The middle ear anatomy with its complicated lever structures, tissue tension and geometrical orientation has been shown to vary among species and depends on the mass, stiffness and other individual characteristics of the resonant system21,22. The middle ear system is not only crucial for matching t...
Anatomy We introduce nomenclature for four anatomical regions not previously defined as distinct regions in the songbird brain: m Area X, l Area X, cRA, and HVo. Area X has been referred to as a unitary structure, but we observed that singing-induced ZENK expression in medial (0.2 mm from...
Abstract Feathers do not have to be especially strong but they do need to be stiff and at the same time resilient and to have a high work of fracture. Syncitial barbule fibres are the highest size-class of continuous filaments in the cortex of the rachis of the feather. However, the ra...
Aphids are thought to assess internal plant chemistry by briefly puncturing the plant epidermal cells to accept or reject a host plant (Harris, 1977; Prado & Tjallingii, 1997). Stylets follow a largely intercellular path until they reach sieve elements, with phloem feeding being the ultimate step...
As an adaptation for flight, bird bones are extremely lightweight. Many bones have air spaces, and the longer limb bones are sometimes completely hollow. The hollow bones have an internal support system of struts. Related Bird Anatomy Pages: ...
6c). Based on the anatomy, we used the following parameter values: thickness of the melanosome membrane a = 30 nm; thickness internal air layer of top melanosomes b1 = 20–50 nm; thickness internal air layer of other melanosomes b2 = 100–125 nm, thickness keratin cortex...
Which of the following is the major molecular evidence that reveals all organisms on Earth share a common ancestor? a) analogous and homologous structures b) similar genetic machinery c) predator-prey anatomy differences d) vestigial structur...