Histology SSN Slide-Based Practice Practical
October 23, 2002
Histology SSN Slide-Based Practice Practical
Epithelia:
1. Fill in the blanks of this sentence with one of the choices below:
The projected EM shows the _________________, and the pointer specifically points
to the ________________, that functions mainly to ________________.
a.
b.
c.
d.
Terminal Web, Zonula Occludens, provide integrity to the epithelial surface.
Terminal Bar, Zonula Occludens, provide a diffusion barrier.
Terminal Web, Hemidesmosome, provide adhesion to the basement membrane.
Terminal Bar, Zonula Adherens, provide integrity to the epithelial surface.
2. The epithelium in the projected tissue is best described as:
a. Simple squamous epithelium specialized for absorption.
b. Simple squamous epithelium that has been keratinized to resist abrasion.
c. Simple squamous epithelium specialized for diffusion.
d. Simple squamous epithelium specialized for secretion.
3. The epithelium at the pointer is most likely:
a. From the fallopian tube where its cilia beat rhythmically to propel ova.
b. From the bladder where it accommodates large changes in volume.
c. From the trachea where it secretes abundant mucus to catch dust from the air.
d. From the small intestine where it is specialized for absorption.
e. From the pancreas where its main function is secretory.
Question 4: Figure A EM junctional complex [bracketed]; Figure B #37 small intestine
(high mag); C #44 Bile duct.
4. The modification indicated by the bracket in Figure A is present in:
a. Figure B only.
b. Figure C only.
c. both Figures B and C.
d. neither Figure B nor C.
Questions 5: Figure #103a Kidney, PAS, high mag, tubule #1 cuboidal epithelium; tubule #2,
simple squamous epithelium.
The figure has been stained with PAS.
5. Which of the following statements is correct regarding the figure?
a. The cells in tubule #1 and tubule #2 each produce a basal lamina.
b. The cells making up tubule #2 are more likely to be involved in transporting
substances against their concentration gradient than the cells in tubule #1.
c. The cells of tubule #1 but not tubule #2 make tight junctions.
d. The cells in tubule #1 are polarized, unlike the cells in tubule #2.
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Histology SSN Slide-Based Practice Practical
October 23, 2002
Question 6: Figure #103 Kidney PAS, tubule #1 cuboidal epithelium; tubule #2 cuboidal
epithelium with brush border and lysosomes.
The figure has been stained with PAS
6. All of the following statements are correct regarding the cells lining tubule #2 in Figure B
EXCEPT:
a. There is evidence for absorption of substances.
b. There is evidence for degradation of substances.
c. There is evidence for an increased apical cell surface.
d. There is evidence for motile apical appendages.
Questions 7-9: Figure A #54 bladder transitional epithelium; Figure B #5 trachea
pseudostratified epithelium.
Questions 7-9:
7. Select the one correct statement regarding the surface epithelium:
a. In both figures all of the cells reach the lumen.
b. In both figures the superficial cells are keratinized.
c. In both figures all of the cells rest on a basal lamina.
d. Only in Figure B do all the cells rest on a basal lamina.
8. The tissue or tissues that are specialized to resist abrasion are shown in:
a. Figure A only.
b. Figures A and B.
c. Figure B only.
9. The tissue or tissues that are specialized to provide a barrier to luminal absorption are shown
in:
a. Figure A only.
b. Figures A and B.
c. Figure C only.
d. Figures A and C.
Answers:
1. EM projection of the Terminal Bar (a.k.a. Junctional Complex). Pointer is specifically on the Zonula
Occludens (a.k.a. tight junction) whose main purpose is to provide a diffusion barrier. Choice B is correct.
2. The slide projected shows lung alveolar tissue. It is simple squamous epithelium specialized for the
exhange of oxygen and carbon dioxide. Choice C is correct.
3. The slide projected shows simple columnar epithelium of the small intestine. Choice D is correct.
4. Junctional Complexes (Terminal Bar) are found between simple columnar epithelial cells, which help
monitor what is absorbed by this kind of epithelia. C is correct.
