digestive system and nutrition Flashcards
gastrointestinal tract
a long hallow tube consisting of accessory glands to release secretions
begins at the mouth and continues through the pharynx, esophagus, stomach, small intestine, and large intestine
lumen
the hollow area of the tube through which food and fluids travel
4 basic layers of the GI tract
mucosa, submucosa, muscularis, serosa
mucosa
the innermost layer
mucus secreting to lubricate the lumen
submucosa
3rd layer
consists of connective tissue containing blood vessels, lymph vessels, and nerves
muscalaris
2nd layer
responsible for movement of materials through the GI tract and for mixing
serosa
1st layer
thin layer of epithelial tissue supportive by connective tissue
saliva
salivary glands releasing their secretions
salivary amylase
an enzyme that begins to chemically digest starches into shorter chains of sugar
pharynx
the passageway commonly called the throat
shared by the respiratory and digestive systems
esophagus
the tube that connects the pharynx to the stomach
peristalsis
rhythmic waves of muscle contraction used to push food along the the esophagus and the rest of the GI
stomach
muscular sac
three important functions of the stomach
- storing food and regulating the release of the food to the small intestine
2.liquefying food - carrying out the initial chemical digestion of proteins
chyme
mechanical digestion that is mixed with secretions produced by the glands of the stomach into a soupy mixture
gastric glands
containing several types of secretory cells
pepsin
a protein splitting, digesting enzyme
two major functions of the small intestine
chemical digestion and absorption
duodenum
the first region of the small intestine that receives chyme from the stomach and digestive juices from the pancreas and liver
bile
a mixture of water, ions, cholesterol, bile pigments, and bile salts
plays a role in mechanical digestion
produced in the liver, stored in the gallbladder, and acts in the small intestine
villi
small fingerlike projections on the small intestine walls that increase surface area for absorption
lacteal
lymphatic vessel in an intestine villus that aids in absorption of lipids
pancreas
an accessory organ behind the stomach that secretes digestive enzymes and hormones that regulate blood sugar
liver
the largest organ in the body that has metabolic and regulatory rules
gallbladder
a muscular pear shaped sac that stores, modifies, and and concentrates bile
large intestine
final segment of the gastrointestinal tract
plays a role in defecation
cecum
a pouch that hangs below the junction of the small and large intestines
the appendix extends from the cecum
appendix
a slender closed pouch that extends from the large intestine near the juncture with the small intestine
colon
division of the large intestine
three colons
ascending colon, transverse colon, descending colon
rectum
receives and temporarily stores the feces
anal canal
the canal between the rectum and the anus
nutrient
a substance in food that provides energy
essential for growth and function
lipid
a compound that does not dissolve in water
fat
consists of glycerol and three fatty acids
low density lipoproteins
a protein carrier in the blood that transports cholesterol into the cells
often called the bad form of cholesterol
high density of lipoproteins
i lipoprotein made in the liver and released into the blood that transports cholesterol away from the cells to the liver
good form of cholesterol
carbohydrates
sugars and starches that provide fuel for the human body
dietary fiber
nondigestible carbohydrate part of plant foods that form support structures and important for heart and colon health
glycemic response
a measure that describes how quickly a serving of food is converted into blood sugar and how much the level of blood sugar is effected
protein
consists of one or more chains of amino acids
essential amino acids
any of the 9 amino acids the body cannot synthesize and therefore must be supplied in the diet
complete proteins
contains ample amount of all the essential amino acids
animal sources are generally complete proteins
incomplete proteins
proteins that are deficient in one or more essential amino acids
plant sources are generally incomplete proteins
complementary proteins
combining incomplete proteins to complete your protein intake
vitamin
organic compound essential for health and growth
mineral
inorganic substances that are not broken down during digestion and are important in regulating cellular processes
basal metabolic rate (BMR)
minimum energy required to keep an awake resting body alive
anorexia nervosa
deliberate self starvation
bullimia nervosa
binge eating followed by purging
