Chapter 41 Vocab

Front 1

Define: absorption

Back 1

The uptake of small nutrient molecules by an organism’s own body; the third main stage of food processing, following digestion.

Front 2

Define: acid chyme

Back 2

A mixture of recently swallowed food and gastric juice.

Front 3

Define: alimentary canal

Back 3

A digestive tract consisting of a tube running between a mouth and an anus.

Front 4

Define: appendix

Back 4

A small, fingerlike extension of the vertebrate cecum; contains a mass of white blood cells that contribute to immunity.

Front 5

Define: bile

Back 5

A mixture of substances that is produced in the liver, stored in the gallbladder, and acts as a detergent to aid in the digestion and absorption of fats.

Front 6

Define: bolus

Back 6

A lubricated ball of chewed food.

Front 7

Define: bulk-feeder

Back 7

An animal that eats relatively large pieces of food.

Front 8

Define: carnivore

Back 8

An animal, such as a shark, hawk, or spider, that eats other animals.

Front 9

Define: cecum

Back 9

A blind outpocket of a hollow organ such as an intestine.

Front 10

Define: chylomicron

Back 10

One of the small intracellular globules composed of fats that are mixed with cholesterol and coated with special proteins.

Front 11

Define: complete digestive tract

Back 11

A digestive tube that runs between a mouth and an anus; also called an alimentary canal. An incomplete digestive tract has only one opening.

Front 12

Define: digestion

Back 12

The process of breaking down food into molecules small enough for the body to absorb.

Front 13

Define: duodenum

Back 13

The first section of the small intestine, where acid chyme from the stomach mixes with digestive juices from the pancreas, liver, gallbladder, and gland cells of the intestinal wall.

Front 14

Define: elimination

Back 14

The passing of undigested material out of the digestive compartment.

Front 15

Define: enzymatic hydrolysis

Back 15

The process in digestion that splits macromolecules from food by the enzymatic addition of water.

Front 16

Define: epiglottis

Back 16

A cartilaginous flap that blocks the top of the windpipe, the glottis, during swallowing, which prevents the entry of food or fluid into the respiratory system.

Front 17

Define: esophagus

Back 17

A channel that conducts food, by peristalsis, from the pharynx to the stomach.

Front 18

Define: essential amino acid

Back 18

An amino acid that an animal cannot synthesize itself and must obtain from food. Eight amino acids are essential in the human adult.

Front 19

Define: essential fatty acids

Back 19

Certain unsaturated fatty acids that animals cannot make.

Front 20

Define: essential nutrient

Back 20

A substance that an organism must absorb in preassembled form because it cannot be synthesized from any other material. In humans, there are essential vitamins, minerals, amino acids, and fatty acids.

Front 21

Define: extracellular digestion

Back 21

The breakdown of food outside cells.

Front 22

Define: feces

Back 22

The wastes of the digestive tract.

Front 23

Define: fluid-feeder

Back 23

An animal that lives by sucking nutrient-rich fluids from another living organism.

Front 24

Define: gallbladder

Back 24

An organ that stores bile and releases it as needed into the small intestine.

Front 25

Define: gastrovascular cavity

Back 25

An extensive pouch that serves as the site of extracellular digestion and a passageway to disperse materials throughout most of an animal’s body.

Front 26

Define: hepatic portal vessel

Back 26

A large circulatory channel that conveys nutrient-laden blood from the small intestine to the liver, which regulates the blood’s nutrient content.

Front 27

Define: herbivore

Back 27

A heterotrophic animal that eats plants.

Front 28

Define: ingestion

Back 28

A heterotrophic mode of nutrition in which other organisms or detritus are eaten whole or in pieces.

Front 29

Define: intercellular digestion

Back 29

The joining of food vacuoles and lysosomes to allow chemical digestion to occur within the cytoplasm of a cell.

Front 30

Define: lacteal

Back 30

A tiny lymph vessel extending into the core of an intestinal villus and serving as the destination for absorbed chylomicrons.

Front 31

Define: large intestine colon

Back 31

lThe tubular portion of the vertebrate alimentary tract between the small intestine and the anus; functions mainly in water absorption and the formation of feces.

Front 32

Define: liver

Back 32

The largest organ in the vertebrate body. The liver performs diverse functions, such as producing bile, preparing nitrogenous wastes for disposal, and detoxifying poisonous chemicals in the blood.

Front 33

Define: malnourished

Back 33

Referring an animal whose diet is missing one or more essential nutrients.

Front 34

Define: microvillus

Back 34

(plural, microvilli) One of many fine, fingerlike projections of the epithelial cells in the lumen of the small intestine that increase its surface area.

Front 35

Define: mineral

Back 35

In nutrition, a chemical element other than hydrogen, oxygen, or nitrogen that an organism requires for proper body functioning.

Front 36

Define: omnivore

Back 36

A heterotrophic animal that consumes both meat and plant material.

Front 37

Define: oral cavity

Back 37

The mouth of an animal.

Front 38

Define: overnourishment

Back 38

A diet that is chronically excessive in calories.

Front 39

Define: pancreas

Back 39

A gland with dual functions: The nonendocrine portion secretes digestive enzymes and an alkaline solution into the small intestine via a duct; the endocrine portion secretes the hormones insulin and glucagon into the blood.

Front 40

Define: pepsin

Back 40

An enzyme present in gastric juice that begins the hydrolysis of proteins.

Front 41

Define: pepsinogen

Back 41

The inactive form of pepsin that is first secreted by specialized (chief) cells located in gastric pits of the stomach.

Front 42

Define: peristalsis

Back 42

Rhythmic waves of contraction of smooth muscle that push food along the digestive tract

Front 43

Define: pharynx

Back 43

An area in the vertebrate throat where air and food passages cross

Front 44

Define: pyloric sphincter

Back 44

In the vertebrate digestive tract, a muscular ring that regulates the passage of food out of the stomach and into the small intestine.

Front 45

Define: rectum

Back 45

The terminal portion of the large intestine where the feces are stored until they are eliminated.

Front 46

Define: ruminant

Back 46

An animal, such as a cow or a sheep, with an elaborate, multicompartmentalized stomach specialized for an herbivorous diet.

Front 47

Define: salivary glands

Back 47

Exocrine glands associated with the oral cavity. The secretions of salivary glands contain substances to lubricate food, adhere together chewed pieces into a bolus, and begin the process of chemical digestion.

Front 48

Define: small intestine

Back 48

The longest section of the alimentary canal; the principal site of the enzymatic hydrolysis of food macromolecules and the absorption of nutrients.

Front 49

Define: sphincter

Back 49

A ringlike valve consisting of modified muscles in a muscular tube, such as a digestive tract; closes off the tube like a drawstring.

Front 50

Define: stomach

Back 50

An organ of the digestive system that stores food and performs preliminary steps of digestion.

Front 51

Define: substrate-feeder

Back 51

An organism that lives in or on its food source, eating its way through the food.

Front 52

Define: suspension-feeder

Back 52

An aquatic animal, such as a clam or a baleen whale, that sifts small food particles from the water.

Front 53

Define: undernourishment

Back 53

A diet that is chronically deficient in calories.

Front 54

Define: villus

Back 54

A finger-like projection of the inner surface of the small intestine

Front 55

Define: vitamin

Back 55

An organic molecule required in the diet in very small amounts. Vitamins serve primarily as coenzymes or parts of coenzymes.