Anatomy and Physiology Chapter 17: Digestive System

Click and drag on elements in order Place the phases of the swallowing mechanism in order, with the beginning phase at the top of the list. Instructions Choice 1 of 3. soft palate elevates; epiglottis covers larynx; esophagus opens Choice 2 of 3. voluntary phase; the tongue forces a bolus into oropharynx Choice 3 of 3. peristalsis transports the food in the esophagus to the stomach

1. voluntary phase; the tongue forces a bolus into oropharynx 2. soft palate elevates; epiglottis covers larynx; esophagus opens 3. peristalsis transports the food in the esophagus to the stomach

What is a peptidase?

An enzyme that digests protein.

The structures forming the lateral walls of the mouth, consisting of outer layers of skin, pads of subcutaneous fat, muscles associated with expression and chewing, and inner linings of moist, stratified squamous epithelium, are the

Cheeks

For each label, determine whether it describes the actions of secretin or the actions of cholecystokinin.

Cholecystokinin - secreted in response to fats in the small intestine stimulates gallbladder to contract and release bile eventually leads to the emulsification of lipid globules stimulates the secretion of pancreatic amylase and pancreatic lipase relaxes the sphincter of the hepatopancreatic ampulla Secretin - secreted in response to low pH of chyme stimulates pancreas to release bicarbonate ions ultimately protects the intestinal wall from HCL

What are functions of saliva?

Cleanses mouth Dissolves food chemicals for taste Moistens food; compacts into bolus Begins breakdown of starch with enzymes

The stimulation of the release of secretin can be caused by which of the following?

Hydrochloric acid in chyme

elect all that apply Identify the functions of the various bacteria (intestinal flora) that inhabit the large intestine.

Production of thiamine and riboflavin Breakdown of cellulose Production of gas (flatus) Production of vitamins B12 and K

Which describes the enterogastric reflex?

Signals from the intestine regulate stomach function.

What is the definition of digestion?

The mechanical and chemical breakdown of foods into smaller forms

What is the main function of the small intestine?

absorption of nutrients

Peptidases are enzymes that split peptides into ______.

amino acids

What is the product of digestion of proteins?

amino acids

Which ion is transported into the bloodstream?

bicarbonate ion

The ion exchange protein in the plasma membrane of parietal cells exchanges ________ ions going out for ________ ions coming in.

bicarbonate, chloride

What is made from cholesterol and is the only component of bile to have a digestive function?

bile salts

A mass of chewed food mixed with saliva that is forced down the esophagus is called a(n)

bolus

Match the enzymes with their digestive action.

breaks down proteins -pepsin, peptidase, trypsin breaks down carbohydrates - salivary amylase, pancreatic amylase

drag each label into the appropriate position in order to identify which type of macromolecule is the target of each digestive enzyme or compound

carbohydrate: salivary amylase, dextranase, maltase, lactase, pancreatic amylase, glucoamylase, sucrase protein: pepsin, HCl, trypsin, chymotrypsin, carboxypeptidase, dipeptidase, aminopeptidase lipid: lingual lipase, pancreatic lipase, gastric lipase, bile salts, lecithin

Pancreatic amylase breaks ______ down into ______.

carbohydrates; disaccharides

In the parietal cells, the enzyme carbonic anhydrase causes a reaction between

carbon dioxide and water.

The hydrogen ions used to form hydrochloric acid in the stomach are derived from what compound?

carbonic acid

Match each phase of gastric secretion with the correct description.

cephalic phase - Sight, smell, taste, or thought of food stimulates gastric secretions. gastric phase - Distension of the stomach stimulates gastric secretions. intestinal phase - Acidic chyme in the duodenum stimulates secretion of hormones that inhibit gastric secretions.

What are the three phases of gastric activity?

cephalic, gastric, intestinal

What is a bolus?

chewed food mixed with saliva

The cells in the gastric glands that secrete pepsinogen, a digestive enzyme, are the _______ cells.

chief

Pepsinogen is secreted by ______ cells of the gastric glands, and is a precursor to ______.

chief; pepsin

The hormone ______ is secreted by the small intestine in response to fat and proteins in gastric contents entering the intestine.

cholecystokinin

What are bile salts made from?

cholesterol

Select all that apply What are some components of bile?

cholesterol bile pigments bile salts

What is contained in bile?

cholesterol, pigments, bile salts, and electrolytes

What is the composition of the secretions of the parotid gland?

clear, watery serous fluid rich in salivary amylase

What is the role of the hormone cholecystokinin?

decrease gastric motility

What do chief cells, found in gastric glands, secrete?

digestive enzymes

Which reflex involves the duodenum sending signals, typically inhibitory, to the stomach?

enterogastric reflex

True or False: The carbonic acid ion is joined to a hydrogen ion by the enzyme carbonic anhydrase.

