A&p.2.digestive.1

Front 1

what are the four layers of the GI tract wall?

Back 1

(from esophagus-->anal canal)
1. mucosa
2. submucosa
3. muscularis externa
4. serosa

Front 2

what type of epithelium surrounds the mouth, pharynx, esophagus, and anal canal?

Back 2

non-keratinized

Front 3

what three components make up the epithelial wall of the stomach?

Back 3

1. simple columnar
2. exocrine cells
3. enteroendocrine cells

Front 4

what role does simple columnar play in the stomach?

Back 4

absorption with transport mechanism and secretory process

Front 5

what role does exocrine cells play in the stomach epithelium?

Back 5

mucous for protection and serous fluid for movement and action of enzymes (absorption)

Front 6

what role do enteroendocrine cells play in the stomach epithelium?

Back 6

secrete hormones into the blood

Front 7

what does the epithelium of the lamina propia (CT) consist of?

Back 7

1. blood and lymph vessels
2. MALT- mucosa associated lymphatic tissue

Front 8

what organs are part of MALT?

Back 8

"pyers patches", tonsils, and appendix

Front 9

what is the muscularis mucosa?

Back 9

a thin layer of smooth muscle

Front 10

what are the 3 functions of the muscularis mucosa?

Back 10

1. increase surface area for secretion and absorption
2, folding in stomach
3. larger role: muscle tone of lumen itself

Front 11

what 4 components make up the submucosa of the GI tract?

Back 11

1. areolar CT
2. blood and lymphatic vessels
3. submucosal plexus
4. glands and lymphatic tissue

Front 12

what is the submucosal plexus?

Back 12

extensive network of neurons (plexus of meissner)

Front 13

what does the submucosa do?

Back 13

controls the secretion of the glans

Front 14

what is the muscularis externa dominated by?

Back 14

smooth muscle

Front 15

what 4 components make up the muscularis externa?

Back 15

1. innter circular sheet
2. myenteric plexus
3. outer longitudinal sheet
4. skii muscles mixed with smooth muscle in muscularis externa

Front 16

what does the myenteric plexus do?

Back 16

controls contraction of muscularis externa

Front 17

where will you see serosa?

Back 17

in visceral abdominal cavity

Front 18

what does the serosa do?

Back 18

serous membrane that secretes serous fluid

Front 19

what is serosa also called?

Back 19

visceral peritoneum

Front 20

what is the serosa consist of?

Back 20

CT and simple squamos epithelium

Front 21

what three organs lack serosa?

Back 21

pharynx, esophagus, and rectum

Front 22

what is adventitia?

Back 22

outermost covering on digestive organs outside of the abdominal cavity; just CT

Front 23

what is the enteric nervous system?

Back 23

brain of our gut; esophagus-->anus

Front 24

what are the 2 plexuses of the enteric nervous system?

Back 24

1. submucosal
2. myenteric

Front 25

what three type of neurons are within these plexuses?

Back 25

1. motor neurons
2. sensory neurons
3. interneurons

Front 26

what do motor neurons do?

Back 26

-supply myenteric- controls motility
-supply submucosa- controls secretory cells (associated with glands)

Front 27

what 2 types of sensory receptors are in the mucosal epithelium of the plexuses?

Back 27

chemoreceptors and stretch receptors

Front 28

what do interneurons do?

Back 28

-connect myenteric and submucosal plexus
-CNS and ANS ties/modifies (interneuron connections)

Front 29

what are the two types of neural controls within the digestive system?

Back 29

1. extrinsic control
2. intrinsic ENS control

Front 30

what 6 things that extrinsic control does?

Back 30

1. enteric system triggers small, sight, sound, and taste
2. direct motor control by CNS--> start things up to ENS
3. modification by ANS
4. affect of emotions
5. we get muscle contractions
6. salivary glands

Front 31

what 5 types of neurons are involved in intrinsic ENS control?

Back 31

1. sensory neurons recieve signals from lumen going to ENS
2. motor neurons that drive smooth muscle
3. interneurons important for local reflexes
4. parasympathetic neurons
5. sympathetic neurons

Front 32

what do motor neurons involve?

Back 32

-drive smooth muscle
-submucosal and myenteric plexus
-secretions and contractions

Front 33

what are interneurons important for?

Back 33

local reflexes; they ONLY connect submucosal plexus to myenteric plexus within GI tract (staying local)

Front 34

what do sympathetic neurons do?

Back 34

shuts enteric down

Front 35

what two type of hormones are involved in hormonal control of the digestive system?

Back 35

1. peptide hormones
2. endocrine hormones

Front 36

what type of cells are involved with peptide hormones?

Back 36

enteroendocrine cells

Front 37

what are 3 functions of peptide hormones?

Back 37

1. released into CT and then blood vessels
2. enhance of inhibit muscle contraction
3. control secretion of gland cells release due to binding

Front 38

what five components are part of the endocrine hormones?

Back 38

peptide hormones, insulin, glucagon, PTH, and calcitonin

Front 39

what are local mechanisms?

Back 39

chemicals in interstitial fluid that effect small areas

Front 40

how do the chemicals coordinate and 2 examples?

