Digestive System

Mass movements of the colon occur __________ times per day.

1 to 3

Which of the following occurs during the gastric phase of gastric secretion?

All of these take place in the gastric phase.

Which of the following is a function of the bacterial flora? Check all that apply.

Bacteria digest cellulose. Bacteria synthesize vitamin K.

How does sucrose change the configuration of sucrase?

By binding to the active site

Which of the following statements is true regarding the absorption of nutrients? Check all that apply

Carbohydrates are absorbed as monosaccharides. Micelles are required for lipid absorption.

Enzyme that breaks down DNA

Deoxyribonuclease

Which of the following inhibits the secretion of the gastric glands?

Duodenal pH of less than two

What are the segments of the small intestine in the order through which food passes?

Duodenum, jejunum, ileum

In which direction do the peristaltic contractions of the stomach's smooth muscle move contents?

From the body to the pyloric region

Acidic compound that activates pepsinogen

HCl

How often can a sucrase molecule be used to hydrolyze sucrose?

Many times

Which of the following is a feature that the stomach and the small intestine have in common?

Mucus-secreting cells

Mass movements in the colon are stimulated by the presence of __________ in the __________

Only the first and second choices are correct.

Which of the following statements is/are true regarding the regulation of digestive secretions? Check all that apply.

Pancreatic enzymes are under both neural and hormonal control. Via the vagus nerve, acetylcholine stimulates the pancreatic acini.

Which of the following does not stimulate the secretion of HCl in the stomach?

Secretin

Which of the following is a method of motility in the small intestine? Check all that apply.

Segmentation Peristalsis Migrating motor complex

Which of the following statements is true regarding sucrase?

Sucrase breaks sucrose into glucose and fructose

Which of the following statements is true regarding the anatomy of the colon and/or small intestine? Check all that apply

The colon and the small intestine both have intestinal crypts. The small intestine and the colon both utilize peristalsis to propel contents. The small intestine and the colon both have circular and longitudinal muscles in the muscularis.

Which of the following statements is true regarding the neural control of defecation? Check all that apply.

The intrinsic defecation reflex results in feces moving from the sigmoid colon to the rectum. The external anal sphincter is under voluntary control. The parasympathetic defecation reflex helps relax the internal anal sphincter.

Which of the following statements is/are true regarding mechanical and/or chemical digestion? Check all that apply.

The muscular contractions of the stomach's muscularis layers contribute to mechanical digestion. The action of pepsin on proteins in the stomach is an example of chemical digestion.

Which of the following statements is true regarding the swallowing reflex? Check all that apply.

The oral phase is voluntary and the phayngoesophageal phase is involuntary. Four different cranial nerves carry the motor impulses of the reflex.

Which of the following statements is/are true about gastric motility? Check all that apply.

The stomach uses the contraction of three layers of muscle to mix, churn, and propel its contents to the duodenum. When the pyloric sphincter is relaxed, chyme moves from the stomach to the duodenum. The receptive-relaxation response of the stomach allows it to accommodate more food.

takes off one amino acid from the amine side of a peptide chain

aminopeptidase

Ion exchange molecules in the plasma membrane of the parietal cells exchange __________ ions going out for __________ ions coming in.

bicarbonate; chloride

In order for digestion to occur, chyme is required to contact the microvilli of the intestinal wall because the __________.

brush border enzymes are not secreted into the lumen

Monosaccharides are

carbohydrates

In the parietal cells, the enzyme carbonic anhydrase causes a reaction between __________ and __________.

carbon dioxide; water

takes off one amino acid from the -COOH side of a peptide chain

carboxypeptidase

Gastric secretion begins during the __________ phase and ends during the __________ phase.

cephalic; intestinal

Secrete the digestive enzymes gastric lipase and pepsinogen

chief cells

What is the mechanical and chemical breakdown of food called?

digestion

Breaks apart the final two amino acids resulting from a former protein

dipeptidase

contents in small intestine stimulate colonic motility

duodenocolic reflex

salts, phosphate, and bicarbonate

electrolytes

The network of nerves that regulate digestive motility, secretion, and blood flow is called the __________ system.

enteric nervous

Secrete hormones and paracrine messengers

enteroendocrine cells

What is the straight muscular tube conveying food from pharynx to the stomach called?

esophagus

Which of the following hormones does not inhibit gastric gland secretions?

gastrin

The hormone __________ stimulates the secretion of the enzyme __________ in the stomach.

gastrin; pepsinogen

contents in stomach stimulate colonic motility

gastrocolic reflex

Brush-border enzyme that breaks down oligosaccharides

glucoamylase

Blood sugar refers to circulating levels of __________ in the blood.

glucose

mixes, churns, promotes absorption and passes content to the next segment of the colon

haustral contaction

What are the microscopic structural subunits of the liver?

hepatic lobules

Secretin is released from the duodenum in response to _________.

hydrochloric acid in chyme

Hydrochloric acid is formed when __________.

hydrogen ions and chloride ions join in the duct of the gastric gland

antibacterial antibody

immunoglobulin A (IgA)

stimulates muscular contractions in the descending and sigmoid colon

intrinsic defecation reflex

Which of the following describes the fundus of the stomach?

it is the domed superior region

brush-border enzyme that is vital to the digestion of breast milk

lactase

digest fats

lingual lipase

mouth secreted enzyme that increases in activity upon contacting the HCl of the stomach

lingual lipase

kills bacteria

lysozyme

Brush-border enzyme that targets the release of glucose from maltose

maltase

The peristaltic movement of colonic contents triggered by the gastrocolic reflex approximately 1-3 times per day is called __________.

mass movement

occurs 1-3 times a day and moves content several centimeters

mass movement

Where is sucrase found in the human body?

microvilli of the small intestine

Fats are

monoglycerides and fatty acids

Secrete mucus and predominate in the cardia and pylorus

mucous cells

binds and lubricates the food bolus

mucus

Nucleic acids are

nucleotides

Which organ is located behind the greater curvature of the stomach and acts as both an endocrine and exocrine gland?

pancreas

enzyme that produces two free fatty acids and a monoglyceride

pancreatic lipase

Defecation is stimulated by __________ and __________ reflexes.

parasympathetic; local

Stimulation from the __________ nervous system via the __________ nerve causes the secretion of HCl in the stomach.

parasympathetic; vagus

Secrete hydrochloric acid, intrinsic factor, and ghrelin

parietal cells

Acidophilic enzyme that cleaves all peptide bonds betweentyrosine and phenylalanine

pepsin

Which of the following enzymes is produced by the stomach?

pepsin

amino acids are?

proteins

Divide rapidly and provide a continuous supply of new cells

regenerative cells

Enzyme that breaks down RNA

riboculease

Hydrolyzes starch, but is deactivated in the stomach

salivary amylase

digests starch

salivary amylase

What is the outermost layer of the digestive tract wall?

serosa