GI Secretions (review w/ handout 10/21 11a) Flashcards Preview

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Flashcards in GI Secretions (review w/ handout 10/21 11a) Deck (54)
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CCK regulation

fat/prot in duodenal lumen
leads to increased CCL release from duodenal mucoasa
CCK acts on panc acinar cells
increased secretion of pancreatic dig enzy into duodenal lumen
digest fat/prot


Exocrine pancreas structure

Acinar cells make the enzymes and duct cells secrete a water/bicarbonate rich solution

**** no myoepithelial cells

rate of secretion much less variable


CCK actions

in GB: contraction
pancreas: stim acinar secretion
in stomach: reduced emptying (inhibitory)
sphincter of Oddi: relaxation

Protein, carbohydrate, lipid absorption and digestion
Matching of nutrient delivery to digestive and absorptive capacity


CCK released from??????

redo this card

I cells

trypsin controls releasing and monitoring peptide

trypsin prefers to act on prot/aa breakdown

Lots of fat? want CCK production to help breakdown fat

So shuts off trypsin protein breakdown

Monitor peptide monitors level of protein in duodenum

turn off CCK


cAMP and Ca in acinar cells

in epi/acinar cells, cAMP and Ca do the same thing

both stim increased secretion

Granules containing zymogens fuse with membrane and secrete contents



trypsin is inactive from pancrease (trypsinogen)
Also released is a trypsin inhibitor.

Trypsin becomes activated in the duodenal lumen when trypsinogen is cleaved by enzymes (enterokinases) located on the surface of enterocytes

Activated trypsin then autoactivates more trypsinogen along with most of the other pancreatic enzymes



acts by increasing cAMP levels in the duct cells. The release of secretin is enhanced by CCK


Panc vs salivary differences??????

salivary secretions are susceptible to changes in flow rate, pancreatic secretions are not

no myoepithelial cells in panc

Panc: neuronal and humorally
Salivary: neuironal

salivary acinus is very vascular and increased blood flow results in a dilute saliva that is modified by duct cells. Salivary ducts, on the other hand, are fairly impermeable to water.

Pancreatic acini are not as vascular and respond to ACh and CCK. Ductal cells actively secrete a water and a bicarbonate rich solution in response to secretin.

Saliva is rich in KHCO3 whereas pancreatic juice is rich in NaHCO3.


Salivary gland diseases

Cytomegaloviral Sialadenitis
Bacterial Sialadenitis
Sjögren’s Syndrome (autoimmune disease, inflammation)
Salivary Lymphoepithelial Lesion
Xerostomia or dry mouth


Benign neoplasms

-Mixed Tumor (pleomorphic adenoma)
-Monomorphic Adenomas
-Ductal papilloma


Pleomorphic adenoma

diverse microscopic pattern
Islands of cuboidal cells arranged in ductlike structures
typically encapsulated

Loose chondromyxoid stroma, connective tissue, cartilage (arrows) and even osseous tissue are observed


Warthin's Tumor

Warthin's tumor (benign papillary cystadenoma lymphomatosum)
the second most common benign tumor of the parotid gland
It accounts for 2-10% of all parotid gland tumors
Bilateral in 10% of the cases
may contain mucoid brown fluid in FNA

ID by aspiration

epithelial component (papillary fronds), stains pink , shows granularity, can undergo metaplasia but rare

and lymphoid component

Both lymphoid and oncocytic epithelial elements must be present to diagnose Warthin’s



Monomorphic adenoma

can be bilateral
rare malignant potential
multiple types

Similar to Pleomorphic Adenoma except no mesenchymal stromal component
Predominantly an epithelial component


Basal cell adenoma

uniform basaloid epithelial cells with a monomorphous pattern.

The arrangement of tumor cells may be trabecular (rod-like), tubular or solid.

Histologically, these tumors are distinguished from pleomorphic adenomas by their absence of stroma and the presence of a uniform epithelial pattern.


Malignant neoplasms by increasing freq

Mucoepidermoid Carcinoma (mucin+)
Polymorphous Low-grade Adenocarcinoma
Adenoid Cyctic Carcinoma
Clear Cell Carcinoma
Acinic Cell Carcinoma (no glycogen, fat & mucin, 3% maligant and bilateral)


Features suggestive of malignancy

Induration (hardness)
Fixed to Overlying Skin or mucosa
Ulceration of skin or mucosa
Rapid Growth; Growth Spurt
Short Duration
Pain, often severe
Facial N. Palsy

pain and palsy go together often


size of T2

T2: 2 cm

Tx t0-4


Mucoepidermoid carcinoma

MECs contain two major elements: mucin-producing cells and epithelial cells (Epidermoid and Mucinous components).

MEC is divided into low-grade (well differentiated) and High-grade (poorly differentiated).

Stains that ID mucous
PAS stain


Adeonid cystic carcinoma

Adenoid cystic carcinoma with Swiss cheese pattern.
It is the second-most common malignant tumor of the salivary glands.
ACC is the most common malignant tumor found in the submandibular, sublingual, and minor salivary glands.

against nerve: risk of spread, pain, palsy


Rare tumors

Carcinoma Ex-mixed Tumor/Malignant Mixed Tumor/Metastasizing Mixed Tumor
Epimyoepithelial Carcinoma
Salivary Duct Carcinoma
Basal cell Adenocarcinoma
Squamous Cell Carcinoma



fatty rich food
linked to gallstones

acute or chronic

Sx: include upper abdominal pain, nausea/vomiting, weight loss and steatorrhea (oily, smelly stool)


Panc cancer endocrine

Gastrinoma (Zollinger-Ellison Syndrome)
Glucagonoma – usually large, often mets, 70% malignant
Insulinoma – the most common pancreatic neuroendocrine tumors
Nonfunctional islet cell tumors (NICT) – Usually malignant and hard to detect; don't produce insulin?
Somatostatinoma – occur anywhere in the pancreas or doudenum
VIP-Releasing Tumor – usually in the body and tail of the pancreas


Panc cancer exocrine

Acinar Cell Carcinoma – Rare, leads to overproduction of lipase
Adenocarcinoma – 90% of all pancreatic cancer starts in duct
Adenosquamous carcinoma - forms glands that flatten as it grows
Intraductal Papillary-Mucinous Neoplasm – fingerlike projections into the duct, prelude to malignancy
Mucinous Cystadenocarcinoma – rare malignant spongy cystic tumor
Pancreatoblastoma – Rare, occurs in kids


What usually "gives away" panc cancer?

Pancreatic cancer: mets elsewhere usually gives it away