human digestive system

Question 1

alimentary canal (digestive tract)

Answer 1

tube which food is processed

Question 2

physical digestion

Answer 2

breaking apart large particles
- mechanical process: teeth, tongue, churning

Question 3

chemical digestion

Answer 3

chemical breakdown of nutrient molecules (occurs in small intestine)
- intracellular digestion: food broken down by enzymes inside cell
- extracellular digestion: enzymes break down food outside cell, then absorbed into cell

Question 4

absorption

Answer 4

micromolecules absorbed out of digestive tract into blood, then taken to cells
- MOST IMPORTANT STAGE OF DIGESTION

Question 5

teeth

Answer 5

• 32 teeth, physical process
• reduce size of food particles, increases surface area of food
• incisors, canines, premolars, molars

Question 6

incisors

Answer 6

• front of mouth
• specialized for cutting and biting

Question 7

canines

Answer 7

sharp, dagger shaped, tearing

Question 8

premolars

Answer 8

• broad flat teeth
• grinding food

Question 9

molars

Answer 9

• broad, flat shape
• crushing food
  ex: wisdom teeth

Question 10

tongue

Answer 10

• physical process, positions food
• pushes food to back of mouth when swallowing
• sense of taste located on tongue (taste buds)

Question 11

saliva

Answer 11

• chemical process, softens and moistens food
• 3 salivary glands: parotid gland, sublingual gland, submandibular gland

Question 12

esophagus

Answer 12

• muscular tube between mouth and mouth
• lined with mucus, extremely flexible
• 2 types of muscles: circular, longitudinal

Question 13

peristalsis

Answer 13

wave-like muscular contractions
- move food down G.I. tract (gastrointestinal)

Question 14

stomach

Answer 14

• food storage
• physical and chemical digestion

Question 15

sphincter

Answer 15

ring of circular muscle that acts like a valve
- ESOPHAGEAL SPHINCTER: junction of stomach and esophagus
- PYLORIC SPHINCTER: junction of stomach and small intestine

Question 16

gastric juices

Answer 16

1. mucous: provides protective coating
2. HCL: kills harmful substances
3. enzymes
4. salt
5. water

Question 17

pepsinogen and pepsin

Answer 17

PEPSINOGEN: inactive precursor to pepsin
PEPSIN: enzyme that break down proteins into shorter chains

Question 18

chyme

Answer 18

• thick liquid produced in stomach
• mixture of gastric juices and digested food

Question 19

small intestine

Answer 19

• most digestion takes place here
• circulatory system carries nutrients to cells and tissues in body

Question 20

parts of the small intestine

Answer 20

1. DUODENUM: majority of digestion occurs
2. JEJUNUM: digestion is completed
3. ILEUM: most absorption occurs, push undigested material into large intestine

Question 21

viili

Answer 21

finger-like projections, contains capillaries, blood picks up nutrients
- each villi contain microvilli

Question 22

liver

Answer 22

• largest organ in body
• secretes bile
• breaks large fat droplets into smaller ones

Question 23

gall bladder

Answer 23

• connected to liver via hepatic duct
• stores and concentrates bile

Question 24

pancreas

Answer 24

• located in first loop of small intestine
• regulates blood sugar (produces hormones- insulin and glucagon)
• produces pancreatic juices

Question 25

lacteal (within villus)

Answer 25

• tiny lymph capillaries
• absorbs fats

Question 26

large intestine

Answer 26

-3 parts: ascending, transverse, descending
- absorption of water, minerals and vitamins into cells, transported in blood
- break down undigested matter
muscle contractions push leftover matter to rectum

Question 27

rectum

Answer 27

stores feces

Question 28

anus

Answer 28

eliminates undigested substances