A&P II Digestive system

Name the cell that phagocytizes bacteria in the liver sinusoids

Kupffer cells

What is the function of the rugae

They help the stomach expand when necessary.

What prevents swallowed food from entering the airways?

Usually when food is swallowed, involuntary muscle contractions cause the soft palate to rise and close off the nasopharynx. The larynx also is pulled up, and the epiglottis folds over the glottis. These actions block off the air passages.

Name the major vitamin of blood clotting that is produced by the bacterial flora of the large intestine.

Vitamin K

Gastric mixing changes

a bolus into chyme

Fatty chyme entering the small intestine stimulates the secretion of _______, which stimulates the pancreas to secrete __________.

cholecystokinin; enzymes

Which structures in the intestine increase the surface area available for absorption

circular folds and villi

Teeth are composed primarily of a bonelike material called

dentin

Which of these cells secrete hormones

enteroendocrine cells

All of the following digestive structures produce secretions that aid in chemical digestion except

esophagus

Name the ligament that divides the liver into four lobes

falciform ligament

Name the connective tissue attached to the greater curvature of the stomach which extends down over the intestines

greater omentum

Large folds of the intestinal wall are called

haustra

Name the blood vessel that drains nutrient-rich blood from the intestine to the liver for processing and filtration

hepatic portal vein

Name the cell type that produces bile

hepatocytes

The condition in which the stomach protrudes above the diaphragm through the esophageal hiatus is known as

hiatal hernia

Which of all the secretions produced by the digestive tract has the lowest pH?

hydrochloric acid (HCl)

Name the type of tooth designed for nipping and biting

incisors

A yellowish coloration of the skin and mucous membranes is due to the buildup of bilirubin is called

jaundice

Name one example of a brush border enzyme produced in the small intestine which acts upon carbohydrates

lactase, maltase, sucrase

Name the layer composed of areolar connective tissue underlying the epithelium of the mucosa of the GI tract.

lamina propria

Where is indigestible waste compacted?

large intestine

Bike is produced by the ____ and stored in the ___.

liver, gallbladder

Name the sphincter muscle at the top of the stomach

lower esophageal sphincter (also called the gastroesophageal or cardiac sphincter)

Which peritoneal fold supports the large intestine?

mesocolon

Where does mechanical and chemical digestion begin

mouth

Which of the following accurately lists the four tissue layers of the alimentary canal, from innermost to outermost

mucosa, submucosa, muscularis, serosa

The taenia coli are bands of _______ running along the outside of the colon

muscle

Name one example of a brush border enzyme produced in the small intestine which acts upon nucleic acids

nucleosidases

Which of the following accurately lists the order of the structures through which food passes as it moves through the digestive system, starting with the entry of food into the mouth through to elimination

oral cavity, pharynx, esophagus, stomach, small intestine, large intestine, rectum, anal canal

The cells that secrete insulin and glucagon are called

pancreatic islets (islets of Langerhans)

Gastric juice secretion is increased by _______ action potentials and the hormone gastrin, which is produced by the ________

parasympathetic; stomach

Which salivary gland is composed almost entirely of serous cells?

parotid glands

Name the activated enzyme of the stomach that breaks down proteins

pepsin

Chief cells of the stomach produce

pepsinogen

Name the substrate that trypsin acts upon

peptides

What organs are involved in swallowing and are just passageways that are not involved in mechanical nor chemical digestion

pharynx and esophagus

Name the modification of the rectum that prevents a person from defecating whenever they pass gas.

rectal valves

The last 15 cm of the large intestine is a storage area called the

rectum

In addition to the normal secretions by the stomach, infants produce ________ to help them digest milk proteins

rennin

Name the folds that are found in an empty stomach

rugae

Name the outer most layer of the digestive tract that forms the peritoneum

serosa

Secretin is a hormone that is secreted by the ______. That causes the pancreas to bicarbonate

small intestine

Name the lymphoid organ located inferior and lateral to the stomach and is responsible for purifying the blood and disposal of worn-out red blood cells

spleen

Name the substrate that salivary amylase acts upon

starch

Name the tissue of the mucosa within the oral cavity, pharynx, and upper esophagus

stratified squamous epithelium (non-keratinized)

Name the hardest substance in the human body

tooth enamel

Finger-like projections within the mucosa of the small intestines that increase surface area for absorption and digestion are called

villi

How many permanent teeth should a healthy adult have

32

Which of the following statements accurately distinguishes a bolus from chyme

A bolus is food that has been chewed and swallowed, whereas chyme is the mixture of food and digestive secretions created in the stomach.