5. The bottom-most layer of epithelial cells secrete the extracellular matrix of the basal lamina. For simple
& pseudostratified epithelia, all cells produce the basal lamina. For stratified & transitional, only the
bottom-most layer produces the basal lamina. A is correct
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Histology SSN Slide-Based Practice Practical
October 23, 2002
6. PAS stains lysosomes & microvilla bright pink. These are cells lining kidney tubules. There are
lysosomes present, indicating degradation of substances. There is a microvilli brush border that is used to
increase apical cell surface for the absorption of substances. There are no mobile apical appendages. Don’t
confuse microvilli with cilia. Microvilli = Absorption, Cilia = Movement. D is correct
7. In the trachea pseudostratified epithelium, all cells rest on the basal lamina. Bladder transitional
epithelium is stratified and therefore not all cells touch the basal lamina. D is correct.
8. Functions of stratified epithelia (don’t forget transitional epithelium is stratified) include protection,
barrier, and resist abrasion. A is correct.
9. Another function of stratified epithelia is that it serves as a barrier. A is correct.
CONNECTIVE TISSUE
1. This tissue is:
a. well-vascularized by blood
b. well-vascularized by lymph
c. well-vascularized by blood & lymph
d. not well-vascularized
2. This tissue contains:
I. type I collagen
II. type II collagen
III. type III collagen
IV. type IV collagen
a. III only
b. II only
c. I & III
d. I, III,& IV
3. The tissue shown is ____________ connective tissue and is secreted by
_____________.
a) reticular, fibroblasts
b) reticular, smooth muscle
c) elastic, fibroblasts
d) elastic, smooth muscle
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Histology SSN Slide-Based Practice Practical
October 23, 2002
4. The tissue type shown here is specialized primarily for withstanding:
a) tearing/shear forces
b) compressive forces
c) acid secretions
d) a and b
e) none of the above
ANSWERS:
1. (pointer on intestinal villus, loose connective tissue) – C.
Loose connective tissue often functions in the immune response, and since the gut is prone to pathogen
invasion, it is well-vascularized by both blood & lymph to bring immune cells to this tissue)
2. (pointer on lymph node - silver stain) – D.
Type I in the capsule, type III in reticular tissue, and type IV in basement membrane of the cells.
3. (Slide of aorta showing elastic tissue) – C.
The tissue shown here (found in the aorta) is an example of elastic connective tissue, NOT reticular tissue.
Elastic tissue in the aorta is one example of where connective tissue is secreted by smooth muscle cells
(whereas normally we think of fibroblasts secreted CT)
4. (Slide of dense, irregular CT in dermis) - A.
Dense irregular CT is specialized for resisting tearing and shearing forces, such as those experienced by the
skin on a daily basis. Its fibers are arranged in many different directions and planes to withstand the stress
from many directions. It does not resist compression in the same way that cartilage does (type II collagen
v. the type I of dense CT); however, it is strong and can withstand a limited amount of forces and pressure.
CARTILAGE AND BONE
Question #1:
Panel C is a low magnification micrograph of the tissue shown in Panel B.
Provide the letter or letters (A and/or B) (or none) of the panel to which the following
apply.
a.
b.
c.
d.
e.
f.
normally calcified
vascularized
collagen type II
cells capable of division
matrix contains proteoglycans
lacunae present
Questions 2 and 3:
2. The three tissues shown have all of the following properties in common EXCEPT:
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Histology SSN Slide-Based Practice Practical
a.
b.
c.
d.
October 23, 2002
They contain capillaries.
They contain proteoglycans.
They can increase in size by interstitial growth.
They can increase in size by appositional growth.
3. Which tissue is the most highly specialized to resist compression?
a. A
b. B
c. C
Questions 4-6: For questions 4 and 5 select the correct combination of terms.
4.
a.
b.
c.
d.
Figure A illustrates_______________and _____________.
membrane bone formation, interstitial growth
formation of Haversian systems, appositional growth
endochondral bone formation, interstitial growth
membrane bone formation, appositional growth
5.
a.
b.
c.
d.
Figure B illustrates_______________and _________________.
membrane bone formation, interstitial growth
formation of Haversian systems, appositional growth
endochondral bone formation, interstitial growth
membrane bone formation, appositional growth
6.
a.
b.
c.
The cells at the pointer in Figure C could be found in:
Figure A only
Figure B only
Figure A and B
Questions 7 and 8:
7.
a.
b.
c.
d.
