What does pinacocytes mean?
Definition of pinacocyte : one of the flat cells covering the external surface and lining the incurrent and excurrent canals of sponges.
What are pinacocytes in porifera?
Pinacocytes. These cells are the “skin cells” of sponges. They line the exterior of the sponge body wall. They are thin, leathery and tightly packed together.
What is pinacoderm in biology?
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 are pinacocytes and Choanocytes?
Choanocytes are body cells of sponges and pinacocytes are flat shaped cells that make up the pinacoderm of sponges. The key difference between choanocytes and pinacocytes is that choanocytes contain flagella while pinacocytes do not contain flagella.
What do porocytes do?
Porocytes control the amount of water that enters pores into the spongocoel, while choanocytes, which are flagellated cells, aid the movement of water through the sponge, thereby helping the sponge to trap and ingest food particles.
What is the function of the osculum?
The osculum (plural “oscula”) is an excretory structure in the living sponge, a large opening to the outside through which the current of water exits after passing through the spongocoel. Wastes diffuse into the water and the water is pumped through the osculum carrying away with it the sponge’s wastes.
What is the function of porocytes?
In the Calcarea, the outer surface of the body also contains flattened granular cells called porocytes because they contain the pores needed to allow water into the sponge. The porocytes can contract, thus closing the pores during unfavourable environmental conditions.
What is pinacoderm and choanoderm Class 11?
Pinacoderm is an epithelial layer of flattened cells called pinacocytes. It is the outer cell layer or external skin of sponges. In contrast, choanoderm is the inner cell layer composed of specialized flagellated cells called choanocytes.
What are 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?
143.7k+ 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 are choanocytes Class 11?
Choanocytes are the collar cells lining the spongocoel and the canals of sponges.