HIS: DIGESTIVE SYSTEM 2

1 Liver 2 Gallbladder 3 Pancreas 4 Salivary Glands Parotid, Sublingual, Submandibular

What are teh accessory organs that contributes to terminal digestion of nutrients, absorption, and metabolism?

Liver

________________ is the Largest accessory gland of the gastrointestinal tract and has developed embryologically as a glandular outgrowth of the primitive foregut.

● Oxidizes Triglycerides to produce energy

● Synthesis of Cholesterol and phospholipids

● Synthesis of Plasma Lipoproteins (p. 288)

What are the fat related functions of the liver?

Synthesis of albumin, clotting factors, and non-essential amino acids

What are the protein related functions of the liver?

⭐Regulates glucose level in blood through glycogenesis, glycogenolysis, and gluconeogenesis

⭐Converting carbohydrates and proteins into fatty acids and triglyceride

What are the carbsrelated functions of the liver?

Glycogen, vitamins, and iron

What are products that the liver store?

● Deamination of amino acids and production of urea

What are the Detoxification related functions of the liver?

hepatocytes

In alcoholic individuals, it can result in liver dysfunction due to the overwork of ___________to detoxify alcohol

Glisson’s capsule:

_________________ is a capsule composed of a collagenous tissue on the outer surface of the liver, covered by a layer of mesothelial cells from the peritoneum.

Sinusoids

_______________ is a pale-stained spaces between the plates of liver cells that form a very low resistant system vascular channels that allow blood to come in contact with the hepatocytes over a huge surface area.

Hepatocytes

____________ is the main functional cell in the liver, which is a type of epithelial cell.

thin plates

Hepatocytes are arranged in __________, separated by fine vascular sinusoids through which blood flows

absorption of nutrients, secretion of products

Hepatocytes has a close association of liver cells in the circulation allows ________________ as well as _____________ into the blood.

Portal tract

___________ is where most of the collagenous connective tissue in the liver is found which contain many blood vessels running into the liver.

Branches of bile duct

________________ are additional structures that run in the portal tracts

Centrilobular venules a.k.a. hepatic venules

_______________ are tributaries of the hepatic vein and take blood away from the liver. Less conspicuous than the portal tracts that drain the liver.

T

(T/F) Certain diseases of the liver cause obliteration of the normal sinusoidal arrangement

Hepatocytes

_________________ are large polyhedral cells with round nuclei, peripherally dispersed chromatin, prominent nucleoli

T

(T/F) More than half of hepatocytes are have tetrapoloid nuclei, mwaning it contain twice the normal or complement of your chromosomes within a single nucleus

F. Binucleate cells (BC), common in normal liver

(T/F) Binucleate cells are rare in normal liver

glycogen

A well-nourished cytoplasm store significant quantities of __________, process large quantities of lipids

numerous mitochondria

In the hepatocytes, there are strongly eosinophilic cytoplasm due to _______________ , which may contain irregular unstained areas due to glycogen and lipid stores

free ribosomes and RER

In the hepatocytes, there are fine basophilic granularity due to_______________ & ______

Sinusoids

____________are lined by flat endothelial lining cells and are istinguishable from hepatocytes by flattened condensed nuclei and attenuated poorly stained cytoplasm

Portal tract

__________ are also called portal triad or hepatic trinity

F. Lymphatics are also present in portal tracts but are less easily identified because their walls are delicate and often collapsed

(T/F) There are no lymphatics in the portal tract

Limiting plate

_______________ are a layer of hepatocytes immediately bordering the portal tract

Portal Vein (terminal branch)

In the portal tract, _______________ is the biggest but it is thin wall lined by endothelial cells

Bile Duct

In the portal tract, _______________ is intermiediate in size

Hepatic Artery (terminal branch)

In the portal tract, _______________ is the smallest but it is thick wall

Reticular Fibers

______________ are the connective tissue septa or framework of the liver and maintains the structural integrity of the liver by this delicate meshwork of extracellular matrix

Collagen type III

What type of collagen fibers are Reticular Fibers?

