digestive system pt2

Question 1

parts of the small intestine

Answer 1

• duodenum
• jejenum
• ileum

Question 2

duodenum

Answer 2

• 10 inches
• gallbladder and pancreas have ducts into duodenum
• most chemical digestion happens here (enzymes)

Question 3

pancreas

what is what it secretes called?

Answer 3

• secretes sodium bicarbonate to neutralize stomach acid (protect intestines)
• secretes pancreatic juice with enzymes to continue chemical digestion (trypsin, pancreatic lipase, pancreatic amylase)

Question 4

gall bladder

why is wht. it makes important?

Answer 4

• stores bile produced by liver
• biles emulsifies fats allowing fat enzymes (lipases) to work

Question 5

gallstones

Answer 5

crystallization of bile components (mostly cholesterol)

Question 6

jejenum

Answer 6

• 4-5 meters long
• some digestion/absorption of nutrients
• longitudinal/circular muscles perform peristalsis
• has structures called villi

Question 7

villi

Answer 7

• fingerlike projections on small intestine lining
• more surface area to absorb nutrients
• villi have microvilli to increase absorption
• perform active transport and passive transport

Question 8

active transport vs passive transport

Answer 8

• villi can perform both
• active transport: transport of nutrients requiring energy
• passive transport: transport of nutrients not requiring energy

Question 9

ileum

Answer 9

• 2-3 meters long
• most absorption of nutrients (has villi)
• absorbs B12 and bile salts

Question 10

caecum

Answer 10

• first part of large intestine
• “dead end”
• appendix attached
• seperated from ileum by ileocaecal valve

Question 11

large intestine

wht doese it have? howlong?

Answer 11

• 1.5 meters long
• absorbs water through osmosis
• passes waste material from body
• more than 500 species of bacteria
• has colonic bacteria (like e. coli) that produce vitamin K, vitamin B12, thiamine, riboflavin

Question 12

parts of large intestine

Answer 12

• caecum
• colon (ascending, transverse, descending, sigmoid)
• rectum
• anus

Question 13

rectum

how long?

Answer 13

• last 20 cm
• holds indigestible materials (e.g. cellulose) until egested
• peristaltic waves expel feces through anal canal
• stretch receptors trigger contractions when rectum is full

Question 14

diagnostics

Answer 14

• barium enema
• endoscopy

Question 15

barium enema

Answer 15

• barium solution inserted in anus to provide contrast for x-ray
• xray shows barium fluid moving through large intestine

Question 16

endoscopy

Answer 16

• endoscope inserted into natural opening of body
• capsule endoscope: takes pics of entire digestive system