A&P Chp 20 Digestive System
our salivary glands secrete how much saliva daily?
1 liter
each day the pancreas secretes _____ of pancreatic juice, essentially digestive enzymes and an alkaline fluid, into the small intestine
1.5 liters
about ______ of residue consisting of undigested food, sloughed off epithelial cells, minerals, salts, and bacteria, enter the _____ intestine each day.
500ml, large
proteins are complex molecules made up of folded and twisted chains of _____ _____ linked together by ____ _____.
amino acids, peptide bonds
the digestive process begins in the mouth, where salivary glands secrete the enzyme ______
amylase
enzymes contained in saliva begin the digestion process: _____ breaks down starch while ______ begins the digestion of fat.
amylase, lipase
where is the pancreas located?
behind the stomach
flow of blood through the liver step 3
blood filters through the sinusoids, allowing cells to remove nutrients (such as glucose, amino acids, iron, & vitamins) as well as hormones, toxins, & drugs. the lover secretes clotting factors, albumin, & glucose into the blood for distribution throughout the body
saliva moistens food and transforms it into a mass called _____ that can be swallowed easily.
bolus
digestion
breaks down food physically and chemically, and transforms it into a substance that cells can use
flow of blood through the liver step 6
canaliculi carry bile secreted by the hepatic cells and ultimately drain into the right and left hypatic ducts
portal vein
carries oxygen-poor but nutrient-rich blood from the digestive organs and spleen to the liver
internal sphincter
composed of involuntary smooth muscle
external sphincter
composed of voulntary skeletal muscle
soft palate
consists of mostly skeletal muscle; forms an arch between the mouth and the nasopharynx
just below the _____, the digestive tube expands to form the ____, a muscular sac whose primary function is to _____ _____.
diaphragm, stomach, store food
the stomach prepares food for ______ (most of which occurs in the intestines)
digestion
while enzymes in the stomach partially digest protein as well as small amounts of starch and fat, most of the _______ ______ and the absorption of ____, takes place in the _______. ____ is also absorbed mostly by the small intestine.
digestion process, nutrients, intestine, alcohol
bile reaches the gallbladder through a series of _____. it leaves the liver by the right and left _____ ducts. these two ducts converge to form the _____ _____ ____, which goes on to become the _____ ____ ____. bile from the liver first fills the common bile duct before backing up into the gallbladder through the cystic duct.
ducts, hepatic, common hepatic duct, common bile duct
the facilitate digestion, the fat must first be broken into small droplets, a process called ______.
emulsification
the pancreas is both an ____ and _____ gland. its endocrine function centers on ____ _____ that secrete insulin and glucagon
endocrine, exocrine, pancreatic islets
proteases
enzymes working in the stomach and small intestine to break peptide bonds
most of the pancreas consists of _______ tissue
exocrine
greater omentum
extends from the greater curvature of the stomach and hangs down over the small intestines like an apron; is a portion of the mesentery
lesser omentum
extends from the lesser curve of the stomach to the liver
T or F: the anus has only one sphincter
false
hard palate
formed by portions of the maxillae and the palatine bones; separates the mouth from the nasal cavity
the liver has _____ lobes, two of the lobes (the right and left lobes) are visible from an ____ view
four, anterior
the muscles of the stomach contract and churn to break food into small particles and to mix it with ______ _____.
gastric juice
hepatic artery
goes to the liver; delivers oxygenated blood from the aorta to the liver
as soon as the chyme enters the duodenum, pepsin is _____. at that point the pancreatic enzymes _____ ______ assumes the task of breaking the peptide bonds.
inactivated, trypsin, chymotypsin
flatus
intestinal gas
duodenum
is the first 10 inches of small intestine; is about 12 finger breadths long; receives chyme from stomach and pancreatic juice and bile; more digestive processes occur here than in any other part of intestine
once the fat is emulsified, pancreatic _____ (the main fat-digesting enzyme) begins to digest the fat.
