digestive exam questions

What two things essential for life does the digestive system provide?

• fuel that keeps our cells running

• building blocks needed for cell growth and repair

List the components of the digestive system.

• consists of the digestive tract

• oral cavity, pharynx, esophagus, stomach, small intestine, large intestine

• accessory organs

• teeth, tongue, salivary glands, liver, pancreas, gall bladder

Describe six functions of the digestive system.

• mechanical processing: tearing, crushing, mixing food

• digestion: chemically breaking the food down into smaller organics that can be absorbed

• secretion: the digestive epithelium and the accessory glands secrete water, acids, enzymes, buffers and salts into the GI tract

• absorption: nutrients and water are absorbed across the digestive epithelium and into the interstitial fluid where blood vessels or lacteals pick them up and distribute them

• excretion: the GI tract and accessory organs discharge waste into the tract which is eventually ejected from the body as the feces

• protection: the lining of the GI tract protects the surrounding tissues

How does mechanical processing aid enzymatic digestion?

• makes it easier to propel food along GI tract

• exposes more surface area which aids enzymatic digestion

List three things that the GI tract protects us against.

• the corrosive effects of the digestive enzymes and acids

• mechanical stresses or abrasion

• bacteria that either are ingested with the food or live in that GI tract

What is the difference between the peritoneum and the abdominopelvic cavity?

• peritoneum: the largest portion of the abdominopelvic cavity

• some structures are retroperitoneal and some are inferior to it

Describe the difference between the visceral and parietal peritoneum. What is the fluid called that occurs between these membranes?

• visceral peritoneum (serosa): most digestive organs are covered

• parietal peritoneum lines the inner surfaces of the body wall

• the two layers slide past each other via a lubricating fluid called peritoneal fluid

What is a mesentary?

double sheet of peritoneal membrane that suspends portions of the GI tract and stabilizes

What do we call the mesentary that stabilizes most of the small intestine?

mesentary proper

What is the name of the large fold of the dorsal mesentary that hangs anterior to the intestines, accumulates fat, and to some extent protects the abdominal organs?

greater omentum

List the four basic layers of the wall of the GI tract in order starting with the innermost.

• mucosa

• submucosa

• muscularis externa

• serosa

Describe the two sublayers that make up the mucosa.

• epithelium

• lamina propria

What is the purpose of having stem cells in the epithelium of the mucosa?

What specific type of tissue makes up much of the lamina propria? What structures are found in the lamina propria?

Where specifically is the muscularis mucosae found? What is its function?

What specific type of tissue makes up the submucosa? What structures may be found in the submucosa?

Describe the type and arrangement of muscle in the muscularis externa.

Contrast the effects of the parasympathetic and the sympathetic nervous systems on the muscular action of the muscularis externa.

What is the function of the myenteric plexus? Where specifically is it found?

What specific type of tissue makes up most of the serosa?

What is meant by “pacesetter” cells of the GI tract?

What is peristalsis? Explain how it works in general.

Explain how segmentation differs from peristalsis.

What are the three major mechanisms that regulate the activity of the digestive tract?

In general what are the hormone secreting cells of the mucosa called? Does the digestive system secrete just a few or many hormones?

What are two local messengers that regulate the activity of a small area of the GI tract?

What cells secrete histamine? In what type of tissue are they found?

What are the basic functions of the oral cavity?

Besides compressing and manipulating food, what two substances does the tongue secrete? What is the function of each?

List the three pairs of salivary glands? Where does each occur?

List five functions of saliva.

What is the mumps?

What are the three regions of a tooth?

What holds the teeth in their bony sockets?

What material makes up the bulk of a tooth? How does this material differ from bone?

What material covers the dentin of the crown? What material covers the dentin of the roots?

Which part of a tooth cannot regenerate?

What is found in the pulp cavity of a tooth?

Explain the difference between plaque and tartar.

What is the common name for deciduous teeth? How many are there? Over what ages are they typically lost?

Why do adults have more teeth than young children? How come some adults have 32 teeth, but others only have 28 teeth?

What are the gingivae?

What bones make up the hard palate? How does the hard palate help in the mechanical processing of food?

Where is the soft palate found? What does it help prevent during the act of swallowing?

Where is the uvula found?

What specific type of tissue lines the oropharynx? Why?

What is the tube called that conducts the food bolus from the oral cavity to the stomach?

What usually prevents air from entering the esophagus?

What is the function of the gastroesophageal sphincter?

What specific type of tissue makes up the mucosa of the esophagus?

List the four basic functions of the stomach.

What is the function of intrinsic factor?

Except for alcohol and some other drugs (e.g., aspirin), what does not occur in the stomach?

List the four regions of the stomach.

What is the function of the numerous mucous glands found in the cardia?

What is chyme?

What structure regulates the passage of chyme into the duodenum?

What are rugae and would they be visible in an empty or a full stomach?

What specific type of epithelium lines the stomach?

Gastric glands contain what two especially important secretory cells?

Besides HCl, what else do parietal cells secrete?

Describe how parietal cells actually produce hydrochloric acid (be sure to include carbonic anhydrase, active transport, and bicarbonate in your answer).

What is meant by the “alkaline tide”?

What is usually the approximate pH of an active stomach?

List several functions of the acidity of the stomach.

What is the function of chief cells?

Why is it advantageous for cells lining the GI tract to secrete proenzymes rather than active enzymes?

Where are pyloric glands found? What do they secrete?

What are some functions of the hormone gastrin?

Where along the GI tract does by far most absorption of nutrients occur?

List the three segments of the small intestine.

What is the main function of the duodenum?

What structure controls the passage of material into the cecum?

Where are Peyer patches found and what are they?

Explain three structural features of the small intestine that lead to an enormous surface area.

What does each intestinal villus contain?

What is secreted in the duodenum that neutralizes the acidity of chyme? How does the pH at the start of the duodenum compare to the pH at the end of the ileum?

List three hormones that are secreted by the small intestine.

What is the functional significance of enteropeptidase? Where is it secreted from?

List the three organs that are functionally linked to the small intestine.

What are the cuboidal cells called that produce pancreatic enzymes?

What are the two major functions of the pancreas?

What are the two hormones secreted by the pancreas that regulate blood glucose?

Describe the composition of pancreatic juice.

Describe the effects that secretin and cholecystokinin have on the pancreas.

What does it mean to say that the small intestine and the pancreas “anticipate” the arrival of chyme into the duodenum?

Explain the basic difference between a lipase, protease, amylase, peptidase, and nuclease.

What is the largest internal organ?

What two blood vessels deliver blood to the liver?

What is the functional unit of the liver?

How many lobes of the liver are there? Most of the bulk of the liver is located on what side of the body?

What are mature liver cells called?

What type of capillaries are found in the liver lobules? How is the function of this type of capillary different from that of a typical capillary in the body?

Where are hepatic triads found? What do they consist of?

List the ducts/structures through which bile flows starting with the liver lobules.

In what way is the liver similar to the kidneys?

Give several examples of how the liver functions in nutrient regulation.

What toxin is produced during amino acid metabolism and how is it neutralized?

Why might it not be a good idea to regularly consume animal livers?

What is the function of Kupffer cells?