digestive system pt1

Question 1

purpose of digestive system

connect to biodiversity… wht r nutrients used for…

Answer 1

• heterotrophs need nutrients
• nutrients transported to body’s cells
• in cell, used for growth/maintenance/tissue repair

Question 2

steps of the digestive system

Answer 2

• ingestion
• digestion
• absorption
• egestion

Question 3

ingestion

Answer 3

• taking in food/nutrients
• mouth/teeth

Question 4

digestion

Answer 4

• breakdown of larger molecules into smaller
• mouth/gallbladder/intestines

Question 5

absorption

Answer 5

• transfer of digested nutrients into blood
• intestines

Question 6

egestion

Answer 6

• removal of waste from body
• rectum/anus

Question 7

mechanical vs chemical digestion

Answer 7

• mechanical: chewing/physical movement of food
• chemical: digestive enzymes/water break food down to absorb at cellular level

Question 8

types of enzymes

Answer 8

• protease
• carbohydrase
• lipase
• amylase (starch to sugar)

Question 9

mouth

Answer 9

• food gets lubricated
• food breaks down (increasing surface area)
• food now called bolus

Question 10

teeth

Answer 10

• mechanically break down food
• incisors: cutting
• canines: tearing
• premolars: grinding
• molars: crushing

Question 11

tongue

Answer 11

• muscular organ
• 10,000 taste buds
• chewing triggers chemicals that trigger olfactory respose (sense of smell)
• push food around in mouth
• pushes bolus to esophagus

Question 12

salivary glands

Answer 12

• produce saliva
• located on jaw and front of ear

Question 13

saliva

Answer 13

• contains enzymes
• breaks down food
• prevents tooth decay
• helps taste buds work
• amylase breaks down starch into glucose

Question 14

pharynx

Answer 14

connects oral cavity to next part of digestive system

Question 15

epiglottis

Answer 15

acts as switch between larynx and esophagus

Question 16

esophagus

Answer 16

• 2 cm diameter muscular tube
• connects pharynx to stomach
• ends w/ esophageal and cardiac sphincter which prevents food going in opposite direction

Question 17

how does the esophagus move food

Answer 17

• has two muscular layers that contract
• circular layer & longitudinal layer
• they contract and release rhythmically, called peristalsis

Question 18

lower esophageal sphincter

also known as… wht happens if it doesn’t function right?

Answer 18

• known as cardiac sphincter
• allows small amounts of bolus to enter stomach
• if not closed properly, stomach acid enters esophagus nd causes heartburn

Question 19

stomach

layers of… ends with…

Answer 19

• j-shaped stretchable organ
• holds 2L of food/water
• thick layers of smooth muscles which mix gastric juice w/ food
• has folds called rugae (enable stretching nd secrete mucus)
• ends w/ pyloric sphincter

Question 20

stomach acid

how acidic…

Answer 20

• known as gastric juice
• hydrochloric acid, gastrin (hormone), and mucus
• pH of 2-3
• has digestive enzymes (pepsin)
• pepsin breaks down protein to amino acid

Question 21

causes of ulcers

Answer 21

• when acid burns through rugae
• bacterial infection
• weak mucosal lining
• anti-inflammatory meds
• smoking

Question 22

pyloric sphincter

what is the food called at this point

Answer 22

• strong ring of smooth muscle connects that stomach to small intestines
• allows chyme to enter duodenum

Question 23

emesis

Answer 23

• strong contractions that force stomach contents out through esophagus (vomiting)
• protective mechanism to remove foreign substances/toxins