A&p Chapter 17

Front 1

Function is to process food, extracts nutrients, eliminates the residue

Back 1

The Digestive System

Front 2

the selective intake of food

Back 2

ingestion

Front 3

The physical breakdown of food into smaller particles. Exposes mere surface area to enzymatic action.

Back 3

mechanical digestion

Front 4

Employs enzymes to breakdown macro-molecules into basic building blocks.

Back 4

chemical digestion

Front 5

All chemical digestion is a process of

Back 5

enzymatic hydrolysis

Front 6

breaking covalent bonds by adding water

Back 6

enzymatic hydrolysis

Front 7

The uptake of nutrient molecules into the epithelial cells of the digestive tract, then into the blood & the lymph

Back 7

absorption

Front 8

the absorption of water & the compaction of indigestible residue into feces.

Back 8

compaction

Front 9

the elimination of feces

Back 9

defecation

Front 10

16' tube. opens to ext. environment-both ends.

Includes the mouth, pharynx, esophagus, stomach, small & large intestines.

Back 10

the digestive tract

Front 11

stomach & intestine are part of.....

Back 11

GI tract

Front 12

teeth, tongue, salivary glands, liver, gall bladder, and pancreas.

Back 12

accessory organs

Front 13

the oral or buccal cavity.

function: ingestion, taste, chewing, mechanical& chemical digestion, swallowing, speech, respiration.

Back 13

the mouth

Front 14

surface is covered with non-keratinized stratified squamous epithelium w/bumps called lingual papillae.

Back 14

tongue

Front 15

anterior 2/3 of the tongue is called.....and occupies the oral cavity

Back 15

the body

Front 16

posterior 1/3 of the tongue is called......and occupies the first part of the pharynx.

Back 16

the root

Front 17

This helps close the trachea by pushing the epiglottis back

Back 17

the tongue

Front 18

collectively called the dentition.

sever to masticate the food, breaking it up into smaller pieces for enzymatic breakdown

Back 18

teeth

Front 19

adults typically have .....teeth in the mandible and maxilla.

Back 19

16

Front 20

most of a tooth consists of a hard, yellowish tissue called

Back 20

dentine

Front 21

teeth are covered by.......in the crown and .......in the root

Back 21

enamel; cementum

Front 22

non-living hardened secretion

Back 22

enamel

Front 23

living connective tissue

Back 23

dentine & cementum

Front 24

damaged dentine or cementum can regenerate but when this is damaged it cannot and must be artificially repaired.

Back 24

enamel

Front 25

a watery solution of mucus, enzymes & electrolytes.

moistens mouth, cleanses teeth, lubricates food, inhibits bacterial growth, dissolves molecules so they can stimulate taste buds

Back 25

saliva

Front 26

anterior to ear lobes

ducts open into mouth opposite 2nd molar

"mumps"-inflammation of this gland

Back 26

parotid

Front 27

1/2 way along medial side of mandible

ducts open beneath tongue

Back 27

submandibular

Front 28

floor of mouth

multiple ducts empty beneath tongue

Back 28

sublingual

Front 29

a muscular funnel that connects

oral cavity to esophagus

nasal cavity to larynx

Back 29

pharynx

Front 30

point of intersection for digestive & respiratory tracts

Back 30

pharynx

Front 31

straight muscular tube 25-30 cm long.

begins posterior to trachea at inferior border of the larynx.

Back 31

esophagus

Front 32

the esophagus penetrates the diaphragm at this structure

Back 32

esophageal hiatus

Front 33

the esophagus meets the stomach at the

Back 33

cardiac orifice

Front 34

prevents stomach contents from regurgitating

Back 34

lower esophageal sphincter

Front 35

acid reflux into esophagus

Back 35

heart burn

Front 36

involves over 22 muscles in mouth, pharynx, esophagus.

coordinated by "swallowing center in medulla oblongata.

Back 36

swallowing "deglutition"

Front 37

voluntary

tongue collects food into a bolus & pushes posteriorly

Back 37

oral phase

Front 38

food accumulates in.......in front of epiglottis

Back 38

oropharynx

Front 39

epiglottis tips posteriorly & bolus slides into

Back 39

laryngopharynx

Front 40

involuntary

initiated by bolus activating touch receptors in laryngopharynx.

Pharyngeal constrictors drive bolus down into esophagus.

breathing is automatically suspended for a moment during this phase

Back 40

pharyngeal phase

Front 41

esophagus constricts behind bolus while re relaxing in front of bolus thus propelling bolus downward

Back 41

esophageal phase

Front 42

wave of involuntary contractions during esophageal phase of swallowing

Back 42

peristalsis

Front 43

when standing gravity works faster than

Back 43

peristaltic wave

Front 44

ensures that you can swallow regardless of body postition

Back 44

peristalsis

Front 45

liquids reach stomach in .......seconds

Back 45

1 to 2

Front 46

bolus reach stomach in .........seconds

Back 46

4 to 8

Front 47

As bolus reaches lower end of esophagus........relaxes to let bolus pass into stomach

Back 47

esophageal sphincter

Front 48

muscular sac in the upper left abdominal cavity inferior to the diaphragm

Back 48

stomach

Front 49

functions primarily as a food storage organ

Back 49

stomach

Front 50

mechanically breaks down food particles

liquifies food

begins chemical digestion of proteins and fats

Back 50

stomach

Front 51

a pasty mixture of semi-digested food in the stomach

Back 51

chyme

Front 52

stomach is j shaped & divides into these 4 regions.

