Gastrointestinal System

Question 1

Digestive functions

Answer 1

• movement:
  Mixes and passes nutrients through system and eliminates waste
• secretion:
  Enzymes, hormones, and other substances necessary for digestion
• digestion:
  Chemical breakdown of nutrients into smaller units
• absorption:
  Passage of nutrients through plasma membranes into blood or lymph and then body

Question 2

Mouth

Answer 2

• begins with chewing and mixing of nutrients with saliva
• salivary glands are stimulated and secrete saliva which enzymes breakdowns starch in digestion
• once swallowed, goes through pharynx and into the esophagus to the stomach

Question 3

Stomach

Answer 3

• mixing and storing food
• dissolving and degrading food via secretions
• controlling passage of food into small intestine
• protein digestion begins
• stomach acid breaks down food and makes nutrients ready for absorption
• smooth muscle moves food by peristalsis

Question 4

Small intestine

Answer 4

• where nutrients are absorbed
• enzymes form pancreas, liver and stomach are transported to SI to aid in digestion. Act on fats, carbs, protein, nucleic acid
• villi (tiny absorptive structure) on the lining and microvilli further increase ability to absorb nutrients

Question 5

Large intestine

Answer 5

• colon, over a meter in length
• mixes and stores waste material
• descends and attached to rectum
• when rectal wall is distended, nervous system triggers impulse to body to expel the waste
• sphincter at the end of anis stimulate to pooping
• speed at which waste is moved through colon is based on volume of fiber
• without adequate bulk, it takes longer to move waste along