Back 40

in response to changing conditions

1. prostaglandins- fatty acids secreted that affect metabolic activities
2. histamine- initiates/enhances inflammatory response; initiate secretion of acids

Front 41

what are the oral or buccal cavity accessory digestive organs?

Back 41

teeth and tongue

Front 42

what 3 components are involves in the tongue?

Back 42

1. extrinsic muscles
2. intrinsic muscles
3. lamina propria

Front 43

what do the extrinsic muscles do?

Back 43

move food from side to side, in and out, back to front

Front 44

what do the intrinsic muscles do?

Back 44

reshape tongue to form words and swallowing

Front 45

what 2 things does the lamina propria contain?

Back 45

1. papillae-tastebuds
2. lingual glands

Front 46

what do lingual glands do?

Back 46

secrete mucousy, serous fluid containing lingual lipase (begins digestion of triglycerides)

Front 47

what is enamel?

Back 47

-hardest substance in the body
-protection again bacteria acids

Front 48

what are 2 functions of enamel?

Back 48

1. protects the tooth from wear and tear of chewing
2. protects against acids that easily dissolve dentin which forms majority of tooth

Front 49

what is mastication?

Back 49

chewing, mov food around, saliva, and teeth

Front 50

what is the result of mastication?

Back 50

bolus (lump)

Front 51

what runs how much saliva we need?

Back 51

the CNS and cerebral cortex

Front 52

why is mouth moist?

Back 52

to decrease bacteria

Front 53

what are 2 functions of the salivary glands?

Back 53

1. saliva keeps mouth and pharynx moist
2. secretions increase when food arrives

Front 54

how do the small salivary glands of mouth and toungue mucous membrane open?

Back 54

directly or through ducts to oral cavity

Front 55

what are the four ducts to oral cavity?

Back 55

labial, buccal, palatal, and lingual glands

Front 56

what are the 3 major salivary glands and where are they located?

Back 56

1. parotid glands-serous
2. submandibular glands- mixed
3. sublingual glands- mucous

Front 57

why is majority of saliva water?

Back 57

because its a medium for dissolving food

Front 58

what are the 7 types of solutes in saliva?

Back 58

1. ions- chloride, phosphate, bicarbonate
2. glycoproteins
3. Antibodies
4. enzymes
6. wastes

Front 59

what do bicarbonate and phosphate ions do?

Back 59

buffer acidic foods

Front 60

what do glycoproteins do?

Back 60

mucous, aids in formation of bolus

Front 61

what do Antibodies- IgA do?

Back 61

prevents invasion

Front 62

what do enzymes do?

Back 62

lysozyme; salivary amylase; kills bacteria

Front 63

what are wastes and what do they do?

Back 63

urea and uric acid; they rid of blood from digestive system

Front 64

what are the 3 phases of deglutition?

Back 64

1. buccal phase
2. pharyngeal phase
3. esophageal phase

Front 65

what happens during the buccal phase of deglutition?

Back 65

-bolus is forced into oropharynx (back of throat with tongue)
-voluntary stage

Front 66

what happens during the pharyngeal phase?

Back 66

bolus stimulates receptors in oropharynx, swallowing reflex begins

Front 67

what are the 4 steps of the pharyngeal phase?

Back 67

1. impulses sent to deglutition center in medulla oblagata
2. bolus moves through oropharynx and laryngopharynx
3. respiratory centers inhibited
4. esophageal sphincter reflexes to push bolus through

Front 68

what does the uvula and soft palate do?

Back 68

lift up to block off nasopharynx

Front 69

what does the epiglottis do?

Back 69

closes the larynx

Front 70

what happens during the esophageal phase?

Back 70

bolus enter esophagus and is pushed toward the stomache
-long fibers-shorten, diameter widens

Front 71

what are the three components of the esophagus's histology?

Back 71

1. smooth muscle in the muscularis mucosae
2. mucous glands in submucosa moisten food
3. muscularis externa- circular and longitudinal

Front 72

what are the three divisions of the muscularis externa of the esophagus?

Back 72

1. Superior 1/3: skeletal muscle, voluntary
2. Middle 1/3: mixed smooth and skeletal, voluntary and involuntary
3. Inferior 1/3: smooth muscle only, involuntary

Front 73

during esophageal phase of deglutition, what is the bolus being pushed by?

Back 73

peristalsis which is a progression of coordinated contractions and relacations of circular and longitudinal muscle layers pushing food down (shorten and lengthen; wave-like)

Front 74

what happens during peristalsis?

Back 74

-circular muscles superior to bolus contract
-longitudinal fibers inferior to bolus contract
-controlled by neurons in myenteric plexus
-contractions repeated in waves

Front 75

when does the esophageal sphincter relax?

Back 75

-as bolus reaches end of esophagus
-bolus moves into stomach

Front 76

what are the three steps of the esophangeal phase?

Back 76

1. bolus pushed by peristalsis
2. lower esophageal sphincter relaxes as bolus reaches end of esophagus
3. bolus moves into stomach

Front 77

what are the four main regions of the stomach?

Back 77

1. cardia
2. fundus
3. body
4 pyloris

Front 78

what is rugae?

Back 78

mucosal folds for expansion

Front 79

what is the pyloric sphincter??

Back 79

-connection to duodenum
-control release of chyme
-regulated depending on chemical in area

Front 80

what is the main/majority region of the stomach

Back 80

body