Digestive System

Partially digested food is usually passed from the stomach to the small intestine about how long after consumption?

2-4 hours

Deciduous teeth

20 teeth, and by 2 years of age most children have all 20

Permanent teeth

32 teeth, and the wisdom teeth are the last to emerge

What is the purpose of stomach acid? How does the stomach protect itself from digestion?

Activates lipase, helps digest. Mucus

The function of the enzyme salivary amylase is to begin digesting proteins.

False, amylase digests starch

Pepsinogen is the precursor to the gastric enzyme for protein digestion and is secreted by the parietal cells.

False, pepsinogen is secreted by the chief cells

Chemical digestion of lipids is initiated in the mouth.

False, starch digestion beings in the mouth

Parietal cells of the stomach produce

HCl

What causes a peptic ulcer?

Peptic ulcers are erosions of the stomach wall. They are most commonly caused by the H. pylori bacterium.

What is heartburn and what causes it?

The acidic gastric juices are regurgitated into the esophagus. This may happen when someone has eaten or drunk to much. It can be caused by extreme obesity or pregnancy. It is sometimes due to obstructions or faults in the esophagus.

As food passes through the digestive tract, it becomes less complex and the nutrients are more readily available to the body.

True

Fats significantly delay the emptying of the stomach.

True

Food is contained in the gastrointestinal tract from the time of ingestion until it is completely digested and the waste prepared for elimination.

True

Kupffer cells are found in the liver and are responsible for removing bacteria and worn out cells.

True

Mumps is an inflammation of the parotid glands caused by myxovirus.

True

The digestive function of the liver is to produce bile.

True

The main chemical activity of the stomach is to begin the digestion of proteins.

True

The pancreas has both endocrine and exocrine function.

True

Define constipation and diarrhea and note possible causes of each.

Watery stools are called diarrhea. Constipation is a condition in which to much water has been absorbed and the stool becomes difficult to pass. Any condition such as irritation of the colon by bacteria that rushes food residue through the large intestine before that organ has had sufficient time to absorb the remaining water, is diarrhea. Constipation may ensue from a lack of fiber in the diet, improper bowel habits, laxative abuse or anything that decreases motility.

Process by which the products of digestion pass through the lumen of the gastrointestinal tract into the blood or lymph.

absorption

Intrinsic factor secreted by parietal cells of the stomach is required for

absorption of vitamin B12

secretes trypsinogen

acini of pancreas

The major digestive enzyme in salvia is

amylase

You have just eaten a meal high in complex carbohydrates. Which of the following enzymes will help to digest the meal?

amylase

_________ is the principal enzyme for breaking down complex carbohydrates.

amylase

Assume you have been chewing a piece of bread for 5 or 6 minutes. Why would the bread begin to taste sweet?

amylase working on starch, breaking down into maltose which is sweet

carbohydrates

amylase-oligosaccharides, disaccharides

Correct order of food movement in colon

ascending colon, hepatic flexure, transverse colon, splenic flexure, descending colon, sigmoid colon

The primary chemical digestion in the large intestine results from the action of

bacterial enzymes

A fluid secreted into the duodenum during digestion that contains cholesterol, emulsification agents and

bile

Trace a drop of bile from production by the hepatocyte until it leaves the body.

bile canaliculi, bile ductus, right and left hepatic ducts, common hepatic duct, cystic duct, bile duct, duct of pancreas, hepatopancreatic ampulla, duodenum, jejunum, ileum, ascending colon, transverse colon, sigmoid colon, rectum

Bile is secreted by hepatocytes into vessels called

bile conaliculi

The chief bile pigment is

bilirubin

The principle bile pigment is _____.

bilirubin

The normal color of feces is due primarily to the

breakdown products of hemoglobin

All of the microvilli of the epithelial cells of the small intestine collectively form a fuzzy line called the

brush border.

The appendix is attached to the

cecum

secretes gastrin

cells of stomach

The _____ phase of gastric secretions occurs before food enters the stomach.

cephalic

secretes pepsinogen

chief cells of stomach

Pepsinogen, an inactive form of the digestive enzyme is secreted by the

chief cells of the stomach

Gallstones are usually made of crystallized

cholesterol

Mixing waves of the stomach covert solid food into a liquid called

chyme.

Salvia

cleanses the mouth, moistens the food and aids in compacting of bolus, dissolves food chemicals so they can be tasted

The function of the hepatic portal circulation is to

collect absorbed nutrients for metabolic processing or storage.

