The pinacoderm is the outermost layer of body cells (
pinacocytes) of organisms of the phylum
Porifera
Sponges, the members of the phylum Porifera (; meaning 'pore bearer'), are a basal animal clade as a sister of the diploblasts. They are multicellular organisms that have bodies full of pores and channels allowing water to circulate throug ...
(sponges), equivalent to the
epidermis
The epidermis is the outermost of the three layers that comprise the skin, the inner layers being the dermis and Subcutaneous tissue, hypodermis. The epidermis layer provides a barrier to infection from environmental pathogens and regulates the ...
in other animals.
Structure
The pinacoderm is composed of
pinacocytes, flattened epithelial cells that can expand or contract to slightly alter the size and shape of the sponge.
It also contains
porocytes, oval-shaped cells extending from the pinacoderm to the
choanoderm
The choanoderm is a type of cell layer composed of flagellated collar cells, or choanocytes, found in sponges. The sponge body is mostly a connective tissue; the mesohyl, over which are applied epithelioid monolayers of cells, the outer pinacoder ...
(the body layer containing
choanocytes).
References
Sponge anatomy
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