Do Chordata have a nervous system?

In chordates, the central nervous system is based on a hollow nerve tube that runs dorsal to the notochord along the length of the animal. In vertebrates, the anterior end of the nerve tube expands and differentiates into three brain vesicles.

Do chordates have nerves and muscles?

Characteristics of Chordata. Animals in the phylum Chordata share five key chacteristics that appear at some stage during their development: a notochord, a dorsal hollow (tubular) nerve cord, pharyngeal gill arches or slits, a post-anal tail, and an endostyle/thyroid gland (Figure 2).

What phylum have a nervous system?

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.

Which animal group has no nervous system?

The only multicellular animals that have no nervous system at all are sponges and microscopic bloblike organisms called placozoans and mesozoans. The nervous systems of ctenophores (comb jellies) and cnidarians (e.g., anemones, hydras, corals and jellyfishes) consist of a diffuse nerve net.

THIS IS INTERESTING:  What muscles are controlled by the somatic nervous system?

What does a chordate not have?

Although tunicates are classified as chordates, the adults do not have a notochord, a dorsal hollow nerve cord, or a post-anal tail, although they do have pharyngeal slits and an endostyle. The “tadpole” larval form, however, possesses all five structures.

Do chordates have a Coelom?

All chordates are coelomates, and have a fluid-filled body cavity called a coelom with a complete lining called peritoneum derived from mesoderm (see Brusca and Brusca).

Do all chordates have a hollow nerve cord?

The dorsal nerve cord is only one embryonic feature unique to all chordates, among the other four chordate features– a notochord, a post-anal tail, an endostyle, and pharyngeal slits. The dorsal hollow nerve cord is a hollow cord dorsal to the notochord.

Do flatworms have a nervous system?

The bilaterally flattened body of flatworms preserves a common organization of the central nervous system (CNS). The CNS of flatworms consists of: (i) the orthogon, composed of main longitudinal nerve cords and transverse commissures that form a ladder-like network.

What type of nervous system does a flatworm have?

Simple bilateral systems

The nervous system of a free-living flatworm such as Planaria consists of a brain, longitudinal nerve cords, and peripheral nerve plexuses (interlacing networks of peripheral nerves; from Latin plectere, “to braid”).

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.

How is the nervous system of chordates different from all other animal phyla?

In contrast to the chordates, other animal phyla are characterized by solid nerve cords that are located either ventrally or laterally. The nerve cord found in most chordate embryos develops into the brain and spinal cord, which comprise the central nervous system.

THIS IS INTERESTING:  Best answer: Can I become a psychiatrist without MBBS?

What creatures have no brain?

Some of the other animals that survive without brains include the sea star, sea cucumber, sea lily, sea urchin, sea anemone, sea squirt, sea sponge, coral, and Portuguese Man-O-War. A brain is basically what results when a large group of nerve cells called neurons form one large cluster.

What animals Cannot feel pain?

Though it has been argued that most invertebrates do not feel pain, there is some evidence that invertebrates, especially the decapod crustaceans (e.g. crabs and lobsters) and cephalopods (e.g. octopuses), exhibit behavioural and physiological reactions indicating they may have the capacity for this experience.

What are the characteristics of Chordata?

Animals in the phylum Chordata share four key features: a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.

What are the defining characteristics of the phylum Chordata?

“The four distinctive characteristics that, taken together, set chordates apart form all other phyla are the notochord; single, dorsal, tubular nerve cord; pharyngeal pouches; and postanal propulsive tail.

What are the main characteristics of phylum Chordata?

Phylum Chordata possesses the following characteristic features:

  • Notochord. It is a longitudinal, cartilaginous rod running between the nerve cord and the digestive tract. …
  • Dorsal Nerve Cord. …
  • Pharyngeal Slits. …
  • Post anal Tail. …
  • Urochordata. …
  • Cephalochordata. …
  • Vertebrata. …
  • Lampreys.