Which of the following is an example of chemical digestion

An enzyme hydrolyzes bonds between glucose molecules

Name the "worm-like" lymphatic organ attached to the cecum

Appendix

If you wanted to explain the function f bacteria in the large intestine to someone who did not understand it, you might include all of the following except

Bacteria absorb water in the colon

Explain the role of bile salts and lecithin in the emulsification of lipids (fats).

Bile salts and lecithin can emulsify large lipid globules because they are amphipathic; they have a nonpolar (hydrophobic) region that attaches to the large fat molecules as well as a polar (hydrophilic) region that interacts with the watery chime in the intestine.

The scientific term for "swallowing" is

Deglutition

Peristalsis moves the bolus down the esophagus and toward the stomach. Esophageal glands secrete mucus that lubricates the bolus and reduces friction. When the bolus nears the stomach, the lower esophageal sphincter relaxes, allowing the bolus to pass into the stomach.

Describe the three processes involved in the esophageal phase of deglutition.

Which one of the following is the correct sequence of regions of the small intestine, from beginning to end?

Duodenum, jejunum, ileum

Which of the following describes how bile enters the duodenum

Hepatocytes in the liver secrete bile, which flows into the right and left hepatic ducts and then into the common hepatic duct. If the bile is not yet needed for digestion, it flows up the cystic duct and is stored in the gall bladder.

Bile and pancreatic enzymes empty into the small intestine through a common opening called the

Hepatopancreatic ampulla

Why is it important that chyme from the stomach is delivered to the small intestine slowly and in small amounts?

If large quantities of chyme were forced into the small intestine, it would result in osmotic water loss from the blood into the intestinal lumen that could cause potentially life-threatening low blood volume and erosion of the duodenum.

Explain the mechanism responsible for gastroesophageal reflux.

If the lower esophageal sphincter does not close completely, the stomach's acidic contents can back up into the esophagus, a phenomenon known as GERD.

How is vitamin B12 absorbed?

Intrinsic factor secreted in the stomach binds to the large B12 compound, creating a combination that can bind to mucosal receptors in the ileum.

If you were summarizing the defecation reflex, you might include all of the following except

Involuntary relaxation of the external anal sphincter allows defecation to occur.

Why is the hepatic portal system important?

It allows nutrients and wastes to be processed in the liver instead of entering the circulation directly

Which of the following statements accurately compares the small and large intestines

Most nutrient absorption takes place in the small intestine, whereas most water reabsorption takes place in the large intestine.

Which of these organs in not considered an accessory digestive structure?

Mouth

What is the correct order for the layers of the GI tract wall, from innermost ( next to lumen) to outermost?

Mucosa - submucosa - muscularis - adventitia/serosa

Explain how nutrients absorbed in the small intestine pass into the general circulation.

Nutrients from the breakdown of carbohydrates and proteins are absorbed through a capillary bed in the villi of the small intestine. Lipid breakdown products are absorbed into a lacteal in the villi, and transported via the lymphatic system to the bloodstream.

The composition of saliva varies from gland to gland. Discuss how saliva produced by the parotid gland differs in action from saliva produced by the sublingual gland.

Parotid gland saliva is watery with little mucus but a lot of amylase, which allows it to mix freely with food during mastication and begin the digestion of carbohydrates. In contrast, sublingual gland saliva has a lot of mucus with the least amount of amylase of all the salivary glands. The high mucus content serves to lubricate the food for swallowing.

Name the prominent bands of smooth muscle running longitudinally along the large intestine wall creating haustra

Taeniea coli

Which of the following is a good description of the function of the stomach sphincters

The cardiac sphincter is where a bolus enters the stomach from the esophagus. The pyloric sphincter is where chyme exits the stomach into the duodenum.

Explain how the enteric nervous system supports the digestive system. What might occur that could result in the autonomic nervous system having a negative impact on digestion?

