What is a pinacoderm in sponge?
The pinacoderm is the outermost layer of body cells (pinacocytes) of organisms of the phylum Porifera (sponges), equivalent to the epidermis in other animals.
What is the pinacocytes function?
Function. Pinacocytes are part of the epithelium in sponges. They play a role in movement (contracting and stretching), cell adhesion, signaling, phagocytosis, and polarity. Pinacocytes are filled with mesohyl which is a gel like substance that helps maintain the shape and structure of the sponge.
What are Ostia?
Ostia are the tiny pores present on the surface of sponges, from where water enters and goes to the spongocoel. The osculum is the opening from where the water goes out after passing through the spongocoel.
What is a Leuconoid?
Leuconoid sponges are the most complex in design in that not all the chambers are flagellated. Water flowing in through incurrent canals is selectively pumped through those chambers which are, and expelled via one of a series of oscula. Leuconoid sponges are the best adapted to increase sponge size.
What is pinacoderm and choanoderm?
The body wall of sponges consist of two layers with non-cellular mesenchyme in between. 1. The outer layer is called pinacoderm (dermal epidermis) consisting of flattened pinacocytes. 2. Inner layer is called choanoderm (gastral epidermis) consisting of specialised flagellated cells called choanocytes or collar cells.
What is pinacocytes 11?
Answer. 171.6k+ views. Hint: The pinacocytes are flat cells which are found on the outermost layer that is pinacoderm of a sponge. The pinacocytes line the canals and spongocoel. With the help of expansions and contractions, pinacocytes maintain the structure of the sponge.
What is the meaning of spongocoel?
Definition of spongocoel : the internal cavity of a sponge discharging by way of the osculum.
What are the ostia of the heart?
An ostium (pl. ostia) is a generic medical term for “hole” – for example, there are coronary ostia in the aorta through which blood flows to the coronary arteries. Most people are born with two coronary ostia, one each for the left coronary artery and the right coronary artery.
What is ascon type?
The simplest, or ascon, type, found only in certain primitive genera of the Calcarea (e.g., Leucosolenia), is characterized by an arrangement of choanocytes around a central cavity that directly communicates with the osculum.
What are Prosopyles and Apopyles?
Water enters the sponge through these pores and moves into the incurrent canal. Water leaves this area to enter the. radial canal (area of choanocytes) via the prosopyle – (a porocyte cell) Water leaves the area of choanocytes via a much larger pore, made by many cells = the apopyle.
Is pinacoderm a tissue?
In the adult, sponge tissues include the choanocyte epithelium (choanoderm), including cells supporting the choanocyte chambers; the pinacocyte epithelium (pinacoderm), including dermal tissues, incurrent, and excurrent canals; the skeletal and collagenous support tissues; and the osculum.
What type of epithelium is the pinacoderm?
pavement epithelium
The sponge surface is formed by a flat cell type called a pinacocyte (literally ‘pavement’ cell and pinacoderm, a pavement epithelium).
What is Collencytes?
The collencytes, found in the mesohyl, secrete fibres and often form a net in the cytoplasm. The mesohyl of sponges contains other types of cells (lophocytes, sclerocytes, myocytes) believed to be derived from archaeocytes.