Butterflies also act as a lower member of the food chain. They are a hearty meal for a number of animals, including birds and mice. As populations of butterfly diminish, so will populations of birds and other animals that rely on them as a food source.
The conus medullaris (Latin for medullary cone) is the tapered, lower end of the spinal cord.It occurs near lumbar vertebral levels 1 (L1) and 2 (L2), occasionally lower. The upper end of the conus medullaris is usually not well defined.After the spinal cord tapers out, the spinal nerves continue to branch out diagonally, forming the cauda equina.onus medullaris syndrome is a collection of signs and symptoms associated with injury to the conus medullaris. It typically causes back pain and bowel and bladder dysfunction but weakness and sensory loss is uncommon.
It exits the brainstem out from the sides of the upper medulla, just rostral (closer to the nose) to the vagus nerve. The motor division of the glossopharyngeal nerve is derived from the basal plate of the embryonic medulla oblongata, while the sensory division originates from the cranial neural crest.pon emerging from the lateral aspect of the medulla the branchial motor component joins the other components of CN IX to exit the skull via the jugular foramen. The glossopharyngeal fibers travel just anterior to the cranial nerves X and XI, which also exit the skull via the jugular foramen.