digestive system review

Of the approximately 9.0 L of fluids contained in the digestive tract daily, only __________ L are eliminated with the feces.

.15

HCl in the stomach produces a pH of between ________ in the luminal fluid.

1.5-2

Only about _______ ml of the 500 ml of chyme that entered the colon is voided as feces.

150ml

Peristaltic contractions of the stomach occur about _____ times per minute when food makes it into the body & fundus.

3-5

Of the approximately 800 g of food ingested during a typical day, only about ____ g are eliminated as undigested food in the feces.

50g

Which of the following carbohydrates is NOT a disaccharide?

50g

Which of the following neurotransmitters stimulates smooth muscle contraction in the digestive tract?

ACh

All preganglionic ANS fibers release _______ while only postganglionic fibers of the sympathetic division release _________.

ACh and NE

List the primary two mechanisms that control the motility and secretion of the digestive system.

ANS hormones

_______ _______protects the wall of the large intestine from mechanical damage and from damage by bacterial acid.

Alkaline mucous

The vomiting reflex is coordinated in the _________.

Brain stem

The hormone ______ released by the duodenum cause gastric motility to decrease when fats are present in the duodenum.

CCK

The hormone _______ causes the gall bladder to contract and release bile into the small intestine

CCK

The intestinal hormone _____ causes contraction of the gall bladder and release of bile into the duodenum.

CCK

Lipids in the intestine cause the release of the hormone_______, while acid in the intestine causes the release of ______.

CCK, Secretin

The frequency of segmentation contractions is greatest in the _____.

Duodenum

The ________ reflex describes the communication between the intestine and the stomach.

Enterogastric

Which of the following is under voluntary control?

External anal sphincter

Gastric emptying would be slowed by which of the following:

Fats in the duodenum Acids in the duodenum Hypertonic solutions in the duodenum Distention of the duodenum All of the above

The hormone _________ causes the ileocecal sphincter to relax during the gastric phase.

Gastric

The hormone ______ regulates gastric secretion during the gastric phase of digestion.

Gastrin

The ________ reflex stimulates mass movements of the colon.

Gastroileal

Pockets formed by the contractions of the transverse and descending colon musculature are called

Haustra

The process by which food is received into the GI tract via the mouth is called _____________________.

Ingestion

____ reflexes stimulate the ileum to increase activity when food is in the stomach

Long

During the inter-digestive period, _______ _______ _______ occur about once every 90 minutes to move undigested materials toward the terminal ileum.

Mass motility complexes

Sustained, intense propulsive peristaltic contractions of the large intestine are called __________ ___________.

Mass movements

_____ regulate gastric juice secretion during the cephalic phase.

Nerves

The frequency of peristaltic contractions is regulated by ________ cells.

Pacemaker

List three emotions that may produce constipation

Pain Fever Depression

________ division innervation stimulates watery, enzyme-rich saliva secretion, whereas ________ division innervation stimulates, a mucus-rich, more viscous saliva secretion.

Parasympathetic, sympathetic

The first wave of contraction of the esophageal muscles is called ______ ______.

Primary peristalsis

If a food bolus does not make it all the way to the stomach, _________ peristalsis forces the bolus the remainder of the way.

Secondary

List the two major functions of the large intestine.

Storage and concentration of feces Absorption of water,salt, and vitamin k

The function of the epiglottis is to prevent a bolus from entering the _____.

Trachea

Parasympathetic innervation to the salivary glands is transmitted by cranial nerves number_______ and _______.

VII, IX

Which of the following is a function of HCl in the stomach?

activates pepsinogen, breaks down cell waslls, kills most bacteria, denatures proteins in food

List two main divisions of the digestive system.

alimentary canal; accessory digestive organs

The breakdown products (monomers) of proteins are __________ _________.

amino acids

List the three major nutrient classes

amino acids; carbohydrates; fats

List the two main brush border proteases

aminopeptidase; dipeptidase

List the only two substances that are absorbed across the stomach's mucosal epithelium

aspirin and alcohol

Chylomicrons exit the intestinal epithelial cells and then enter the ________ lymphatic capillaries.

basement

The single digestive function of the liver is to produce _____.

bile

List the four organic components of bile:

bile salts, lecithin, cholesterol, bilirubin,

Absorption of nutrients occurs through the mucosal epithelium and into either _______ or ______ vessels.

blood; lymphatic

The microvilli of the small intestine's epithelial cells form the ______ border.

brush

Intestinal digestive enzymes that are embedded in the epithelial microvilli membranes are called ________ ________ enzymes.

brush border

The final digestion of carbohydrates is accomplished with ______ ______ enzymes.

brush border

List the four regions of the stomach:

cardia; fundus; body; pylorus

List the three phases of digestive system processes

cephalic, gastric, intestinal

Triglycerides combine with lipoproteins inside the intestinal epithelial cells to form __________.

chylomicrons

List the three sheets of muscle in the stomach's muscularis externa:

circular; longitudinal; oblique

Sympathetic nervous system stimulation ________ digestive system activity.

decreases

List, in order from the pylorus to the colon, the three regions of the small intestine:

duodenum; ileum; jejunum

_____ slow intestinal motility and cause the pyloric sphincter to contract.

enkephalins

_________ cells of the mucosa secrete hormones into the blood.

enteroendocrine

Intestinal ________ converts (activates) trypsinogen into trypsin.