false

True or False: The first step in the formation of hydrochloric acid is the active transport of carbon dioxide into the parietal cells.

false

True or false: Most absorption of digestive products occurs in the stomach.

false

When chyme enters the duodenum, gastric secretions increase.

false

The storage and concentration of bile between meals is the function of the

gallbladder

Collectively, hydrochloric acid, water, pepsin, and mucus all are components of what fluid?

gastric juice

What do parietal cells, found in gastric glands, secrete?

hydrochloric acid

What does the stomach secrete that helps with digestion?

hydrochloric acid

Match each component of gastric juice with its source and function.

hydrochloric acid - Provides the acid environment needed for production and action of pepsin. Produced by parietal cells. intrinsic factor - Aids in vitamin B12 absorption in the intestine. Produced by parietal cells. pepsinogen - Inactive form of pepsin. Produced by chief cells of the gastric glands. mucus - Provides a viscous, alkaline protective layer on the lining of the stomach. Produced by mucous cells.

Where are the sublingual glands located?

in the floor of the mouth under the tongue

What is the function of bile salts?

increases surface area of fatty substances, allowing better access for lipase enzymes

Match the enzyme name with the source that produces/secretes the enzyme.

intestinal mucosal cells - sucrase, intestinal lipase, peptidase pancreas - pancreatic lipase, trypsin, nucleases gastric chief cells - pepsin

Identify the phase of gastric regulation that inhibits gastric juice secretion.

intestinal phase

Match the nutrient with the means of absorption from the small intestine.

into blood in capillaries - monosaccharides, amino acids, water, electrolytes into lymph in lacteals - fatty acids

Microorganisms within the colon aid in the breakdown of cellulose, in the production of thiamine, riboflavin, vitamin B12, and vitamin

k

The enzyme __________ splits lactose into glucose and galactose.

lactase

The portion of the pharynx that begins at the level of the hyoid bone and opens into the esophagus behind the larynx is the

laryngopharynx

The portion of the pharynx that extends from the upper border of the epiglottis downward to the lower bridge of the cricoid cartilage of the larynx is the

laryngopharynx

What is the name of the median fold that attaches the body of the tongue to the floor of the mouth?

lingual frenulum

An enzyme that digests dietary fats in the stomach is called gastric

lipase

The pancreatic enzyme that digests fats is called pancreatic

lipase

When stomach contents splash back into the esophagus, it causes a sensation called heart burn. This involves a failure of what sphincter to close?

lower esophageal sphincter

The structure that prevents the stomach contents from spilling into the esophagus is the ________ esophageal sphincter.

lower, cardiac , or Lower

Where are sensory signals from the stomach and small intestine sent to trigger a vomiting reflex?

medulla oblongata

What are functions of the stomach?

mixes food with gastric juice absorbs small amounts of nutrients starts the digestion of protein

What is the correct order of organs of the upper digestive tract?

mouth,esophagus,stomach

Which cells in gastric glands release a viscous, alkaline secretion to prevent the stomach from digesting itself?

mucous neck cells

The large intestine's only significant secretion is

mucus

Select all that apply Indicate the components of gastric juice.

mucus pepsin hydrochloric acid intrinsic factor pepsinogen

The portion of the pharynx that extends from the soft palate to the hyoid bone is the

oropharynx

The cells in the gastric glands that secrete hydrochloric acid and intrinsic factor are the _________ cells.

parietal

Which salivary gland is primarily composed of serous cells and secretes a clear, watery fluid rich in salivary amylase?

parotid glands

The three pairs of major salivary glands are the ______ glands.

parotid, submandibular, and sublingual

The enzyme ______________ begins digestion of protein in the stomach

pepsin

The enzyme that begins digestion of protein in the stomach is

pepsin

What enzyme is produced by the stomach?

pepsin

List four components of gastric juice.

pepsin lipase hydrochloric acid water

The inactive form of pepsin is

pepsinogen

Select all that apply Which are substances produced by the liver?

phospholipids glycogen plasma proteins bile

When hydrogen ions pass from the parietal cell into the duct of the gastric gland, they are exchanged for what ion?

potassium ion

Pepsin breaks down ______ into ______.

proteins and polypeptides

Select all that apply Indicate which of the following are functions of the adult liver.

removal of toxins from blood secretion of bile storage of glycogen, iron, vitamins A, D, and B12 carbohydrate, lipid, and protein metabolism

Select all that apply Which are functions of the liver?

removal of worn-out red blood cells detoxify blood formation of plasma proteins break glycogen down into glucose

The longitudinal wrinkles in the lining of the stomach are called gastric

rugae

The organ that is most effective in absorbing digestive products, water, and electrolytes is the ______.

small intestine

Which organ absorbs the greatest amount of nutrients?

small intestine

Select all that apply List the substances absorbed from the stomach.

