Biology Vocab From Chapter 29

Front 1

alimentary canal

Back 1

a tube where digestion occurs

Front 2

saliva

Back 2

a liquid that contains digestive enzymes, mucus and other chemicals

Front 3

bolus

Back 3

chewed clump of food

Front 4

pharynx

Back 4

the upper portion of the throat – junction of the alimentary canal and the air passageway which air enters the lungs

Front 5

esophagus

Back 5

a long muscle encased tube which connects the pharynx to the stomach

Front 6

peristalsis

Back 6

muscle contractions

Front 7

stomach

Back 7

an elastic muscular sac capable of stretching to hold up to two liters of food

Front 8

Chyme

Back 8

thru the process of mechanical digestion the bolus is turned into an acidic liquid

Front 9

Small intestine

Back 9

a long narrow tube where digestion is completed and absorption of most nutrients takes place

Front 10

Liver

Back 10

the bodies largest internal organ – produces bile, stores glucose and glycogen and transforms ammonia to urea

Front 11

Gallbladder

Back 11

saclike structure that stores bile until it is secreted into the duodenum

Front 12

Pancreas

Back 12

produces and secretes pancreatic juice into the duodenum

Front 13

Villa

Back 13

small finger-like projections that line the small intestine

Front 14

Large intestine

Back 14

also known as the colon – wide and short tube from which water is absorbed into the body

Front 15

Feces

Back 15

undigested food material and other waste products

Front 16

Essential nutrients

Back 16

materials that must be ingested because your cells cannot construct them from other molecules

Front 17

Malnutrition

Back 17

diet lacking one or more essential nutrients

Front 18

Undernutrition

Back 18

a person whose diet is deficient in calories

Front 19

Obesity

Back 19

the condition of being seriously overweight with consequences to ones health

Front 20

Anorexia

Back 20

an extreme pursuit of thinness characteristic of self-starvation and weight loss

Front 21

Bulimia

Back 21

an eating disorder characterized by purging after bingeing

Front 22

six types of nutrients in food

Back 22

carbohydrates, fats, proteins, vitamins, minerals & water

Front 23

Digestion occurs on two steps:

Back 23

Step 1 – mechanical digestion – chewing
Step 2 – chemical digestion – breaking of bonds in large molecules to make smaller molecules

Front 24

Six main organs make up the alimentary canal

Back 24

1. Mouth
2. Pharynx
3. Esophagus
4. Stomach
5. Small intestine
6. Large intestine

Front 25

Small intestines

Back 25

major function is to absorb nutrients into the circulatory and lymphatic system-epithelial cells lining each villus have projections called microvilli each villus has small lymph vessels and a network of capillaries - when fatty acids and glycerol have been absorbed by the epithelial cells, they are recombined into fats and transported into the lymph vessel. Sugar and amino acids are absorbed into bloodstream through capillaries and villus

Front 26

Large Intestine (colon)

Back 26

– wide short tube –water is absorbed into the body here –contains bacteria that produces vitamin K and several B vitamins –job is to reabsorb water-saliva, gastric juice and other digestive juices contain large amounts of water –the large intestine finishes the job of digestion by absorbing the remaining water-re-absorption of water causes feces to be more solid-once again peristalsis is the mechanism that moves the material through the large intestine

Front 27

Pancreases

Back 27

produces and secretes pancreatic juice into the duodenum-pancreatic juice neutralizes the acid chime and also contains enzymes that hydrolyze carbohydrates, proteins and lipids
Pancreatic enzymes and enzymes secreted by the lining of the small intestine complete the chemical digestion of food

Front 28

Bile

Back 28

contains no enzymes, but contains substances that help prepare fats such as those in butter, ice cream or nuts for digestion.
Bile separates small fat droplets preventing them from clumping into globs – this enables digestive enzymes to break the fats down more efficiently.

Front 29

Stomach

Back 29

Gastric juice (mixture of hydrochloric acid, mucus and enzymes) is secreted by glands in the stomach lining – bathes the bolus after it enters the stomach lining
Hydrochloric acid breaks apart cells in food-kills bacteria swallowed with food
Pepsin (one of the gastric enzymes) hydrolyzes large protein molecules into polypeptides
Mechanical digestion turns the bolus into chyme (an acidic liquid)
Stomach muscles contract and stir the chyme eventually forcing it into the small intestine
Heartburn is caused when the passageway may open at inappropriate times allowing acidic chyme to flow backwards into the esophagus
Pyloric sphincter – regulates the flow of chyme into the small intestine – it is located at the opposite end of the stomach – takes two to six hours for the stomach to empty

Front 30

Esophagus

Back 30

In the esophagus food is moved by muscle contractions called peristalsis – not gravity.
A. Muscle at top of esophagus are striated (voluntary)
B. Rest of the esophagus have smooth muscles (involuntary)
C. When food reaches the pharynx – smooth muscles trigger swallowing reflex
D. Smooth muscles contract moving food toward the stomach
E. Food continues to move along the alimentary canal by peristalsis

Front 31

Pharynx

Back 31

Tongue pushes food down the throat – when you swallow a cartilage flap called the epiglottis temporarily seals off the airway and prevents food from entering