enterokinase

The mucosa includes a type of columnar ________that forms the inner lining of the lumen

epithelium

Migrating motility complexes are controlled by the central nervous system. true or false

false

Most water and salt are absorbed in the colon. . true or false

false

Once food is acidified in the stomach, amylase continues to digest starch. true or false

false

Only single amino acids are absorbed in the small intestine. true or false

false

Secretin stimulates gastric HCl secretion.

false

Segmentation moves chyme in only one direction. true or false

false

The cephalic phase of digestion is regulated by short reflexes. true or false

false

The colon epithelium produces substantial amounts of digestive enzymes. true or false

false

The esophagus is digestive in function. true or false

false

The esophagus secretes digestive enzymes. true or false

false

The breakdown products of triglycerides include monoglycerides and _______ _________.

fatty acids

List four functions of duodenal CCK.

gallbladder contraction and release of bile release digestive enzymes inhibits gastric emptying stimulates growth of pancreas and gall bladder mucousa

List 5 peptide hormones of the GI tract:

gastrin, cholecystokinin, secretin, glucose dependent insulinotropic peptide, motilin

List the two secretions that stimulate HCl release from parietal cells.

gastrin, histamine

Gastric motility ________ as the stomach begins to receive food.

increases

The muscularis mucosa has both ________ and _______ fibers that function in moving the villi to aid in digestion and absorption.

inner circular; outer longitudinal

GIP stimulates the pancreas to secrete_________.

insulin

The pancreatic hormone _______ regulates the absorptive state, while ______ regulates the postabsorptive state.

insulin, glucagon

Without _______ _______, vitamin B12, necessary for normal RBC development, can not be absorbed by the intestine.

intrinsic factor

Blood and lymph vessels of the mucosa are found in its ______ _______ connective tissue layer.

lamina propria

Pancreatic __________ is responsible for the majority of fat digestion.

lipase

During the cephalic phase _________ neural reflexes stimulate an increased production of gastric juice.

long

Digestive system reflexes that involve the brain are called ______ _______.

long reflexes

A meal consisting largely of fatty foods will take __________ to digest than a meal consisting of mainly of starchy food

longer

Bile salts surround monoglycerides and free fatty acids to form tiny droplets called ________.

micelles

From largest to smallest, list the three modifications of the small intestine's inner wall that function to increase surface area:

microvilli; villi; circular layer of muscle

______ stimulates motility of the intestine, thereby moving its contents toward the terminal ileum.

motilin

The four main layers of the digestive tract wall are

mucosa, submucosa, muscularis, serosa

The four main components of gastric juice are:

mucous, pepsinogen, HCl, intrinsic factor

The function of epithelial goblet cells is to secrete ________.

mucus

The smooth muscle layer of the mucosa is called the ________ _______.

muscularis mucosae

The built-in (intrinsic) network of nerve cells in the submucosa is the ______ ______.

nerve plexus

The network of neurons in between the two muscle layers of the muscularis externa is the ___________ ___________.

nerve plexus

Gastrin producing G-cells are found in the gastric glands located in the ________ region of the stomach

pH

The main digestive enzyme-producing organ in the body is the ______.

pancreas

The digestive enzyme ________ begins the breakdown of proteins in the stomach.

pepsin

The two types of movements produced by contractions of the muscularis externa are ____________ and ____________.

peristalsis; segmentation

Sympathetic NS innervation of the digestive tract is via____________ fibers.

postganglionic

_______ occurs when the combined action of two hormones is greater than the sum of their individual effects.

potentiation

List the four major functions of saliva.

protection, taste, lubrication, digestion

Gastrin is released from the ______ region of the stomach

pyloric

Three pairs of _____ _____ function to moisten food in the mouth.

salivary glands

List the three main substances that are absorbed in the large intestine.

salt, water, vitamins B&K

List the 4 main responses during the intestinal phase of digestion

secretion of bicarbonate secretion of digestive enzymes release of bile segmentation contractions of SI

List the two mechanisms that help to increase the surface area of lipids for subsequent digestion with pancreatic lipase.

segmentation; emulsification

Which of the following is not typically a stimulus for the vomiting reflex?

sleep

The small intestine typically________.

slows gastric emptying

The stimulation of __________ receptors triggers the gastric phase of digestion.

stomach stretch

The anus is lined with ______ _______ epithelium

stratified squamous

The mouth, with its ____ ____ epithelium, is involved in both chemical and ____ digestion.

stratified squamous; mechanical

The ___________ and ______________ plexuses are the two components of the enteric nervous system.

submucosal and myenteric

Name the brush border enzymes.

sucrase, dextrinase, glucoamylase

Both the sympathetic and parasympathetic divisions of the ANS stimulate the salivary glands. . true or false

true

Pepsin is inactivated in the duodenum.. true or false

true

Swallowing has both voluntary and involuntary components. true or false

true

The active transport of sodium is necessary for water absorption in the small intestine.

true

List the three major pancreatic proteases.

trypsin; chymotrypsin; carboxypeptidase

List the three major proteases (inactive forms) secreted by the exocrine pancreas

trypsinogen, chymotrypsinogen, procarboxypeptidase

List the 6 sphincters of the digestive tract:

upper esophageal; lower esophageal; pyloric; ileocecal' anal; external anal

The _______ nerve carries electrical signals from the brain to the stomach.

vagus

The ___________ nerve triggers the responses during the cephalic phase of digestion

vagus

The ____________ and _________ ____________ nerves carry parasympathetic impulses to the enteric nervous system.

vagus and pelvic splanchnic

Colic bacteria produce substantial quantities of ________ ___ as a by product of their metabolism.

vitamin K

The large intestine absorbs __________, __________, and ___________.

water; electrolytes; vitamins