The progenitor that gave rise to the type of cell at the pointer in Figure A was a:
chondroblast.
osteoclast.
osteoblast.
chondrocyte.
8.
a.
b.
c.
d.
The eosinophilic component of the matrix in Figure B provides for:
tensile strength.
diffusion.
interstitial growth.
protein synthesis.
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Histology SSN Slide-Based Practice Practical
October 23, 2002
Answers
Question #1: A. Hyaline cartilage (trachea), B. decalcified bone, tibia (high mag), C. decalcified bone (low
mag)
a.
B – hyaline cartilage is not calcified – it is made up of type II collagen and ground substance; the bone
shown in slide B is decalcified in this preparation, but would normally be calcified
b.
B – hyaline cartilage is not vascularized – vessels run only in the perichondrium and nutrients and
waste diffuse through the ground substance; bone is made up of Haversian systems through which
vessels travel via the Haversian canals
c.
A – hyaline cartilage is made up of type II collagen, bone is made up of type I collagen
d.
A – cartilage is capable of cell division via proliferation of chondroblasts and chodrocytes. Mature
chondrocytes, as seen in this image of calcified bone, cannot proliferate.
e.
A, B – the matrix for both hyaline cartilage and bone is made up of proteoglycans
f.
A, B – chondrocytes in cartilage reside in lacunae, surrounded by matrix; osteocytes are also found in
lacunae within the lamellae of the Haversian systems
Questions 2 and 3: Figure A #6 elastic cartilage; Figure B #5 hyaline cartilage; Figure C #104
fibrocartilage
Question 2: a – these three tissues are all cartilage, which does not have capillaries; the blood supply to all
types of cartilage runs in the perichondrium. All types of collagen contain proteoglycans in
their ground substance, are capable of interstitial and appositional growth.
Question 3: c – fibrocartilage is highly specialized to resist compression – as it functions in the
intervertabral disc, supporting the weight of our bodies
Questions 4-6: Figure A. #93 fetal endochondral bone formation; Figure B #94 parietal membrane bone
with osteoblasts; Figure C same as Figure B but with pointer on osteoclasts.
Question 4: c – The tissue shown in Figure A was endochondral bone formation, which is the formation of
new bone be growth of a cartilage model via interstitial growth. A is wrong because
membrane bone does not form from a cartilage model. B is wrong because although
appositional growth is the way the bone is growing (vs. the cartilage also shown), we are not
seeing the formation of Haversion systems. D is incorrect because, once again, this is
endochondral bone, not membrane bone.
Question 5: d – Figure B shows parietal membrane bone with osteoblasts. Membrane bone grows without
cartilage model, growing via appositional growth. A is wrong because interstitial growth
applies to cartilage only. B is wrong because we are not seeing Haversian channels, and C is
wrong because this is not endochondral bone (since there’s no cartilage model) and thus there
is no interstitial growth.
Question 6: c – Figure C shows the same as Figure B but with pointer on osteoclasts, which are found in all
types of bone.
Questions 7 and 8 Slides: Figure A #9 ground bone, pointer on osteocyte; Figure B #10 decalcified bone
Question 7: c – Figure A shows ground bone, pointer on osteocyte, which started out as an osteoblast, but
as it secreted bone matrix, it became embedded in bone and confined to a lacunae where it
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Histology SSN Slide-Based Practice Practical
October 23, 2002
remained as an osteocyte. Chondroblasts and chondrocytes are found in cartilage only, and
osteoclasts break down bone and do not form osteocytes.
Question 8: a – Figure B shows decalcified bone, which appears eosinophilic due to collagen (matrix is
basophilic). Collagen is important for tensile strength of bone. Bone is not capable of
diffusion (except via Haversian systems) nor of interstitial growth. Collagen cannot produce
proteins as it is itself a long polymer of proteins.
Nerve
Questions 1 and 2:
1. Which of the following statements is correct regarding the cells at the pointers in Figures A
and B? The cells in Figure B have been treated with an antibody to calbindin.
a. The cells are situated in white matter.
b. The cells are situated in a ganglion.
c. The cells are situated in the gray matter.
d. The cells are situated between the white and gray matter.
2. In Figure B the processes at the arrow are:
a. myelinated fibers.
b. axons.
c. collagen fibers.
d. dendrites.
