Biology: Chapter 9 - The Digestive System
__-cells secrete gastrin, a peptide hormone that increases HCl secretions and gastric motility.
G
Gut ____ produce vitamin K and biotin (vitamin B7)
bacteria
There are ____ in the intestines that hydrolyze the disaccharides and produce a methane gas as a product. When disaccharides are left undigested, they can have an osmotic pull resulting in diarrhea.
bacteria
Complex fluid composed of bile salts, pigments, and cholesterol
bile
The liver synthesizes ___, which can be stored in the gallbladder or secreted into the duodenum directly.
bile
Connects liver with both the gallbladder and small intestine.
bile duct
Connects the liver with both the gallbladder and small intestine. The bile is produced in the liver and travels down the bile ducts where it may be stored in the gallbladder or secreted into the duodenum.
bile ducts
Derived from cholesterol and serve role in mechanical digestion of fats and ultimately facilitates chemical digestion of lipids.
bile salts
Combination of secretions from the other two cell types in the gastric glands, chief and parietal.
gastric juice
A peptide hormone that increases HCl secretions and gastric motility.
gastrin
G-cells secrete ___.
gastrin
Induces parietal cells in the stomach to secrete more HCl and signals stomach to contract, mixing its contents
gastrin
Hormone secreted by the stomach and pancreas to stimulate feelings of hunger
ghrelin
Secreted by the stomach and the pancreas and stimulates feelings of hunger
ghrelin
Hormone secreted by the pancreas to stimulate feelings of hunger
glucagon
Secreted by the pancreas and stimulates feelings of hunger.
glucagon
____ and ____ promote hunger
glucagon, ghrelin
The liver can take excess sugar to create ____, the storage form of glucose. It also stores fats as _____.
glycogen, triacylglycerols
Bilirubin is the byproduct of ___ breakdown. It travels to the liver where it is conjugated and secreted into bile.
hemoglobin
Molecules absorbed by the capillaries in the villi of the small intestine travel to the liver via the ___ ___ circulation
hepatic portal
Vessel where all the blood from the abdominal portion of the digestive tract drains into to be processed by the liver and drain back into the inferior vena cava.
hepatic portal vein
Where all the blood from the abdominal portion of the digestive tract drains. This blood is processed by the liver and drains in the inferior vena cava.
hepatic portal vein
Parietal cells secrete ____ ____ and ____ ____
hydrochloric acid, intrinsic factor
Bile emulsifies fats and cholesterol into micelles, and also ___ surface area of fats to increase the rate at which lipase can act.
increases
Digestion that involves the oxidation of glucose and fatty acids for energy
intracellular
Type of digestion that involves the oxidation of glucose and fatty acids to make energy.
intracellular
Needed for vitamin B12 absorption
intrinsic factor
Parietal cells can secrete ___ ___, which is a glycoprotein involved in the proper absorption of vitamin B12
intrinsic factor
The ___ and ___ of the small intestine are primarily involved in absorption
jejunum, ileum
A lymphatic channel that takes up fats for transport into the lymphatic system
lacteal
Each villus has a capillary bed for absorption of water-soluble nutrients and a ___
lacteal
Fat-soluble compounds, such as fats, cholesterol, and fat-soluble vitamins enter the ____.
lacteal
Chylomicrons enter the lymphatic system through ____, which converge and enter the venous circulation through the thoracic duct, which empties into the left subclavian vein.
lacteals
The ___ ___ absorbs water and salts, forming semisolid feces.
large intestine
___ and ____ stimulate feelings of satiety
leptin, cholecystokinin
____ and ____ (CKK) promote satiety
leptin, cholecystokinin
Enzyme produced by the salivary glands that catalyzes the hydrolysis of lipids.
lipase
Pancreatic enzyme that breaks fats into fatty acids and glycerol.
lipase
The liver provides glucose through glycogenolysis and gluconeogenesis. It also mobilizes fats in ___
lipoproteins
Organ that contains 2 unique structures for communication with the digestive system: bile duct and hepatic portal vein.
liver
Organ that synthesizes bile, processes nutrients (through glycogenolysis, storage and mobilizations of fats, and glucogenesis), produces urea, detoxifies chemicals, activates or inactivates medications, produces bile, and synthesizes albumin and clotting factors
liver
Processes nutrients, produces urea, produces bile, synthesizes albumin, and clotting factors.
liver
Food enters the stomach through the ____ _____ (cardiac) sphincter.
