Unit 3 Digestive Glands Flashcards
(27 cards)
salivary glands
parotid
submandibular
sublingual
saliva functions
- lubricates food
- initiates digestion of carbohydrates
- immune function – secrete IgA and lysozyme
salivary gland structure
- capsule of connective tissue
- lobules
- serous acini
- mucous acini
- myoepithelial cells
- ducts
myoepithelial cells
a) highly branched contractile cells
b) within basal lamina
salivary gland ducts
a) intercalated ducts – initial segments; simple cuboidal
b) striated ducts – intralobular ducts; cuboidal to columnar
c) excretory ducts – interlobular ducts; stratified cuboidal to stratified
columnar
d) main duct of each gland empties into oral cavity; stratified squamous nonkeratinized
salivary gland innervation
Autonomic nervous system
1. parasympathetic stimulates large amount of watery secretion; little protein
2. sympathetic stimulates small amount viscous saliva rich in organic
material
parotid gland
- largest gland
- compound acinar
- serous only – granules rich in amylase
- plasma cells in connective tissue add IgA
submandibular gland
- compound tubuloacinar gland
- mucous and serous cells
- serous demilunes secrete lysozyme
sublingual gland
- compound tubuloacinar gland
- serous and mucous cells
- serous cells only in demilunes
pancreas structure
- capsule thin connective tissue with septa divides into lobules
- regionally divided into exocrine and endocrine gland
- endocrine – islets of Langerhans (2% of total gland)
- exocrine – compound acinar gland
pancreatic exocrine portion
- serous secretory units – digestive enzymes
- duct system
- secretions
- hormonal control
pancreatic duct system
a) centroacinar cells – penetrate acinus
b) intercalated ducts – secrete bicarbonate to neutralize chyme in intestine
c) main excretory duct – duct of Wirsung
d) accessory duct – duct of Santorini
pancreatic secretions
a) trypsinogen, carboxypeptidase, chymotrypsin
b) amylase
c) lipases
d) ribonuclease, deoxyribonuclease
pancreatic hormone control
a) chyme in duodenum stimulates enteroendocrine cells to release
secretin and cholecystokinin
b) secretin – duct cells secrete bicarbonate
c) CCK – acinar cells secrete digestive enzymes
pancreatic endocrine portion
islets of Langerhans
1. alpha cells produce glucagon; increases blood glucose levels
2. beta cells produce insulin; decreases blood glucose levels
3. delta cells produce somatostatin; inhibits secretion of glucagon and insulin
4. PP cells (F cells) produce pancreatic polypeptide; blocks CCK and inhibits
secretion of pancreatic enzymes
liver stroma
a) thin connective tissue capsule (Glisson’s capsule)
b) hilum: portal vein and hepatic artery enter; hepatic ducts and lymphatics exit
c) reticular connective tissue
liver functional unit
lobule
a. central vein in center
b. portal areas at periphery
c. hexagonal in shape
d. duel blood supply
periphery portal areas
portal vein
hepatic artery
bile duct
liver blood supply
hepatic portal vein (80%) hepatic artery (20%)
hepatic portal vein
- nutrient rich from intestinal tract
2. blood from spleen
hepatic artery
- branch from celiac trunk
2. well-oxygenated blood
liver sinusoids
a) specialized large capillary
b) discontinuous fenestrated endothelial cells
c) Kuppfer cells – macrophages
d) space of Disse – between endothelial cells and hepatocytes
hepatocytes
functional units of liver
a) plates of cells
b) polyhedral shape
c) apical surface open to sinusoids
d) basolateral surfaces attach to other hepatocytes
bile ducts drain bile from hepatocytes
a) bile canaliculus
b) Hering’s canal
c) bile ducts of the portal triads
d) right and left hepatic ducts
e) common hepatic duct
f) cystic duct
g) common bile duct
