HSS 206 directed reading digestion
1. Compare and contrast the alimentary canal vs. accessory organs. Note the organs and their
Function.
The alimentary canal is in control of food getting digested, it processes the food, extracts
nutrients, then removes the leftovers. It consists of the mouth, the pharynx, the esophagus, the
stomach, the small intestine and the large intestine. The accessory organs are in charge of the
endocrine process related to digestion, detoxifying the blood, and creating bile. The organs
included are the liver, pancreas, gallbladder.
2. What are the four layers of the alimentary canal? What is the function of each layer?
The four layers of the alimentary canal are the Mucosa, Submocas, Muscularis, and
Serosa. The serosa secretes a serous fluid that keeps the outside of digestive organs to keep
them slippery so they slide around each other. The Muscularis are key in moving food down the
digestive tract. The Submucosa joins the mucus and muscularis layers, to each other, as well as
hold lumpy nodules to fight infection in the digestive tract. The Mucosa secretes digestive
enzymes and goblet cells for digestion.
3. Name and describe the different papillae found on the tongue.
The different papillae on the tongue are filiform, fungiform, foliate, and circumvallate.
They differentiate the flavors of sweet, salty, sour, bitter and umami flavors.
4. Compare and contrast primary vs. permanent teeth. Consider the number, shape, age in
which they appear.
Primary teeth come in from years 0-2m where permanent teeth replace them after. There
are 20 primary teeth and 32 permanent teeth. Baby teeth are more square and less diverse than
adult teeth.
5. Compare and contrast gum disease vs. tooth decay.
Gum disease is an infection of the gums which leads to bone loss, and loose teeth.
Tooth decay is the corrosion of teeth due to plaque and bacteria, this leads to a toothache and
continues to destroy the tooth.
6. Name the types of cells of the stomach and describe what they secrete, state the function of
the specific secretions as well.
The stomach contains chief cells, parietal cells, enteroendocrine cells, and mucous cells.
They create gastric juice. Chief cells secretes pepsinogen which becomes a protein digesting
enzyme pepsin. Parietal cells secrete hydrochloric acid, which kills most bacteria in food, and