lower esophageal
The oral cavity plays a role in mechanical digestion through ____ and chemical digestion through ____ production.
mastication, saliva
_____ starts mechanical digestion of food in the oral cavity, while the ____ ____ begin chemical digestion.
mastication, salivary glands
Digestion that includes the physical breakdown of large food particles into smaller food particles. This does not involve breaking chemical bonds.
mechanical
The physical breakdown of large food particles into smaller food particles.
mechanical digestion
Bile = ___ digestion whereas lipase = ____ digestion
mechanical, chemical
Found on villi and serve to increase the surface area available for absorption.
microvilli
Starches and Carbs --> ____
monosaccharides
starches and carbohydrates --> ____
monosaccharides
Secretion is also considered an entergastrone, which means it slows ____ through digestive tract to allow for increased time for digestive enzymes to act on chyme
motility
Cells that produce bicarbonate rich mucus that protects the muscular wall from the harshly acidic environment and proteolytic environment
mucous
Cells that produce bicarbonate rich mucus that protects the muscular wall from the harshly acidic environment and proteolytic environment of the stomach.
mucous
____ cells produce bicarbonate-rich mucus to protect the stomach
mucus
The pharynx is divided into 3 parts: ___, ___, and ___
nasopharynx, oropharynx, laryngopharynx
Pancreatic juices are a complex mixture of several enzymes in a bicarbonate rich alkaline solution. The bicarbonate is used to ____ the acidic chyme and provide an ideal environment of 8.5
neutralize
Organ responsible for blood sugar maintenance through insulin, glucagon, and somatosatin. Also made up of exocrine cells called acinar cells that produce pancreatic juices
pancreas
Juices that break down large polysaccharides into small disaccharides and is responsible for carbohydrate digestion.
pancreatic
____ peptidases include trypsinogen, chymotrypsinogen, and carboxypeptidases that are all released in their zymogen form. They are activated by enteropeptidases.
pancreatic
The bile duct system merges with the ___ ___ before emptying into the duodenum.
pancreatic duct
All of the glands of the body except the sweat glands are innervated by the ____ nervous system
parasympathetic
Nervous system that increases secretion from all of the glands of the digestive system and promotes peristalsis.
parasympathetic
The presence of food in the oral cavity triggers a neural circuit that ultimately leads to increased ___ stimulation of the glands.
parasympathetic
Small fatty acids are diffused into the capillaries in the villi of the small intestine via _____ _____ transport or facilitated diffusion
secondary active
Glucose, fructose, galactose, and amino acids are absorbed by the small intestine by ___ ___ transport and ___ ___.
secondary active, facilitated
Simple sugars such as glucose, fructose, galactose, and amino acids are absorbed by ___ ___ transport, and ___ ___ into the epithelial cells lining the small intestine
secondary active, facilitated diffusion
Anus consists of __ sphincters
2
Fat soluble vitamins
ADEK
Hormones that trigger the sensation of thirst encouraging the behavior of fluid consumption.
ADH, aldosterone
Parietal cells secrete intrinsic factor, a glycoprotein involved in the proper absorption of vitamin ___.
B12
Hormones that stimulate feelings of saiety
CKK and leptin
The pyloric glands contain ___ cells that secrete ___, a peptide hormone.
G, gastrin
The stomach is a highly muscular organ located in the upper left quadrant of the abdominal cavity. It uses __ and enzymes to digest food.
HCl
Organ responsible for majority of chemical digestion and has some minor involvement in absorption.
Small intestine
Involves the transport of products of digestion from the digestive tract into the circulatory system for distribution to the body's tissues and cells.
absorption
The salivary glands, pancreas, liver, and gallbladder are the _____ ______ of digestion
accessory organs
___ ___ help provide the enzymes and lubrication necessary to aid the digestion of food.
accessory organs
___ cells in the pancreas produce pancreatic juices that contain bicarbonate, pancreatic amylase, pancreatic peptidases (trypsinogen, chymotrypsinogen, carboxypeptidases A and B) and pancreatic lipase
acinar
Protein that maintains plasma oncotic pressure; also a carrier for many drugs and hormones.
albumin
Runs from the mouth to the anus and is sectioned off by sphincters.
alimentary canal
Proteins ---> ___ ___
amino acids
Brush border enzyme that removes the N terminal amino acid from a peptide.
