GI

Question 1

What are the two enteric plexuses that innervate the GI

Answer 1

Submucosal (Meissner Plexus) and the Myenteric (Auerbach Plexus)

Question 2

Myenteric plexus is responsible for:

Answer 2

GI movement/motility- increased tonicity, intensity, rate, velocity, and local blood flow
Inhibits sphincter tone (pylorus & ileocecal valve)

Question 3

what does the meissner (submucosal) plexus do

Answer 3

GI secretion & local blood flow

-very small segments of GI wall, lead to various degrees of unfolding wall

Question 4

what does the ptyalin secrete

Answer 4

salivary amylase, digest starch

Question 5

parietal cells of the oxyntic gland in the mucosal layer of the stomach secrete:

Answer 5

HCL & intrinsic factor

Question 6

What do chief cells secrete

Answer 6

pepsinogen

Question 7

How does pepsinogen become activated?

Answer 7

HCl splits it into an active form of pepsin

Question 8

D cells secrete:

Answer 8

somatostatin (inhibits gastric juices)

Question 9

G cell

Answer 9

secrete gastrin increasing gastric juice

Question 10

ECL cells in the Oxyntic gland secrete

Answer 10

histamine (stimulates gastric acid juice)

Question 11

Where is the swallowing center located

Answer 11

medulla and pons

Question 12

Splanchnic flow describes::

Answer 12

nutrients from the gut, spleen, and pancreas travel via portal vein to liver

Question 13

Describe rhythmic slow waves

Answer 13

smooth muscle that shows undulating changes in resting membrane potential but don’t cause contraction

Question 14

What causes contaction of GI

Answer 14

Channels open allow for Ca++ along with Na+ to enter and cause long AP, contraction

Question 15

What occurs in liver

Answer 15

removes bacteria/particles

Question 16

what are the accessory organs of digestion

Answer 16

liver, gallbladder, and pancreas

Question 17

what is saliva made up

Answer 17

water, mucus, amylase, bicarbonate, K+, and lingual lipase

Question 18

Where and why would you see a apthous ulcer

Answer 18

“cold sore” disruption in mucousal surface from trauma infection, or inflammation

Question 19

What two things occur in order to move the bolus from mouth into esophagus

Answer 19

pharynx muscles raise soft palate closing entry to nasopharynx, and epiglottis slides back to close off larynx & trachea

Question 20

whats the main function of the UES

Answer 20

prevent air into esophagus during respiration

Question 21

whats the main function of LES

Answer 21

prevents backflow from stomach

Question 22

How do both Esophageal Sphincters perform there function

Answer 22

maintaining tonicity

Question 23

Describe the muscularis propria in the esophagus

Answer 23

Proximal 1/3 smooth
middle 1/3 skeletal, smooth
Distal 1/3 smooth

Question 24

what is achalasia

Answer 24

LES fails to relax preventing food from entering stomach

Question 25

how would u tx achalasia

Answer 25

antispasmodics, balloon placement

Question 26

Esophageal strictures are caused by

Answer 26

scar tissue, sometimes from GERD

Question 27

Describe the gastroileal reflex

Answer 27

it increases ileal motility (emptying ileum, preparing for more chyme)

Question 28

describe gastroenteric reflex

Answer 28

distension of the stomach triggers peristalsis

Question 29

how do rugae help aid digestion

Answer 29

allow for increased volume without change in pressure, and increase surface area

Question 30

Describe retropulsion in the stomach

Answer 30

as the pyloris contracts sending chyme to duodenum, the remaining gets propelled back away from sphincter for further mixing

Question 31

what cells mediate the pace of peristalsis in stomach

Answer 31

Cajal cells

Question 32

What two structures of the GI are retroperitoneal

Answer 32

esophagus and duodenum

Question 33

what structures are intraperitoneal

Answer 33

jejunum, ileum, liver and stomach

Question 34

What do the Brunner's Glands do in the duodenum

Answer 34

secrete alkaline mucus for protection via neutralizing acid

Question 35

why does a patient become constipated with an inflamed appendix?

Answer 35

irritates the cecum (close in location) hence, sphincter spasms cause partial paralysis of ileum

Question 36

what does the Crypt of Leiberkuhn do to contribute to the health of the SI

Answer 36

contains undifferentiated cells to replace the epithelial layer, secretes some digestive juices

Question 37

how do gastrin, insulin, motilin, and serotonin act on peristalsis

Answer 37

increase

Question 38

what acts to delay emptying of the stomach?

Answer 38

distension, irritation, acidity, CCK, GIP, & Secretin

Question 39

Cholecystokinin CCK functions to:

Answer 39

stimulate release of bile & pancreatic juices to break down lipids & aa Inhibits: gastric emptying & parietal cells secretion HCL

Question 40

these two enzymes are secreted from the pancreas to aid with digestion of proteins

Answer 40

trypsinogen and chymotrypsin

Question 41

why aren't trypsinogen and chymotrypsin able to act immediately on digestion

Answer 41

they are inactive forms to prevent them from destructing the pancreas... must be modified.

Question 42

How are fats aided in digestion?

Answer 42

bile salts from the liver and lipase from the pancreas both facilitate fat breakdown.

Question 43

what is the route of bile once it is ejected from the gallbladder to the SI

Answer 43

to cystic duct, common bile duct, and to the Sphincter of Oddi at the Ampulla of Vater at junction of the duodenum

Question 44

what carries bile from hepatocytes to the bile ducts

Answer 44

bile canalculi

Question 45

What does the liver store

Answer 45

fat, glycogen iron, copper, Vitamin B12, A, D, and E

Question 46

what does the liver synthesize

Answer 46

fat, phospholipids, cholesterol, plasma proteins, non-essential aa, serum enzymes (AST, ALT, LDH, and alk phosp)

Question 47

where is calcium primarily absorbed

Answer 47

ileum

Question 48

how is calcium absorbed

Answer 48

via passive, active, and carrier proteins

Question 49

what enhances calcium absorption

Answer 49

bile salts, which also enhances vitamin D

Question 50

What does vitamin B12 bind to

Answer 50

intrinsic factor making it resistant to digestion

Question 51

where does most absorption of vitB12 occur

Answer 51

ileum terminally

Question 52

Whats vitamin B12 necessary for

Answer 52

erythrocyte maturation

Question 53

why does a deficiency of vitB12 cause pernicious anemia

Answer 53

without B12, one wouldn't have RBC formatioin

Question 54

what is pernicious anemia caused from

Answer 54

lack of B12 in order to have erythrocyte maturation

Question 55

Secretin is stimulated to be secreted by what

Answer 55

low pH

Question 56

GIP does what

Answer 56

secretes insulin, it also inhibits parietal/chief/paralysis

Question 57

Iron and calcium have a special regulation in the body

Answer 57

amount absorbed dependent on amount needed

Question 58

iron absorption is facilitated by

Answer 58

vitamin C

Question 59

Describe the ileogastric reflex

Answer 59

when ileum is distended, it inhibits gastric motility

Question 60

describe gastrocolic

Answer 60

distended gastric promotes propulsion through colon

Question 61

What do the I cells in Small Intestine secrete

Answer 61

Cholecystokinin- responsible for ejecting bile (inhibits gastrin motility)