ANATOMY 1 Lecture Notes - Lecture 23: Commissure, List Of Lumbar Nerves, Occipital Bone
Document Summary
Central letter h of gray matter surrounded by white matter. Cell bodies of neurons, neuroglia, unmyelinated axons, dendrites of interneurons + motor neurons. Neuronal cell bodies form functional groups called nuclei. Receive input from receptors via sensory neurons. Provide output to effector tissues via motor neurons. Provide nerve impulses for contraction of skeletal muscles. Only in thoracic, upper lumbar, and sacral segments. Contain cell bodies of autonomic motor nuclei. *grey matter largest @ lower cervical levels + lumbar upper sacral. Regulate activity smooth muscle, cardiac muscle, + glands. Bundles of myelinated axons of sensory neurons, interneurons, + motor neurons. Each column = bundles of axons w/ common origin or destination + carrying similar info. Axons conducting nerve impulses from spinal cord to brain. Axons carrying nerve impulses away from brain down to spinal cord. *more white matter @ cranial end of spinal cord than caudal end. Ascending tracts become thicker as they progress caudal cranial.
