Advertisement
Journal Articles
Expansion of the tunica albuginea during penile inflation in the nine-banded armadillo (Dasypus novemcinctus)
D.A. Kelly
Journal of Experimental Biology 1999 202: 253-265;

Summary

Artificial inflation of corpora cavernosa from the nine-banded armadillo (Dasypus novemcinctus) showed that the expansion of the tunica albuginea during erection increases both components of flexural stiffness: the second moment of area and Young's modulus of elasticity. Folded tissue and crimped collagen fibers in the tunica albuginea permit its expansion during erection. As the tunica albuginea's radii increase in size, its second moment of area also increases. The crimped collagen fibers permit the flaccid tunica albuginea to expand to strains of 25 % longitudinally and 15 % circumferentially, after which tissue stiffness increases by 3–4 orders of magnitude. Radial expansion of the corpus cavernosum is limited by collagenous trabeculae. The trabeculae maintain the non-circular cross section of the corpus cavernosum during erection. Restricting expansion appears to protect the corpus spongiosum and urethra from occlusion, but has the side effect of reducing the potential flexural stiffness of the corpus cavernosum by reducing the second moment of area of the tunica albuginea.

REFERENCES

    1. Arvy, L.
    (1978). Le penis des Cetaces. Mammalia 42, 491–.
    OpenUrl
    1. Bitsch, M.,
    2. Kromann-Andersen, B.,
    3. Schou, J. and
    4. Shontoft, E.
    (1990). The elasticity and the tensile strength of tunica albuginea of the corpus cavernosum. J. Urol 143, 642–.
    OpenUrlPubMedWeb of Science
    1. Brainerd, E. L.
    (1994). Pufferfish inflation, functional morphology of postcranial structures in Diodon holocanthus (Tetradontoformes). J. Morph 220, 243–.
    OpenUrlCrossRef
    1. Clark, R. B. and
    2. Cowey, J. B.
    (1958). Factors controlling the change of shape of certain nemertean and turbellarian worms. J. exp. Biol 35, 731–.
    OpenUrlAbstract
    1. Deysach, L. J.
    (1939). The comparative morphology of the erectile tissue of the penis with especial emphasis on the probable mechanism of erection. Am. J. Anat 64, 111–.
    OpenUrlCrossRef
    1. Dowling, H. G. and
    2. Savage, J. M.
    (1960). A guide to the snake hemipenis: a survey of basic structure and systematic characteristics. Zoologica 45, 17–.
    OpenUrl
    1. Fung, Y. C.
    (1984). Structure and stress—strain relationship of soft tissues. Am. Zool 24, 13–.
    OpenUrl
    1. Goes, P. M.,
    2. Wespes, E. and
    3. Schulman, C.
    (1992). Penile extensibility: to what is it related?. J. Urol 148, 1432–.
    OpenUrlPubMed
    1. Goldstein, A. M. B.,
    2. Meehan, J. P.,
    3. Morrow, J. W.,
    4. Buckley, P. A. and
    5. Rogers, F. A.
    (1985). The fibrous skeleton of the corporacavernosa and its probable function in the mechanism of erection. Br. J. Urol 57, 574–.
    OpenUrlPubMed
    1. Hanyu, S.
    (1988). Morphological changes in penile vessels during erection: the mechanism of obstruction of arteries and veins at the tunica albuginea in dog corpora cavernosa. Urol. Int 43, 219–.
    OpenUrlPubMed
    1. Hanyu, S.,
    2. Iwanaga, T.,
    3. Kano, K. and
    4. Sato, S.
    (1987). Mechanism of penile erection in the dog. Urol. Int 42, 401–.
    OpenUrlPubMed
    1. Hsu, G.-L.,
    2. Brock, G.,
    3. Martinez-Pineiro, L.,
    4. Von Heyden, B.,
    5. Lue, T. F. and
    6. Tanagho, E. A.
    (1994). Anatomy and strength of the tunica albuginea: its relevance to penile prosthesis extrusion. J. Urol 151, 1205–.
    OpenUrlPubMed
    1. Hsu, G.-L.,
    2. Brock, G.,
    3. Von Heyden, B.,
    4. Nunes, L.,
    5. Lue, T. F. and
    6. Tanagho, E. A.
    (1994). The distribution of elastic fibrous elements within the human penis. Br. J. Urol 73, 566–.
    OpenUrlPubMed
    1. Kelly, D. A.
    (1997). Axial orthogonal fiber reinforcement in the corpus cavernosum of the nine-banded armadillo (Dasypus novemcinctus). J. Morph 233, 249–.
    OpenUrlCrossRefPubMedWeb of Science
    1. Koehl, M. A. R.,
    2. Quillian, K. and
    3. Pell, C.
    (1995). Mechanical consequences of fiber orientation in the walls of hydraulic skeletons. Am. Zool 35, 53–.
    1. Orton, L. S. and
    2. Brodie, P. F.
    (1987). Engulfing mechanics of fin whales. Can. J. Zool 65, 2898–.
    OpenUrl
    1. Purohit, R. C. and
    2. Beckett, S. D.
    (1976). Penile pressures and muscle activity associated with erection and ejaculation in the dog. Am. J. Physiol 231, 1343–.
    OpenUrl
    1. Tejada, I. S.,
    2. Moroukian, P.,
    3. Tessier, J.,
    4. Kim, J. J.,
    5. Goldstein, I. and
    6. Frohrib, D.
    (1991). Trabecular smooth muscle modulates the capacitor function of the penis. Am. J. Physiol 260, 1590–.
    OpenUrl
    1. Vardi, Y. and
    2. Siroky, M. B.
    (1990). Hemodynamics of pelvic nerve induced erection in a canine model. I. Pressure and flow. J. Urol 144, 794–.
    OpenUrlPubMed
    1. Wainwright, S. A.,
    2. Vosburgh, F. and
    3. Hebrank, J. H.
    (1978). Shark skin: Function in locomotion. Science 202, 747–.
    OpenUrlAbstract/FREE Full Text
    1. Wake, M. H.
    (1998). Cartilage in the cloaca: phallodeal spicules in caecillians (Amphibia: Gymnophiona). J. Morph 237, 177–.
    OpenUrlCrossRef
    1. Watson, J. W.
    (1964). Mechanism of erection and ejaculation in the bull and ram. Nature 204, 95–.
    OpenUrlCrossRefPubMed
    1. Wourms, J. P.
    (1981). Viviparity: the maternal—fetal relationship in fishes. Am. Zool 21, 473–.
    OpenUrl
Back to top

