Examples of dorsal nerve cord in the following topics:
-
- Animals in the phylum Chordata share four key features: a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.
- It is located between the digestive tube and the nerve cord, providing skeletal support through the length of the body.
- The dorsal hollow nerve cord derives from ectoderm that rolls into a hollow tube during development.
- The nerve cord found in most chordate embryos develops into the brain and spinal cord, which comprise the central nervous system.
- In chordates, four common features appear at some point during development: a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.
-
- Adults only maintain pharyngeal slits and lack a notochord, a dorsal hollow nerve cord, and a post-anal tail.
- Members of Cephalochordata possess a notochord, dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail in the adult stage.
- (b) The larval stage of the tunicate possesses all of the features characteristic of chordates: a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.
- (c) In the adult stage, the notochord, nerve cord, and tail disappear.
- Adult lancelets retain the four key features of chordates: a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.
-
- A notochord, or a longitudinal, flexible rod between the digestive tube and the nerve cord .
- A dorsal nerve cord which develops from a plate of ectoderm that rolls into a tube located dorsal to the notochord.
- Other animal phyla have solid nerve cords ventrally located.
- A chordate nerve cord splits into the central nervous system: the brain and spinal cord.
- While tunicates are invertebrates and may seem very different from the more familiar members of Chordata, the tunicate larva possesses both a notochord and a dorsal nerve cord, although both are lost in adulthood.
-
- Most nematodes possess four longitudinal nerve cords that run along the length of the body in dorsal, ventral, and lateral positions.
- The ventral nerve cord is better developed than the dorsal or lateral cords.
- All nerve cords fuse at the anterior end, around the pharynx, to form head ganglia, or the "brain" of the worm (taking the form of a ring around the pharynx), as well as at the posterior end to form the tail ganglia.
-
- As chordates, all vertebrates have a similar anatomy and morphology with the same qualifying characteristics: a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.
- All vertebrates are built along the basic chordate body plan: a stiff rod running through the length of the animal (vertebral column), with a hollow tube of nervous tissue (the spinal cord) above it and the gastrointestinal tract below.
- These vertebrae are always found on the dorsal side of the animal.
- 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.
-
- The CNS contains the brain and spinal cord.
- Flatworms of the phylum Platyhelminthes have both a central nervous system, made up of a small "brain" and two nerve cords, and a peripheral nervous system containing a system of nerves that extend throughout the body.
- It contains a brain, ventral nerve cord, and ganglia (clusters of connected neurons).
- One interesting difference between the nervous systems of invertebrates and vertebrates is that the nerve cords of many invertebrates are located ventrally (near the abdomen), whereas the vertebrate spinal cords are located dorsally (near the back).
- (d) In addition to a brain, arthropods have clusters of nerve cell bodies, called peripheral ganglia, located along the ventral nerve cord.
-
- The spinal cord is a bundle of nerves that is connected to the brain and relays information from the brain to the body and vice versa.
- Connecting to the brainstem and extending down the body through the spinal column is the spinal cord: a thick bundle of nerve tissue that carries information about the body to the brain and from the brain to the body.
- The spinal cord is contained within the bones of the vertebral column, but is able to communicate signals to and from the body through its connections with spinal nerves (part of the peripheral nervous system).
- Axons and cell bodies in the dorsal (facing the back of the animal) spinal cord convey mostly sensory information from the body to the brain.
- Spinal cord injuries are notoriously difficult to treat because spinal nerves do not regenerate, although ongoing research suggests that stem cell transplants may be able to act as a bridge to reconnect severed nerves.
-
- Spinal nerves transmit sensory and motor information between the spinal cord and the rest of the body.
- The sensory neuron cell bodies are grouped in structures called dorsal root ganglia .
- Each sensory neuron has one projection with a sensory receptor ending in skin, muscle, or sensory organs, and another that synapses with a neuron in the dorsal spinal cord.
- The cell bodies of sensory neurons are located in dorsal root ganglia.
- The cell bodies of motor neurons are found in the ventral portion of the gray matter of the spinal cord.
-
- This suggested that the dorsal cells were genetically programmed to form the notochord and define the dorsal-ventral axis.
- High Wnt signaling establishes the dorsal region while high Shh signaling indicates in the ventral region.
- Wnt proteins guide the axons of the spinal cord in an anterior-posterior direction.
- Wnt is also involved in the formation of the limb dorsal-ventral axis.
- Specifically, Wnt7a helps produce the dorsal patterning of the developing limb.
-
- This suggested that the dorsal cells were genetically programmed to form the notochord and define the axis.
- In the developing chordate (including vertebrates), the neural tube is the embryo's precursor to the central nervous system, which comprises the brain and spinal cord.
- In secondary neurulation, the cells of the neural plate form a cord-like structure that migrates inside the embryo and hollows to form the tube.
- The dorsal part of the neural tube contains the alar plate, which is primarily associated with sensation.
- The central region of the ectoderm forms the neural tube, which gives rise to the brain and the spinal cord.