Exocrine pancrease and salivary gland - Collins

Question 1

List the constituents of saliva (8).

Answer 1

Water
Bicarb
Mucins
Amylase (alpha 1,4 bonds in starch. Hence, alpha-amylase)
Lysozyme (pore forming antibacterial - pops them)
lactoferrin (sequesters iron from bacteria)
IgA (opsonizes)
Epidermal and nerve growth factors (dogs licking wounds - healing facilitation)

Question 2

Acinar cells make the saliva and _____cells modify its ionic content

Answer 2

striated duct

Question 3

Pressure in the mouth (increases or decreases) salivary secretion?

Answer 3

increases

Question 4

Three things that decrease salivary secretions?

Answer 4

Sleep, fear, fatigue

Question 5

Release of this neurotransmitter from the octic ganglion or the submandibular ganglion onto the parotid/submandibular glands will increase salivation.

Answer 5

Ach

Question 6

Type I secretions. Describe

Answer 6

Plenty of water, parasympathetic.

Question 7

Type II secretions. Describe.

Answer 7

Thick, crusty secretion driven by sympathetic nervous system. Vasoconstriction, less water into the secretions, more proteinaceous, etc.

Question 8

Saliva content and secretion is dependent on ____?

At a low rate of flow, duct cells absorb _____ and secrete _____.

Answer 8

blood flow rate.

absorb Na+ and Cl- and secrete K+ and HCO3-.

Faster flow rate limits the action of duct cells on ionic/water content

Question 9

What do the salivary acinar cells do? What path do secretions take?

Answer 9

Acinar cells make the saliva and secrete it into the acinus. It then proceeds into the intercalated duct and then the striated duct.

Question 10

What are the secretory products of the exocrine pancreas? (many)

Answer 10

Trypsinogen
Chrmotrypsinogen
Proleastase
Procarboxypeptidase A and B

Amylase
Lipase
Deoxyribonuclease/Ribonuclease
Procolipase
Monitor peptide
Trypsin inhibitor

Question 11

WHat three compounds regulate pancreatic secretion?

Answer 11

Ach, Secretin, CCK

Question 12

How does Ach regulate pancreatic secretions?

Answer 12

released from the vagus and ENS nerves; stimulates the release of digestive enzymes from acinar cells (mostly cephalic stage)

Question 13

How does Secretin regulate pancreatic secretions?

Answer 13

released from endocrine cells in the proximal small intestines in response to acid; stimulates the release of a bicarbonate rich solution from pancreatic duct cells

Question 14

How does CCK regulate pancreatic secretions?

Answer 14

released from endocrine cells in the proximal small intestines in response to fats & proteins; stimulates the release of digestive enzymes from acinar cells but has other effects in the duodenum

Question 15

What is one difference in the secretion of HCO3 between the salivary and pancreatic glands?

Answer 15

Salivary - kHCO3

Pancreatic/duodenal - NaHCO3

Question 16

What is a key structural difference between the salivary and pancreatic acinus?

Answer 16

Pancreatic acini lack myoepithelial cells

Question 17

What is the effect of CCK  in the duodenum on: 
Gallbladder
Pancreas
Stomach
Sphincter of Oddi

Answer 17

Gallbladder - contraction
Pancreas - Acinar secretion
Stomach - REduced emptying
Sphincter of Oddi - relaxation, facilitation and release

**Balance between buffering acid and having the necessary enzymes present to digest

Question 18

In the duodenum, CCK is released from the ___ cells.

Answer 18

I cells.

Question 19

Which are more sensitive to changes in flow rate between the pancreas and salivary glands?

Answer 19

Salivary glands more susceptible to changes in flow rate.

Question 20

What are 4 differences between salivary and pancreatic acini?

Answer 20

Myoepithelium–> salivary only
Rate of secretion–> affected more in salivary
K/Na–> K salivary Na pancreatic
Neuronal vs hormonal–> salivary is neuronal pancreatic is hormonal.

Question 21

At high flow rates, saliva is slightly (hypotonic OR hypertonic) and rich in bicarbonate, while at low flow rates it becomes quite (hypotonic OR hypertonic).

Answer 21

High flow rate–> Hypotonic

Low flow rate–> hypertonic

Question 22

_____ activates trypsinogen.

Answer 22

Enterokinase

Question 23

The presence of chyme in the duodenum stimulates the release of ____ which is the primary stimulator of enzymatic release from acinar cells.

Acidity in the lumen triggers release of ____, which increases NaHCO3 to raise the pH.

Answer 23

CCK; secretin

CCK and secretin are inhibitory to gastric acid production and delay gastric emptying until the chyme has been processed and the intestine is ready for more.

Additionally, CCK potentiates release of secretin.

Question 24

____ cells in the pancreas secrete digestive enzymes.

____ cells secrete aqueous component

Answer 24

Acinar

Duct

Question 25

As the flow rate of secretion of pancreatic juices increases, the solution becomes more (acidic or alkaline) in response to the increased (H+ or HCO3) concentration.

Answer 25

alkaline; bicarbonate

Mediated by secretin

Question 26

Secretin is secreted from ____ cells in the duodenal mucosa which act as a pH meter for the GI tract. As the pH decreases, secretin is released.

Answer 26

S cells