What are the body forms of cnidarians?
There are two basic cnidarian body shapes: a polyp form, which is attached to a surface; and an upside-down free-floating form called a medusa.
What are the stinging cells present in cnidarians?
Cnidocytes, also known as stinging cells, are specialized neural cells that typify the phylum Cnidaria (sea anemones, corals, hydroids, and jellyfish) [1,2,3]. These cells contain an organelle called cnida or cnidocyst, which is the product of extensive Golgi secretions.
What are stinging cells?
Cnidocytes (‘stinging cells’) are specialized cells that define the phylum Cnidaria (sea anemones, jellyfish, corals and hydras). They contain an “explosive” organelle called cnidocyst that acts as a 600 million-years-old microscopic injection system and is important for prey capture and anti-predator defense.
What are the two body forms that cnidarians come in?
Cnidarians have two body forms—polyp and medusa—which often occur within the life cycle of a single cnidarian.
What opening the cnidarians use to remove the waste?
Waste removal: Waste removal occurs in the Cnidaria through the mouth/anus. Any undigested remains are expelled through the mouth/anus.
How do tentacles give a cnidarian an advantage?
How do tentacles give a cnidarian an advantage? They are able to reach out and perceive the world. They have nematocysts on their tentacles that have poisons to get their prey.
What is the function of Gastrodermis?
The gastrodermis is the inner layer of cells that serves as a lining membrane of the gastrovascular cavity of Cnidarians. The term is also used for the analogous inner epithelial layer of Ctenophores. It has been shown that the gastrodermis is among the sites where early signals of heat stress are expressed in corals.
What is a epidermis and gastrodermis?
There are two tissue layers: the epidermis, which lines the outside of the animal, and the gastrodermis, which lines the inside of the animal. These layers are separated by a nonliving layer of elastic, gelatinous material known as the mesoglea, which provides structure and buoyancy without metabolic cost.
What is the difference between epidermis and gastrodermis?
The outer layer (from ectoderm) is called the epidermis and lines the outside of the animal, whereas the inner layer (from endoderm) is called the gastrodermis and lines the digestive cavity. Between these two membrane layers is a non-living, jelly-like mesoglea connective layer.
What is epidermis in human body?
The epidermis is the thin outer layer of the skin. It consists of 3 types of cells: Squamous cells. The outermost layer is continuously shed is called the stratum corneum.
How does the epidermis protect the body?
The primary function of the epidermis is to protect your body by keeping things that might be harmful out and keeping the things your body needs to function properly in. Bacteria, viruses and other infectious agents are kept out, helping prevent infections on your skin.
What do the 5 layers of the epidermis do?
The epidermis provides a protective waterproof barrier that also keeps pathogens at bay and regulates body temperature. The main layers of the epidermis are: stratum corneum, stratum lucidium, stratum granulosm, stratum spinosum, stratum germinativum (also called stratum basale).
How does skin protect against internal injury?
Disease: skin works to neutralise aggressors such as bacteria, viruses and pollution and prevent them for entering the body. UV rays: over-exposure to these harmful rays generates free radicals – aggressive molecules that cause cell damage. Pressure, blows and abrasion: skin recognises pain and alerts us to danger.
How does the skin help the immune system?
Skin immunity is a property of skin that allows it to resist infections from pathogens. In addition to providing a passive physical barrier against infection, the skin also contains elements of the innate and adaptive immune systems which allows it to actively fight infections.
Why the skin is the most important part of the immune system?
As a protective interface between internal organs and the environment, the skin encounters a host of toxins, pathogenic organisms, and physical stresses. To combat these attacks on the cutaneous microenvironment, the skin functions as more than a physical barrier: it is an active immune organ.
Why is skin a good defense mechanism for the immune system?
The skin acts as an external barrier to bacteria, preventing infection and protecting the internal organs. The skin also protects the body from ultraviolet radiation using the pigment barrier formed from melanocyte cells found in the top of the papillary dermis and a protein layer found in the epidermis.