ANAT 321 Lecture Notes - Lecture 5: Cauda Equina, Dorsal Root Ganglion, Subarachnoid Cisterns

• School: McGill University
• Department: Anatomy & Cell Biology
• Course: ANAT 321
• Professor: David Ragsdale

Document Summary

Segment: 31 places along spinal cord where sensory neurons coming in (dorsal), motor neurons coming out (ventral) As grow: backbone gets bigger, spinal cord doesn"t get bigger; spinal cord ends before vertebrae. Spinal nerves that exit vertebrae at bottom (ie. for legs) travel from spinal cord down through inside of vertebrae (lumbar cistern), opening in vertebrae form bundles of nerves (cauda equina) Foramen magnum: hole in skull where spinal cord enters form medulla, expands, part of brainstem. Peripheral nerves in body carry information out to muscles and sensory information from body; axons bundled together. Sever peripheral nerve in arm lose ability to move muscles beyond part where severed, also lose sensory; mixed nerve. Mixed nerve approach spinal cord splits in 2. Cell bodies of sensory neurons are outside spinal cord 31 groups on either side of spinal cord, correspond to 31 segments going into spinal cord. Thoracic & lumbar part: sympathetic ganglia (another set of ganglia)