Nutrition Chapter 3 Study Guide
Crohn's disease
A form of ulcerative colitis in which ulcers form throughout the GI tract and not just in the colon.
Cholecystokinin
A hormone released by the duodenum that stimulates the gallbladder to release bile
gastrointestinal tract (GI)
A long tube comprised of the organs of the digestive tract. Extends from the mouth through the esophagus, stomach, and small and large intestines to the anus
cecum
A pouch at the beginning of the large intestine that receives waste from the small intestine
digestion
A process that breaks down food into the individual molecules small enough to be absorbed through the intestinal wall
Large intestine action
Chemical Digestion: Some remaining food residues are digested by bacteria Absorption: Salts, water, and some vitamins, are reabsorbed Propulsion: Compacts waste into feces
The bolus slides down this tube, called the _________ , which connects the pharynx to the stomach.
ESOPHAGUS
Rectum action
Elimination: Feces are temporarily stored before voluntary release through the anus
what does the excretory system do?
Filters blood and eliminates waste
gastric pits
Indentations or small pits in the stomach lining where the gastric glands are located
gastroenteritis
Inflammation of the lining of the stomach and intestines; also known as stomach flu.
Mouth action
Ingestion: food enters GI tract Mechanical digestion: Mastication mixes food with saliva, forming bolus Chemical digestion: Salivary amylase begins carbohydrate breakdown
Stomach action
Mechanical Digestion: Mixes and churns the bolus with acid, enzymes, and gastric fluid into liquid called chyme Chemical Digestion: Pepsin begins digestion of proteins Absorption: A few fat-soluble substances are absorbed through the stomach wall
Small intestine action
Mechanical Digestion: Segmentation mixes chyme with digestive juices; peristaltic waves move it along the tract Chemical Digestion: Digestive enzymes from pancreas and brush border digest most classes of food Absorption: Nutrients are absorbed into blood and lymph through enterocytes
What controls the flow of food from one organ to the next
Peristalsis
Pharynx and Esophagus action
Propulsion: Swallowing and peristalsis move the bolus from mouth to stomach
hemorrhoid
Swelling in the veins of the rectum and anus.
gastroesophageal reflux disease (GERD)
The backward flow of stomach contents into the esophagus due to improper functioning of the LES, resulting in heartburn.
constipation
The infrequent passage of dry, hardened stools.
enterohepatic circulation
The process of recycling bile from the large intestine back to the liver to be reused during fat digestion
sphincter
a circular ring of muscle that opens and closes in response to nerve input -acts as a oneway door allowing the mixture of food in one organ but not back out
emulsify
a compound that keeps two incompatible substances mixed together
enterogastrones
a group of GI tract hormones, produced in the stomach and small intestine, the controls gastric motility and secretions
gastric inhibitory peptide
a hormone produced by the small intestine that slows the release of chyme from the stomach
peptide YY
a hormone produced in the small intestine that reduces hunger
ghrelin
a hormone produced in the stomach that stimulates hunger
secretin
a hormone secreted from the duodenum that stimulates the stomach to release pepsin, the liver to make bile, and the pancreas to release digestive juices
bolus
a soft mass of chewed fodo
gastrin
a stomach hormone releases after eating a meal the stimulates the release of hydrochloric acid
endocytosis
a type of active transport in which the cell membrane forms an indentation, engulfing the substance to be absorbed
enterocytes
absorptive epithelial cells that line the walls of the small intestine
more than one organ secretes
amylase and lipase
colon
another name for the large intestine
When fat enters the duodenum, the gallbladder secretes an emulsifier called __________ to break up the large fat globules.
bile
describe how the cardiovascular system distributes nutrients throughout the body
blood transports oxygen, nutrients, hormones, and waste products
What does segmentation do?
breaks mixtures into smaller pieces and combining with digestive juices
hydrolysis
breaks the bond between two molecules with water
pancreas secretes
carboxypeptidase and trypsinogen
hepatic vein
carries blood away from liver
epiglottis
cartilage at the back of the tongue that closes off the trachea during swallowing
Disorders related to small intestine
celiac disease
which of the following gastrointestinal tract conditions alters the structure of the small intestine resulting in malabsorption?
celiac disease
goblet cells
cells throughout the GI tract that secrete mucus
mastication
chewing food
secretes digestive enzymes only
chief cells of the stomach
lymphatic system
circulates fat soluble nutrients throughout body
salivary glands
cluster of glands located underneath and behind the tongue that release saliva in response to the sight, smell, and taste of food
hepatic portal vein
connects intestinal tract to liver
small intestine secretes
dipeptidase, sucrase, and lactase
segments of the small intestine
duodenum, jejunum, and ileum
These absorptive epithelial cells of the small intestine are called _________ .
