Structure of the Nervous System PDF
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This document provides information on the structure of the nervous system, including anatomical directions, slicing methods, and neurulation. It features diagrams of human and crocodile anatomy, highlighting key terms. The document also discusses the development of the central nervous system.
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# The Structure of the Nervous System ## Terms used denoting anatomical direction - Neuraxis - imaginary line drawn through the center of the length of the CNS, from the bottom of the spinal cord to the front of the forebrain. - Anterior/rostral - located near or toward the head - Posterior/caud...
# The Structure of the Nervous System ## Terms used denoting anatomical direction - Neuraxis - imaginary line drawn through the center of the length of the CNS, from the bottom of the spinal cord to the front of the forebrain. - Anterior/rostral - located near or toward the head - Posterior/caudal - located near or toward the tail - Dorsal - toward the back - Ventral - toward the belly ## Slicing the NS in 3 ways - Cross sections or frontal sections when referring to the brain: traversely, like a salami - Horizontal sections: parallel to the ground - Sagittal sections: perpendicular to the ground and parallel to the neuraxis. Divides the brain into two symmetrical halves ## Neurulation In summary, neurulation occurs during the third week of embryonic development. The transformation of the neural plate into a neural tube marks the beginning of the formation of the central nervous system. ## Development of the Nervous System The CNS develops from a plate of cells to a hollow tube and maintains this basic shape even after it is fully developed. The image shows a diagram with two different parts: a diagram of a human body from the side view and another diagram with a crocodile from the top. - The human body diagram is labeled with: - Rostral or anterior - Caudal or posterior - Dorsal - Ventral - Lateral Medial - Lateral Medial - Lateral Medial - The crocodile diagram is labeled with: - Rostral or anterior - Caudal or posterior - Dorsal - Ventral The image of the brain shows various directions in which the brain can be sliced. The diagram of the neurulation shows 3 different stages of the process. - The first image shows a neural plate of thickened cells forming in a cranio-caudal direction. - The second image shows the lateral edges of the neural plate elevate & fuse to form the neural tube. - The third image shows that neural crest cells contribute to the formation of the peripheral nervous system.
