APHY102- Digestive system chapter 17
It typically takes chyme ____ hours to move through the small intestine.
3-10
What secretes a thick, alkaline mucus into the duodenum in response to stimuli?
Brunner's glands
______ from the intestinal wall stimulates the release of pancreatic juice that has a high concentration of digestive enzymes.
Cholecystokinin
What stimulates goblet cells and intestinal glands to secrete their products?
Chyme provides both mechanical and chemical stimulation.
Place the segments of the small intestine in order of which food travels.
Duodenum, Jejunum, Ileum
What is the composition of mucosa?
Epithelium, connective tissue, smooth muscle
What is the forth step of fat absorption in the small intestine?
Fats are carried off by lymph in lacteals as chylomicrons.
What is the third step of fat absorption in the small intestine?
Fats are encased in chylomicrons
What is the second step of fat absorption in the small intestine?
Fats are reconstructed into intestinal cells
What products of fat digestion are absorbed by the small intestine?
Fatty acids and glycerol
What is the first step of fat absorption in the small intestine?
Fatty acids diffuse through intestinal cells.
The mesentery that extensors from the greater curvature of the stomach and loosely hangs over the small intestine like an apron is the ______ omentum.
Greater
What does pancreatic juice do?
Has a high bicarbonate ion concentration that helps neutralize chyme and cause the intestinal contents to be alkaline
Indicate where chemical digestion of carbohydrates occurs.
In the small intestine, using enzymes secreted by pancreas and those present on the intestinal mucosa; in the mouth, using enzymes secreted in saliva.
The second and longest part of the small intestine is the ______ which delivers chyme to the last part of the small intestine called the ______.
Jejunum; Ileum
The ______ is a highly vascular organ, enclosed in a fibrous capsule, and divided into lobes.
Liver
What is the function of the liver?
Metabolize carbohydrates. lipids & proteins; stores some substances; removes toxic substances from the blood; and secretes bile
What are the functions of motor movements in the alimentary canal?
Move the contents along the tract; mix the contents with fluids.
peptidase
Mucosal cells; breaks down peptides into amino acids
What stimulates the secretion of large volume of watery saliva?
Parasympathetic impulses
What factors enhance movements in small intestines?
Parasympathetic stimulation dissension of the stomach wall dissension of the duodenal wall
The mesentery is a double-layered extension of the ______, and is attached to the small intestine.
Peritoneum
pancreas
Produces and secretes pancreatic juice, containing digestive enzymes and bicarbonate ions, into small intestine
liver
Produces bile, which emulsifies fat
stomach
Secretes acid and enzymes. Mixes food with secretions to begin enzymatic digestion of proteins
______ from the duodenum stimulates the release of pancreatic juice that contains few digestive enzymes but has a high bicarbonate ion concentration.
Secretin
What is the lumen?
The opening in the digestive tract that food passes through
cephalic phase
The sight, taste, smell, or thought of food triggers parasympathetic reflexes. Gastric juice is secreted in response.
What function do the circular folds, villi, and microvilli lining the small intestine have in common?
They increase the surface area for maximum nutrient absorption.
Name the microscopic fingerlike projections of the small intestine lining that increase the surface area, allowing increased absorption.
Villi
double contrast barium enema
X-ray exam following ingestion of contrast agent highlights blockage in large intestine
pepsin
a protein-splitting enzyme that digests nearly all types of dietary protein into polypeptides; formed from pepsinogen in the presence of hydrochloric acid
What is the function of the large intestine?
absorbs water and electrolytes and forms and stores feces
large intestine
absorbs water and forms feces
Peptidases are enzymes that split peptides into what smaller molecules?
amino acids
What is a peptidase?
an enzyme that digests protein.
intestinal phase
as food enters the small intestine, it stimulates intestinal cells to release intestinal gastrin, which, in turn, briefly promotes the secretion of gastric juice from the stomach wall. this phase primarily inhibits gastric juice secretion
colon is divided into
ascending, transverse, descending, sigmoid
Where are the lingual tonsils located?
base of tongue
What does bile contain?
bile salts, bile pigments, cholesterol, electrolytes
fecal occult blood test
blood detected in feces sample
teeth
break food particles into smaller pieces; help mix food with saliva during chewing
Digestion of ______ begins in the mouth with the activity of salivary amylase and is completed in the small intestine by enzymes from the intestinal mucosa and pancreas
carbohydrates
What is the stomach divided into?
