Histology Practice
Stephen M. Smith
(Hope this helps)
Notice
• Note: Slides alternate between questions and
answers.
• Images are courtesy Basic Histology, 11th ed.
Junqueira & Carneiro, 2007.
– This is an awesome textbook, btw.
Name the Tissue/Organ present in the
micrograph
a)
b)
c)
d)
e)
Thymus
Spleen
Lymph node
Skin (dermis)
None of the above
ANSWER
• This is a section of Spleen (B).
– We can eliminate lymph node, as the morphology of
the surrounding tissue is inconsistent with lymph
node (there are no medulary cords; no visible capsule)
– The key characteristic is the presence of the central
artery (#2) near the lymphoid nodule. In no other
lymphatic tissue do you see a central artery associated
with the germinal center. In lymph nodes and thymus,
vessels are either external (in the capsule), or within
the medulla. Further, vessels in the thymus would
show little diffuse tissue surrounding the germinal
centers.
The bracketed layer is…
a) Capsule
b) Pseudostatefied
columnar
epithelium
c) Tunica intima
d) Stratum
granulosum
e) None of the Above.
ANSWER
• The Correct answer is (E): None of the above.
– Hopefully, you recognized this as skin. The
indicated layer is the stratum corneum. Notice
that there are no cell bodies in the indicated layer
due to keratin.
This is a section of a lymph node (A), with corresponding computer graphics
(B). What is the area marked by arrow 1?
a)
b)
c)
d)
e)
Thymus
Spleen
Lymph node
Skin (dermis)
None of the above
a) Medullary sinus
b) PALS
c) Capsule
d) Cortical trabeculae
e) None of the Above.
ANSWER
• The Correct answer is (E): None of the Above.
– We can clearly rule out Choice B (PALS), as we’re told this
is lymph node, not spleen. The capsule of the lymph node
is on the outside of the entire node, and is made of diffuse
lymph tissue; not dense.
– The key here is recognizing that the arrow is pointing to
dense lymphoid tissue, not diffuse. You must first ask
yourself, “Am I in the cortex of the lymph node, or the
medulla?” There are no nodules or trabeculae present; we
are clearly in the lymph node medulla. There are two
structures in the medulla worth noting: medullary sinuses,
and medullary cords. Cords are dense lymphoid tissue;
sinuses are much more diffuse. Arrow #1 points to
medullary cords; Arrow #2 points to medullary sinuses.
The pointer indicates a diagnostic structure telling us we are in the:
a)
b)
c)
d)
e)
Thymus
Spleen
Lymph node
Skin (dermis)
None of the above
a) Medullary area of lymph node
b) Medullary area of spleen
c) Cortex of lymph node
d) Medullary area of thymus
e) None of the Above.
ANSWER
• The Correct answer is (D): Medullary area of the
Thymus
– The indicated cell is Hassall’s corpuscle. Hassall’s
corpuscle is only found in the medullary area of the
thymus. If you didn’t recognize this, the question is
somewhat still answerable:
– We are clearly not near lymphoid nodules; the
indicated cells are located in a medullary area. We
also can identify this as lymphoid tissue (which didn’t
really help). In spleen, we would expect to see diffuse
lymphoid tissue (Red pulp) and occasional patches of
lymphoid nodules (white pulp). Also, this looks
nothing like lymph node – either cortex or medulla.
The white blood cells indicated here are located in _________ and contain
_________ type(s) of granules
a)
b)
c)
d)
e)
Peripheral blood; 2
Peripheral blood; 3
Bone marrow; 3
Bone marrow; 2
None of the Above.
ANSWER
• The Correct answer is (B): Peripheral Blood; 3
types of granules
– The indicated cells are neutrophils; they are the only
white blood cell that has 3+ nuclear lobes.
– Though genesis of these cells occurs in the bone
marrow, these cells are found in peripheral blood.
