1. EM

2. Parietal cell
The cell is indicated by the
pointer. Note the
intracellular canaliculi with
microvilli (c) and abundant
mitochondria (m) in its
cytoplasm. The large
number of mitochondria
accounts for the acidophilia
of parietal cells when seen
with light microscopy.

3. Enterocyte
The epithelium is indicated by the pointer. The epithelium is columnar in shape; mitochondria (m) are
gathered in both apical aspect and basal aspect of the epithelium. There are microvilli on the apical surface.
Note the intercellular cleft (IC) between epithelial cells and a intraepithelial lymphocyte (Ly). A capillary (c) in
lamina propria is also shown.

4. Chief cell
Note the nucleus and the extensive
Rough ER (rER) in the basal region
and membrane bound zymogen
granules (ZG) crowed in the apical
cytoplasm. Zymogen granules in
chief cells are not electron-dense
and they are newly packed. The
extensive Rough ER accounts for the
intense basophilia of chief cells when
seen with light microscope.

5. Exocrine pancreas
Pure serous acinus is shown. Note
the lumen (L) of the acinus. In each
serous-secreting cell surrounding the
lumen, there are extensive Rough
ER (rER) and a nucleus in the basal
aspect and numerous zymogen
granules crowded in the apical region
of the cell. A large Golgi complex (G)
is located above the nucleus. Note
that there are two types of zymogen
granules in the exocrine pancreas
acini: newly packed zymogen
granules (Z1) are large and much
less electron-dense than the smaller
mature granules (Z2). Note a
capillary (c), a fibroblast and collagen
in the supporting tissue which
surrounds the acinus.

6. Exocrine pancreas
Note the RER and nucleus in the basal
region and zymogen granules and Golgi
complex in the apical region of the
acinar cell. Two types of zymogen
granules are seen: newly formed
condensing granules (c) and mature
granules (s).

7. Paneth cell
Note the extensive Rough ER (rER) and nucleus (N) in the basal aspect and zymogen granules in the
apical region of the cell. The zymogen granules in Paneth cells are unique for having a dense protein core
which is surrounded by a halo of polysaccharide-rich material (the pale region).

8. Enteroendocrine cell (EEC or APUD cell)
The open type EEC, whose apex reaches the
lumen of the intestinal gland. Note the basally
located secretory granules (S).
s

9. Absorptive cells in large intestine
Note the epithelium in columnar shape with microvilli on their luminal surface. Large Golgi complex are seen.
Mitochondria (M) are gathered in the apical aspect of the cells. Note the obvious intercellular cleft (IC) with cell
membrane leaflets projecting in it, which is characteristic of cells carrying out water absorption function.
M
IC

10. Simple columnar cells
in gallbladder
Similar to the absorptive cells in large
intestine, epithelium in gallbladder is
columnar in shape with microvilli on
their luminal surface. Mitochondria (M)
are gathered in both apical and basal
aspect of the cell. Note the large
intercellular clefts (IC) which are
indicative of a water absorption
function.
M
IC

11. Submandibular
gland
Note both serous-secreting
cells and mucus-secreting cells
in the acinus. Serous secreting
cells have zymogen granules
(Z) in their apical aspect and
mucus-secreting cells contain
mucinogen-containg vesicles
(V) in their cytoplasm.
Z
V

12. Liver
Hepatocytes (H) line
up forming the hepatic
cords. Abundant
mitochondria (M) and
lipid droplets (L) are
seen in hepatocytes.
Between two
hepatocytes, bile
canaliculus is
delimited (BC).
Fenestrated
endothelial cells lining
the sinusoids have
large gaps between
them. Erythrocytes (E)
are seen in the
sinusoids. Between
the hepatic cord and
endothelial cells,
space of Disse is
shown (D).

13. Liver
Space of Disse (D)
is located between
the hepatic cord
and endothelial
cells (S) of the
sinusoid.
Mitochondria (M),
Rough ER (rER),
smooth ER (sER),
and lysosomes (Ly)
are abundant in the
hepatocytes. The
side of hepatocytes
facing the space of
Disse have many
microvilli (Mv)
projecting into the
space of Disse.

14. Renal medulla
The ultrastructural
features of
collecting tubule
(CT), thin limb of
loop of Henle (H)
and vasa recta (V)
are illustrated. All
epithelium are
supported by thin
basement
membrane (BM).
Between tubules is
interstitium (S)
which contains a
little collagen and
scatted fibroblasts
(F).

15. Glomerulus
Several capillary loops are illustrated (C). Fenestrated endothelium (E) with open
fenestrations (F) are seen. The thick common basement membrane (BM) is obvious.
In the Bowman’s space, podocyte (P), primary process (P1) and pedicels (P2) are
illustrated. Pedicels are separated by filtration slit (FS).

16. Glomerulus
The fenestrated endothelium (E)
with wide fenestrations (F),
common basement membrane
(BM) and pedicels (P2) of
podocyte are illustrated.

17. A mesangial cell (MC) is illustrated with amorphous mesangial matrix surrounding it.
A capillary is seen with a RBC and a leukocyte (L) in its lumen. Common basement
membrane (BM) and podocyte (PN) with its processes are also shown. U: Urinary
space; Asterisks indicate some of the mesangial cell’s processes (arrow) reaching
the capillary lumen, passing between the endothelial cells.

18. Proximal convoluted tubule
Prominent tall microvilli on the apical aspect and the deep infoldings of cell
membrane with columns of mitochondria at the basal aspect of the cell are
revealed. Immediately beneath the microvilli, pinocytotic vesicles (V) and
lysosomes (L) which are involved in resorption and degradation of small proteins
are illustrated.

19. The cell bodies of two podocytes and the alternation of secondary processes from two
different cells are shown. The urinary space and the glomerular capillary are indicated.

20. Filtration barrier in a renal corpuscle. E: fenestrated endothelium; P2: pedicel of the podocyte;
FS: filtration slit covered with a thin diaphragm; BM: common basement membrane which
consists of a central lamina densa bounded on both sides by a electron-light lamina rara.
E
P2
FS
FS
BM

21. Spermatid
In the center is the nucleus,
covered by the acrosome. The
flagellum can be seen emerging
below the nucleus. The
manchette, which is a cylindrical
bundle of microtubules, can be
seen limiting the nucleus
laterally.