Polyp is a noun that has various meanings in biology. It may refer to a stage in the development of some invertebrates, or it can relate to the growth of organ tissues. Both are covered in the following sections.
Types of Polyp
Polyps as a Life Cycle
Cnidarians, such as jellyfish, anemones, and coral, have nematocysts on the surface of their tentacles. These little explosive cells are used to transmit poison to the prey or to attach to it. It is possible to devour the prey after it has been caught. Nematocysts are found in all cnidarians, and many of them are polypoid, while others are not.
Planula, or small, free-swimming larvae, are the starting point for these tiny creatures. When two coral gametes encounter in the open water, these larvae develop. The larvae migrate away from the parents in order to start new colonies. When a planula comes across a hard surface with enough nutrients in the surrounding water, it may grow into a polyp and start a new colony. The overall arrangement of polyps in most species is the same.
A polyp adheres to a hard surface using a specific tissue called the pedal disc on the bottom. The stalk, which extends away from the pedal disc, keeps the mouth and tentacles suspended in the water column. These tentacles filter food from the surrounding water and bring it to the mouth of the polyp. By budding apart, the polyps may reproduce asexually. Large coral structures are created in this manner. When the corals are ready to reproduce sexually, they discharge their gametes into the water column. New planula larvae will develop when the gametes unite, and they will look for new areas to colonize.
Sea anemones, which belong to the same Anthozoa class as sea anemones, spend most of their lives in polyp form. Sea anemones, although considerably larger than individual coral polyps, function in the same manner. The anemone is attached to a hard surface by a pedal plate, and its tentacles gather food and carry it to the mouth. Many nematocysts are found on each tentacle, which may hurt and cripple passing animals.
Coral polyps and sea anemones both reproduce in the same manner. They exist as polyps that produce gametes that develop into new larvae capable of conquering new territory. Asexual reproduction is also possible, with the polyp budding out little fragments that may mature into entire anemones.
Other cnidarians, such as jellyfish, have a polyp stage as well. The medusa stage is the most common kind of free-swimming jellyfish. Jellyfish polyps resemble those of coral and anemones, but instead of gametes, they produce the medusa stage. After that, the medusas grow and discharge gametes. Once fertilized, the gametes develop into planula larvae, which then develop into polyps. Scyphistoma, or jellyfish polyps, create little medusa and discharge them as they mature. Some jellyfish lack a polyp stage, and the larvae grow into another medusa right away.
Polyps as a Medical Condition
In medical terms, a polyp is an overgrowth of organ tissue. Some tissue polyps have a small stalk that connects them to the mucous membrane, similar to invertebrates. Medical polyps, unlike invertebrate polyps, are not separate creatures. Instead, they’re caused by some tissue developing faster than the surrounding tissue. The colorectal polyp is a common form of polyp that may be seen in many people. These polyps are usually non-cancerous and do not pose a threat to health.
These little growths may be removed during a normal colonoscopy to reduce the risk of them becoming cancerous. Malignant neoplastic tissue may form large, aberrant polyps. These polyps will expand and mix with the surrounding tissues to form a tumour. Polyps are often recognized by the increased bleeding they produce in the tissues they originate in, whether cancerous or not. A blood test that shows greater amounts of particular proteins, which suggest internal bleeding, may identify their existence.
What Causes Polyps?
Polyps may develop for a number of reasons. Much like malignant cells, polyps are formed when cell division is disrupted. DNA damage, tissue inflammation, or any other stress on the cell that induces accelerated cell division might be the source of the dysregulation. An increase in polyps or the early beginning of polyps may be caused by a variety of hereditary disorders. Carcinogens in the environment may potentially induce genetic alterations. Carcinogens are substances that may alter DNA, resulting in accelerated cell division and the formation of polyps. Other polyps, such as nasal polyps, might be induced by allergies’ repeated irritation. Inflammation induced by drug usage or exposure to harmful substances might potentially produce polyps.
Related Biology Terms
Medusa: Medusa is a free-swimming mammal that may also be found as polyps clinging to the seabed.
Polypoid: A polyp’s overall form, which is an upside-down bell linked to a stalk.
Hyperplasia: Hyperplasia is a disorder in which a region of the body has an excessive number of cells.
Tumour: A tumour is any clump of cells that has grown too big or out of place, including polyps.