mixing)
2) Secretion: digestive juices secreted
3) Digestion: breakdown into units
4) Absorption: transfer into blood
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
,What are the two types of motility? - Correct answer-1) Propulsive: moves the
content forward
2) Mixing: acid digestion (exposes food to absorbing surfaces)
What do the lips, tongue, palate, and uvula do? - Correct answer-The lips and
tongue contain and guide food.
The palate or roof of your mouth allows for chewing and breathing at the same
time
The uvula seals off the nasal passage during swallowing
What is the cephalic phase response in the mouth? - Correct answer-We salivate
from thinking about food in order to prep the food intake and speed up the
digestive effects. This speed/prepping is crucial for metabolism and homeostasis
What do the three salivary glands in the mouth do and secrete? - Correct answer-
They secrete saliva due to autonomic stimulation. The saliva contains mucus,
lysosomes, bicarbonate buffer, and amylase. Mucus moistens the food, lysosomes
break bacteria, bicarbonate buffer neutralizes acids, and amylase begins digestion
of carbohydrates into sugar.
Saliva also helps facilitate speech
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
,The two parts of the esophagus? - Correct answer-It consists of an upper sphincter
and lower sphincter. The upper sphincter is normally closed to prevent air from
entering the esophagus and the lower one is normally closed to prevent acid reflux
What does the pharynx share? - Correct answer-It is the rear of the mouth and
shares both food and air
How does swallowing work? - Correct answer-It is an all-or-nothing reflex that
starts when food is pushed into the pharynx. Pressure receptors there activate the
swallowing center and the correct muscles are activated
What are the two stages of swallowing? - Correct answer-1) Oropharyngeal stage:
the bolus moves through the pharynx into the esophagus
2) Esophageal stage: esophagus into the stomach through peristaltic waves (push
from the top)
What are the three parts of the stomach? - Correct answer-1) Fundus: the part
above the lower sphincter (gastroesophageal sphincter)
2) Body: middle of the stomach
3) Antrum: bottom section, it is thick and has a lot of contractions
What does the stomach do? - Correct answer-It delivers food into the small
intestine at an appropriate rate. It also secretes HCl to begin protein digestion.
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
, What is chyme? - Correct answer-Ingested food plus gastric secretions. It is a thick
liquid mixture.
Also, the stomach can expand btw and hold 1000mL of chyme
What are the two different types of gastric mucosa? - Correct answer-Oxyntic
mucosa: lines the body and fundus
Pyloric gland area: lines antrum
Oxyntic mucosa cells and purpose - Correct answer-Its goal is to protect us from
injury, self digestion from pepsin, and acid injury.
The main cells present are chief cells, and parietal cells. Chief cells secrete
pepsinogen and parietal cells release HCl and intrinsic factor. There are also cells
that create mucus
How does HCl activate pepsinogen? - Correct answer-Pepsinogen is secreted
inactively. HCl cleaves off a piece of it to form pepsin which works well in acid
and digests proteins.
How do parietal cells release HCl and what does HCl do? - Correct answer-Parietal
cells secrete H+ and Cl- separately through active pumps bc its less dangerous.
HCl activates pepsinogen, breaks connective tissue, and kills microorganisms
©COPYRIGHT 2025, ALL RIGHTS RESERVED 4