enterocytes
Without the cartilage at the back of the tongue called the ________ , food would enter the trachea during swallowing.
epiglottis
elimination
excretion of undigested and unabsorbed food through feces
Describe how the lymphatic system distributes certain nutrients through the lymph
fat soluble nutrients are transported
rectum
final 8 inch portion of the large intestine
stores bile
gallbladder
Disorders related to stomach
gastroenteritis and peptic ulcers
Disorders related to esophagus
gastroesophageal reflux disease
crypts
glands at the base of the villi; they contain stem cells that manufacture young cells to replace the cells of the villi when they die
how do enzymes chemically digest foods
hydrolysis: enzymes speed up the breakdown of foods
Chyme passes through the _______, a sphincter that connects the ileum with the ascending colon.
ileocecal valve
liver
largest organ in the body, aids in digestion by secreting bile
probiotics
live organisms which confer a health benefit on the host
The bolus passes through the _______ into the stomach to mix with gastric digestive juices.
lower esophageal sphincter
what is the difference about the nutrients transported through the lymph
lymph carries fat soluble
During __________, teeth mechanically cut and grind food into smaller pieces as the tongue mixes it with saliva.
mastication
What does peristalsis do?
moves food through the digestive system, influencing motion
stomach
organ that mixes and churns food with digestive juices and acid to form chyme
This large gland, located near the stomach, releases digestive enzymes after a meal and also secretes insulin and glucagon to control blood glucose levels. This accessory organ is called the _______ .
pancreas
secretes hydrochloric acid
parietal cells of the stomach
stomach secretes
pepsinogen
Food is propelled forward by rhythmic contractions called _______ that move food down the esophagus and through the stomach.
peristalsis
gastric glands
produce gastric juices
enzymes
proteins that increase the rate of chemical changes or catalyze chemical reactions
how does the nervous system communicate with the GI tract
receptors within the walls of the GI tract respond to charge in the cells
pancreas
releases digestive enzymes after a meal. also secretes the hormones insulin and glycogen, which control blood glucose
The secretions that make up _________ are produced in the glands located underneath and behind the tongue and contain the enzyme amylase to chemically digest carbohydrate.
saliva
saliva
secreted from the salivary glands that softens and lubricates food, and begins the chemical breakdown of starch
Where does most digestion occur?
small intestine
secretes digestive enzymes and other substances
small intestine, pancreas, and salivary glands
villi
small, fingerlike projections that line the interior of the small intestine; increasing the surface area to maximize absorption
parietal cells
specialized cells in the stomach that secret the gastric juices hydrochloric acid and intrinsic factor
chief cells
specialized cells in the stomach that secrete and inactive protein-digesting enzyme called pepsinogen
gallbladder
stores bile produced in the liver and secretes bile through the common bile duct in the small intestine
pharynx
the area of the GI tract between the mouth and the esophagus
lumen
the channel or inside space of a vessel such as the intestine or artery
small intestine
the long coiled chamber that is the major site of food digestion and nutrient absorption
large intestine
the lowest portion of the GI tract, where water and electrolytes are absorbed and waste is eliminated
upper esophageal sphincter
the muscular ring located at the top of the esophagus
lower esophageal sphincter
the muscular ring located between the base of the esophagus and the stomach
anus
the opening of the rectum; end of GI tract
ferment
the process by which yeast converts sugars in grains or fruits into ethanol and carbon dioxide
passive diffusion
the process of absorbing nutrients freely across the cell membrane
facilitated diffusion
the process of absorbing nutrients with the help of a carrier molecule
active transport
the process of absorbing nutrients with the help of a carrier molecule and energy expenditure
transport
the process of moving absorbed nutrients throughout the body through the circulatory and lymph systems
absorption
the process of moving nutrients from the GI tract into the circulatory system
propulsion
the process that moves food along the gastrointestinal tract during digestion
chyme
the semiliquid, partially digested food mass that leaves the stomach and enters the small intestine
illeocecal valve
the sphincter that separates the small intestine from the large intestine
microvilli
tiny projections on the villi in the small intestine
esophagus
tube that connects the mouth to the stomach
Disorders related to large intestine
ulcerative colitis, hemorrhoids, constipation, irritable bowel syndrome
stool
waste product in the large intestine; feces
