Lesson 6 (Chapter 2: Structures of the Digestive System)

Question 1

Mouth (Oral Cavity)

Answer 1

Food begins its journey through the digestive system in the mouth. Other organs of the oral cavity also aid in the digestion of food: lips, tongue, palate (roof of the mouth), teeth, and salivary glands. The lips hold the food in the mouth while the teeth chop it into small pieces. The food is moistened by saliva before the tongue pushes it into the throat. The soft palate prevents food and liquid from moving upward into the nasal cavity during swallowing.

Question 2

Pharynx (Throat)

Answer 2

The pharynx allows the chewed food to pass from the mouth to the esophagus. A flap of tissue, known as the epiglottis, closes off the entrance to the trachea (windpipe) during swallowing.

Question 3

Esophagus

Answer 3

The esophagus is a muscular tube that carries food and liquids from the pharynx to the stomach. The esophagus walls propel food to the stomach by rhythmic waves of muscular contractions called peristalsis.

Question 4

Stomach

Answer 4

The stomach is a hollow sac that serves as a storage area for food. It also mixes the food with acid and enzymes, so it is more easily digested. Mucus coats the cells of the stomach lining to protect them from damage by the acid and enzymes.

Question 5

Small Intestine

Answer 5

The stomach releases food into the small intestine. This coiled organ takes up most of the space in the abdominal cavity and consists of three sections: duodenum, jejunum, and ileum. Ultimately, by the time food leaves the small intestines, about 90% of the nutrients have been absorbed into the bloodstream.

Question 6

Large Intestine

Answer 6

The large intestine wraps around the top and sides of the small intestine. Here, the waste products of digestion are processed in preparation for excretion from the body. The many bacteria that inhabit the large intestine can further digest some material. The major parts of the large intestine are the cecum, colon, rectum, and anus.

Question 7

Liver

Answer 7

The liver is the largest internal organ in the body. The liver has many different functions, but its primary function in digestion is to produce bile and secrete it into the small intestine. Bile is a greenish-yellow fluid that is necessary for the digestion of fat.

Question 8

Gallbladder

Answer 8

The gallbladder stores bile for later use.

Question 9

Pancreas

Answer 9

The pancreas is a glandular organ in the upper abdomen. It secretes pancreatic juices (water, salt, sodium bicarbonate, and digestive enzymes) to aid in digestion and help neutralize stomach acids.

Question 10

Ingestion

Answer 10

The intake of food provides the nutrients that the body uses to provide energy for all the functions of the body.

Question 11

Secretion

Answer 11

The digestive system secretes saliva, mucus, hydrochloric acid, enzymes, and bile to aid in digestion, lubricate the GI tract, and protect the body from bacteria present in food.

Question 12

Movement

Answer 12

Peristalsis is the wave-like motion that moves the digested food down the GI tract.

Question 13

Digestion

Answer 13

Mechanical digestion is the physical breakdown of pieces of food into smaller pieces. Chemical digestion breaks down complex food molecules by the action of acid, enzymes, and pancreatic juice into smaller molecules that are easier to absorb.

Question 14

Absorption

Answer 14

Most absorption of nutrients takes place in the small intestine, where blood and lymphatic vessels in the intestinal wall pick up the molecules and carry them to the rest of the body.

Question 15

Excretion

Answer 15

The final function of the digestive system is the removal of indigestible substances and other waste products from the body in a process known as defecation.

Question 16

Stomat/o

Answer 16

Mouth

Question 17

Deglutition

Answer 17

Swallowing

Question 18

Mastication

Answer 18

Chewing

Question 19

Bucc/o

Answer 19

Cheeks

Question 20

Cheil/o

Answer 20

Lips

Question 21

Gloss/o or Lingu/o

Answer 21

Tongue

Question 22

Pharyng/o

Answer 22

Pharynx

Question 23

Peristalsis

Answer 23

The wavelike movement of the digestive tract

Question 24

Cardiac Valve, Lower Esophageal Sphincter (LES)

Answer 24

Prevents gastric juice from splashing into the esophagus

Question 25

Pyrosis

Answer 25

Heartburn

Question 26

Pyloric Sphincter

Answer 26

Valve between the stomach and the small intestine

Question 27

Rugae

Answer 27

Folds in an empty stomach lining that disappear when the stomach fills

Question 28

Pylor/o

Answer 28

Pyloric Sphincter

Question 29

Duodenum

Answer 29

First part of the small intestine

Question 30

Duoden/o

Answer 30

Duodenum

Question 31

Jejunum

Answer 31

Second part of the small intestine, about 8 feet long

Question 32

Ileum

Answer 32

Third part of the small intestine

Question 32

Jejun/o

Answer 32

Jejunum

Question 33

Ile/o

Answer 33

Ileum

Question 34

Cecum

Answer 34

Small pouch at the start of the Large Intestines

Question 35

Cec/o

Answer 35

Cecum

Question 36

Ileocecal

Answer 36

Junction of the Ileum and the Cecum

Question 37

Ileocecal Valve

Answer 37

Prevents backflow of fecal matter from the large intestines

Question 38

Append/o, Appendic/o

Answer 38

Appendix

Question 39

Appendicitis

Answer 39

Inflammation of the appendix

Question 40

Appendectomy

Answer 40

Surgical removal of the appendix

Question 41

Sigmoid/o

Answer 41

Sigmoid solon

Question 42

Proct/o

Answer 42

Rectum and Anus