aminopeptidase
Brush border peptidases include ____ and ____
aminopeptidase, dipeptidase
Enzyme produced by the salivary glands that hydrolyzes starches into smaller sugars.
amylase
Saliva contains ___ and ___ enzymes
amylase, lipase
The salivary enzymes include ___ and ___.
amylase, lipase
___ ___ and ____ promotes thirst.
antidiuretic hormone, aldosterone
____ ____ and ___ trigger the sensation of thirst encouraging the behavior of fluid consumption
antidiuretic hormone, aldosterone
Opening through which waste is eliminated.
anus
Finger like projection once through to be vestigial, but plays a role in warding off certain bacterial infections.
appendix
The main components of bile are ___ ___, ___, and ____.
bile salts, pigments, bilirubin.
When chyme goes through the pyloric sphincter and enters the duodenum, this causes the release of ___ ___ enzymes.
brush border
Enteropeptidases, dissacsharidases, chymotrypsinogen, aminopeptidases, and dipeptidases.
brush border enzymes
Water-soluble compounds, such as monosaccharides, amino acids, water-soluble vitamins, small fatty acids, and water, enter the ____ ____.
capillary bed
Villi contain a ___ ___ and a ___, a vessel of the lymphatic system.
capillary bed, lacteal
Digestion of ___ and ___ are initiated in the mouth.
carbohydrates, fats
Outpocketing of large intestine that accepts fluid exiting the small intestine through the ileocecal valve. Also the site of attachment of the appendix.
cecum
The ___ is an outpocketing that accepts fluid from the small intestine through the ileocecal valve and is the site of attachment of the ___.
cecum, appendix
Digestion that involves the enzymatic cleavage of chemical bonds.
chemical
The enzymatic cleavage of chemical bonds, such as the peptide bonds of proteins or the glycosidic bonds of starches.
chemical digestion
Cells that secrete pepsinogen
chief
Cells that secrete pepsinogen, an inactive form of a proteolytic enzyme that becomes active upon exposure to acid
chief
___ cells secrete pepsinogen, a protease activated by the acidic environment of the stomach.
chief
Hormone secreted in response to entry of chyme into the duodenum and stimulates the release of both bile and pancreatic juices; also promotes satiety.
cholecystokinin
____ stimulates bile release from the gallbladder, release of pancreatic juices, and sateity.
cholecystokinin
Fat soluble vitamins dissolve directly into ___ and either the body. Water-soluble vitamins diffuse across the cells into the plasma.
chylomicrons
Larger fats such as glycerol and cholesterol move separately into the intestinal cells before reforming into triglycerides and being packaged into ____.
chylomicrons
After mechanical and chemical digestion in the stomach, the food particles are called ___.
chyme
The released of CCK from the pancreas causes the gallbladder to ___ and push bile out into the ____ __.
contract, biliary tree
The stomach has a lesser and greater ____, and is thrown into folds called ____. It has numerous cells secretory cells that line the stomach.
curvature, rugae
The fundus and body contain mostly ___ glands
gastric
Combination of secretions from the other two cell times in the gastric glands, chief and parietal.
gastric juice
The liver ___ exogenous and endogenous compounds. It can modify ammonia to ___. It also detoxifies and metabolizes alcohol and medications.
detoxifies, urea
The breakdown of food into its constituent organic molecules.
digestion
Brush border enzyme that cleaves the peptide bonds of dipeptides to release free amino acids.
dipeptidases
_____ are brush-border enzymes that break down maltose, isomaltose, lactose, and sucrose into monosaccharides.
disaccharidases
Pancreatic juices are transferred to the duodenum via the ___ system, which empties through the major and minor duodenal ___.
duct, papillae
Brush border enzymes are present on the luminal surface of cells lining the _____ and breaks down trimers and dimers into absorbable monomers.
duodenum
The ____ is responsible for most of chemical digestion
duodenum
The ____ is the first part of the small intestine and is primarily involved in chemical digestion.
duodenum
The _____ nervous system is in the wall of the alimentary canal and controls peristalsis. Its activity is upregulated by the parasympathetic nervous system and downregulated by the sympathetic nervous system
enteric
Collection of 100,000,000 neurons present in the walls of the digestive tract that govern the function of the gastrointestional system.
enteric nervous system
Collection of more than 100,000,000 neurons present in the walls of the digestive system that govern the function of the gastrointestional system.
enteric nervous system
Enzyme critical for activation of trypsinogen, a pancreatic protease, to trypsin.