Hepatic Lobule

___________ are the structural unit of the liver conceptually

Hepatic acinus

_____________ are the unit structure more accurately representing the physiology of the liver

hepatic venule , portal tracts

Hepatic lobules are roughly hexagonal in shape, centred on a terminal _____________and has _____________ at the angles of the hexagon

F. pigs

T/F) The lobule in human is clearly defined by bands of fibrous tissue

portal tract

Hepatic acini are each centred on a ____________

terminal hepatic venule

In acini, Sinusoids originate at the lobule margin and course between plates of hepatocytes to converge upon the _____________

blood

In acini, each hepatocyte is exposed to ____on at least two sides, which branch and anastomose to form a 3D sponge-like structure

Blood flow from the tracts → sinusoids → venules

What is the blood flow in Hepatic acinus?

agglomerate of acini

Large branches of the portal vein and hepatic artery supply ____________________

ZONE I

What zone of hepatic acinus is teh closest to the portal tract and receives most oxygenated blood and is said to be the most resistant to ischemia

ZONE III

What zone of hepatic acinus is the farthest to the portal tract and receives the least oxygenated blood and is said to be the most susceptibleto ischemia

false opposite

(T/F) ZONE III has low level of esterase and high level of oxidative enzymes

portal vein and hepatic artery

The blood supply of the liver is unique as it receives blood supply from 2 sources: ___________________

hepatic vein

In liver, Both sources merge in the sinusoids and empty into the central vein / terminal hepatic venule / centrilobular venule which all drains into _____________

Hepatic venule → intercalated vein → hepatic vein → IVC

Blood flow from hepatic venule

Canalicular network → bile ducts in portal tracts → extrahepatic biliary tree → 2nd part of duodenum

Bile secretion flow

Portal Vein (75%)

______________ receives most nutrients from the GIT

Hepatic Artery (25%)

____________ supply oxygen rich blood in the liver

centrilobar venule/central vein

Portal vein and hepatic artery converge into the sinusoid and drain into the _________________

bile ductule

Bile canaliculi will later form into your _____________ in the portal tract

Bile canaliculus

_____________ is an enlargement of the intercellular space between two hepatocytes.

Canal of Hering

Bile canaliculus forms the ______________ and eventually draining to the Bile Duct

ATPase and Alkaline Phosphatase (ALP)

The Bile Canalicular Membrane is rich in _______ & ____________

biliary obstruction

High ALP levels are detected in the blood when ______________ is noted

epithelial cells with fenestrations

Hepatic sinusoids are lined by __________________and indistinct basement membrane

Space of Disse

Blood in the sinusoids will head to the _____________for easier access to nutrients and oxygen

Space of Disse

_______________ is the space between sinusoids and hepatocytes

Endothelial cell

The ______________ of the sinusoids are flattened cells with darkly stained nucleus, thin fenestrated cytoplasmand indistinct basement membrane

Stellate cells of Kupffer

The ________________ of sinusods are large, plump phagocytic cells with ovoid nuclei and contains phagocytosed debris, like RBCs or Iron

Ito cells (Hepatic lipocytes)

The _____________ of sinusoids contains lipid droplets and serve as the storage of Vitamin A

extracellular matrix and collagen, fibrosis

Ito cells (Hepatic lipocytes) are responsible for the production of ________ & _______ and are iInvolved with _________in Liver Cirrhosis due to its function

Gallbladder

____________ is the Muscular sac lined by simple columnar epithelium and has a capacity of about 100mL in humans.

Cholecystokinin-pancreozymin (CCK)

_______________stimulates gallbladder contraction, forcing bile into the duodenum.

storage and concentration of bile

What are teh functions of thegallbladder?