Back 52

cardiac, fundic, body, and pyloric region.

Front 53

most inferior region of the stomach.

terminates at the pylorus

Back 53

pyloric region

Front 54

surrounds the pyloric region and regulates passage of chyme

Back 54

pyloric sphincter

Front 55

Gastric glands produce 2-3 liters of gastic juice per day

Back 55

gastric secretions

Front 56

produced by parietal cells, activates pepsin, converts dietary iron into usable form, breaks up CT, contributes to disease resistance

Back 56

HCL

Front 57

produced by chief cells called pepsinogens and digests proteins to shorter chains

Back 57

pepsin

Front 58

produced by chief cells and digest fats

Back 58

lipase

Front 59

produced by parietal cells

essential for the absorption of vitamin B 12

w/out B 12, hemoglobin cannot be synthesized.

Back 59

intrinsic factor

Front 60

the only indispensible function of the stomach

Back 60

intrinsic factor

Front 61

the forceful ejection of stomach contents

Back 61

vomitting

Front 62

vomitting is controlled and integrated by this center located in the medulla oblongata

Back 62

emetic center

Front 63

why doesnt the stomach digest itself?

Back 63

1. mucosa covered w. a thick, highly alkaline mucus that neutralizes HCL & resists enzymes.

2. tight junctions between epithelial cells.

3. rapid epithelial cells replacement. 3-6 days.

Front 64

small pear shaped organ on the posterior inferior portion of the liver

Back 64

gallbladder

Front 65

the gallbladder stores and concentrates this substance produced by the liver.

Back 65

bile

Front 66

yellowish green fluid containing minerals, cholesterol, phospholipids, bile pigments, bile acids.

Back 66

bile

Front 67

principal pigment in bile derived from decomposition of hemoglobin

Back 67

bilirubin

Front 68

steroids synthesized from cholesterol. Aids in the breakdown of fats and their absorption.

Back 68

bile acids (salts)

Front 69

if bile becomes excessively concentrated they many form these

Back 69

gallstones

Front 70

both and endocrine and exocrine gland-sugar regulation

Back 70

the pancrease

Front 71

endocrine (1%)

Back 71

islets of langerhans

insulin,glucagon

Front 72

99% of pancreas is........with a digestive function

Back 72

exocrine

Front 73

secretes @ 1500 ml of pancreatic juices per day

Back 73

pancreas

Front 74

the pancreas flows to the duodenum(small intestine) vial the............to join the bile duct

Back 74

pancreatic duct

Front 75

pancreatic juice is alkaline(to buffer HCL) and consists mainly of

Back 75

enzymes

Front 76

digests proteins

Back 76

trypsin & chymotrypsin

Front 77

digests starch

Back 77

pancreatic amylase

Front 78

digests fat

Back 78

pancreatic lipase

Front 79

digests RNA

Back 79

ribonuclease

Front 80

Deoxy ribonuclease

Back 80

digest DNA

Front 81

a coiled mass filling most of the abdominal cavity.

divided into 3 regions: Duodenum, Jejunum, Ileum.

Back 81

small intestine

Front 82

first 25 cm of the small intestine.

begins at pyloric valve

secretes an abundance of mucus to neutralize the stomach acids.

Back 82

duodenum

Front 83

stomach acids neutralized fats broken up by bile acids. Pancreatic enzymes begin chemical digestion.

Back 83

emulsified

Front 84

most digestion & nutrients absorption occurs here

Back 84

jejunom

Front 85

end at the cecum (large intestine) and the passage of food residue is controlled here by the ileocecal valve

Back 85

ileum

Front 86

ring-like constrictions appear at several places along the intestine as they relax, new constrictions appear elsewhere.

the purpose is to knead or churn the intestine contents

Back 86

segmentation

Front 87

when most nutrients have been absorbed & what is left is undigestible residue, segmentation declines and peristalsis begins, thus moving material towards the colon.

Back 87

peristalsis

Front 88

receives @ 500 ml of indigestible food residue per day.

reduces this to @ 150 ml of feces by absorbing water and salts

Back 88

large intestine

Front 89

begins in the lower right quadrant at the ileocecal valve

Back 89

large intestine

Front 90

start of the large intestine. The appendix attaches to it.

Back 90

cecum

Front 91

highly populated with lymphocytes and is a significant source of immune cells

Back 91

appendix

Front 92

the portion of the large intestine between the ileocecal valve and the rectum.

Back 92

colon

Front 93

we house over 800 species of bacteria here, which digest substances that we do not have enzymes for

Back 93

colon

Front 94

bacteria also synthesizes.......

Back 94

B-vitamins and Vitamin K

Front 95

used for clotting blood

our diet alone does not provide enough to ensure adequate blood clotting

Back 95

Vitamin B & K

Front 96

takes 12-24 hours to reduce the residue of a meal to feces

Back 96

absorption and motility

Front 97

75% water

25% solids

Back 97

feces

Front 98

clonic motility is predominantly a type of segmentation

Back 98

haustral contractions

Front 99

pouches in the large intestine

Back 99

haustra