 Download PDF

Email
Journal Articles
Expansion of the tunica albuginea during penile inflation in the nine-banded armadillo (Dasypus novemcinctus)
D.A. Kelly
Journal of Experimental Biology 1999 202: 253-265;
del.icio.us logo Digg logo Reddit logo Twitter logo CiteULike logo Facebook logo Google logo Mendeley logo
Citation Tools
Alerts

Article navigation

Other journals from The Company of Biologists

Advertisement

Meet the Editors at SICB Virtual 2021

Reserve your place to join some of the journal editors, including Editor-in-Chief Craig Franklin, at our Meet the Editor session on 17 February at 2pm (EST). Don’t forget to view our SICB Subject Collection, featuring relevant JEB papers relating to some of the symposia sessions.

2020 at The Company of Biologists

Despite 2020's challenges, we were able to bring a number of long-term projects and new ventures to fruition. As we enter a new year, join us as we reflect on the triumphs of the last 12 months.

The Big Biology podcast

JEB author Christine Cooper talks to Big Biology about her research. In this fascinating JEB sponsored podcast she tells us how tough zebra finches adjust their physiology to cope with extreme climate events. 

Developmental and reproductive physiology of small mammals at high altitude

Cayleih Robertson and Kathryn Wilsterman focus on high-altitude populations of the North American deer mouse in their review of the challenges and evolutionary innovations of pregnant and nursing small mammals at high altitude.

Read & Publish participation extends worldwide

“Being able to publish Open Access articles free of charge means that my article gets maximum exposure and has maximum impact, and that all my peers can read it regardless of the agreements that their universities have with publishers.”

Professor Roi Holzman (Tel Aviv University) shares his experience of publishing Open Access as part of our growing Read & Publish initiative. We now have over 60 institutions in 12 countries taking part – find out more and view our full list of participating institutions.