Digestive Glands-1-8-16 Flashcards
A ___ secretory mechanism is defined by secretion of the whole cell
Holocrine
A ____ secretory mechanism is defined by gland releasing its products together with a small amount of the apical cytoplasm of the secretory cell
Apocrine
List the correct sequence of features in a compound gland
Acinus –> Intercalated duct –> Striated duct –> Intralobular duct –> Interlobular duct –> Lobar duct –> Main duct
What are the components of the lobule in a compound gland?
Acinus –> Intercalated duct –> Striated duct –> Intralobular duct
What are the major salivary glands?
Parotid
Sublingual
Submandibular
Which salivary gland produces the majority (70%) of saliva?
Submandibular
The production of saliva is under the control of the ___ nervous systems
Autonomic
Plasma cells in the parotid gland secrete ___ which binds to the secretory piece inserted in the plasma membrane of acinar, intercalated, and striated epithelial cells
IgA
What are the protective functions of saliva?
- Lysozyme-attacks walls of bacteria
- Lactoferrin-chelates Fe necessary for bacterial growth
- IgA-neutralizes bacteria and viruses
What are the digestive functions of saliva?
- Amylase-initiates the digestion of carbs in the oral cavity
- Lingual lipase-participates in the hydrolysis of dietary lipids
This salivary gland is exclusively serous acini:
Parotid
This salivary gland is mixed serous and mucus and has serous demilunes; Pure mucus acini are rare
Submandibular
This salivary gland is mixed serous and mucus and the mucus acini predominate
Sublingual
What are the enzymes and functions of the parotid gland secretions?
Enzymes: Amylase, peroxidase, lysozyme
Functions: Antimicrobial proteins including Proline-rich proteins, histatinsm, cystatins, and statherin have imporant implications for bacterial clearance, selective bacterial aggregation on the tooth surface, and control of mineralization and demineralization
This gland is the primary target of the rabies and mumps virus
Parotid
What are 2 complications of mumps?
Orchitis and meningitis
This gland is the most frequent site for slow-growing benign salivary gland tumors. Surgical removal is complicated by the need to protect the Facial nerve (CN VII)
Parotid
This salivary gland has mucous cells that secrete mucin which aids in the lubrication of the food bolus as it travels through the esopohagus. The serous cells of this gland produce salivary amylase.
Submandibular
This gland is a branched tubuloalveolar gland with both serous and mucous cells. Most secretory units are mucous.
Sublingual
What is the endocrine component and function of the pancreas?
Islets of langerhands-Regulation of glucose metabolism by hormones secreted into the bloodstream
THe functional histological unit of the exocrine pancreas is the ___
Acinus
The exocrine pancreas lacks ___ ducts and ___ cells
Striated
Myoepithelial
This exocrine pancreas cell is recognized by its location in the center of the pancreatic acinus and by its pale cytoplasm:
Centroacinar cell
This endocrine component of the pancreas is surrounded by serous acini
Islet of langerhans
This component of the exocrine pancreas is the continuation into the connective tissue stroma of the centroacinar cells
Intercalated duct
This part of the exocrine pancreas is present at the apical portion of the pancreatic acinar cell
Zymogen granules
These spindle-shaped cells of the pancreas secrete aq. HCO3 under stimulation of secretin and can also secrete mucin
Centroacinar cells
___, produced in enteroendocrine cells of duodenal mucosa, binds to specific receptors of acinar cells and stimulates release of zymogen
CCK
Amylase gene expression is regulated by this hormone
Insulin
The clinical features of acute pancreatitis are severe abdominal pain, nausea, and vomiting and rapid elevation of these serum enzymes (within 24-72 hrs):
Amylase and lipase
What type of epithelium is the hepatic a.?
What type of epithelium is the bile duct?
What type of epithelium is the portal v.?
- Simple squamous
- Simple cuboidal
- Simple squamous
The structural and functional unit of the liver is the ___
Hepatic lobule
This part of the hepatic lobule collects sinusoidal blood containing a mixture of blood supplied by branches of portal vein and hepatic artery
Central venule (or vein)
___ convey blood into the liver and bile out of the liver
___ drains blood from the liver
___ synthesizes bile, metabolizes nutrients and toxic material in the blood
Portal triads
Hepatic venule
Hepatocytes
This organizational unit within the liver is a hexagonal lobule surrounding a central vein and has portal triads at the angles
Classic hepatic lobule
This organization unit within the liver has a triangular arrangement with the center of the triangle possessing the bile duct collecting from 3 hepatic lobules. The angle of the triangle are the central veins of the 3 hepatic lobules
Portal lobule
This organizational unit within the liver is based on the oxygen gradient of venous sinusoids of adjacent lobules. It is divided into 3 zones based on the blood supply to the hepatocytes from the branch of the hepatic artery
Liver acinus
In regards to the portal triad and central venule, which way does blood flow? Which way does bile flow?
Blood flows from portal triad –> central venule
Bile flows from central venule –> portal triad
This part of the liver lobule receives O2-rich blood from the hepatic a. And nutrients from the intestines via the portal vein and sends it to the central canal (blood flow out of the liver)
Hepatic sinusoids
These liver cell types can be found within the sinusoids and are involved in the recycling of old RBCs
Kupffer cells
What type of endothelium lines the liver sinusoids?
Fenestrated and lacks a continuous basement membrane (discontinuous capillaries)
The space between the fenestrated endothelium and the cord of hepatocytes is known as the:
Space of Disse
These liver cells are stellate cells of the liver, located at intervals within the space of Disse
Ito cells
These liver cells function as storage sites for fat and vitamin A
Ito cells
These are the functional endocrine and exocrine cells of the liver:
Hepatocytes
The ____ domain of hepatocytes participates in absorption of blood-borne substances (bilirubin, peptide and steroid hormones, B12) and the secretion of plasma proteins (albumin, fibrinogen, prothrombin, coagulation factors, C proteins)
Basolateral
What are functions of Smooth ER in hepatocytes?
Synthesis of cholesterol and bile salts
Glucuronide conjugation of bilirubin, steroids, and drugs
Breakdown of glycogen into glucose
Detox of lipid-soluble drugs
The Rough ER and Golgi of hepatocytes do what?
Participate in the synthesis and glycosylation of secretory proteins
What do peroxisomes of hepatocytes do?
Generate hydrogen peroxidase
____ is the end product of heme catabolism
Bilirubin
These cells convert heme into biliverdin
Macrophages
What are the main functions of the gall bladder?
Storage, concentration ,and release of bile
The smooth muscle of the gall bladder contracts to force bile out of the bladder and into the intestine by ____
CCK
A ___ secretory mechanism is defined by exocytosis
Merocrine
