GI System Physiology 1

Question 1

What are the 2 types of tissue that forms the spleen?

Answer 1

Red pulp

White pulp

Question 2

What are the 2 motor activities of the mouth?

Answer 2

Mastication

Deglutition (swallowing)

Question 3

What is the motor activity of the esophagus?

How is this accomplished?

Answer 3

Propulsion by peristalsis

Question 4

What are the 3 motor activities of the stomach?

Answer 4

Mixing

Storage

Emptying

Question 5

What 2 things regulate stomach emptying?

Answer 5

Gastrin

Stomach distention

Question 6

How do long chain fatty acids affect stomach emptying?

Answer 6

They decrease it by causing release of cck which inhibits gastrin

Question 7

How does duodenal distention and irritation affect stomach emptying time?

Answer 7

The decrease emptying time

Question 8

What is the purpose of rhythmic segmentation in the S.I.?

Answer 8

To mix up the chyme to expose it to enzymes and absorptive surface

Question 9

What structure prevents backflow from colon and separates S. I. bugs from L.I. bugs?

Answer 9

Ileocecal valve/sphincter

Question 10

What causes the sphincter to relax?

Answer 10

Gastric distention via gastroileal reflex

Gastrin

Question 11

Where does most of the water absorption take place?

Answer 11

In cecum and transverse colon

Question 12

What does rectal dissension cause?

Answer 12

A desire to defecate

Question 13

What are the 2 types of electrical activity in the G.I.?

Answer 13

Slow waves (Basic Electrical Rhythm ber)

Spike potentials

Question 14

Which of the 2 types of electrical activity leads to smooth muscle contraction?

Answer 14

Spike potentials

Question 15

Which of the 2 electrical activities keeps G.I. in a state of readiness by helping set up gut tone?

Answer 15

Slow waves

Question 16

What helps set up frequency and rhythm of action potential and smooth muscle contraction?

Answer 16

Slow waves

Question 17

Which branch of the ans has most affect on the G.I.?

Answer 17

Parasympathetics

Question 18

What are the 2 areas of intrinsic nervous control on the gut?

Answer 18

Myenteric (Auerbach’s) plexus

Submucosal (Meissner’s) plexus

Question 19

Which of the 2 plexuses control motility and contraction?

Answer 19

Myenteric plexus

Question 20

Which of the 2 plexuses controls secretions?

Answer 20

Submucosal plexus

Question 21

Which of the 2 extrinsic nervous system controls will decrease blood flow leading to decreased secretions?

Answer 21

Sympathetics

Question 22

Which of the 2 extrinsic nervous system controls will increase motility and secretions?

Answer 22

Parasympathetics

Question 23

What are the antibacterial substances found in saliva?

Answer 23

Lactoferrin - binds iron to prevent bacterial cell growth

IgA

Muramidase (Breaks down bacterial cell walls)

Question 24

What enzymes are found in saliva?

Answer 24

Lingual lipase

Amylase

Question 25

What affect does increased parasympathetics have on saliva secretion?

Answer 25

It will increase rate of secretion

Question 26

What are some of the functions of hcl?

Answer 26

(1) Activation of pepsinogen into pepsin (2) Provides the adequate pH for pepsin activity, micronutrient absorption (3) Storage and mixing up of chyme (4) Denatures proteins (5) Antibacterial

Question 27

What is secreted from parietal cells?

Answer 27

hcl Intrinsic factor

Question 28

What is secreted from chief cells?

Answer 28

Pepsinogen

Question 29

What is secreted from goblet cells?

Answer 29

Mucous

Question 30

What breaks down the aromatic amino acid bonds of proteins?

Answer 30

Pepsin

Question 31

What are 3 stimulants for hcl secretion?

Answer 31

(1) Parasympathetics (2) Gastrin release stimulated by stomach distention and secretagogues (3) Histamine

Question 32

What enzyme is present in infants but not adults?

Answer 32

Rennin, which breaks down milk protein. Don't confuse this with renin.

Question 33

What neutralizes the acidic chyme as it moves into the duodenum?

Answer 33

Bicarbonate

Question 34

What causes release of bicarbonate?

Answer 34

Secretin

Question 35

Where are zymogen granules produced and released from? (organ and cells)

Answer 35

From acinar cells in pancreas

Question 36

Which pancreatic cells secrete both insulin and glucagon?

Answer 36

Islet of Langerhans or Pancreatic islets

Question 37

Which cells produce bicarbonate?

Answer 37

Ductal cells

Question 38

What activates trypsinogen into trypsin?

Answer 38

Enterokinase. Kinase enzymes transfer phosphates from ATP to another molecule.

Question 39

What activates the remaining zymogens?

Answer 39

Trypsin

Question 40

What 2 enzymes cleave proteins into smaller peptides?

Answer 40

Trypsin and chymotrypsin

Question 41

Which enzymes cleave off individual amino acids off of peptides?

Answer 41

Carboxypeptidase, aminopeptidase, and dipeptidase

Question 42

What is the difference between carboxypeptidase and aminopeptidase?

Answer 42

Carboxypeptidase cleaves amino acids off of the carboxyl end Aminopeptidase cleaves them off the amine end

Question 43

What is major stimulus for zymogen release?

Answer 43

cck

Question 44

What stimulates release of cck?

Answer 44

Fat in S.I. Partially digested proteins

Question 45

What hormone enhances activity of cck?

Answer 45

Insulin

Question 46

What 2 hormones inhibit pancreatic juice production and activity?

Answer 46

Somatostatin Glucagon

Question 47

Where is secretin produced?

Answer 47

In the duodenum of the S.I.

Question 48

What effects does secretin have on its target organs?

Answer 48

Pancreas: Stimulates duct cells to release bicarb Liver: stimulates bile and bicarb release

Question 49

What action does acetylcholine have on pancreatic secretions?

Answer 49

It will increase secretion due to parasympathetic action

Question 50

What does gelatinase breakdown?

Answer 50

Proteoglycans that are present in connective tissue of flesh products

Question 51

Facilitated diffusion of sugars across gut epithelium is dependent on Co-transport of what?

Answer 51

Sodium

Question 52

How are D verus L amino acids transported across the gut lumen?

Answer 52

D-amino acids are diffuses L-amino acids are actively transported across the mucosa

Question 53

What nutrients are stored within the liver?

Answer 53

Vitamin A, D, E, K, and B12 and iron and copper

Question 54

What does the P450 system do to xenobiotics?

Answer 54

Makes them more hydrophilic with addition of -OH group

Question 55

Which components of bile are responsible for solubilizing fat?

Answer 55

Bile salts and lecithin

Question 56

What are the active phagocytes of the liver?

Answer 56

Kupffer cells

Question 57

Which plasma protein makes up 50% of the liver's total protein production?

Answer 57

Albumin