dorsal

Examples of dorsal in the following topics:

• Vertebrate Axis Formation

  • 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 is also involved in the dorsal-ventral formation of the central nervous system through its involvement in axon guidance.
  • Wnt is also involved in the formation of the limb dorsal-ventral axis.
  • Specifically, Wnt7a helps produce the dorsal patterning of the developing limb.

• 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.
  • The dorsal hollow nerve cord derives from ectoderm that rolls into a hollow tube during development.
  • In chordates, it is located dorsally (at the top of the animal) to the notochord.
  • 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.

• Establishing Body Axes during Development

  • Animal bodies have three axes for symmetry (lateral-medial, dorsal-ventral and anterior-posterior) which are established in development.
  • However, animal bodies have lateral-medial (left-right), dorsal-ventral (back-belly), and anterior-posterior (head-feet) axes .
  • This suggested that the dorsal cells were genetically programmed to form the notochord and define the axis.
  • The dorsal part of the neural tube contains the alar plate, which is primarily associated with sensation.
  • The dorsal (back) surface of the embryo is toward the top of this page, while the ventral (front) surface is toward the bottom.

• Phylum Chordata

  • The phylum Chordata contains all animals that have a dorsal notochord at some stage of development; in most cases, this is the backbone.
  • A dorsal nerve cord which develops from a plate of ectoderm that rolls into a tube located dorsal to the notochord.
  • 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.

• Chordates and the Evolution of Vertebrates

  • Members of these groups also possess the four distinctive features of chordates at some point during their 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.
  • Adult lancelets retain the four key features of chordates: a notochord, a dorsal hollow nerve cord, pharyngeal slits, and a post-anal tail.

• Animal Body Planes and Cavities

  • A frontal plane (also called a coronal plane) separates the front (ventral) from the back (dorsal).
  • The posterior (dorsal) and anterior (ventral) cavities are each subdivided into smaller cavities.
  • The brain and spinal cord are protected by the bones of the skull and vertebral column and by cerebrospinal fluid, a colorless fluid produced by the brain, which cushions the brain and spinal cord within the posterior (dorsal) cavity.
  • The dorsal cavity, indicated in green, contains the cranial and the spinal cavity.

• Sensory-Somatic Nervous System

  • 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.

• Animal Characterization Based on Body Symmetry

  • Animals with bilateral symmetry have a "head" and "tail" (anterior vs. posterior), front and back (dorsal vs. ventral), and right and left sides.
  • This monarch butterfly demonstrates bilateral symmetry down the sagittal plane, with the line of symmetry running from ventral to dorsal and dividing the body into two left and right halves.

• Phylum Mollusca

  • It is the ventral-most organ, whereas the mantle is the limiting dorsal organ.
  • The mantle (also known as the pallium) is the dorsal epidermis in mollusks; shelled mollusks are specialized to secrete a chitinous and hard calcareous shell.

• Characteristics of Vertebrates

  • 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.
  • 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.