Digestive System

Question 1

Structures of the gastrointestinal (GI) tract

Answer 1

Mouth
Pharynx
Esophagus
Stomach
Small intestine
Large Intestine
Anus

Question 2

mucosa

description/function

Answer 2

Innermost layer of GI tract which lubricates the lumen, protects cells of the GI tract, and assists in digestion and assilimation.

Question 3

submucosa

description/function

Answer 3

The second innermost layer of the GI tract which consists of connective tissue, blood vessels, lymph vessels and nerves. It provides the blood supply which maintains the cells of the digestive system, transports products of digestion, and provides the nerves which coordinate the contractions of the muscularis.

Question 4

serosa

description/function

Answer 4

The outermost layer of the GI tract consisting of a thin layer of epithelial and connective tissue which secretes a fluid that lubricates the outside of the GI tract to reduce friction between it and other abdominal organs.

Question 5

saliva

Answer 5

The secretions of the salivary glands which make food easier to pass through the digestive system by moistening and binding food particles together. It also contains an enzyme which helps to break down starches.

Question 6

salivary amylase

Answer 6

The enzyme contained in saliva which assists in the breakdown of starches.

Question 7

pharynx

Answer 7

The common passageway for air, food, and drink–commonly called the throat.

Question 8

esophagus

Answer 8

The tube that connects the pharynx to the stomach.

Question 9

peristalsis

Answer 9

The process which occurs in the muscularis which propels food along the GI tract.

Question 10

stomach

Answer 10

A J-shaped muscular sac which stores and liquifies food and begins the digestion of proteins.

Question 11

chyme

Answer 11

The liquid mixture resulting from the churning of food and gastric juices in the stomach.

Question 12

gastric glands

Answer 12

Pits in the stomach which release hydrochloric acid and pepsinogen, which mix to become gastric juices. They also secrete mucus, which protects the walls of the stomach, and intrinsic factor, a protein necessary for the absorption of vitamin B-12.

Question 13

pepsin

Answer 13

A protein-digesting enzyme released by the gastric glands in the stomach as pepsinogen and activated by hydrochloric acid.

Question 14

small intestine

Answer 14

A long tube between the stomach and large intestine which has many circular folds and small projections called villi to increase the surface area used for absorption of nutrients

Question 15

duodenum

Answer 15

The first region of the small intestine which regulates the amount of chyme entering the small intestine by squirting small amounts at one time.

Question 16

bile

Answer 16

A mixture of water, ions, cholesterol, bile pigments and bile salts which plays an important role in the mechanical digestion of fats.

Question 17

villi

Answer 17

Small projections out of the inner surface of the small intestine which increase absorption through increased surface area.

Question 18

lacteal

Answer 18

A lymphatic vessel found in the core of the villi in the small intestine

Question 19

pancreas

Answer 19

An accessory organ of the digestive system which sits behind the stomach. It releases pancreatic juices which combine with bile in the duodenum. Pancreatic juices play an important role in neutralizing acidic chyme.

Question 20

liver

Answer 20

An accessory organ of the digestive system which sits above and to the left of the stomach

Question 21

gallbladder

Answer 21

Accessory organ of the digestive system which squirts bile into the duodenum.

Question 22

large intestine

Answer 22

Tube of the digestive tract between the small intestine and the rectum which is responsible for absorbing water and forming/expelling feces.

Question 23

colon

Answer 23

The largest region of the large intestine.

Question 24

rectum

Answer 24

Where feces are deposited from the large intestine which stimulates the defecation reflex.

Question 25

List the types of nutrients.

Answer 25

lipids carbohydrates proteins

Question 26

lipid

Answer 26

fats, oils, and cholesterols 95% of lipids found in foods are triglycerides

Question 27

cholesterol

Answer 27

A type of lipid. Gives structure to cell membranes and steroid hormones.

Question 28

low-density lipoproteins

Answer 28

A form of cholesterol which brings cholesterol to cells and deposits cholesterol in vessel walls. Considered the bad form of cholesterol.

Question 29

high-density lipoproteins

Answer 29

A form of cholesterol which carries cholesterol from the body to the liver for elimination. Considered the good form of cholesterol.

Question 30

carbohydrates

Answer 30

Nutrient coming from sugars, starches and dietary fiber. Basic unit is a monosaccharide

Question 31

dietary fiber

Answer 31

A type of carbohydrate which the human body cannot digest and is passed into the large intestine, giving bulk to feces.

Question 32

glycemic response

Answer 32

How quickly a serving of food is converted into blood sugar and how much the blood sugar level is affected.

Question 33

protein

Answer 33

A nutrient consisting of amino acids delivered to the cells to make more proteins.

Question 34

essential amino acids

Answer 34

Those amino acids which the body cannot synthesize and must be supplied by the diet.

Question 35

complete protein

Answer 35

A source of protein which contains all 20 amino acids. Usually from a meat source.

Question 36

incomplete protein

Answer 36

A source of protein which does not contain all 20 amino acids. Usually

Question 37

complementary proteins

Answer 37

Combinations of food sources containing incomplete proteins which together provide all 20 amino acids.

