Written Exam One Q121 - Q150

Question 1

121. The A band of striated muscle:
A. is bisected by the Z line (band)
B. contains both thick and thin filaments
C. decreases in size during contraction
D. is isotropic

Answer 1

B. contains both thick and thin filaments

Question 2

122. Cardiac myocytes:
     A. branch
     B. contain peripherally positioned nuclei
     C. have a T-tubule system identical to that seen in skeletal muscle
     D. are connected by intercalated disks
     E. both “A” and “D”

Answer 2

E. both “A” and “D”

Question 3

123. In skeletal muscle:
     A. Z lines (bands) are located at A-I junctions
     B. nuclei are multiple and centrally located
     C. calcium is stored in sER during relaxation
     D. intercalated disks join adjacent fibers end to end
     E. mitochondria are much more numerous than in cardiac muscle

Answer 3

C. calcium is stored in sER during relaxation

Question 4

124. In a sarcomere of skeletal muscle, which molecule or molecular aggregate connects Z disk to M line?
A. actin
B. myosin
C. nebulin
D. titin
E. tropomyosin

Answer 4

D. titin

Question 5

125. Which of the following is NOT found in smooth muscle?
A. alpha-actinin
B. thin filaments
C. triads
D. thick filaments
E. centrally located nuclei

Answer 5

C. triads

Question 6

126. Unmyelinated axons in the peripheral nervous system:
     A. have no special glial investment
     B. are immediately surrounded by an endoneurium
     C. are infrequent
     D. occupy troughs in the cytoplasm of Schwann cells
     E. do none of the above

Answer 6

D. occupy troughs in the cytoplasm of Schwann cells

Question 7

127. In axons and dendrites, kinesin functions:
     A. to transport synaptic vesicles from the soma to presynaptic terminals
     B. to move mitochondria from synaptic terminals back to the soma
     C. in retrograde fast axonal transport
     D. both “A” and “B”
     E. both “B” and “C”

Answer 7

A. to transport synaptic vesicles from the soma to presynaptic terminals

Question 8

128. The neurons of the dorsal root (sensory) ganglia are \_\_\_\_\_\_\_\_\_\_ in form.
A. unipolar
B. pseudounipolar
C. bipolar
D. multipolar
E. both "A" and "B"

Answer 8

B. pseudounipolar

Question 9

129. Collagen fibrils with 64-68 nm cross-banding are visible adjacent to Schwann cells in a TEM of peripheral nerve tissue. The collagen is part of the:
A. basal (external) lamina
B. endoneurium
C. perineurium
D. epineurium
E. deep fascia

Answer 9

B. endoneurium

Question 10

130. In a histologic section of spinal cord, rows of nuclei are seen aligned between myelinated axons in the white matter. The observed nuclei are evidence of which cell type?
A. pseudounipolar neurons
B. satellite cells
C. oligodendrocytes
D. Schwann cells
E. multipolar neurons

Answer 10

C. oligodendrocytes

Question 11

131. Positive identification of the central or peripheral nervous system source of a myelinated axon in a TEM can be based on the presence or absence of:
A. basal (external) laminae
B. major & minor dense lines
C. Nissl substance
D. incisures of Schmidt-Lantermann
E. nodes of Ranvier

Answer 11

A. basal (external) laminae

Question 12

132. The endothelium of capillaries in cardiac muscle have all of the following EXCEPT:
A. a basal lamina
B. fenestrations
C. rER
D. tight junctions
E. plasmalemmal vesicles

Answer 12

B. fenestrations

Question 13

133. When comparing lymphatics and veins, which of the following features would be seen ONLY in lymphatics and not in veins?
     A. presence of valves
     B. a continuous endothelium
     C. a distinct three-layered wall with the t. externa as the most prominent
     layer
     D. only lymphocytes and tissue fluid in the lumen
     E. both “A” and “D”

Answer 13

D. only lymphocytes and tissue fluid in the lumen

Question 14

134. Which of the following features enable one to distinguish veins from arteries?
     A. presence of a fenestrated endothelium
     B. smooth muscle in the tunica media
     C. a tunica externa that forms the most prominent layer
     D. presence of valves
     E. both “C” and “D”

Answer 14

E. both “C” and “D”

Question 15

135. Endothelial cell intercellular junctions include:
     A. tight junctions
     B. occasional desmosomes with tonofilaments
     C. zonula occludens
     D. all of the above

Answer 15

D. all of the above

Question 16

136. Arterioles:
A. regulate blood flow to capillary beds
B. have a continuous endothelium
C. contain only a few layers of smooth muscle in the t. media
D. all of the above
E. only "A" and "C"

