Practice important
Sertoli Cell Junctions
MCQ questions and answers.
Page 1
of
1
|
10
MCQ Questions
1. The blood-testis barrier is formed primarily by which junctional arrangement between adjacent Sertoli cells?
A.
Tight junctions located near the basal region of the seminiferous epithelium
B.
Gap junctions surrounding the lumen of the seminiferous tubule
C.
Desmosomes connecting Sertoli cells directly to Leydig cells
D.
Adherens junctions between Sertoli cells and peritubular myoid cells
Correct Answer:
Tight junctions located near the basal region of the seminiferous epithelium
Explanation:
Sertoli-Sertoli tight junctions near the basal region form the principal structural basis of the blood-testis barrier, separating the basal and adluminal compartments.
2. Which consequence most directly results from the division of the seminiferous epithelium by Sertoli cell tight junctions?
A.
Leydig cells are separated from the interstitial blood supply
B.
Developing germ cells in the adluminal compartment are isolated from many circulating immune factors
C.
Spermatogonia are prevented from contacting the basement membrane
D.
Sertoli cells are prevented from communicating with one another
Correct Answer:
Developing germ cells in the adluminal compartment are isolated from many circulating immune factors
Explanation:
The Sertoli cell barrier creates an immunologically protected adluminal compartment in which meiotic and postmeiotic germ cells develop.
3. During the passage of a preleptotene spermatocyte from the basal to the adluminal compartment, what must occur at the Sertoli-Sertoli barrier?
A.
Permanent destruction of all Sertoli cell tight junctions
B.
Transient remodeling of junctions so the cell can pass while barrier integrity is maintained
C.
Detachment of Sertoli cells from the basement membrane
D.
Fusion of the spermatocyte with an adjacent Sertoli cell
Correct Answer:
Transient remodeling of junctions so the cell can pass while barrier integrity is maintained
Explanation:
Germ-cell translocation requires coordinated restructuring of Sertoli-Sertoli junctions, allowing passage without producing a lasting breach in the blood-testis barrier.
4. Which junctional feature best explains how Sertoli cells can maintain a barrier while allowing developing germ cells to move through the epithelium?
A.
Simultaneous breakdown and permanent loss of the barrier
B.
A coordinated exchange between junctional complexes above and below the migrating germ cell
C.
Replacement of tight junctions by Leydig cell processes
D.
Movement of the basement membrane toward the lumen
Correct Answer:
A coordinated exchange between junctional complexes above and below the migrating germ cell
Explanation:
The barrier is remodeled in a coordinated manner, with junctional complexes reorganized around the migrating germ cell so that a continuous barrier is preserved.
5. A mutation selectively disrupting claudin-based sealing between adjacent Sertoli cells would most directly impair which function?
A.
Formation of testosterone by Leydig cells
B.
Maintenance of the permeability barrier between basal and adluminal compartments
C.
Attachment of sperm tails to the epididymal epithelium
D.
Production of seminal vesicle secretions
Correct Answer:
Maintenance of the permeability barrier between basal and adluminal compartments
Explanation:
Claudins are important tight-junction proteins. Their disruption would weaken Sertoli-Sertoli sealing and compromise the blood-testis barrier.
6. Which statement correctly distinguishes Sertoli-Sertoli tight junctions from Sertoli-germ cell junctions?
A.
Only Sertoli-germ cell junctions contribute to compartmentalization of the seminiferous epithelium
B.
Sertoli-Sertoli tight junctions form the principal barrier, whereas Sertoli-germ cell junctions mainly anchor and position germ cells
C.
Sertoli-Sertoli junctions are located only in the interstitial tissue
D.
Sertoli-germ cell junctions directly connect the seminiferous lumen to the bloodstream
Correct Answer:
Sertoli-Sertoli tight junctions form the principal barrier, whereas Sertoli-germ cell junctions mainly anchor and position germ cells
Explanation:
The blood-testis barrier is chiefly established by Sertoli-Sertoli tight junctions, while junctions between Sertoli cells and germ cells provide adhesion and positional support during spermatogenesis.
7. If Sertoli-Sertoli tight junctions were experimentally disrupted while Sertoli cells remained viable, which structural change would be expected first?
A.
Loss of separation between the basal and adluminal compartments
B.
Immediate conversion of Sertoli cells into Leydig cells
C.
Complete disappearance of the seminiferous lumen
D.
Formation of additional interstitial capillaries inside Sertoli cells
Correct Answer:
Loss of separation between the basal and adluminal compartments
Explanation:
Disruption of the tight junctions would compromise the blood-testis barrier and eliminate the normal compartmental separation within the seminiferous epithelium.
8. Which combination of junctional roles is most characteristic of Sertoli cells within seminiferous tubules?
A.
Barrier formation with neighboring Sertoli cells and adhesion of developing germ cells
B.
Hormone secretion into the bloodstream and contraction of the seminiferous lumen
C.
Phagocytosis of Leydig cells and formation of the tunica albuginea
D.
Production of sperm flagella and transport of sperm through the vas deferens
Correct Answer:
Barrier formation with neighboring Sertoli cells and adhesion of developing germ cells
Explanation:
Sertoli cells use junctional complexes both to form the blood-testis barrier with one another and to maintain physical associations with developing germ cells.
9. Why is a temporary opening in Sertoli cell junctional complexes during germ-cell migration not equivalent to permanent failure of the blood-testis barrier?
A.
The opening occurs only in Leydig cells, not Sertoli cells
B.
Junctional remodeling is spatially coordinated and rapidly re-established around the migrating germ cell
C.
The blood-testis barrier is formed exclusively by the basement membrane
D.
Developing germ cells become impermeable to all extracellular substances during migration
Correct Answer:
Junctional remodeling is spatially coordinated and rapidly re-established around the migrating germ cell
Explanation:
During translocation, Sertoli junctions are reorganized rather than simply destroyed; this preserves barrier continuity while permitting germ-cell movement.
10. A defect in Sertoli cell adhesion complexes that support germ-cell attachment would most likely cause which junction-related problem?
A.
Premature release or mispositioning of developing germ cells within the seminiferous epithelium
B.
Failure of testosterone synthesis by interstitial Leydig cells
C.
Inability of blood vessels to enter the tunica vaginalis
D.
Loss of smooth muscle contraction in the epididymal duct
Correct Answer:
Premature release or mispositioning of developing germ cells within the seminiferous epithelium
Explanation:
Sertoli-germ cell adhesion complexes help retain and position germ cells. Their disruption can lead to abnormal germ-cell movement or premature release, even if the Sertoli-Sertoli barrier remains partly intact.
Short Questions and Answers
Practice short questions and answers related to
Sertoli Cell Junctions
.
Short questions are currently unavailable for this page.