Simple columnar epithelium with microvilli

The mucosa of the gallbladder is made up of _______________

Mucosa

The ____________ is the layer which absorbs the 5-10x of the water, therefore concentrating the bile content.

tunica propria

In the gallbladder mucosa, the reabsorbed water drains into the lymphatics in the ___________ of the gallbladder

F.

The muscle layer of the gallbladder is made up of smooth muscle in different directions (tangential, horizontal, circular)

(T/F) The muscle layer of the gallbladder is made up of smooth muscle in on direction.

Rokitansky-Aschoff Sinus

______________ is the gland-like invaginations produced from the diverticulation of the gallbladder mucosa.

Chronic Cholecystitis (Pathologic)

In _____________________, the Rokitansky-Aschoff sinus increases in number and may invade the muscular layer of the gallbladder.

Spiral Valve of Heisters

_____________ is the region of the cystic duct containing complicated mucosal folds

primitive foregut

Pancreas develops embryonically as an outgrowth of the_____________

Exocrine

The ________of the pancreas forms bulk of the glands and produces alkaline fluid and digestive enzymes from pancreatic duct

High bicarbonate (HCO3)

The exocrine of teh pancrease produces a ________________ amount which neutralizes acidic chyme as it enters small intestine

luminal digestion

Pancreatic enzymes degrade proteins, carbohydrates, lipids, and nucleic acids via________________

Enterokinase

_______________(enzyme) is secreted by duodenal mucosa and activates protrypsin to trypsin

Trypsin

___________ activates prochymotrypsin tochymotrypsin

F. Pancreatic secretion occurs continuously with its rate being modulated by hormonal and nervous influences.

(T/F) Pancreatic secretionare heavily regulated and stopped

Secretin

____________stimulates secretion of copious watery fluid rich in bicarbonate (HCO3), which is released by neuroendocrine cells scattered in the duodenum

Cholecystokinin (CCK)

_______________, also known as pancreozymin, stimulates secretion of enzyme-rich pancreatic fluid

Gastrin

___________ is secreted by neuroendocrine cells at the gastric pylorus

thin collagenous capsule

The pancreas is a lobulated gland covered by a _________________which extends as a delicate septa between the lobules

Exocrine Component

The _________________ of the pancreas is a closely packed secretory acini draining into highly branched duct system

Small pancreatic duct → Main pancreatic duct → JOINS Common bile duct → Ampulla of Vater → Duodenum

What is teh flow from teh Exocrine Component of the pancreas?

Endocrine Component

The ____________________ of the pancreas contains the scattered islets of Langerhans throughout the exocrine tissue with occasional adipocytes seen in the parenchyma

False. Scanty in young adults but increases in numbers with age, reflecting natural atrophy of the gland

(T/F)The Endocrine Component of the pancreas is scanty in old aged adults but high in numbers with a young age, reflecting natural atrophy of the gland

serous

Exocrine component is a purely _____________ acinar gland

Zymogen granules

_____________ are found in apical region of the pancreatic acinar cell

Intercalated Duct

__________________ is the area where terminal cells are telescoped into the lumen of secretory acinar cells, forming the centroacinar cells

Parotid gland, Sublingual gland, Submandibular gland

What are the major salivary glands that operates under parasympathetic control?

minor accessory glands

The _________________ are scattered throughout the oral mucosa, where they continuously secrete saliva and are generally under local control

600-1500 ml/day

Daily salivary production in humans = ___________________

Saliva

_____________ is a hypotonic, watery secretion that contains variable amounts of mucus, enzymes, specially and principally amylase, and anti-bacterial enzymes (lysozymes) along with antibodies and inorganic ions

salivary secretory unit

The ______________ is the terminal branched tubulo-acinar structure

purely serous, purely mucus, or mixed

The salivary secretory unit is can be ______, _______or ________

Serous demilunes

_____________ are a characteristic of mucous acini , that serves as the envelope the mucous acini in the shape of half moon

crescents of Giannuzzi

Serous demilunes are also known as ______________ that only cap certain acinar cells