What is a planarian ventral nerve cords?

Planarians are considered to be among the most primitive animals which developed the central nervous system (CNS). ... The planarian CNS is located on the ventral side of the body, and composed of a mass of cephalic ganglions in the head region and a pair of ventral nerve cords (VNC).

1. What is nerve cord in planaria?
2. Do flatworms have ventral nerve cord?
3. What does the ventral nervous system do?
4. Do sponges have a ventral nerve cord?
5. Where is the ventral nerve cord located in a worm?
6. Do snakes have ventral nerve cord?
7. What animals have a ventral nerve cord?
8. Which of these animals has a ventral nerve cord?
9. What does the nervous system of invertebrates and vertebrates have in common?
10. What type of nervous system does a flatworm have?
11. What does the ventral nerve cord do in a crayfish?
12. What is the simple brain found in the anterior end of a planarian called?
13. Does cockroach have ventral nerve cord?
14. Are nerve cord present in platyhelminthes?
15. What is the difference between ganglion and nerves?

What is nerve cord in planaria?

…Planaria consists of a brain, longitudinal nerve cords, and peripheral nerve plexuses (interlacing networks of peripheral nerves; from Latin plectere, “to braid”). The brain, located in the anterior portion of the animal, is composed of two cephalic ganglia joined by a broad connection called a commissure.

Do flatworms have ventral nerve cord?

Two main ventral thick nerve cords were consistently present in all examined species. These always extended posteriorly, whereas most other nerve cords were radially distributed in the anterior part of the animal. Several thinner commissures of different arrangements connected the major nerve cords.

What does the ventral nervous system do?

Arthropods, such as insects and crustaceans, have a nervous system made up of a series of ganglia, connected by a pair of ventral nerve cords running along the length of the abdomen (Chapman, 1998). Most body segments have one ganglion on each side, but some are fused to form the brain and other large ganglia.

Do sponges have a ventral nerve cord?

Sponges are the only multicellular animals without a nervous system. They do not have any nerve cells or sensory cells. However, touch or pressure to the outside of a sponge will cause a local contraction of its body. The hydra has a nervous system characterized by a nerve net.

Where is the ventral nerve cord located in a worm?

The visceral ganglia supply the mantle, adductor muscles (which close the shell), and internal organs. A second pair of nerve cords travels ventrally to the pedal ganglia. Most of the sense organs are found at the edge of the mantle.

Do snakes have ventral nerve cord?

The spinal cord extends the length of the vertebral column to the tip of the tail and gives rise to dorsal (sensory) and ventral (motor) roots at each vertebral segment.

What animals have a ventral nerve cord?

Ventral nerve cord

Among the phyla exhibiting ventral nerve cords are nematodes (roundworms), annelids (such as earthworms, and arthropods (such as insects and crayfish).

Which of these animals has a ventral nerve cord?

Ventral nerve cords are found in some phyla of the bilaterians, particularly within the nematodes, annelids and the arthropods. Ventral nerve cords are well-studied within insects, have been described in over 300 species covering all the major orders, and have remarkable morphological diversity.

What does the nervous system of invertebrates and vertebrates have in common?

Compared to invertebrates, vertebrate nervous systems are more complex, centralized, and specialized. While there is great diversity among different vertebrate nervous systems, they all share a basic structure: a CNS that contains a brain and spinal cord and a PNS made up of peripheral sensory and motor nerves.

What type of nervous system does a flatworm have?

Flatworms have a cephalized nervous system that consists of head ganglion, usually attached to longitudinal nerve cords that are interconnected across the body by transverse branches.

What does the ventral nerve cord do in a crayfish?

The ventral nerve cord of crayfish contains axons of five pairs of excitatory interneurons, each of which can activate the swimmeret system. Perfusion of the ventral nerve cord with the neuropeptide proctolin also activates the swimmeret system.

What is the simple brain found in the anterior end of a planarian called?

Two clusters of nerve cells called ganglia are located near the anterior of the animals. This pair of ganglia constitutes the brain of the flatworm. Two ventral nerve cords extend from the brain to the posterior of the planarian. The two ventral nerve cords are connected to one another by smaller nerves.

Does cockroach have ventral nerve cord?

The ventral nerve cord of the cockroach contains several very large-diameter axons that originate in the last (6th) abdominal ganglion and extend up to the brain. It is easy to elicit action potentials in these so-called giant neurons (or giant fibers).

Are nerve cord present in platyhelminthes?

Flatworms of the phylum Platyhelminthes have both a central nervous system (CNS), made up of a small “brain” and two nerve cords, and a peripheral nervous system (PNS) containing a system of nerves that extend throughout the body. The insect nervous system is more complex but also fairly decentralized.

What is the difference between ganglion and nerves?

Difference Between a Nerve and a Ganglion

Both nerves and ganglia are structures found in the nervous system. However, a ganglion refers to a collection of nerve cells outside of the CNS whereas a nerve is the axon of a neuron.