5. Structure of the liver.
The liver lobule in the
center is surrounded by the
portal space. Arteries, veins,
and bile ducts occupy the
portal spaces.
In the lobule, note the radial
disposition of the plates formed
by hepatocytes; the
sinusoidal capillaries separate the
plates. The bile canaliculi can be
seen between the hepatocytes.
The sublobular (intercalated)
veins drain blood from the
lobules.
6. Anatomy of a Lobule: A Portal Tract
Notice the
direction of
various flows.
19. Gland with Double Duties
• Endocrine and exocrine functions
• Exocrine anatomy
– CT capsule surrounds pancreas
– Septa divide it into sections
– Compound acinar gland
• Secretions
– 1500 – 3000 ml pancreatic fluid (alkaline)
– Contain water, ions, proteases, lipases, amylake,
nucleases, ribonuclease
20. The structure of pancreatic acini. Acinar cells are pyramidal, with
granules at their apex and rough endoplasmic reticulum at their
base. The duct partly penetrates the acini.
24. A section of the pancreas
showing an islet of
Langerhans surrounded
by pancreatic acinar cells.
The islet cells form cords
separated by blood
capillaries, here seen as
white spaces.
Islet is surrounded by
reticular fibers separating
it from acinar cells.
25. An islet of
Langerhans showing
{a} (A) cells
and {b} (B) cells.
Gomori’s trichrome
stain.
26. Electron-microscope
immunocytochemical localization
of insulin in a B cell of an islet of
Langerhans.
The black granules are gold
particles used to label anti-
insulin.
They indicate the sites where this
antibody was attached to the
insulin in the secretory granules.
Note also the clear zone between
the secretory material and the
granule membrane.
27. The main steps of
insulin synthesis
and secretion by a
B cell in the islets
of Langerhans.
RER, rough
endoplasmic
reticulum. (Based
on Orci L: A
portrait of the
pancreatic B cell.
28. Gallbladder
The gallbladder is a hollow,
pear-shaped organ attached to
the lower surface of the liver
It can store 30-50 mL of bile.
The wall of the gallbladder
consists of a mucosa composed
of simple columnar epithelium
and lamina propria, a layer of
smooth muscle, a perimuscular
connective tissue layer, and a
serous membrane
