Digestive System

Question 1

is characterized by a stratified squamous epithelium and is found in the oral cavity, pharynx, esophagus, and anal canal.

Answer 1

Protective mucosa

Question 2

contains cells that are responsible for the secretion of digestive enzymes and acid and is found exclusively in the stomach.

Answer 2

Secretory mucosa

Question 3

is responsible primarily for absorbing digested nutrients and is found along the entirety of the small intestine.

Answer 3

Absorptive mucosa

Question 4

is responsible primarily for absorbing digested nutrients and is found along the entirety of the small intestine.

Answer 4

Absorptive mucosa

Question 5

primarily involved in water absorption and electrolyte balance is found in the large intestine

Answer 5

Absorptive mucosa

Question 6

stimulate acid production through physical and chemical mechanisms

Answer 6

gastric phase

Question 7

, digested protein and amino acids trigger G cells in the duodenum to release gastrin.

Answer 7

intestinal phase

Question 8

_________are found in the base of the gastric glands and produce pepsinogen, which is stored in large apical secretory granules.

Answer 8

Chief cells

Question 9

Both ________________ stimulate chief cells to release pepsinogen by activating pathways that increase cytosolic calcium.

Answer 9

acetylcholine and gastrin

Question 10

The _______ is a circumferential ring about 3 centimeters deep distal to the gastro-esophageal junction.

Answer 10

cardia

Question 11

is the main part of the stomach and is bounded by the greater and lesser curvatures. Its glands are straight with limited branching and are lined by a smaller population of mucus-secreting cells than those of the cardia. The neck and isthmus contain large numbers of parietal cells whereas the base contains chief cells and enterochromaffin-like (ECL) cells that release hormones. The muscularis mucosa and submucosa are also visible.

Answer 11

body

Question 12

is the distal third of the stomach. It possesses glands with deeper pits and large amounts of coiling and branching. These glands contain many mucus-secreting cells, D-cells, and G-cells but lack parietal cells. The antrum is connected to the initial segment of small intestine by short section of stomach called the pylorus.

Answer 12

antrum

Question 13

The duodenum contains the same wall layers seen in the previous portions of the GI tract:

mucosa, submucosa, and muscularis externa.

Question 14

The duodenum contains the same wall layers seen in the previous portions of the GI tract:

Answer 14

mucosa, submucosa, and muscularis externa.

Question 15

The __________ is a region of tremendous nutrient absorption and to support this absorption creates the largest surface area of the three segments of the small intestine.

Answer 15

jejunum

Question 16

The _________ has the shortest villi and is characterized by abundant Peyer’s patches in the submucosa. Peyer’s patches are diffuse lymphoid tissue that play an important immunological role in sampling the contents of the GI tract.

Answer 16

ileum

Question 17

The small intestine ends with the ________

Answer 17

ileo-cecal junction

Question 18

______________ processes the indigestible material that comes from the small intestine. It absorbs sodium, chloride and water to concentrate waste material that is formed into feces. The large intestine can either absorb or secrete potassium and absorbs vitamins.

Answer 18

The large intestine or colon

Question 19

The lamina propria has many

Answer 19

macrophages, plasma cells, eosinophils, and lymphoid nodules

Question 20

features an important change in epithelial structure. The rectum is characterized by the same columnar epithelium that lines the majority of the gastrointestinal tract’s secretory and absorptive areas. The anus, on the other hand, has a stratified squamous epithelium that provides a greater deal of protection to the underlying tissue.

Answer 20

Recto-Anal Junction

The recto-anal junction

Question 21

. The inactive enzymes are called .

Answer 21

zymogens

Question 22

synthesize and secrete digestive enzymes and duct cells that mainly secrete fluid rich in bicarbonate.

Answer 22

Acinar cells

Question 23

are enzymes that are synthesized in an inactive form and are converted to active form through proteolytic removal of a domain within the protein that keeps the enzyme inactive.

Answer 23

Zymogens

Question 24

store the digestive enzymes in cytosolic granules called zymogen granules and release digestive enzymes at a very slow rate when not eating.

Answer 24

Acinar cells

Question 25

Three molecules increase the rate of release during eating:

Answer 25

acetylcholine, gastrin and cholecystokinin (CCK)

Question 26

Structurally, the pancreas consists of two functionally distinct parts:

Answer 26

an exocrine part that produces digestive enzymes and an endocrine part consisting of the islets of Langerhans that secrete insulin and glucagon to regulate carbohydrate metabolism. The islets of Langerhans stain more lightly by H&E than the exocrine portion.

Question 27

secrete saliva, a lubricant composed of mucus, lysozyme, antibodies, inorganic ions, and amylase. Saliva is released in response to parasympathetic stimulation, and up to 1500 milliliters can be produced each day.

Answer 27

Salivary glands

Question 28

The ___________ produces saliva that is watery and rich in enzymes (amylase and lysozyme) and antibodies. Two types of cells are visible in this section.

Answer 28

parotid gland

Question 29

The ___________ is composed primarily of mucus cells.

Answer 29

sublingual gland

Question 30

Structural Organization of the Liver

Hepatocytes are arranged in lobules which in cross section appear hexagonal. At the points of the lobule are a structure called the portal triad which contains the

Answer 30

hepatic artery (freshly oxygenated blood), portal vein (blood from small intestine) and the bile duct.

Question 31

are composed of three major tubes. Branches of the hepatic artery carry oxygenated blood to the hepatocytes, while branches of the portal vein carry blood with nutrients from the small intestine.

Answer 31

Portal triads

Question 32

are the resident macrophages of the liver and are typically found within the lumen of the sinusoids.

Answer 32

Kupffer cells