Physiology Exam 4

Front 1

Outermost layer to innermost layer

Back 1

1. serosa

2. longitudinal muscle

3. myenteric plexus

4. circular muscle

5. submucosal plexus

6. submucosa

7. muscularis mucosa

8. mucosa

Front 2

2 Parts of Muscularis Externa

Back 2

longitudinal and circular muscle

Front 3

2 parts of enteric nervous system

Back 3

myenteric and submucosal plexus

Front 4

Gastrin

1. Which cells, and where release gastrin?

2. List 3 types of stimulation for release

3. What causes inhibition?

4. What two things does it do?

Back 4

1. G cells in gastric antrum

2. distension of antrum, vagal stimulation, presence of amino acid/peptides in antrum

3. inhibited by presence of acid in antrum

4. stimulate acid secretion and growth of gastric mucosa

Front 5

Cholecystokinin (CCK)

1. Where is it located

2. What stimulates release?

3. What does it do?

Back 5

1. upper small intestine

2. aminoacids, fatty acids, HCl in small intestine

3. stimulates enzyme secretion of pancreas, stimulates pancreatic growth, stimulates gallbladder contraction, sphincter of Oddi relaxation, inhibits gastric emtpying, gastric acid, and inhibits feeding behavior

Front 6

Secretin

1. Where is it located?

2. What stimulates release?

3. What does it do?

Back 6

1. Upper small intestine

2. Presence of acid in duodenum

3. Stimulates secretion of bicarb (from pancreas), pancreatic growth, and inhibits acid secretion

Front 7

GIP - 2 main actions

Back 7

stimulates insulin secretion by pancreas and inhibits acid secretion by the stomach.

Front 8

GLP-I

Back 8

Glucagon-like Peptide I - it's released from ileum and proximal colon in response to fat, carbs, and bile. It stimulates insulin release, inhibits gastric emptying, and decreases feeding behaviors

Front 9

Paracrine

1. What two things control gastric function?

2. What initiates motility?

Back 9

Local control mechanism

Somatostatin/histamine control gastric function

Serotonin helps initiate motility

Front 10

What factors inhibit Gastric Peristalsis

Back 10

1. Acid (by release of secretin)

2. Lipid digestion products (release of GIP and CCK)

3. Protein digestion products (release of gastrin and CCK)

4. Osmolarity (low and high)

5. Duodenal distension

Front 11

ENS mediated intestinal motility

1. which cells release serotonin?

2. What's the signal release mechanism of afferent neuron?

Back 11

1. Enterochromafin like (ECL) cells

2. CGRP

Front 12

Tubular Glands

Back 12

Some are located in the gastricpits/crypts in the stomach and secrete HCl (parietal cells) and pepsinogen(chief cells)

Front 13

Compound glands

Back 13

More complex consisting of an acinarportion that secrete the material through primary secretion and the ductalportion where modification of the material can occur through secondarysecretion (salivary and pancreatic glands)

Front 14

Salivary Secretion

1. Function

2. Components

Back 14

1. helps initiate digestion, directed by ANS

2. mucous, amylase (starch), lingual lipase (lipid digestion), growth factors, serous (pH neutralization, sensory stimulation, taste)

Front 15

Composition of Saliva

1. Characteristic of Primary Secretion

2. Characteristics of Secondary Secretion

Back 15

1. similar Na, Cl, HCO-, K to plasma

2. removal of Na for K, removal of Cl for HCO-

Front 16

Which cells release HCl in the stomach?

Back 16

Parietal cells

Front 17

What does vagal input cause to happen in the gastric secretions?

Back 17

release of pepsinogen and HCl

release of histamine

release of gastrin to act hormonally

Front 18

Which 2 cells are activated by Gastrin?

Back 18

Gastrin activates ECL cells to release histamine and parietal cells to release HCl.

Front 19

What cells release somatostatin in response to acid in the stomach?

Back 19

D cells.

Front 20

What does somatostatin do? (2 functions)

Back 20

inhibits release of gastrin from G cells and inhibits HCl release from parietal cells

Front 21

2 Portions of Pancreatic Secretions

Back 21

1. Acinar portion - digestive enzymes

2. Ductal portion - release of Bicarb

Front 22

Zymogen

Back 22

Where pancreatic enzymes are stored. They have trypsin inhibitor added to them to maintain an acidic environment

Front 23

Exocrine secretions of Pancreas - list 4 and their actions

Back 23

Protease (digests proteins)

Amylase (digests carbs)

Lipase (digests lipids)

Procolipase (needed for lipase to function)

Front 24

What three factors cause release of pancreatic enzymes from acinar cells?

Back 24

VIP, GRP, and Ach

Front 25

Pancreatic Polypeptide - stimulation and action

Back 25

Released by pancreas in response to vagal input, and acts by decreasing vagal input

Front 26

Peptide YY

Back 26

Released in ileum in response to lipids and act hormonally to decresae meal-stimulated GI function

Front 27

Exocrine Pancreas

1. What 4 factors secrete pancreatic enzymes by increasing intracellular calcium

Back 27

1. CCK, GRP, substance P, muscarinic receptors

Front 28

What two factors causes increase in intracellular cAMP in pancreas, and what does that do?

Back 28

VIP and CGRP - it stimulates pancreatic enzymes

Front 29

Intestine - what cells secrete mucus

Back 29

goblet cells

Front 30

Intestine - which glands secrete water and bicarbonate?

Back 30

duodenal glands

Front 31

Enterocytes

1. how long is villus migration?

2. from where to where does it go?

3. how does it change during migration?

Back 31

1. about 6 days

2. it goes from crypts to surface

3. it go from secretory to absorptive cells

Front 32

What does CFTR stand for and do?

Back 32

cystic fibrosis transmembrane regulator

It helps move chloride out of the cell, sodium and water follow (mainly by action of VIP and cAMP alterations)

Front 33

How does cholera work?

Back 33

It irreversibly activates the Gs GPCR, increasing cAMP and maintaining channel open. This leads to secretion of Cl and Na and water.

Front 34

What two methods of absorption can occur in the intestines?

Back 34

1. transcellular via active or passive carriers

2. paracellular through tight junctions. duodenum is more leaky than others.

Front 35

How are glucose and galactose carried into enterocyte and then secreted to blood?

Does this require energy?

Back 35

1. absorbed by SGLT 1 (sodium linked)

2. GLUT 2 (passive)

3. SGLT 1 requires ATP (secondary active transport)

Front 36

How is fructose carried into enterocyte than secreted to blood? does this require energy?

Back 36

1. absorbed by GLUT5

2. secreted by GLUT 2

3. no

Front 37

What happens when vagal input or top 1/3 of pons is cut? What is top 1/3 of pons referred to as?

Back 37

breathing becomes slower and deeper. It's called pneumotaxic center

Front 38

What happens when BOTH vagal input and top 1/3 of pons are cut?

Back 38

You see apneustic breathing, where you have sustained inspiratory effort with short expiratory gaps.

Front 39

What happens to breathing when pons is cut off entirely?

Back 39

You have adequate ventilation, but is irregular.

Front 40

From which part of brain does basic drive for breathing occur?

Back 40

Medulla, specifically dorsal respiratory group.

Front 41

What is VRG responsible for?

Back 41

Some inspiratory effort, but also expiratory effort. If there is need for active expiration, VRG will send signal to contract expiratory muscles.