The common bile duct is formed by the union of the

common hepatic and cystic ducts

Pancreatic amylase does NOT get into the small intestine via the

cystic duct

Increased activity of the sympathetic nervous system will

decrease production of digestive juices

The liver produces urea to

detoxify ammonia produced via deamination of protiens

Chemical or mechanical process of breaking down foodstuffs to substances that can be absorbed.

digestion

secretes alkaline mucus

duodenal glands of small intestine

Where is most of the water that enters the small intestine absorbed?

duodenum

____ is another word for vomiting.

emesis

Gastrin, histamine, endorphins, seotonin, cholecystokinin, and somatostatin are hormones or paracrine that are released directly into the lamina propria. Which cells yes synthesize and secrete these products.

enteroendocrine cells

The major stimulus for secretion of secretin is

entry of acid chyme into the small intestine

The opening in the diaphragm through which the esophagus passes is called the

esophageal hiatus

The stomach is considered an accessory digestive organ

false, it is an alimentary organ of the digestive system

The soft palate rises reflexively to open the nasopharynx when we swallow food.

false, rises to close

Bicarbonate ions are secreted into the lumen of the stomach along with the hydrogen ions to buffer them

false, the hydrogen bonds bind with chloride to create the acidic environment of the stomach. The bicarbonate goes into the blood.

The jejunum is the longest region of the small intestine

false, the ileum is longer

Cuspids are teeth specialized for grinding food

false, the molars specialize in grinding

cystic ducts

gallbladder

What has the lowest pH

gastric juice

During the gastric phase of the gastric digestion, acetylcholine from parasympathetic neurons stimulates secretion of the hormone ____.

gastrin

The end products of the hydrolysis reactions catalyzed by sucrase are ____ and _______.

glucose, fructorse

The greenish color of the bile is the result of the presence of breakdown products of

hemoglobin

The portal triad contains a branch of the _____ , a branch of the ______, and a _______.

hepatic artery, hepatic portal vein, bile duct

secrets bile

hepatocytes

The ducts that deliver bile and pancreatic juice from the liver and pancreas, respectively , unite to form the

hepatopancreatic ampulla

Enzymatic breakdown of any type of food molecule

hydrolysis

The type of chemical reaction catalyzed by the digestive enzymes in the digestive juices of the alimentary canal is

hydrolysis

The major chemical digestion that occurs in the adult stomach is

hydrolysis of proteins by pepsin

The function of bile is to

hydrolyze fats

Aggregated lymphatic follicles (Peyer's patches) are located in the mucosa of the ______ of the small intestine.

ileum

The longest portion of the small intestine is the

ileum

The terminal portion of the small intestine is the

ileum

In addition to storage and mechanical breakdown of food, the stomach

initiates protein digestion and denatures proteins

secretes maltase, lactase, sucrase

intestinal glands of small intestine

specific disaccharides are hydrolyzed by enzymes found in

intestinal juice

Parietal cells of the stomach secrete ______ and ________

intrinsic factor, HCL

What is not true of the large intestine

its longer than the small intestine ( It is shorter)

Hepatic macrophages called ____ cells are found in the liver sinusoids and they remove debris from the blood as it flows past.

kupffer

cecum

large intestine

Short chain triglycerides found in foods such as butterfat molecules in milk are spilt by a specific enzyme for preparation for absorption. Which enzyme is responsible?

lipase

fats and triglycerides

lipase- free fatty acids , monoglycerides

Digestion of which of the following would be affected the most if the liver were severely damaged?

lipids

Gastric emptying is the slowest after a meal rich in

lipids.

The _____ contains lobules with macrophage-lined sinusoids that lead to a central venous canal.

liver

caudate lobe

liver

The process of ______ results in the mechanical mixing of food with salvia and shaping of food into a bolus.

mastication

Which of the following is an example of mechanical digestion?

mastication

The sheet of peritoneal membrane that holds the small intestines in place is called

mesentery

The small intestine is attached to the posterior abdominal wall by a fold of the peritoneum called the

mesentery

The plicae circulares and intestinal villi are found in which of the four layers of the alimentary tube wall?

mucosa

The four basic layers of the lumen

mucosa , submucosa, muscularis externa , serosa

What causes lactose intolerance?