Question 38

vitamin

Answer 38

An organic compound essential for health which is needed in small quantities (milligrams or micrograms)

Question 39

mineral

Answer 39

An inorganic substance which is essential for many life processes.

Question 40

basal metabolic rate (BMR)

Answer 40

The minimum amount of energy needed to keep an awake, resting body alive.

Question 41

obese

Answer 41

The state of being overweight as a result of excess fat.

Question 42

overweight

Answer 42

The state of weighing more than the ideal weight specified on a height/weight chart.

Question 43

Follow a bite of food through the GI tract from the mouth.

Answer 43

Mouth > Pharynx > Esophagus > Stomach > Small Intestine > Large Intestine > Colon > Rectum

Question 44

What are the functions of the teeth and tongue in processing food?

Answer 44

The teeth are responsible for mechanically tearing and grinding food into smaller pieces. The tongue is responsible for taste and for moving food to the teeth for processing, as well as to the back of the mouth for swallowing.

Question 45

What causes tooth decay? What structures of the tooth are affected?

Answer 45

Food particles caught in teeth containing sugar attract acid-producing bacteria which wears away the enamel of the tooth. If untreated, the bacteria can reach the dentin underneath the enamel.

Question 46

List three primary functions of the stomach.

Answer 46

1) storing food and regulating its release into the small intestine 2) liquefying food 3) carrying out the initial chemical digestion of proteins

Question 47

how does bile assist in the digestion and absorption of fats?

Answer 47

Bile salts emulsify oils creating a larger surface area for lipase to absorb from.

Question 48

Where are carbohydrates digested?

Answer 48

The mouth begins the process of digestion, and it is finished in the small intestine.

Question 49

Where are fats digested?

Answer 49

the stomach begins the process of digestion, and it is finished in the small intestine.

Question 50

What structure in the small intestine helps to increase absorption? How?

Answer 50

villi are small projections off the inner surface of the small intestine which each have many projections of their own. this dramatically increases the surface area available for absorption.

Question 51

What are the functions of the large intestine?

Answer 51

- Absorption of remaining water from food residue which adjusts the consistency of the feces - Storage of feces - Elimination of feces

Question 52

Where does the digestion of oil begin?

Answer 52

In the stomach, where bile salts emulsify oils to increase the surface area available for absorption.

Question 53

What is the most major concern for someone with diarrhea?

Answer 53

Dehydration.

Question 54

Eating _____ helps to lower blood levels of LDL cholesterol.

Answer 54

Fiber

Question 55

Which of the following is NOT a function of saliva? a) begins the chemical breakdown of starches b) helps clean the mouth c) contains fluoride to harden tooth enamel d) moistens food and helps stick it together to make it easier to swallow

Answer 55

c) contains fluoride to harden tooth enamel

Question 56

_____ is a liquid mixture of food and gastric juices found in the stomach.

Answer 56

Chyme

Question 57

The ______ is the organ that produces bile.

Answer 57

gallbladder

Question 58

Saliva contains an enzyme that begins the chemical digestion of _____.

Answer 58

starches

Question 59

_____ is a hormone produced by the small intestine that causes the gallbladder to contract and release bile.

Answer 59

Cholecystokinin

Question 60

List the four layers of the GI tract from the inside out.

Answer 60

mucosa, submucosa, muscularis, serosa

Question 61

muscularis | description/function

Answer 61

The second outermost layer of the GI tract consisting of two layers of smooth muscle which is responsible for peristalsis and mixing ingested materials with digestive fluids.

Question 62

Which layer of the GI tract is responsible for preventing friction with other abdominal organs?

Answer 62

serosa

Question 63

Which layer of the GI tract is responsible for peristalsis?

Answer 63

muscularis

Question 64

Which layer of the GI tract is responsible for supplying blood to the digestive system?

Answer 64

submucosa

Question 65

Which layer of the GI tract is responsible for protecting the cells of the GI tract?

Answer 65

mucosa

Question 66

Which layer of the GI tract transports the products of digestion in some parts of the digestive system?

Answer 66

submucosa

Question 67

Which layer of the GI tract increases the surface area for absorption in some parts of the digestive system?

Answer 67

mucosa

Question 68

Where are proteins digested?

Answer 68

Small intestine

Question 69

When is food no longer external in the body?

Answer 69

When it reaches the liver.

Question 70

Which of these is not an accessory organ in the digestive system? a) salivary glands b) oral cavity c) pancreas d) liver

Answer 70

b) oral cavity

Question 71

How does the digestive system play a role in protecting against pathogens?

Answer 71

By releasing hydrochloric acid into the stomach which kills bacteria.

Question 72

What are some benefits that beneficial bacteria in the large intestine provide?

Answer 72

Production of vitamins, digestion of fiber

Question 73

What role does the esophageal sphincter play? What happens when the esophageal sphincter is dysfunctional?

Answer 73

Prevents backflow of stomach contents into the esophagus. Heartburn

Question 74

What role does the pyloric sphincter play?

Answer 74

Regulates flow of chyme into the small intestine.