Answer 16

D. all of the above

Question 17

137. The cardiac skeleton functions to:
     A. support the tricuspid, mitral, aortic and pulmonic valves
     B. electrically insulate the atria from the ventricles
     C. provide an origin for “nested baskets” of cardiac myocytes as they encircle the heart chambers
     D. all of the above
     E. none of the above

Answer 17

D. all of the above

Question 18

138. The tissue forming the impulse-generating and impulse-conduction
     system of the heart consists of modified:
     A. motor neurons
     B. collagen fibers
     C. myelinated axons
     D. smooth muscle
     E. cardiac myocytes

Answer 18

E. cardiac myocytes

Question 19

139. One tissue listed below forms a continuum throughout the
cardiovascular system. Which one?
A. smooth muscle
B. stratified cuboidal epithelium
C. Purkinje fibers
D. simple squamous epithelium
E. cardiac myocytes

Answer 19

D. simple squamous epithelium

Question 20

140. Purkinje fibers are most obvious in histologic sections of which of the following?
A. AV node
B. epicardium of the ventricles
C. interventricular septum
D. myocardium of the atria
E. SA node

Answer 20

C. interventricular septum

Question 21

141. A blood vessel 2 mm in diameter that, on histologic examination, is seen to have a distinct internal elastic lamina and a prominent tunica media is most likely a/an:
A. elastic artery
B. muscular artery
C. arteriole
D. pericytic venule
E. small vein

Answer 21

B. muscular artery

Question 22

142. White pulp of spleen:
     A. contains periarterial lymphatic sheaths (PALS)
     B. filters lymph from afferent lymph vessels
     C. contains T-cell-rich lymphoid nodules
     D. shows a cortico-medullary arrangement
     E. contains splenic (Billroth’s) cords

Answer 22

A. contains periarterial lymphatic sheaths (PALS)

Question 23

143. Hassall’s corpuscles:
     A. occur in both cortex and medulla of the thymus
     B. are epithelial whorls of function that was unknown until 2005
     C. are present in all lymphoid tissues
     D. are formed by mesodermally derived reticular cells

Answer 23

B. are epithelial whorls of function that was unknown until 2005

Question 24

144. Which of the following occurs or resides within the paracortex (deep cortex) of lymph nodes?
     A. HEVs
     B. T cell area
     C. macrophages
     D. dendritic cells (interdigitating dendritic cells)
     E. All of the above

Answer 24

E. All of the above

Question 25

145. "Class switching" refers to: A. production of IgM during the initial humoral immune response B. production of an immunoglobulin other than IgM during the later stages of a humoral immune response. C. an alteration between surface expression of MHC class I or MHC class II on the plasma membrane of APCs. D. alternate expression of immunoglobulin light chains (either k or l chains) along with the same heavy chain

Answer 25

B. production of an immunoglobulin other than IgM during the later stages of a humoral immune response.

Question 26

146. Which of the following is NOT a feature shared by TCRs and BCRs? A. antigen binding by variable domains B. specificity of antigen binding results from DNA rearrangements of the receptor genes in the absence of antigen (i.e., antigen does not direct the DNA recombinations) C. antigen binding domain created by sites located on more than a single polypeptide chain D. affinity maturation in secondary lymphoid tissues generates receptors with better and better binding affinities for the antigen E. transmembrane domains anchor the receptor to the surface of the plasma membrane

Answer 26

D. affinity maturation in secondary lymphoid tissues generates receptors with better and better binding affinities for the antigen

Question 27

``` 147. Aggregated lymphoid nodules form (in) which of the following? A. thymus B. Peyer's patches C. appendix D. All of the above E. only "B" and "C" above ```

Answer 27

E. only "B" and "C" above

Question 28

148. At which point in the vasculature of a lymph node would a B lymphocyte leave the blood stream to enter the lymphatic tissue of the node? A. capillaries of the superficial (nodular) cortex B. venules of the deep (non-nodular) cortex C. capillaries of the superficial medulla D. venules of the deep medulla

Answer 28

B. venules of the deep (non-nodular) cortex

Question 29

``` 149. The predominant cell type found in a germinal center is a: A. macrophage B. T lymphocyte C. reticular cell D. B lymphocyte E. plasma cell ```

Answer 29

D. B lymphocyte

Question 30

``` 150. Surgical removal of the thymus from a neonate would result in drastically depleted numbers of which of the following cell types? A. B cells B. Mast cells C. T cells D. plasma cells ```

Answer 30

C. T cells