Ch. 14 Digestive System Exam
Terms in this set (117)
taking in food
breaking food into nutrient molecules
movement of nutrients into bloodstream
elimination of feces from the digestive tract through the anus (rid of waste)
alimentary canal (GI tract)
extends from mouth to anus
Accessory digestive organs
teeth, tongue, digestive organs (assist digestion)
Function of mouth
mastication, tongue initiates swallowing, and taste buds allow for taste
function of pharynx
passageway for foods, fluids, and air
Food passes posteriorly from the pharynx into the....
oropharynx and laryngopharynx
Function of esophagus
conducts food by peristalsis, passageway for food only
alternating contractions of the muscle layers
Function of the stomach
temporary storage of food, site of food breakdown, chemical breakdown of protein begins, delivers chyme to the small intestine
function of small intestine
nutrient absorption and chemical digestion
large intestine function
dries out the indigestible food residue by absorbing water and eliminating these residues as feces
opening for elimination of feces
What does the tongue do?
mixes food with saliva and initiates swallowing
anchors tongue to floor of mouth
What are the four layers of the alimentary canal?
mucosa, submucosa, muscularis externa, serosa
innermost moist membrane that is mostly simple columnar epithelium and has a scanty smooth muscle layer; lines LUMEN
soft connective tissue with blood vessels, nerve endings, lymphoid tissue, and lymphatic vessels
smooth muscle; inner circular and outer longitudinal
outermost layer of the wall; contains fluid-producing cells
What are the sublayers of the serosa?
visceral and parietal peritoneum
innermost layer that is continuous with the outermost layer
the outer layer of the peritoneum that lines the interior of the abdominal wall
What are the two intrinsic nerve plexuses
submucosal and myenteric; they regulate mobility and secretory activity of the GI tract organs
where food enters the stomach from the esophagus
food empties into the small intestine at this location
cardia of stomach
body of stomach
pyloris of stomach
folds in the stomach that increase surface area
How does the stomach protect itself?
mucous cells produce alkaline mucus which protects wall from being damaged by acid and digestive enzymes
How does pepsinogen become pepsin?
When pepsinogen comes in contact with hydrochloric acid it breaks down into pepsin
helps with protein digestion
Where does protein digestion begin?
stomach (with pepsin)
regulates digestive activities of the stomach
Endocrine cells produce...
food storage tank, site of food breakdown, chemical breakdown of protein begins, and delivers chyme to the small intestine
What are the three muscle layers of the stomach?
longitudinal, circular, oblique
Location from the pyloric sphincter to the ileocecal valve
Subdivisions of small intestine
duodenum (5%), jejunum (35%), ileum (55%)
connective tissue that supports the small intestine and contains blood vessels to supply nutrients
What substance does the liver produce?
where is bile stores?
posterior end of oral cavity
base of tongue
where the main pancreatic duct and bile ducts join;
Where do the liver, gallbladder, and pancreas release their secretions?
How does the small intestine increase surface area?
villi, microvilli, and circular folds
Finger-like extensions of the intestinal mucosa that increase the surface area
on top of the villi; tiny projections of plasma membrane (brush border enzymes)
deep folds of the mucosa and submucosa; less and less of these as you go through the small intestine
collections of lymphatic tissue; capture and destroy bacteria in submucosa
subdivisions of large intestine
cecum, appendix, ascending, transverse, descending, sigmoid (colon), rectum and anus
external anal sphincter
skeletal muscle, voluntary
internal anal sphincter
smooth muscle, involuntary
accessory digestive organs
tongue, tonsils, teeth, liver, gallbladder, pancreas
How many permanent teeth are there?
Two major regions of the tooth
crown and root
process of chewing
visible part of tooth
Parts of crown
enamel, dentin, pulp cavity, and root canal
hardest substance in the body; outer substance of the body
found deep to the enamel and forms the bulk of the tooth; surround pulp cavity
mixture of mucus and serous fluids
A soft mass of chewed food formed by saliva/mucus
begins starch digestion
Where is the pancreas?
behind the stomach (posterior to peritoneum); extends across the abdomen from spleen to the duodenum
Functions of pancreas
produces insulin and glucagon; neutralizes acidic chyme coming from the abdomen
Largest gland in the body
What is the digestive role of the liver?
to produce bile
Where does bile leave the liver?
through the common hepatic duct and enters the duodenum through the bile duct
What do bile salts break down?
What happens when bile is in the gallbladder for too long?
the cholesterol it contains can crystalize and form gallstones
yellowing of the skin that occurs when bile is backed up in the liver and is in the bloodstream
chemical energy that drives cellular activities
substance used by the body for growth, maintenance, and repair
carbohydrates, lipids, proteins, water
vitamins and minerals
5 food groups
fruits, vegetables, grains, dairy, protein
the starches and sugars present in foods; mostly derived from fruits and vegetables, lactose from milk and glycogens from meats
saturated fats from animal products
all of the chemical reactions necessary to maintain life
substances are BROKEN DOWN to simpler substances
larger molecules are built from smaller ones (proteins building up structures)
major breakdown product product of carbohydrate digestion; fuel used to make ATP
as glucose is oxidized, carbon dioxide, water and ATP are formed
What are the steps of cellular respiration?
glycolysis, krebs cycle, electron transport chain
Occurs in cytosol; energizes a glucose molecule so it can be split into two pyruvic acid molecules and yield ATP
Krebs Cycle (Citric Acid Cycle)
occurs in mitochondria; produces all the carbon dioxide and water resulting from cellular respiration; yields a small amount of ATP
electron transport chain
hydrogen atoms are removed during glycolysis and krebs cycle and delivered to protein carriers; they are then split into hydrogen ions and electrons in the mitochondria; ELECTRONS give off tons of ATP
high blood sugar (glucose levels)
low blood sugar (glucose levels)
Functions of fat
insulate body, protect organs, build cell structures, and provide reserve energy
What role do fats have when carbohydrates are in limited supply?
Fats are oxidized to produce ATP
when fat oxidation/breakdown causes the blood to become acidic (when too much fat is broken down); can be very dangerous
Aside from producing bile, what other digestive roles does the liver have?
detoxifies drugs and alcohol, degrades hormones, produces cholesterol
T o F; the liver can regenerate if part of it is damaged or removed
stores carbohydrates in the liver; glucose molecules are removed from blood and combined to form this
formation of glycogen from glucose
glucose is released from the liver after conversion from glycogen
making more glucose from fats and proteins
Is cholesterol used to make ATP?
functions of cholesterol
building block of plasma membranes; basis of steroid hormones and vitamin D
Most cholesterol in the body is...
manufactured by the liver
low-density lipoprotein (LDL)
"bad cholesterol"; transports cholesterol from the liver to the body tissues
High-density lipoprotein (HDL)
"good cholesterol" in the blood, which protects against cardiovascular disease