Chapter 25 Homework - Digestive

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.

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 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?

-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 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.

Which of the following is a function of the bacterial flora?

-bacteria digest cellulose -bacteria synthesize vitamin K

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

Starting after it leaves the pyloris, place the following anatomical structures in order to identify the correct sequence that food would pass through the body.

1. duodenum 2. jejunum 3. ileum 4. cecum 5. ascending colon 6. transverse colon 7. descending colon 8. sigmoid colon 9. rectum

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

1. segmentation 2. peristalsis 3. migrating motor complex

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

Duodenum, jejunum, ileum

Acidic compound that activates pepsinogen

HCl

What are the microscopic structural subunits of the liver?

Hepatic lobules

Which of the following describes the fundus of the stomach?

It is the domed superior region.

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

Mucus-secreting cells

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

Pancreas

Which of the following enzymes is produced by the stomach?

Pepsin

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

aminopeptidase

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

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

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

Eznymes that break down fats and proteins are secreted by ____________ cells.

chief

Secrete the digestive enzymes gastric lipase and pepsinogen

chief cells

Trypsin then works on converting both chymotrypsinogen and procarboxypeptidase into ____________ and carboxypeptidase, respectively.

chymotrypsin

The pancreas produces a number of zymogens that are released in the GI tract at the duodenum including procarboxypeptidase, ____________ , and trypsinogen.

chymotrypsinogen

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

Enzyme that breaks down DNA

deoxyribonuclease

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

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

enteric nervous

The ____________ cells are associated with chemical regulation of digestion.

enteroendocrine

Secrete hormones and paracrine messengers

enteroendocrine cells

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

esophagus

The final step in allowing defecation is voluntary relaxation of the ____________ sphincter, which is composed of skeletal muscle.

external anal

As long as there is chyme in the duodenum, it will continue to stimulate gastric secretion. (true or false)

false

The term contact digestion refers to the fact that segmentation must occur in order to propel intestinal contents distally within the digestive tract. (true or false)

false

Hormonal secretions like ____________ and secretin are released into the blood and stimulate relatively distant parts of the digestive tract.

gastrin

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

gastrin; pepsinogen

Contents in stomach stimulate colonic motility

gastrocolic reflex

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

gastrolienal reflex; ileal papilla

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

Paracrine secretions like ____________ and prostaglandins diffuse through the tissue fluids and stimulate nearby target cells.

histamine

Secretin is released from the duodenum in response to _________.

hydrochloric acid in chyme

The junction of the small and large intestines is marked by a pronounced muscular swelling known as the ____________ papilla, which regulates movement into the large intestine.

ileal

The involuntarily controlled ____________ sphincter is composed of smooth muscle that relaxes at the onset of defecation.

internal anal

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

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

lingual lipase

____________ reflexes utilize the parasympathetic nervous system, specifically, the ____________ nerve.

long; vagus

At the terminal end of the esophagus is the ____________ sphincter, which subconsciously controls the entrance of food into the stomach.

lower esophageal

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

The ____________ cells are found mostly in the proximal and distal regions of the stomach.

mucous

Secrete mucus and predominate in the cardia and pylorus

mucous cells

The first sphincter of the digestive system, called the ____________ muscle, surrounds the entrance to the oral cavity.

orbicularis oris

1.) When stimulated, the ____________ will secrete trypsinogen.

pancreas

Enzyme that produces two free fatty acids and a monoglyceride

pancreatic lipase

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

parasympathetic; vagus

The ____________ cells secrete the substance that converts pepsinogen to pepsin as well as a hormone that regulates appetite.

parietal

Secrete hydrochloric acid, intrinsic factor, and ghrelin

parietal cells

Acidophilic enzyme that cleaves all peptide bonds betweentyrosine and phenylalanine

pepsin

The chief cells of the stomach secrete ____________ into the stomach lumen; which in the presence of HCl becomes ____________ , the active form of the enzyme.

pepsinogen; 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

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

proteins

The ____________ sphincter regulates the movement of food from the stomach to the small intestine.

pyloric

Replacing both surface cells as well as glandular cells, the ____________ cells divide rapidly.

regenerative

Divide rapidly and provide a continuous supply of new cells

regenerative cells

Enzyme that breaks down RNA

ribonuclease

Hydrolyzes starch, but is deactivated in the stomach

salivary amylase

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

secretin

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

segmentation

What is the outermost layer of the digestive tract wall?

serosa

____________ reflexes are stimulated by stretching or chemical stimulation of the myenteric plexus, which can result in peristaltic contractions.

short

Drag each label into the appropriate position in order to identify whether the structure is associated with the large or small intestine.

small intestine- aggregated lymphoid nodules

Cholecystokinin, which is produced in the small intestine, inhibits gastric secretions in the stomach. (true or false)

true

Gastrin functions to increase the production of HCl in the stomach. (true or false)

true

Secretin is released from the duodenum in response to acidic chyme. (true or false)

true

2.) The duodenum, in turn, will secrete enteropeptidase, which will convert trypsinogen into ____________ .

trypsin

After contacting the intestinal enzyme enteropeptidase, ____________ is converted into ____________ .

trypsinogen; trypsin

The ____________ sphincter separates the pharynx from the esophagus and regulates the passage of food into the esophagus.

upper esophageal

A ____________ is an inactive or pro-enzyme that is only activated after it has been secreted and had some of its amino acids cleaved.

zymogen

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

zymogens