digestive system

Question 1

mucus cells

Answer 1

• secrete mucus
• lubricates and protects the stomachs epithelial lining

Question 2

chief cells

Answer 2

• secretes pepsinogen
• activated by low pH in stomach
• converts to pepsin (digests proteins)

Question 3

parietal cells

Answer 3

secretes HCl

Question 4

G cells

Answer 4

secretes gastrin, which stimulates parietal cells to secrete stomach acid

Question 5

small intestine

Answer 5

• food enters from the stomach through the pyloric sphincter
• most digestion and absorption occurs here
• villi increase surface area, increasing absorption
• each villi has microvilli

Question 6

3 segments of the small intestine

Answer 6

1. duodenum
2. jejunum
3. ileum

Question 7

duodenum

Answer 7

continues breakdown of starches and proteins and remaining food types (majority of digestion)

Question 8

jejunum

Answer 8

majority absorption of nutrients occurs here

Question 9

ileum

Answer 9

absorption continues; contains Peyer’s patches (lymphoid tissue)

Question 10

large intestine

Answer 10

• enters from small intestine via the ilocecal valve
  4 segments:
• ascending, transverse, descending, and sigmoid
• large intestine stops at rectum
• functions: water and electrolyte absorption
• symbiotic bacteria aid in digestion and provide vitamin K and B12

Question 11

liver

Answer 11

• produces bile, which contains no digestive enzymes but emulsifies fats (mechanical digestion) and contains sodium bicarbonate
• bile: created in liver, stored in gall bladder
• if bile cannot be released, lipid breakdown would be compromised

Question 12

biliary flow

Answer 12

1. cystic duct + hepatic duct –> common bile duct
2. common bile duct + pancreatic duct –> secretes into duodenum

Question 13

pancreas

Answer 13

• secretes bicarbonate and digestive enzymes to the duodenum
  ** digestive enzyme flow**:
  produced in pancreas –> flow from pancreatic duct into duodenum –> neutralizes acidic chyme from stomach and allows for digestion to occur

Question 14

digestive enzymes in pancreas

Answer 14

1. trypsin/chymotrypsin
2. lipase
3. amylase
4. nucleases

Question 15

trypsin/chymotrypsin

Answer 15

digest proteins

Question 16

lipase

Answer 16

digest lipids

Question 17

amylase

Answer 17

digests carbohydrates

Question 18

nucleases

Answer 18

digests nucleic acids

Question 19

digestive enzyme flow

Answer 19

produced in pancreas –> pancreatic duct into duodenum –> neutralizes acidic chyme from stomach and allows digestion to occur

Question 20

chyme

Answer 20

creamy mass of digested food