lipase
the digestive tract includes the
mouth, pharynx, esophagus, stomach, large intestines, small intestines, rectum, & anus
flow of blood through the liver step 1
nutrient-rich blood from stomach and intestine enters the lobule through small branches of the portal vein
flow of blood through the liver step 2
oxygen-rich blood enters the lobule through small branches of the hepatic artery
in the stomach, the enzyme _____ hydrolyzes the peptide bonds between certain amino acids
pepsin
brush border enzymes called _____ break the remaining chains into individual amino acids, which are then absorbed into the bloodstream.
peptidases
flow of blood through the liver step 4
phagocytic cells called Kupffer cells remove bacteria, worn-out red blood vells, and debris from the bloodstream
haustra
pouches along the length of the large intestines
chyme leaves the stomach and enters the duodenum by passing through the _____ _____ which is in between the end of the stomach and before the duodenum
pyloric sphincter
_______ moistens the mouth and lubricates and protects the teeth; also plays an important role in taste
saliva
acinar cells
secrete digestive enzymes in an inactive form
parietal cells
secrete hydrocholric acid and intrinsic factor (which is necessary for the absorption of vitamin B12). hydrocholric acid helps kill microbes in swallowed food
mucous cells
secrete mucus, which protects the stomach lining and keeps the stomach from digesting itself
enteroendocrine cells
secrete the hormone ghrelin (which stimulates the hypothalamus to increase appetite)
saliva
secreted by salivary glands; a clear fluid consisting mostly of water; also contains mucus, an enzyme that kills bacteria, antibacterial compounds, electrolytes, and two digestive enzymes
chyme
semi-fluid mixture consisting of particles of food mixed with digestive juices
falciform ligament
separates the right and left lobes; also serves to anchor the liver
most chemical digestion and most nutrient absorption occurs in the _____ ____
small intestine
gallbladder
stores and concentrates bile
the liver is responsible for
storing and releasing glucose, processing vitamins and minerals, filtering toxins, and recycling old blood cells
hepatitis
swelling and inflammation of the liver; is a symptom rather than a condition; term often used to refer to a viral infection of the liver
hemmorrhoids
swollen, engorged veins in the anal canal
the accessory organs include the
teeth, tongue, salivary glands, liver, pancreas, gallbladder
ascites
the accumulation of fluid in the peritoneal cavity
secretin
the acid in chyme also triggers the duodenum to release secretin. secretin causes the bile and pancreatic ducts to release bicarbonate, which helps neutralize the stomach acid entering the duodenum.
cholecystokinin (CCK)
the arrival of chyme in the duodenum stimulates the duodenum to secrete the hormone CCK. CCK causes gallbladder contraction, forcing bile into the bile duct, and the release of pancreatic enzymes
flow of blood through the liver step 5
the central vein carries the processed blood out of the liver
where is stomach acid neutralized and pancreatic enzymes begin the task of chemical digestion?
the duodenum
mechanical digestion
the first phase of digestion; involves physically breaking down food into smaller pieces, beginning with chewing and continuing contractions and churning in the stomach and small intestines
what is the body's largest gland?
the liver
chemical digestion
the second phase of digestion uses digestive enzymes produced in the salivary glands, stomach, pancreas, and small intestines to break down food particles into nutrients (such as glucose, amino acids, and fatty acids) that cells can use
wheres the liver located?
the upper right abdomen, below the diaphragm
gastrin
this hormone from the stomach and the duodenum triggers both gallbladder contraction and pancreatic enzyme secretion. however, it exerts a much less powerful effect than does the CCK
hepatic lobules
tiny, six-sided cylinders; fill the interior of the liver; are the functional units of the liver
T or F: teeth help start digestion because they help chew food
true
the _____ nerve and the hormones cholecystokinin, gastrin, and secretin stimulate the secretion of bile and pancreatic juice.
vagus
the large intestines absorbs large amounts of _____ from the residue before passing the resulting waste material (______) out of the body
water, feces
peristalsis
wave-like muscular contractions that propel food toward the stomach once a bolus enters the esophagus