Digestive System

Front 1

4 Basic Functions of Digestive System

Back 1

1. Ingestion

2. Secretion

3. Mixing/Propulsion

4. Digestion

5. Absorption

6. Defecation

Front 2

Describe the Journey of the Digestive System

Back 2

(Main)

1. Mouth

2. Esophagus

3. Stomach

4. Small Intestine (bowel)

5. Large Intestine (bowel)/Colon

6. Rectum/Anus

Front 3

What are 3 accessory organs

Back 3

1. Pancreas

2. Liver

3. GallBladder

Front 4

7 Layers of the Digestive System

Back 4

1. Lumen

2. Mucosa

3. Submucosa

4. Muscularis

5. Serosa

6. Abdominal cavity/peritoneum

Front 5

This process involves taking foods and liquids into the mouth (eating)

Back 5

Ingestion

Front 6

Release of water, acid, buffers, and enzymes into the lumen of the GI tract

Back 6

Secretion

Front 7

Churning and propulsion of food through GI tract

Back 7

Mixing and propulsion

Front 8

mechanical and chemical breakdown of food

Back 8

Digestion

Front 9

Passage of digested products from GI tract into blood and lymph

Back 9

Absorption

Front 10

Elimination of feces from GI tract

Back 10

Defecation

Front 11

Inner lining of the GI tract; composed of epithelium

Back 11

Mucosa

Front 12

Thin layer of connective tissue in mucosa that contains blood and lymph vessels

Back 12

Lamina Propria

Front 13

Thin layer of smooth muscle in mucosa

Back 13

Muscular mucosae

Front 14

Areolar connective tissue that binds the mucosa to the muscularis; contains many blood and lymphatic vessels, nerves, and glands that receive absorbed food molecules

Back 14

Submucosa

Front 15

contains inner circular and outer longitudinal muscles

Back 15

Muscularis

Front 16

Composed of areolar connective tissue and simple squamous epithelium

Back 16

Serosa

Front 17

2 Functions of the mouth

Back 17

1. Ingestion

2. Secretion

Front 18

Gland that releases a secretion into the oral cavity

Back 18

Salivary glands

Front 19

Located inferior and anterior to the ears; Where most of the saliva is secreted (water,

electrolytes)

Back 19

Parotid glands

Front 20

Found on the floor of the mouth; where salivary amylase and mucus is secreted

Back 20

Submandibular glands

Front 21

Beneath the tongue; creates a thick mucus

Back 21

Sublingual Glands

Front 22

Accessory digestive organ that cuts, tears, and pulverizes food. Solid foods reduced into smaller particles for swallowing.

Back 22

Teeth

Front 23

Taste and friction

Back 23

Tongue

Front 24

Decision to swallow is

Back 24

Involuntary

Front 25

The muscles that complete swallowing are

Back 25

Reflexive (gag)

Front 26

Mainly transports food; and secretes mucus

Back 26

Esophagus

Front 27

Involuntary motion of food by smooth muscle of GI tract

Back 27

Peristalsis

Front 28

Regulates the movement of food from the

pharynx into the esophagus

Back 28

Upper Esophageal Sphincter (UES)

Front 29

Regulates the movement of food from the esophagus into the stomach

Back 29

Lower Esophageal Sphincter

Front 30

If the lower esophageal sphincter fails to close adequately after food has entered the stomach, the stomach contents can reflux (back up) into the inferior portion of the esophagus

Back 30

Gastroesophageal Reflux Disease (GERD)

Front 31

Hydrochloric acid (HCl) from the stomach contents can irritate the esophageal wall, resulting in a burning sensation

Back 31

Heartburn

Front 32

Functions include Mixing/ Propulsion, Secretion, and Digestion

Back 32

Stomach

Front 33

Pump acid from the blood (against gradient); active transport

-Produce intrinsic factor (needed for absorption vitamin B12) and Hal

- Blood leaving the stomach is alkalotic and moves to the pancreas

Back 33

Parietal cells

Front 34

Secrete pepsinogen and gastric lipase

(Pepsin breaks down proteins into peptides

Back 34

Chief cells

Front 35

Secrete Gastrin into the bloodstream; located mainly in the pyloric antrum

Back 35

G cells

Front 36

G cells are activated by stomach ________ and neural __________

Back 36

Distension and Stimulation

Front 37

G cells help contract____ and _________ (last part of stomach)

Back 37

LES and Pyloric Sphincter

Front 38

G cells help activate ______ and ______ cells

Back 38

parietal and chief

Front 39

Inactive enzymes

Back 39

Zymogens

Front 40

Activated by acid to become pepsin, which digest proteins

Back 40

Pepsinogen

Front 41

Chemical by acid and enzymes; physical by mixing within the stomach

Back 41

Digestion

Front 42

Most digestion and absorption of nutrients occur in a long tube

Back 42

Small intestine

Front 43

The small intestine is made up of 3 parts:

Back 43

1. Duodenum

2. Jejunum

3. Ileum

Front 44

Fingerlike projections of the mucosa; increases the surface area of the epithelium available for absorption and digestion and gives the intestinal mucosa a velvety appearance

Back 44

Villi

Front 45

Projections of the apical (free) membrane of the absorptive cells

Back 45

Microvillus

Front 46

Hazy layer of microvilli extending into the lumen of the small intestine

Back 46

Brush border

Front 47

Circular muscles contract when distended; Inner muscles

-localized, mixing contractions that occur in portions of intestine distended by a large volume of chyme

-Mix chyme with the digestive juices and bring the particles of food into contact with the mucosa for absorption

Back 47

Segmentations

Front 48

Longitudinal muscles contract when less distended, by absorption of fluids; outer muscles

-After most of a meal has been absorbed, lessens dissension of the wall of the small intestine, segmentation stops and peristalsis begins.Lower portion of the stomach pushes chyme forward

Back 48

Migrating Motility Complex (MMC)

Front 49

secrete mucus, mostly for lubrication

Back 49

Goblet cells

Front 50

secrete alkaline watery mucus to assist in absorption

Back 50

Duodenal glands

Front 51

Three types of enteroendocrine cells found in the intestinal glands of the small intestine are

Back 51

S cells and CCK cells

Front 52

secrete hormone secretin in response to acid

Back 52

S cells

Front 53

secrete cholecystokinin

Back 53

CCK cells

Front 54

secrete lysozyme, a bactericidal enzyme, and are capable of phagocytosis. May have a role in regulating the microbial population in the small intestine

Back 54

Paneth cells

Front 55

Nodules that react to materials not recognized by the immune system, only found in the ileum

Back 55

Peyer's patches

Front 56

Perform most of the absorption

Back 56

Absorptive cells

Front 57

Blood that enters the intestines are generally nutrient_______________

Back 57

Poor

Front 58

Therefore, in absorptive cells absorption is by _________ _____________

Back 58

Passive Transport

Front 59

Since all nutrients must be absorbed, majority of absorption is by ________ __________

Back 59

Active Transport

Front 60

Water follow by ______ in small intestine

Back 60

osmosis

Front 61

absorptive cells secrete ________

Back 61

Enterokinase

Front 62

Brush border enzymes include _______, ______, ________, and ___________ in small intestine

Back 62

Nucleases, Proteases, Lipases, and Amylases

Front 63

Must be _______ or ________ to be absorbed in small intestine

Back 63

Monomeric or dimeric

Front 64

Not everything in the small intestine will be absorbed. Give an example.

Back 64

Vegetables

Front 65

Large space made by the microvilli where all of the secretions mix together and make intestinal juice

Back 65

Intestinal glands ( Crypts of Lieberkuhn