enteropeptidase
Enzyme involved in the activation of other digestive enzymes from the accessory organs of digestion.
enteropeptidase
_____ activates trypsinogen and procarboxypeptidases, initiating an activation cascade.
enteropeptidase
Critical for activation of trypsinogen and procarboxypeptidases A and B
enteropeptidases
Cartilaginous structure that folds down to cover the laryngeal inlet to prevent food from entering the larynx during swallowing.
epiglottis
Cartilaginous structure that folds down to cover the laryngeal inlet to prevents food from entering the larynx during swallowing.
epiglottis
The ____ propels food to the stomach using peristalsis.
esophagus
Digestion that includes the process by which nutrients are obtained from food within the lumen of the alimentary canal
extracellular
Type of digestion that occurs in the lumen of the alimentary canel
extracellular
Lipids ---> free ___ ___ and ___
fatty acids, glycerol
Lipids ---> ___ ___ ___ and ____
free fatty acids, glycerol
The stomach has four parts: ___, ___, ___, ___.
fundus, body, antrum, pylorus
Organ that stores and concentrates bile.
gallbladder
The ___ stores and concentrates bile
gallbladder
Cells that secrete hydrogen ions as HCl, which cleaves pepsinogen to pepsin.
parietal
Gastrin induces ____ cells in the stomach to secrete more acid and signals the stomach to contract, mixing its contents.
parietal
____ cells secrete hydrochloric acid and intrinsic factor.
parietal
A protease activated by the acidic environment of the stomach
pepsin
Digests proteins by cleaving peptide bonds near aromatic amino acids resulting in short peptide fragments
pepsin
Stomach enzyme that digests proteins by cleaving peptide bonds near aromatic amino acids resulting in short peptide fragments.
pepsin
Chief cells secrete _____.
pepsinogen
Enzymes that break down proteins.
peptidases
Rhythmic contractions of the gut tube to move materials through the system
peristalsis
The pathway of the digestive tract is: oral cavity ---> ___ ---> ___ ---> ___ ---> ___ ---> ___ ---> ____
pharynx, esophagus, stomach, small intestine, large intestine, rectum
The antrum and pylorus contain mostly ___ glands
pyloric
Chyme passes into the duodenum through the ___ ___
pyloric sphincter
Storage site for feces and consists of indigestible material, water, bacteria, and certain digestive secretions that are not reabsorbed.
rectum
The ___ stores feces, which are then excreted through the ___.
rectum, anus
Aids mechanical digestion by moistening and lubricating the food. The presence of food triggers a neural circuit that leads to increased PSNS stimulation of the glands. This contains amylase and lipase.
saliva
A peptide hormone that causes pancreatic enzymes to be released into the duodenum, regulates digestive tract pH by reducing HCl digestion from parietal cells, and bicarbonate secretion from the pancreas
secretin
Peptide hormone that causes pancreatic enzymes to be released into the duodenum, regulates digestive tract pH, and slows motility through the digestive tract for maximal absorption.
secretin
____ stimulates the release of pancreatic juices into the digestive tract and slows motility
secretin
The duodenum not only secretes brush border enzymes, it also secretes hormones like ___ and ___ into the bloodstream.
secretin, CKK
Muscular tube that connects the pharynx to the stomach. The upper half consists of ___ muscle, whereas the bottom half consists of ___ muscle.
skeletal, smooth
The top of the esophagus mostly consists of ___ muscle, whereas the bottom mostly consists of ___ muscles.
skeletal, smooth
Circular smooth muscles around the canal that can contract to allow compartmentalization of function.
sphincters
The villi and microvilli increase the ___ ___ available for absorption
surface area
Large and small intestine are home to many different species of bacteria, with which humans have a ____ relationship with.
symbiotic
Nervous system that slows peristalsis.
sympathetic
Enteropeptidase activates _____ and _____ into active forms
trypsin, procarboxypeptidases
Enteropeptidase activates ____ into ___. This then activates zymogens and ______ A&B.
trypsinogen, trypsin, procarboxypeptidases
Gastric glands respond to signals from the ___ nerve of the PSNS, which is activated by the brain in response to the sight, taste, and smell of food.
vagus
Small fingerlike projections from the epithelial lining.
villi
The small intestine is lined with ___, which are small, fingerlike projections from the epithelial lining; each with a microvilli
villi
The small intestine is lined with ___, which are covered with ___
villi, microvilli
Passes intracellularly and paracellularly to reach blood.
water
