Basic Structures of the Digestive System

Question 1

Mouth

Answer 1

-tongue and teeth are accessory organs
-tongue helps mix food with saliva and gathers chewed food into ball called the bolus

Question 2

Saliva

Answer 2

-contains lysozymes to protect against bacteria
-Amylase: enzymes that starts chemical breakdown of complex carbohydrates

Question 3

What is scientific name for chewing and swallowing

Answer 3

-mastication
-deglutition

Question 4

Pharynx

Answer 4

-throat
-receives food from mouth

Question 5

Esophagus

Answer 5

-uses peristalsis (rhythmic contractions) to move bolus down to stomach
-upper and lower esophageal sphincter are valves
-Heartburn or reflux is when lower value allows food mixed with stomach acid to come back up the esophagus

Question 6

Stomach

Answer 6

-has folds called rugae that increase surface area and help break down food mechanically

Question 7

Parietal cells of stomach

Answer 7

make HCL or hydrochloric acid
-acid helps break down food and protect from pathogens that were ingested in food

Question 8

Goblet cells of stomach

Answer 8

produce mucus to mix with food and protect the stomach lining from HCL

Question 9

Chief cells of stomach

Answer 9

secrete enzyme pepsinogen that makes pepsin which break down protein into peptides

Question 10

Chyme

Answer 10

mix of partially digested food, water, and gastric juice

Question 11

Pyloric sphincter

Answer 11

valve at the end of stomach that release a little bit of chyme into the duodenum

Question 12

Duodenum

Answer 12

-main site for chemical digestion

Question 13

What does the gallbladder release to help with digestion?

Answer 13

bile from the bile duct

Question 14

What does the pancreas release to help with digestion?

Answer 14

-pancreatic juice
-sodium bicarbonate to help neutralize the stomach

Question 15

What is in pancreatic juice?

Answer 15

-amylase for starch
-peptidases and trypsin for proteins
-lipases for fat
-nucleases for nucleic acids

Question 16

Jejunum

Answer 16

-middle section of small intestine
-has villi and microvilli that increase surface area for nutrient absorption
-uses brush border enzymes for chemical digestion
-Segmentation or rhythmic back and forth continue to mix digesting food with enzymes
-fats absorbed by lacteals in small intestine

Question 17

Ileum

Answer 17

-continues with absorption, including bile salts and iron for the body to recycle
-controls movement of chyme into large intestine
-ileocecal valve prevents back up

Question 18

Large Intestine

Answer 18

-reabsorb water and produce mucus to help move feces
-bacteria breaks down fiber, creating gas bc of fermentation

Question 19

What are the 5 sections of the large intestine?

Answer 19

1. cecum
2. ascending colon
3. transverse colon
4. descending colon
5. sigmoid colon

Question 20

Appendix

Answer 20

right before cecum
-vestigial organ (useless)
some relation to immune system