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Most cnidarians, such as those of the genus Hydra, have what is called a nerve net—a meshlike system of individual and separate nerve cells and fibres dispersed over the organism.
- Why cnidarians have diffuse type nervous system?
- What is diffuse CNS?
- What type of neural network occurs in cnidaria?
- What is arthropod nervous system?
- Do cnidarians have muscles?
- What is CNS toxoplasmosis?
- Which is a neurotransmitter?
- What is the work of central nervous system?
- How are nervous responses in cnidarians controlled?
- Do Cnidaria have a respiratory system?
- Do cnidarians have a Coelom?
- What is sympathetic and parasympathetic?
Why cnidarians have diffuse type nervous system?
In the cnidarian body, the nerve net serves as a sensory locator; neuron cells stretch all around the animal's body and allow the cnidarian to detect chemical changes, to capture prey, and to move in response to a stimulus. This kind of expansive nerve net is also known as a diffuse nerve net.
What is diffuse CNS?
The diffuse nervous system is the most primitive nervous system. In diffuse systems nerve cells are distributed throughout the organism, usually beneath the outer epidermal layer.
What type of neural network occurs in cnidaria?
Cnidarians are considered “nerve net animals” even though their nervous systems include various forms of condensation and centralization. Yet, their broad, two-dimensional muscle sheets are innervated by diffuse nerve nets.
What is arthropod nervous system?
The arthropod nervous system consists of a dorsal brain and a ventral, ganglionated longitudinal nerve cord (primitively paired) from which lateral nerves extend in each segment. The system is similar to that of annelid worms, from which arthropods may have evolved. ... The stomatogastric system regulates digestion.
Do cnidarians have muscles?
Muscles in cnidarians are extensions of the bases of ectodermal and endodermal cells. Individual muscle cells are relatively long and may occur in dense tracts in jellyfish or sea anemones. Most cnidarian muscles, however, are thin sheets at the base of ectodermal and endodermal layers.
What is CNS toxoplasmosis?
CNS toxoplasmosis results from infection by the intracellular parasite Toxoplasma gondii. It is almost always due to reactivation of old CNS lesions or to hematogenous spread of a previously acquired infection. Occasionally, it results from primary infection.
Which is a neurotransmitter?
Neurotransmitters are often referred to as the body's chemical messengers. They are the molecules used by the nervous system to transmit messages between neurons, or from neurons to muscles. Communication between two neurons happens in the synaptic cleft (the small gap between the synapses of neurons).
What is the work of central nervous system?
The central nervous system (CNS) controls most functions of the body and mind. It consists of two parts: the brain and the spinal cord. The brain is the center of our thoughts, the interpreter of our external environment, and the origin of control over body movement.
How are nervous responses in cnidarians controlled?
The nerve net is the simplest form of a nervous system found in multicellular organisms. Unlike central nervous systems, where neurons are typically grouped together, neurons found in nerve nets are spread apart. This nervous system allows cnidarians to respond to physical contact.
Do Cnidaria have a respiratory system?
Cnidarians lack organs. This means that they do not have respiratory or circulatory systems. Like the cells in sponges, the cells in cnidarians get oxygen directly from the water surrounding them.
Do cnidarians have a Coelom?
A coelom is a fully-encased, fluid-filled body cavity (gut) lined with mesodermic tissue. ... Cnidarians are not considered to have a coelom because they are diploblastic, so they don't have any mesodermic tissue. Cnidaria are a phylum consisting of aquatic animals like jellyfish, anemones, and corals.
What is sympathetic and parasympathetic?
The autonomic nervous system comprises two parts- the sympathetic and parasympathetic nervous system. The sympathetic nervous system activates the fight or flight response during a threat or perceived danger, and the parasympathetic nervous system restores the body to a state of calm.