The enteric nervous system helps regulate alimentary canal motility and the secretion of digestive juices, thus facilitating digestion. If a person becomes overly anxious, sympathetic innervation of the alimentary canal is stimulated, which can result in a slowing of digestive activity.

What involuntary movement prevents the bolus from entering the trachea?

The epiglottis folds down and covers the trachea.

Describe the location of hepatocytes in the liver and how this arrangement enhances their function.

The hepatocytes are the main cell type of the liver. They process, store, and release nutrients into the blood. Radiating out from the central vein, they are tightly packed around the hepatic sinusoids, allowing the hepatocytes easy access to the blood flowing through the sinusoids.

During a hockey game, the puck hits a player in the mouth, knocking out all eight of his most anterior teeth. Which teeth did the player lose and how does this loss affect food ingestion?

The incisors. Since these teeth are used for tearing off pieces of food during ingestion, the player will need to ingest foods that have already been cut into bite-sized pieces until the broken teeth are replaced.

All of the following are layers of the stomach wall except

The innermost serosa

What layer of the alimentary canal tissue is capable of helping to protect the body against disease, and through what mechanism?

The lamina propria of the mucosa contains lymphoid tissue that makes up the MALT and responds to pathogens encountered in the alimentary canal.

Offer a theory to explain why segmentation occurs and peristalsis slows in the small intestine.

The majority of digestion and absorption occurs in the small intestine. By slowing the transit of chyme, segmentation and a reduced rate of peristalsis allow time for these processes to occur.

Name the connective tissue found in the folds of the small intestine and anchors the large intestine

The mesentery

Describe three of the differences between the walls of the large and small intestines.

The mucosa of the small intestine includes circular folds, villi, and microvilli. The wall of the large intestine has a thick mucosal layer, and deeper and more abundant mucus-secreting glands that facilitate the smooth passage of feces. There are three features that are unique to the large intestine: teniae coli, haustra, and epiploic appendages.

Explain how the stomach is protected from self-digestion and why this is necessary.

The mucosal barrier protects the stomach from self-digestion. It includes a thick coating of bicarbonate-rich mucus; the mucus is physically protective, and bicarbonate neutralizes gastric acid. Epithelial cells meet at tight junctions, which block gastric juice from penetrating the underlying tissue layers, and stem cells quickly replace sloughed off epithelial mucosal cells.

If you were showing a friend a cross-section of a tooth, you could use all of the following to explain it except

The neck of the tooth sits in the alveolar process of the jaw bone

Why does the pancreas secrete some enzymes in their inactive forms, and where are these enzymes activated?

The pancreas secretes protein-digesting enzymes in their inactive forms. If secreted in their active forms, they would self-digest the pancreas. These enzymes are activated in the duodenum.

It has been several hours since you last ate. Walking past a bakery, you catch a whiff of freshly baked bread. What type of reflex is triggered, and what is the result?

The smell of food initiates long reflexes, which result in the secretion of digestive juices.

Describe unique anatomical features that enable the stomach to perform digestive functions.

The stomach has an additional inner oblique smooth muscle layer that helps the muscularis churn and mix food. The epithelium includes gastric glands that secrete gastric fluid. The gastric fluid consists mainly of mucous, HCl, and the enzyme pepsin released as pepsinogen.

What is the role of the tongue in chewing and swallowing

The tongue manipulates the chewed food into a small mass and moves it into the oropharynx.

The primary function of the large intestine is the _______

absorption of water and certain minerals and vitamins

Name the exocrine cells of the pancreas

acinar cells

Name one brush border enzyme produced in the small intestine which acts upon proteins.

aminopeptidase, dipeptidase, carboxypeptidase

From the cecum to the rectum, the regions of the colon are the

ascending colon, transverse colon, descending colon, sigmoid colon

"Segmentation" within the small intestine refers to the

back-and-forth motion that mixes chyme with glandular secretions.

Each of the following organs is a component of the digestive tract except the

bladder

The scientific term for food that is swallowed is

bolus

The large intestine includes the

cecum, colon, rectum

Gastric secretion occurs in three phases

cephalic, gastric, intestinal

The hormone produced by the brush border cells of the intestine that stimulates the ejection of bile from the liver and gallbladder and pancreatic juice from the pancreas is

cholecystokinin