3. Which figure(s) demonstrates smooth muscle?
a. Figure A
b. Figure B
c. both Figures A and B
4. The region at the pointer is required for: (choose all that apply)
a. protein synthesis.
b salutatory conduction.
c. insulation.
d. production of endoneurium.
5. All of the following characterize the organ depicted by the slide except:
a. Microglia
b. Myelinated axons
c. Fibroblasts
d. Oligodendrocytes
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Histology SSN Slide-Based Practice Practical
October 23, 2002
Answers:
1.
2.
3.
4.
5.
Questions 1 and 2: Figure A #86 cerebellum, H&E, pointer on Purkinje cell; Figure B Calbindin
(DAB) slide of cerebellum, pointer on Purkinje cell dendrites. This is a Purkinje cell in the
cerebellum, found at the junction between the molecular and granular layers. The cell body lies in
the granular layer. Its dendrites branch out in the molecular layer. C is correct.
The arrow points to the dendrites in the of the Purkinje cell in the molecular layer. D is correct
Question 3: Figure A #5 trachea peripheral nerve; Figure B #34 stomach, smooth muscle in
cross section. Peripheral nerve and smooth muscle are hard to tell apart. Here are some
distinctions:
-nerve tissue tends to be more compact, less eosinophilic, wavy and bubbly because there are
regions where myelin has leaked out.
-smooth muscle is more diffuse, more intense eosinophilic color.
B is correct.
Question 4: This is a preparation of peripheral nerve that has been stained with H&E The myelin
sheath is layers of lipid wrapping around the axon. It is required for saltatory conduction. It is
also used for insulation. Both B and C are correct
Question 5: A slide of the CNS. There are different support cells in the CNS and PNS. This is a
section from the CNS. There are fibroblasts in the PNS but not the CNS. C is correct.
MUSCLE
1)
Which of the following is true about the band at the pointer?
a. A-band; does not change length during contraction
b. A-band; shortens during contraction
c. I-band; does not change length during contraction
d. I-band; shortens during contraction
2)
Which of these statements is false about the muscle type at the pointer?
a. The cells in this muscle type are electrically coupled.
b. This muscle type utilizes a T-tubule system for calcium delivery.
c. This muscle type is not capable of regeneration.
d. Calcium regulation occurs at the level of thick filaments.
3)
What kind of tissue is at the pointer?
a. skeletal muscle
b. smooth muscle
c. dense, irregularly-arranged connective tissue
d. dense, regularly-arranged connective tissue
4)
The structure at the pointer is composed of all of the following except:
a. desmosomes
b. tight junctions
c. gap junctions
d. fascia adherens
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Histology SSN Slide-Based Practice Practical
October 23, 2002
This tissue contains…
a. actin, myosin, troponin
b. myosin, troponin, gap junctions
c. desmin, intercalated discs, calmodulin
d. actin, myosin, calmodulin
5)
ANSWERS:
1)
a. EM of skeletal muscle with pointer on the A-band. The A-band is the complete region of
myosin. During contraction, there is an increase in the overlap of the thick and thin filaments
in the sarcomere as the filaments slide past one another. The I-band (the region of actin that is
not overlapping myosin) decreases with contraction while the length of the A band remains
fixed. Answer option D is a true statement but is not applicable given the indicated band.
2)
d. This is cardiac muscle. The cells are electronically coupled via gap junctions, thus allowing
contractile signals to pass from cell to cell and allowing cardiac muscle to behave as a
syncytium. T tubules are used for calcium delivery in both skeletal and cardiac muscle.
Smooth muscle cells have no T tubule system. Cardiac muscle is not capable of regeneration
(mature cardiac muscle cells do not divide). If injury to cardiac muscle tissue leads to death
of cells, fibrous connective tissue forms (scarring) with consequent loss of cardiac function.
Since tropomyosin and troponin wind around the actin filaments, calcium regulation does not
occur at the level of the thick filament.
3)
c. This is Slide 59, showing both dense irregularly arranged connective tissue (the paler tissue)
and smooth muscle (the darker tissue with wrinkled, cigar-shaped nuclei). The pointer is on
the dense, irregularly-arranged connective tissue.
4)
b. Pointer is at an intercalated disc. An intercalated disc does not have tight junctions. The
desmosomes are on both the transverse and lateral components of the intercalated disc, while
the fasciae adherens are on the transverse component and the gap junctions are on the lateral
component.