not producing enough lactase

hard palate

oral caivty

List the tubing in correct order of food movement

oropharynx, laryngopharynx, esophagus, stomach, pyloric valve

Which of the following would be considered an accessory organ of the digestive system?

pancreas

You have just eaten french fries, buttered toast, ice cream and whole milk. What gland is active in helping to digest this food?

pancreas

acini

pancreas

secretes insulin and glucagon

pancreatic islets

The principle triglyceride digesting enzyme in adults is

pancreatic lipase

________ is a hormone released from the duodenum in response to acidic chyme. It stimulates the pancreas to secrete more ________ to raise/lower the pH in the duodenum.

pancreatic protease, HCO3

Hydrochloric acid is secreted by which of the secretory cells of the stomach?

parietal

_____ cells of the stomach secrete HCl.

parietal

secretes hydrogen ions and chloride ions

parietal cells of stomach

secretes salvia

parotid glands

Proteins

pepsin - polypeptides

Chief cells of the stomach produce _____ and _____

pepsinogen , gastric lipase and chymosin

The hydrolytic reactions catalyzed by trypsin and chymotrypsin would result in the production of

peptides

The ______ ligament anchors a tooth in the alveolus of the jaw.

periodontal

The regular contractions of the muscular that push food through the entire gastrointestinal tract are known as

peristalsis

Wavelike smooth muscle contractions that move foodstuffs through the alimentary tube.

peristalsis

What increases the surface area of the mucosal lining?

plicae circulares and intestinal villi

What describes the location of the esophagus best

posterior to the trachea, anterior to the vertebral cool,m from laryngopharynx to stomach

Hepatocytes do not

produce digestive enzymes

The function of the goblet cells is to

produce mucus that protects parts of the digestive organs from the effect of powerful enzymes and acid

Gastrin is a digestive hormone that is responsible for the stimulation of acid secretions in the stomach. These secretions are stimulated by the presence of

proteins and peptide fragments

List the correct order of food movement in small intestine

pyloric valve, duodenum, jejunum, ileum, ileocecal valve

The ingestion of a meal high in fat content would cause what to occur?

release of bile from the gallbladder to emulsify the fat in the duodenum

nucleic acids

ribonuclease, deoxyrib. - pentase, sugars, N bases, phosphate ions

The folds of the gastric mucosa are called

rugae

Chemical digestion in the small intestine involves all of the following except

secretions from the spleen that contain all enzymes necessary for complete digestion

Chyme and digestive juices are mixed by localized contractions of the muscularis of the small intestine called ____________.

segmentations

Salivary glands are composed of which two types of secretory cells

serous cells and mucous cells

cephalic stage of gastric digestion

sight, smell , thought or taste of food trigger parasympathatic impulses

Most absorption of nutrients occurs in the

small intestine

jejunum

small intestine

About 90 percent of all absorption of nutrients occurs in the ______ , the other 10 percent occurs in the ____ and ________.

small intestine, stomach, large intestine

Chyme is created in the

stomach

fundus

stomach

The pyloric sphincter is located at the junction of the _____ and the _______.

stomach , duodenum

The muscularis of most organs of the gastrointestinal tract consists of two layers of smooth muscle except the

stomach, it has three layers.

The functions of the gallbladder include

storage and concentration of bile

cementum

teeth

Thickened portions of the longitudinal muscles of the large intestine are called _______ that gather the colon into pouches called ______.

teniae coli , haustra

Peristalsis occurs during

the pharyngeal stage of deglutition and the esophageal stage

Bicarbonate ions diffuse into blood capillaries of the stomach after a meal because

they are being exchanged for chloride ions that enter the stomach lumen ( chloride shift)

papillae

tongue

CCK stimulates ejection of bile from the gallbladder

true

Oxygenated and deoxygenated blood mix in the liver sinusoids

true

Peristalsis begins in the esophagus

true

The brush border of the small intestine is formed by the microvilli of the epithelial cells

true

The gastrocolic reflex triggers mass peristalsis

true

The substrate for salivary amylase is starch

true

Which of the following enzymes is specific for protiens

trypsin

The found ligament is a remnant of the fetal __________.

umbilical vein

During swallowing the nasal cavity is closed off by the soft palate and the

uvula

Folds in the mucosa of the small intestine that increase the surface area for diffusion are called

villi

The large intestine absorbs mostly

water

List the components of pancreatic juice

water, enzymes, electrolytes, (bicarbonate ions)