small volumes of water alcohol lipid-soluble drugs

What structure(s) assist(s) with blocking the opening between the nasal cavity and the pharynx during swallowing, to prevent food from entering the nasal cavity?

soft palate and uvula

The organ that starts the digestion of proteins is the

stomach

What is the function of the gallbladder?

stores and concentrates bile

The salivary glands located on the floor of the mouth on the inside surface of the lower jaw, and that secrete a viscous fluid, are the __________ glands.

submandibular

What stimulates the secretion of hydrochloric acid (HCL) in the stomach? Select all that apply

the smell of food the taste of food the distention of the stomach secretin

What is the function of the uvula?

to block the entrance of food or drink into the nasal cavity

Describe the primary function of bile salts. They serve

to emulsify fats

What is the role of the secretions of the mucous neck cells?

to prevent the stomach from digesting itself

Gastrin functions to increase the production of HCl in the stomach.

true

The body utilizes the absorbed nutrients to produce ATP.

true

True or false: The large intestine has little or no digestive function.

true

The lingual frenulum is located _____, and attaches the tongue to the _____.

under the tongue; floor of the mouth

Intrinsic factor is necessary for the absorption of ______ from food in the small intestine.

vitamin b12

Each term relates to either mechanicaldigestion/propulsion or to chemical digestion. Drag each label into the appropriate box.

Mechanical Digestion and/or Propulsion - peristalsis, swallowing, segmentation, mastication Chemical Digestion - hydrochloric acid, salivary amylase, bile salts, pancreatic lipase

Put the steps of the enterogastric reflex in order.

1) chyme enters duodenum 2) stretch receptors are stimulated 3) sensory impulses travel to central nervous system 4) motor impulses inhibit peristalsis in stomach wall

Serous cells in salivary glands secrete a fluid containing an enzyme called salivary ___________ which aids in digestion of starch and glycogen. Mucous cells secrete a thick liquid called ___________, which lubricates the food during swallowing.

Blank 1: amylase Blank 2: mucus

Which events take place during the swallowing reflex?

Constrictor muscles relax to open the esophagus. Soft palate raises, preventing food from entering the nasal cavity. The epiglottis covers the larynx.

How does the function of the digestive system relate to the characteristics of life?

It provides energy that can be used in metabolic processes.

The structures surrounding the mouth opening that contain skeletal muscles and sensory receptors useful in judging the temperature and texture of foods are the

Lips

Classify each enzyme based on the substrate it decomposes.

PROTEINS: -pepsin-trypsin-chymotrypsin TRYPSINOGEN: -enterokinase FATS: -pancreatic lipase-intestinal lipase NUCLEIC ACIDS: -nucleases STARCH AND GLYCOGEN: -salivary amylase-pancreatic amylase DISACCHARIDES: -maltase-lactase-sucrase

Place the following labels in the appropriate spot to show the substrates and products of digestion.

SUBSTRATE 1 proteins 2 carbohydrates 3 lipids PRODUCT 1 amino acids 2 glucose 3 fatty acids & glycerol

The pancreatic enzyme that digests starch is called pancreatic

amylase

Produced in the stomach, a factor that is essential for the absorption of vitamin B12 by the small intestine is called ____________ factor.

intrinsic

Which gastric enzyme digests dietary fats in the stomach?

lipase

Label the events that lead to bile secretion.

1) chyme with fat enters duodenum 2) cholecystokinin (CCK) secretion 3) CCK stimulates gallbladder wall to contract 4) bile passes to duodenum 5) hepatopancreatic sphincter relaxes

What does pancreatic lipase break down?

fats

Most nutrients are absorbed from the small intestine into the blood capillaries, except for ______ which are absorbed into the lacteals.

fatty acids

What are gastric rugae?

folds of the stomach lining

In the ducts of the gastric glands, __________ ions are actively transported into the ducts in exchange for __________ ions which enter the parietal cells.

hydrogen;chloride

Once nutrients are absorbed into the body, what organ stores the nutrients for a later use?

liver

What molecules are absorbed into the lymph?

long chain fatty acids

Match the enzymes produced by intestinal mucosal cells with their digestive action.

peptidase - breaks down peptides into amino acids sucrase, maltase, lactase - breaks down disaccharides into monosaccharides intestinal lipase - breaks down fats into fatty acids and glycerol enterokinase - converts trypsinogen into trypsin

A salivary gland has two types of cells: ______ cells that produce a watery fluid containing salivary amylase to digest starch and glycogen, and ______ cells that produce a thicker secretion that binds food particles together and lubricates the bolus for swallowing.

serous; mucous

What are the three major salivary glands?

submandibular gland parotid gland sublingual gland

Which pair of salivary glands is located on the floor of the mouth and contains equal amounts of mucous and serous cells?

submandibular glands