ventral

Examples of ventral in the following topics:

• 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 .
  • The ventral part of the neural tube contains the basal plate, which is primarily associated with motor (i.e., muscle) control.
  • Retinoic acid is required ventrally along with Shh to induce Pax6 and Olig2 during differentiation of motor neurons.
  • Three main ventral cell types are established during early neural tube development: the floor plate cells, which form at the ventral midline during the neural fold stage; as well as the more dorsally located motor neurons and interneurons.

• 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.
  • Animal bodies have three axes for symmetry: anterior/posterior (front/behind), dorsal/ventral (back/belly), and lateral/medial (side/middle).

• Sensory-Somatic Nervous System

  • Motor neurons have cell bodies in the ventral gray matter of the spinal cord that project to muscle through the ventral root.
  • The cell bodies of motor neurons are found in the ventral portion of the gray matter of the spinal cord.

• 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 ventral cavity, indicated in yellow, contains the thoracic cavity and the abdominopelvic cavity.

• 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.

• Neurons and Glial Cells

  • 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.

• Phylum Annelida

  • Annelids possess a closed circulatory system of dorsal and ventral blood vessels that run parallel to the alimentary canal as well as capillaries that service individual tissues.
  • Excretion is facilitated by a pair of metanephridia (a type of primitive "kidney" that consists of a convoluted tubule and an open, ciliated funnel) that is present in every segment towards the ventral side.
  • The nerve cord is ventral in position, bearing enlarged nodes or ganglia in each segment.

• Body Plans

  • The most common terms used when describing positions in the body are anterior (front), posterior (rear), dorsal (toward the back), and ventral (toward the stomach).

• Phylum Nemertea

  • A mouth opening that is ventral to the rhynchocoel leads into the foregut, followed by the intestine.
  • This image shows the internal structures of a basic nemertean, including the proboscis and the rhynchocoel: 1: Proboscis 2: Rhynchocoel 3: Dorsal commissure of brain 4: Rhynchodeum 5: Proboscis pore 6: Ventral commissure of brain 7: Mouth 8: Foregut 9: Stomach

• Phylum Nematoda

  • 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.