A fenestra ( fenestration; : fenestrae or fenestrations) is any small opening or pore, commonly used as a term in the biology.
Biological morphology
In morphology, fenestrae are found in
, particularly in the skull.
In
anatomy, the
round window and
oval window are also known as the
fenestra rotunda and the
fenestra ovalis.
In
microanatomy, fenestrae are found in
endothelium of fenestrated capillaries, enabling the rapid exchange of
between the blood and surrounding tissue.
The elastic layer of the
tunica intima is a fenestrated membrane. In
surgery, a fenestration is a new opening made in a part of the body to enable drainage or access.
Plant biology and mycology
In
plant biology, the perforations in a
perforate leaf are also described as fenestrae, and the leaf is called a fenestrate leaf. The
leaf window is also known as a fenestra,
and is a translucent structure that transmits light, as in
Fenestraria.
Examples of fenestrate structures in the fungal kingdom include the symmetrically arranged gaps in the indusium ("skirt") of the mushroom Phallus duplicatus,
Zoology
In
zoology, the trilobite
Fenestraspis possessed extensive fenestrae in the posterior part of the body.
In the
Paleognathae, there is an ilio–ischiatic fenestra.
Fenestrae are also used to distinguish the three types of amniote:
