DIGESTIVE SYSTEM:Components

Question 1

Functions of the digestive system?

AIDES

Answer 1

Ingest food
Secretes
Digests macromolecules
Absorbs food
Eliminates indigestible waste

Question 2

Why does the digestive system absorb food?

Answer 2

to make energy

help with growth and repair

Question 3

4 steps of digestion?

Answer 3

1-ingestion of food in mouth
2-Mechanical and chemical digestion
3-Absorption of molecules
4-Elimination of indigestible substances

Question 4

Mechanical vs Chemical digestion

Answer 4

Mechanical- large piece of food becomes smaller (WITHOUT BECOMING NEW PRODUCT)
ex) chewing
Chemical-Enzymes chemically breakdown macromolecules into smaller products
ex)polymer to monomer

Question 5

Digestive pathway?

Answer 5

mouth-pharynx-esophagus-stomach-small intestine-large intestine-rectium-anus
(ALIMENTARY CANAL)

Question 6

Organization of the human body?

Answer 6

cells-tissues-organs-organ systems

Question 7

Tissue?

Answer 7

group of cells that have a common function within the body

Question 8

4 types of tisse? and where are they found?

Answer 8

Epithelial-lines body surfaces
Connective-blood/cartilage
Muscle-cardiac, smooth and skeletal
Nervous-Nuerons

Question 9

Homeostasis?

Answer 9

Consistency of the body’s internal environment through negative feedback
EQUILIBRUIM

Question 10

Mouth/Oral cavity function? Components?

Answer 10

Ingestion
Begins digestion(chemical and mechanical)

Teeth, salivary glands, tongue

Question 11

Structure of teeth?

Answer 11

Teeth-begin mechanical digestion to increase SA for enzyme reactions

Question 12

Structure of Salivary glands?

Answer 12

Salivary glands- produce saliva to:
liquify food
Chemical digestion (optimal pH =7)
Lubricates and softens bolus
Enzymes in saliva kill bacteria
Starch---------Maltose (from salivary amalyase)

Question 13

Structure of tongue?

Answer 13

Contains taste buds
moves food around
Pushes bolus to the back of throat to swallow reflux centre

Question 14

What is bolus?

Answer 14

Chewed up food and saliva

Question 15

Pharynx Function?

Answer 15

Swallowing-when food is placed on the reflex centre:
The soft palate covers nasopharynx
The epiglottis covers the trachea
Peristalsis of esophagus begins

Question 16

Pharynx Structure?

Answer 16

Region at back of the throat

opens to respiratory and digestive system

Question 17

Epiglottis?

Answer 17

Flap of tissue that covers the trachea when we swallow food and liquid

Question 18

Esophagus Function?

Answer 18

Moves food through esophagus through peristalsis

-Slow rhythmic contraction that pushes the bolus along

Question 19

Esophagus Structure?

Answer 19

30cm muscular tube that connects pharynx to stomach
(No digestion occurs here)
At end of Esophagus, there is ring of muscle called cardiac sphincter that stops chyme from reentering esophagus

Question 20

what is chyme?

Answer 20

pulpy acidic fluid in stomach

Question 21

Stomach structure?

Answer 21

J shaped organ with 3 muscles layers

begins and ends with sphincters (pyloric and cardiac)

Question 22

Stomach Function?

Answer 22

Mechanical- churns and liquifies food with ridges in stomach

Chemical-chemically digests proteins with gastric juices

Question 23

What do gastric juices contain?

Answer 23

Pepsinogen
hydrochloric acid
mucous
water

Question 24

Function of gastric juices?

Answer 24

HCl released when proteins enter stomach
-creates pH of 2.5 that kills bacteria and salivary amylase
-changes pepsinogen to active enzyme pepsin
Pepsinogen———Pepsin (HCl)
-begins protein digestion
Protein————-smaller polypeptides
MUCOUS secretions protect stomach wall from HCl

Question 25

What does the pyloric sphincter do?

Answer 25

meters out the chyme into duodenum at a controlled rate

Question 26

Small Intestine Structure?

Answer 26

REGIONS: duodenum—-Jejunum—–Ileum
high absorption rate due to convoluted walls
contains villi and microvilli

Question 27

What is Villi and Microvilli?

Answer 27

Villi-folds in layer of S.I (contain blood capillaries that absorb glucose, aa’s, & nucleotides. Also lacteals that absorb glycerol and fatty acids)
Microvilli- folds in villi

Question 28

What does the duodenum do? Jejunum? Ileum?

Answer 28

D- chemically digests pancreatic juices
J-digestion and absorption
I-absorption of nutrients

Question 29

Function of Small Intestine?

Answer 29

CHEMICAL- completes digestion of the nutrient types (proteins, carbs, nucleic acids & lipids)
Begins absorption of nutrients- AA’s, glucose, & nulceotides into blood.
Fatty acids and glycerol into lacteal
PHYSICAL- peristalsis
ABSORPTION- villi contains blood capillaries for nutrient absorption, and lacteals for glycerol and fatty acids

Question 30

Appendix

Answer 30

Has lymph tissue to fight infection

can be removed

Question 31

Large intestine Structure?

Answer 31

large in diameter

colon, anus, rectum

Question 32

Large intestine function?

Answer 32

Absorption of water and salts
Stores ingestible materials
Anaerobic bacteria (eColi)

Question 33

What does anaerobic bacteria do? And where is it found?

Answer 33

Eats waste and produces useful things for survival
Produces growth factors
produce waste of their own
Found in L.I

Question 34

Rectum

Answer 34

End of large intestine

Where waste is stored until message is sent to nervous system for bowel movement

Question 35

Anus

Answer 35

Sphincter muscle where feces exits