Ch. 23 - The Digestive System

Which of these best describes a lacteal?

a lymphatic vessel designed to help introduce fats to the blood

Which layer of the alimentary canal is constructed from either stratified squamous or simple columnar epithelium?

mucosa

Which layer of the stomach contains the gastric pits that secrete mucous, acid, and digestive enzymes?

mucosa

Which layer of the alimentary canal is responsible for segmentation and peristalsis?

muscularis externa

Which layer of the digestive tract controls digestive propulsion?

muscularis externa

What is a major function of pancreatic juice?

neutralizing chyme entering the small intestine from the stomach

Which of the following is NOT a means of mechanically breaking down food?

peristalsis

Which of the following is NOT a function of the large intestine?

production of intrinsic factor

Which of the following functions is NOT correctly matched with its description?

propulsion: physical breakdown of ingested food in the GI tract

Which of the following are NOT correctly matched?

protease: lipid digestion

Which area of the stomach adjoins the small intestine?

pylorus

Which of the following is NOT a structural modification of the small intestine that increases surface area?

rugae

An increase in HCl (hydrochloric acid) arriving in the duodenum would stimulate which hormone that would help to counteract the effects of HCl?

secretin

The outermost tissue layer of the alimentary canal is the __________.

serosa

Which organ of the digestive tract is the body's major digestive organ?

small intestine

Which layer of the alimentary canal contains not only glands and blood vessels but also a nerve plexus that helps regulate digestive activity?

submucosa

What triggers the release of secretion from the small intestine?

the presence of acidic, fatty chyme in the small intestine

The __________ is the serous membrane that lines the abdominal organs.

visceral peritoneum

Which of the following is the primary physiological function of the large intestine?

water absorption and feces elimination

_______ and ________ are water-soluble vitamins.

B complex and C vitamins

Functions of the saliva;

-Saliva dissolves food chemicals so that they can be tasted. -Saliva moistens food and helps compact it into a bolus. -Saliva cleanses the mouth.

characteristic of the stomach?

-The stomach produces a double-layered coat of alkaline mucus. -The stomach mucosa is folded into rugae. - The stomach has three layers of muscle in the muscularis tunic.

Functions of the large intestine include:

-absorption of water -absorption of vitamins -absorption of electrolytes

Secretion of the pancreas?

-nutrient enzymes -bicarbonate -insulin

Means of mechanically breaking down food?

-segmentation -mastication -churning

Bacteria that reside in the large intestine make vitamin C. (T/F)

False

Chief cells secrete inactive pepsinogen in order to prevent acid erosion inside of the chief cells.(T/F)

False

Which of the following is NOT a function of saliva?

Saliva contains enzymes that begin the chemical breakdown of proteins.

Which of the following is NOT a characteristic of the stomach?

The stomach releases enzymes to digest carbohydrates.

Which major process involves the removal of water from intestinal contents?

absorption

Correctly matched

absorption; passage of digested nutrients into the blood or lymph ingestion: intake of food nutrients mechanical breakdown: churning movements in the GI tract

In response to a steak dinner, certain secretions are needed to aid digestion. What cells in the pancreas would provide these secretions?

acinar cells

Correctly matched

amylase: carbohydrate digestion nuclease: DNA and RNA digestion lipase: fat digestion

Which of these structures is found in the stomach but nowhere else in the alimentary canal?

an oblique muscle layer

The secretion in the large intestine consists of which of the following?

bicarbonate- and potassium-rich mucus

Which of the following is NOT a secretion of the pancreas?

bile

Which of the following is the major process or function that occurs in the stomach?

mechanical digestion Mechanical digestion occurs in the stomach by churning.

Carbohydrates are digested into __________.

monosaccharides

HCl secretions convert pepsinogen to the active hormone pepsin. What cells in the gastric pits produce pepsinogen?

chief

What structural modification of the small intestine slows the movement of chyme through the lumen?

circular folds

The __________ is the first segment of the small intestine.

duodenum

Salivation is controlled almost entirely by the nervous system. Which of the following stimuli would inhibit salivation?

fear

Which cells in the small intestine's mucosa secrete mucus?

goblet cells Goblet cells, which secrete mucus and are found in several areas of the digestive tract, are located on the villi of the small intestine.

The __________ circulation drains all of the organs of the digestive system.

hepatic portal The hepatic portal circulation drains all of the blood from the digestive organs and routes that blood through the liver for processing.

Most absorption of nutrients occurs in the __________.

jejunum

Bile is produced by the __________ under the influence of the hormone __________.

liver; secretin