cardia, fundus, body, & pylorus
What does the large intestine consist of?
cecum, colon, rectum, anal canal
The condition in which the autoimmune response to eating gluten damages and destroys microvilli in the small intestine called ______ disease.
celiac
What are the three phases of gastric secretion?
cephalic, gastric, intestinal
pharynx
connects mouth to esophagus
lips
contain sensory receptors used to judge characteristics of foods
Protein metabolism in liver
dominates amino acids; forms urea; synthesizes plasma proteins; converts certain amino acids into other amino acids
Where are the palatine tonsils located?
either side of the tongue in the back of the mouth
Sigmoidoscopy and colonoscopy
endoscope views rectum and lower colon
Pancreatic juice contains
enzymes that digest carbohydrates, fats, proteins, nucleic acids
What is the composition of serosa?
epithelium, connective tissue
The ______ passes through the mediastinum and penetrates the diaphragm.
esophagus
gastric phase
food in stomach chemically and mechanically stimulates release of gastrin, which, in turn, stimulates secretion of gastric juices; reflex responses also stimulate gastric juice secretion
What are the stages of swallowing?
food mixes with salvia and forced into pharynx; involuntary reflex actions move the food into the esophagus; peristalsis transports food in the esophagus to the stomach
gastric lipase
gastric glands; begins butterfat digestion
pepsin
gastric glands; begins protein digestion
What hormone enhances gastric secretion?
gastrin
The tubular glands within the mucosa and submucosa of the small intestine are called intestinal ______.
glands
cheeks
hold food in mouth; muscles chew food
palate
holds food in mouth; directs food to pharynx
What controls movement of the intestinal contents from the small intestine into the large intestine?
ileocecal sphincter
As the food leaves the ______, it enters the large intestine.
ileum
pepsinogen
inactive form of pepsin; chief cells of the gastric glands
The sympathetic nervous system _______ propelling and mixing movements in the GI tract, which is the ______ effect by the parasympathetic nervous system
inhibits; opposite
What structures secrete a large amount of watery fluid that has a nearly neutral pit and is devoid of enzymes?
intestinal glands
What is the small intestine functions?
it receives secretion from the pancreas and liver, completes digestion of nutrients, absorbs the products of digestion and transports the residues to the large intestine.
Lactose intolerance involves a lack of functioning ______, an enzyme that degrades lactose.
lactase
The enzyme ______ digests lactose into glucose and galactose
lactase
A lymphatic capillary within the core of an intestinal villus, necessary for the absorption of lipids, is called a(n) ______.
lacteal
Describe the parotid salivary glands?
largest and secrete saliva rich in amylase
A chylomicron is a ______ droplet surrounded by ______.
lipid; protein
VLDL molecules transport triglycerides from the ______ to cells of the body. Once the triglyceride has been removed they are converted into ______ molecules.
liver; LDL
Describe the submandibular salivary gland
located in the floor of the mouth, produce viscus salvia containing amylase
Describe the sublingual salivary gland
located on the floor of the mouth, primary secrete mucus.
What is the jejunum?
longest part of the small intestine
What is the composition of submucosa?
loose connective tissue, blood vessels, lymphatic vessels, nerves
The ______ ______ ______, at the end of the esophagus, help prevent regurgitation of food from the stomach.
lower esophageal sphincter
mouth
mechanical breakdown of food; begins chemical digestion of carbohydrates
Intestinal digestive enzymes are embedded in the membranes of the ______, microscopic projections on a cell wall.
microvilli
What is the brush border?
microvilli from epithelial cells lining the small intestine
Which structures increase the surface area in the small intestine lining?
microvilli; circular folds; villi
small intestine
mixes food with bile and pancreatic juice; final enzymatic breakdown of food molecules; main site of nutrient absorption
tongue
mixes food with saliva; moves food toward pharynx; contains taste receptors
The movements of the small intestine include segmentation which ______ intestinal contents and peristaltic contracts which ______ intestinal contents.
mixes; propels
What product of carbohydrates digestion gets absorbed into the blood stream by the small intestine?
monosaccharides
What are the functions of the tongue?
move food toward the pharynx during swallowing; mix food with saliva during chewing
What is the function of muscularis?
movements of the tube and its contents
What are the four layers of the structure of the wall of the alimentary canal?