5)
d. This is smooth muscle. As in striated muscle, contraction is initiated by a rise in calcium in the
cytosol, but this does not act through a troponin-tropomyosin complex on the actin filament.
A rise in calcium stimulates a myosin light-chain kinase to phosphorylate one of the two light
chains of myosin. When this chain is phosphorylated, the myosin head can react with actin
and produce contraction. Intercalated discs are specific to cardiac muscle.
SKIN
1.
What is the function of the structure at the pointer?
a) senses light touch.
b) pain and temperature sensation.
c) deep pressure and vibration sensation.
d) increases rate of neuronal transmission.
2.
The structure at the pointer is a(n) ____________; it is located in the _________________ layer,
and its ducts terminate in the __________________.
a) sebaceous gland, hypodermal, stratum granulosum.
b) eccrine sweat gland, dermal, stratum granulosum.
c) eccrine sweat gland, dermal, stratum corneum.
d) sebaceous gland, hypodermal, stratum conrneum.
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Histology SSN Slide-Based Practice Practical
October 23, 2002
3. The structure at the arrow shown in Figure B is involved in:
a) heat loss in thermal regulation
b) production of Vitamin D
c) production of mucus
d) sensing vibration
4. The organs shown in Figures A and C both contain all of the following EXCEPT:
a) stratified squamous keratinized epithelium
b) dermis
c) sebaceous glands
d) melanocytes
ANSWERS
1.
What is the function of the structure at the pointer? (slide 4 – Pacinian corpuscle)
senses light touch – NO. This better describes a Meissner’s corpuscle, which senses 2
point discrimination.
b) pain and temp. sensation – NO. This describes free nerve endings in the epidermis.
c) deep pressure and vibration sensation – YES.
d) increases rate of neuronal transmission – partly true. At best, this answer is only partly
correct, as the STRUCTURE is the corpuscle. A myelin sheath (composed of Schwann
cells) surrounds the nerve axon entering the corpuscle and does ensure an increased rate
of transmission relative to transmission in unmyelinated nerves – but the myelin sheath
only extends for one or two nodes. The inner core of the corpuscle is composed of
lamellae of attenuated Schwann cells, while the outer core of the corpuscle is composed
of lamellae of extra-corpuscular endoneurial cells. Lymph-like fluid and collagen sit
between the lamellae; displacement of lamellae causes an action potential – so the
Schwann cells are also involved in whether the transmission will happen at all (their role
is not limited to ensuring speed).
a)
2.
The structure at the pointer is a(n) ____________; it is located in the _________________ layer,
and its ducts terminate in the __________________.
(slide 4 – eccrine sweat gland)
Choice A is not correct because sebaceous glands are only associated with hair follicles. Choice B
is not correct because if this were true, sweat would have to percolate to the outer surface of the
epidermis. Choice C is correct. Choice D is not correct because, again, sebaceous glands are
only associated with hair follicles.
3. Answer: a
Arrow points to a sweat gland on Slide #4 (thick skin). Although the vascular system is the most important
factor in thermoregulation, sweat glands are also able to cool the skin through evaporation. The skin does
have a somewhat “secretory” function in converting precursor molecules to Vitamin D, but the sweat gland
is not specific for that function. The skin contains sebaceous glands secreting an oily sebum, eccrine sweat
glands that secrete sweat, and specialized apocrine sweat glands whose serous secretion functions in sexual
attraction in animals. There are no mucus glands present. Pacinian corpuscles, located in deeper skin
regions, are responsible for sensing vibration. Vibration sense has nothing to do with sweat glands.
4. Answer: c
Figure A (Slide #4) is thick skin, low magnification. Figure C (#46) is scalp. Sebaceous glands are
associated only with hair follicles, as in the thin skin slide of the scalp. Thick skin, found on volar surfaces,
is not hairy, and therefore does not have sebaceous glands. The remaining answer choices are
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Histology SSN Slide-Based Practice Practical
October 23, 2002
characteristic of all skin, whether it is thick or thin. Stratified squamous keratinized epithelium refers to the
epidermis. The dermis is a connective tissue layer underlying the epidermis. Melanocytes are pigmentproducing cells that comprise 10-15% of the total skin cell population.
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