A&P II Chapter 25

Which of the following statements is/are true regarding mechanical and/or chemical digestion?

- 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 absorption of nutrients?

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

Which of the following statements is/are true regarding the regulation of digestive secretions?

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

Which of the following statements is true regarding the swallowing reflex?

-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?

-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.

The following anatomical features of the small intestine function to increase the surface area of the intestinal wall and maximize its capacity for absorption. Rank these structures 1 through 3 in order from largest to smallest.

1. circular folds 2. villi 3. microvilli

cholecytokinin

1. secreted in response to fats in small intestine 2. strong stimulatory effect on gallbladder 3. eventually leads to emulsification of lipid globules 4. stimulates pancreatic lipase and amylase secretions 5. relaxes sphincter of hepatopancreatic ampulla 6. stimulates bile release in duodenum

Secretin

1. secretes in response to chyme's low pH 2. protects intestinal wall from HCl 3. results in sodium bicarbonate release by liver and pancreas 4. helps flush pancreatic enzymes into duodenum

Which of the following is a method of motility in the small intestine?

1. segmentation 2. peristalsis 3. migrating motor complex

Enzyme that breaks down DNA

Deoxyribonuclease

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

From the fundus to the pylorus

Acidic compound that activates pepsinogen

HCl

The luminal diffusion of sodium to the ____________ is coupled with glucose and galactose ____________ into the cell.

ICF,cotransport

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

aminodipeptidase

Sodium-potassium pumps in the ____________ work to actively transport sodium out of the cell towards the interstitium while cotransporting potassium to the intracellular fluid.

basal membrane

The ____________ collect bile produced in the hepatic lobules and deliver it to the hepatic ducts on their way to the ____________ for storage.

bile ductules, gallbladder

The absorption of ____________ from the intestinal lumen occurs directly through ____________ transport.

carbohydrates, secondary active

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

carboxydipeptidase

Contractions of the small intestine have three functions: mix chyme with digestive juices, allow for ____________ with the brush border, and move contents toward the lumen of the ____________ .

contact digestion, large intestine

With a ____________ intracellular concentration of sodium, sodium now diffuses from the ____________ to the ICF of the epithelium.

declining, intestinal lumen

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

dipeptidase

Contents in small intestine stimulate colonic motility

duodenocolic reflex

Contents in stomach stimulate colonic motility

gastrocolic reflex

The ____________ enhances segmentation in the ileum and relaxes the ____________ , allowing contents to enter the cecum.

gastroileal reflex, ileocecal valve

Brush-border enzyme that breaks down oligosaccharides

glucoamylase

Mixes, churns, promotes absorption, and passes contents to the next segment of the colon

haustral contraction

The ____________ is responsible for delivering oxygen ____________ blood to the hepatocytes and thus providing for the large metabolic demand for this tissue.

hepatic artery, rich

Three main vessels make up the ____________ . These include the hepatic portal vein, hepatic artery, and bile ductules.

hepatic triad

Stimulates muscular contractions in the descending and sigmoid colon

intrinsic defecation reflex

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

lactase

Carbohydrates (macromolecule is the target of each digestive enzyme)

lactase, glucoamylase, pancreatic amylase, dextrinase, salivary amylase, maltase, sucrase

Lipid (macromolecule is the target of each digestive enzyme)

lecithin, bile salts, lingual lipase, gastric lipase, pancreatic lipase

mouth-secreted enzymes that increase in activity upon contacting the HCL of the stomach

lingual lipase

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

maltase

Occurs 1-3 times per day and moves contents several centimeters

mass movement

Successive peristaltic waves of contraction overlap with each other, called the ____________ .

migrating motor complex

When stimulated, the ____________ will secrete trypsinogen.

pancreas

Enzyme that produces 2 free fatty acids and monoglycerides

pancreatic lipase

Acidophilic enzyme that cleaves all peptide bonds between tyrosine and phenylanine

pepsin

As segmentation declines, ____________ begins in the duodenum.

peristalsis

Blood arrives at the liver through both the hepatic portal vein and the hepatic artery, although the hepatic portal vein delivers nutrient rich, oxygen ____________ blood to the liver cells.

poor

Trypsin will digest dietary ____________ and also catalyzes the conversion of more trypsinogen into trypsin.

proteins

Enzyme that breaks down RNA

ribonuclease

Hydrolyzes starch, but is deactivated in the stomach

salivary amylase

The process of ____________ consists of muscular contractions whose effect is to knead and churn the contents.

segmentation

The duodenum, in turn, will secrete enterokinase which will convert trypsinogen into ____________ .

trypsin

Protein (macromolecule is the target of each digestive enzyme)

trypsin, hcl, dipeptidase, aminodipeptidase, pepsin, chymotripsin, carboxydipeptidase

Finally, trypsin will also activate two other pancreatic ____________ , called chymotrypsinogen and procarboxypeptidase.

zygomens