mucosa, submucosa, muscular, serosa
sucrase, maltase, lactase
mucosal cells; breaks down disaccharides into monosaccharides
intestinal lipase
mucosal cells; breaks down fats into fatty acids and glycerol
Enterokinase
mucosal cells; converts trypsinogen into trypsin
Salivary glands including mucous cells secrete what?
mucus
colorectal cancer gene test
mutations associated with colorectal cancer detected in DNA of cells shed with feces
What are the structures of the pharynx?
nasopharynx, oropharynx, laryngopharynx
intrinsic factor
necessary for vitamin b12 absorption in the small intestines; parietal cells of the gastric glands
What is the function of submucosa?
nourishes surrounding tissues, transports absorbed materials
What is the main function of the small intestine?
nutrient absorption
In the digestive system, water is absorbed through the process of ______, following the absorption of salts and organic nutrients.
osmosis
lipid metabolism in liver
oxidizes fatty acids, synthesizes lipoproteins, phospholipids and cholesterol, converts excess portions of carbohydrates molecules into fat molecules
The ______ is closely associated with the duodenum.
pancreas
nucleases
pancreas; break down nucleic acids into nucleotides
pancreatic lipase
pancreas; breaks down fats into fatty acids and glycerol
carboxypeptidase
pancreas; breaks down peptides into amino acids
trypsin, chymotrypsin
pancreas; breaks down proteins or partially digested proteins into peptides
pancreatic amylase
pancreas; breaks down starch and glycogen into disaccharides
The wavelike set of muscular contractions within the digestive tract that helps to propel contents along is called ________?
peristalsis
esophagus
peristalsis pushes food to stomach
Diarrhea is the result of a ______ in the small intestine that pushes all the contents, and water, into the large intestine.
peristaltic rush
digital rectal exam
physician palpates large intestine and rectum
carbohydrate metabolism in liver
polymerizes glucose to glycogen; breaks down glycogen to glucose; converts noncarbohydrates to glucose
secretion in liver
products and secretes bile
What is the function of serosa?
protection and lubrication
What is the function of mucosa?
protection, secretion, absorption
mucus
provides a viscous, alkaline protective layer on the stomach's inner surface; mucous cells
hydrochloric acid
provides the acid environment needed for protection and action of pepsin; parietal cells of the gastric glands
Bile pigments are products of ______ breakdown
red blood cell
rectum
regulates elimination of feces
blood filtering in liver
removes damaged red blood cells and foreign substances by phagocytosis
Detoxification in liver
removes toxins from the blood
Where is the liver located?
right upper quadrant
Salivary glands including serous cells secrete what?
salivary amylase
salivary amylase
salivary glands; begins carbohydrate digestion by breaking down starch and glycogen to disaccharides
What do the salivary glands do?
secrete saliva
salivary glands
secrete saliva, which contains enzymes that initiate breakdown of carbohydrates
The type of movement in the small intestine that is alternately contracting and relaxing of muscles that results in mixing the contents is called __________?
segmentation
In the small intestine, normal mixing movements are called ______ and normal propelling movements are ______.
segmentation; peristalsis
The ______ _____ extends from the pyloric sphincter to the large intestine.
small intestine
The byproduct of protein digestion gets absorbed into the blood stream in the ______ by the process of ______.
small intestine; active transport
What is the composition of muscularis?
smooth muscle cells in circular and longitudinal groups
The prefix "gastro" means
stomach
Chemical digestion of proteins begins in the ______ as a result of ______ activity, and is completed in the small intestine by enzymes from the intestinal mucous and the ______.
stomach; pepsin; pancreas
gallbladder
stores and concentrates bile and releases it into small intestine
What does the gallbladder do?
stores bile between meals
storage in liver
stores glycogen, vitamins A, D, and B12, iron and blood
The ______ plexus in the GI tract controls secretions and the _______ plexus is important in controlling GI motility.
submucosal; myenteric
The enzyme ______ digests sucrose into glucose and fructose.
sucrase
Where is the small intestines located?
suspended from the posterior abdominal wall from mesentery
What is mastication?
the act of chewing
What is digestion?
the process of mechanically and chemically breaking down food so they can be absorbed.
The parasympathetic nervous system controls digestive functions and alters the activity of the digestive system via the ______ nerve
valgus
many bacteria inhabit the large intestine, where they breakdown what undigestible substances?
vitamin K, vitamin B12, thiamine, and riboflavin