– There are, per Dr. Howard’s lecture, 3 types of
granules. She did not, however, note what the third
type of granule is. Wikipedia notes that in addition to
specific and azurophilic granules, there are “tertiary
granules” containing gelatinase and cathespin.
The large cells on the Left and Right respectively are:
a)
b)
c)
d)
e)
Monocyte; basophil
Eosinophil; macrophage
Neutrophil; basophil
Eosinophil; Eosinophilic myelocyte
None of the Above.
ANSWER
• The Correct answer is (C): A neutrophil is on
the left; a basophil is on the right.
– The basophil is quite characteristic; it has
numerous granules and is a dark-staining cell with
no clear nucleus and a light-staining cytoplasm.
– The neutrophil is multi-lobed, with a pale-staining
cytoplasm (slightly basophilic).
– Again, both are located within peripheral blood.
The large cell below has the major function of :
a)
b)
c)
d)
e)
Fighting off parasites
Differentiating into lymphocytes
Oxygen transportation
Release of Anti-histamine
None of the Above.
ANSWER
• The Correct answer is (E): None of the Above.
– The large cell is a monocyte; it has a light-stained
nucleus, no granules, and a kidney-shaped
nucleus. Again, this is located in peripheral blood.
– The major function of monocytes is to
differentiate into macrophages. Perhaps indirectly,
they might “fight off parasites”, but this by no
means is the major function of this cell.
The indicated cell:
a)
b)
c)
d)
e)
Is a basophil
Contains 2 types of granules
Was once a proerythoblast
Is a macrophage precursor
None of the Above.
ANSWER
• The Correct answer is (C): The indicated cell was
once a proerythoblast
– Note that the indicated cell is an orthochromatophilic
erythroblast. The picnotic nucleus gives it away.
– You can rule out “basophil” because we are clearly in
bone marrow, not peripheral blood. The first question
of “bone marrow” cells is, “is the cell of eythroid or
lymphoid/leukoid origin?” The round shape of the
nucleus, along with the non-basophilic cytoplasm,
suggests that this cell is erythroid. Thus, there are no
granules. Any cell in the erythroid line that is not a
proerythoblast once began as a proerythroblast.
The Green arrow points to:
a)
b)
c)
d)
e)
Proerythroblast
A cell which may become a basophil
A cell involved in anti-histamine reactions
A cell which will create platelets
None of the Above.
ANSWER
• The Correct answer is (D): The indicated cell
was once a megakaryocyte
– The primary function of a megakaryocyte is to
create thrombocytes. This is not a proerythroblast, as it does not have a basophilic
cytoplasm and its nucleus is not nearly as large as
its cytoplasm.
– The megakaryocyte doesn’t really further
differentiate; it just breaks apart
The Red-bracketed layer is
a)
b)
c)
d)
e)
Epicardium
Tunica Media
Medulla
Lamina propria
None of the Above.
ANSWER
• The Correct answer is (E): None of the above.
– The red-bracketed region most clearly refers to
the Tunica Adventitia of a large elastic artery. We
know it’s a large elastic artery because of the
presence of vasa vasorum within the adventitia.
As the endothelium is marked, we know that this
is a vessel and neither heart nor trachea.
The micrograph below is a section of…
a)
b)
c)
d)
e)
trachea
Large elastic artery
Primary bronchiole
epiglottis
None of the Above.
ANSWER
• The Correct answer is (E): None of the above.
– This section is a section of bronchus. It cannot be
trachea, as the cartilage ring has broken (it is not
in the distinct“C” shape), which happens after the
trachea bifurcates. It cannot be bronchiole, as
there is cartilage present. More than likely, this is
a primary or secondary bronchus.
Cells found in the bracketed region include all of the following except:
a)
b)
c)
d)
e)
keratinocytes
squames
Langerhans cells
Endothelial cells
None of the Above.
ANSWER
• The Correct answer is (D): Endothelial cells
– Hopefully, you recognized this as the epidermis
region of skin. The epidermis is avascular, thus
there are no endothelial cells in this region.