BIO 181 NCSU Unit 4: Nutrition and Transport, Questions and answers, VERIFIED.

BIO 181 NCSU Unit 4: Nutrition and Transport, Questions and answers, VERIFIED. Types of Digestive Tracts - -Incomplete: digestive cavity with one opening Complete: digestive cavity with two openings Digestive System Functions - -1. Digestion 2. Absorption/Elimination 3. Circulation Mouth - -Physical Digestion - teeth break food apart Chemical Digestion - amylase in saliva breaks down food Pharynx/Esophagus - -Pharynx: passageway between oral/nasal cavities and trachea/esophagus Epiglottis: covers trachea, prevents food in lungs Stomach - -Physical Digestion - muscular contractions - breaks down food Chemical Digestion - secretes pepsin - digests amino acids Accessory Glands - -liver: produces bile gall bladder: stores and secretes bile pancreas: bicarbonate neutralizes stomach acid, lipase digests lipids Absorption Organs - -Smal Intestine - absorb nutrients into bloodstream - around 20 feet in length Villi Line - increase surface area Large Intestine - absorption of water - bacterial symbosis - excretion Variations in Digestive Systems - -- some animals have symbiotic bacteria that breaks down cellulose - herbivores have longer digestive