Seta

Indenfor biologi er setae (/ ˈsiːtiː/ ; ental seta /ˈsiːtə/ ; fra latin saeta 'børstehår') en hvilken som helst af en række forskellige børstehårslignende eller hårlignende strukturer på levende organismer.

Dyre-setae

Protostome

Afhængigt af deres form og funktion kan protostomernes setae kaldes macrotrichia, chaetae, skæl eller uformelt hår. Setalmembranen er ikke kutikulariseret, så bevægelse er mulig.

Deuterostome

Trædepuderne på en gekko's fødder er små hårlignende udstikkere, der spiller en rolle i dyrets evne til at klamre sig til lodrette overflader. De mikrometerstore børster forgrener sig til nanometerstore fremspring kaldet spatulae.^[1] En tokay-gekkos to forreste fødder kan modstå en kraft på 20,1 N parallelt med overfladen ved at bruge cirka 14.400 børster pr. mm^2. Dette svarer til ~6,2 pN pr. børste, men tager ikke tilstrækkeligt højde for den samlede klæbrighed, som trædepuderne viser.^[2]

Se også

Referencer

^ Santos, Daniel; Matthew Spenko; Aaron Parness; Kim Sangbae; Mark Cutkosky (2007). "Directional adhesion for climbing: theoretical and practical considerations". Journal of Adhesion Science and Technology. 21 (12-13): 1317-1341. doi:10.1163/156856107782328399. ISSN 0169-4243. S2CID 53470787. Gecko "feet and toes are a hierarchical system of complex structures consisting of lamellae, setae, and spatulae. The distinguishing characteristics of the gecko adhesion system have been described [as] (1) anisotropic attachment, (2) high pulloff force to preload ratio, (3) low detachment force, (4) material independence, (5) self-cleaning, (6) anti-self sticking and (7) non-sticky default state. ... The gecko’s adhesive structures are made from ß-keratin (modulus of elasticity [approx.] 2 GPa). Such a stiff material is not inherently sticky; however, because of the gecko adhesive’s hierarchical nature and extremely small distal features (spatulae are [approx.] 200 nm in size), the gecko’s foot is able to intimately conform to the surface and generate significant attraction using van der Waals forces.
^ Autumn, K.; Puthoff, J. (2006). "Properties, principles, and parameters of the gecko adhesive system". I Smith, A.M., Callow, J.A. (red.). Biological adhesives. Springer. s. 245-280. ISBN 978-3-540-31048-8.{{cite book}}: CS1-vedligeholdelse: Flere navne: editors list (link)

[Santos2007-1] Santos, Daniel; Matthew Spenko; Aaron Parness; Kim Sangbae; Mark Cutkosky (2007). "Directional adhesion for climbing: theoretical and practical considerations". Journal of Adhesion Science and Technology. 21 (12-13): 1317-1341. doi:10.1163/156856107782328399. ISSN 0169-4243. S2CID 53470787. Gecko "feet and toes are a hierarchical system of complex structures consisting of lamellae, setae, and spatulae. The distinguishing characteristics of the gecko adhesion system have been described [as] (1) anisotropic attachment, (2) high pulloff force to preload ratio, (3) low detachment force, (4) material independence, (5) self-cleaning, (6) anti-self sticking and (7) non-sticky default state. ... The gecko’s adhesive structures are made from ß-keratin (modulus of elasticity [approx.] 2 GPa). Such a stiff material is not inherently sticky; however, because of the gecko adhesive’s hierarchical nature and extremely small distal features (spatulae are [approx.] 200 nm in size), the gecko’s foot is able to intimately conform to the surface and generate significant attraction using van der Waals forces.

[Puthoff2006-2] Autumn, K.; Puthoff, J. (2006). "Properties, principles, and parameters of the gecko adhesive system". I Smith, A.M., Callow, J.A. (red.). Biological adhesives. Springer. s. 245-280. ISBN 978-3-540-31048-8.{{cite book}}: CS1-vedligeholdelse: Flere navne: editors list (link)

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