Chapter 13-The Spinal Cord and Spinal Nerves Flashcards
The structure composed of axons of motor (efferent) neurons that emerges from the anterior aspect of the spinal cord and extends laterally to join a posterior root, forming a spinal nerve.
Anterior root or ventral root
The middle of the three meninges (coverings) of the brain and spinal cord.
Arachnoid mater or arachnoid
Extension of the great toe, with or without fanning of the other toes, in response to stimulation of the outer margin of the sole; normal up to 18 months of age and indicative of damage to descending motor pathways such as the corticospinal tracts after that.
Babinski sign
A network of nerve axons of the ventral rami of spinal nerves C5, C6, C7, C8, and T1. The nerves that emerge from this structure supply the upper limb
Brachial plexus
A tail-like array of roots of spinal nerves at the inferior end of the spinal cord
Cauda equina
A microscopic tube running the length of the spinal cord in the gray commissure. A circular channel running longitudinally in the center of an osteon (haversian system) of mature compact bone, containing blood and lymphatic vessels and nerves.
Central canal or haversian canal
A network formed by nerve axons from the ventral rami of the first four cervical nerves and receiving gray rami communicantes form the superior cervical ganglion
Cervical plexus
The tapered portion of the spinal cord inferior to the lumbar enlargment
Conus medullaris
The cutaneous area developed from one embryonic spinal cord segment and receiving most of its sensory innervation from one spinal nerve. An instrument for incising the skin or cutting thin transplants of skin
Dermatome
The outermost of the three meninges (coverings) of the brain and spinal cord
Dura meter
An organ of the body, either a muscle or a gland, that is innervated by somatic or autonomic motor neurons
Effector
Connective tissue wrapping around individual nerve axons
Endoneurium
A space between the spinal dura mater and the vertebral canal, containing areolar connective tissue and a plexus of veins
Epidural space
The superficial connective tissue covering around an entire nerve
Epineurium
A small bundle or cluster, especially of nerve or muscle fibers (cells).
Fascicle
Non-nervous fibrous tissue of the spinal cord that extends inferiorly from the conus medullaris to the coccyx
Filum terminale
A narrow strip of gray matter connecting the two lateral gray masses within the spinal cord
Gray commissure
Paralysis of the upper limb, trunk, and lower limb on one side of the body
Hemiplegia
An area of gray matter (anterior, lateral, or posterior) in the spinal cord
Horn
A network formed by the anterior (ventral) branches of spinal nerves L1 through L4
Lumbar plexus
Three membranes covering the brain and spinal cord, called the dura mater, arachnoid mater, and pia mater.
Meninges (singular is meninx)
Neurons that conduct impulses from the brain toward the spinal cord or out of the brain and spinal cord into cranial or spinal nerves to effectors that may be either muscles or glands
Motor neurons or efferent neurons
An encapsulated proprioceptor in a skeletal muscle, consisting of specialized intrafusal muscle fibers and nerve endings; stimulated by changes in length or tension of muscle fibers
Muscle spindle
An encapsulated proprioceptor in a skeletal muscle, consisting of specialized intrafusal muscle fibers and nerve endings; stimulated by changes in length or tension of muscle fibers
Muscle spindle
A sustained, partial contraction of portions of a skeletal or smooth muscle in response to activation of stretch receptors or a baseline level of action potentials in the innervating motor neurons
Muscle tone
A sustained, partial contraction of portions of a skeletal or smooth muscle in response to activation of stretch receptors or a baseline level of action potentials in the innervating motor neurons
Muscle tone
Paralysis of both lower limbs
Paraplegia
Paralysis of both lower limbs
Paraplegia
Connective tissue wrapping around fascicles in a nerve
Perineurium
Connective tissue wrapping around fascicles in a nerve
Perineurium
The innermost of the three meninges (coverings) of the brain and spinal cord
Pia mater
The innermost of the three meninges (coverings) of the brain and spinal cord
Pia mater
A network of nerves, veins, or lymphatic vessels
Plexus
A network of nerves, veins, or lymphatic vessels
Plexus
Paralysis of four limbs; two upper and two lower
Quadriplegia
Paralysis of four limbs; two upper and two lower
Quadriplegia
Branches of a spinal nerve
Rami communicantes (singular is ramus communicans)
Branches of a spinal nerve
Rami communicantes (singular is ramus communicans)
Fast response to a change (stimulus) in the internal or external environment that attempts to restore homeostasis
Reflex
A space between the arachnoid mater and the pia mater that surrounds the brain and spinal cord and through which the cerebrospinal fluid circulates
Subarachnoid space
Inflammation and pain along the sciatic nerve; felt along the posterior aspect of the thigh extending down the inside of the leg
Sciatica
Neurons that carry sensory information from cranial and spinal nerves into the brain and spinal cord or from a lower to higher level in the spinal cord and brain
Sensory neurons or afferent neurons
A mass of nerve tissue located in the vertebral canal from with 31 pairs of spinal nerves originate
Spinal cord
One of the 31 pairs of nerves that originate on the spinal cord from posterior and anterior roots
Spinal nerve
A period from several days to several weeks following transection of the spinal cord that is characterized by the abolition of all reflex activity
Spinal shock
Sensory (ascending) tracts that convey information up the spinal cord to the thalamus for sensations of pain, temperature, crude touch, and deep pressure
Spinothalamic tracts
Any stress that changes a controlled condition; any change in the internal or external environment that excites a sensory receptor, a neuron, or a muscle fiber
Stimulus
A space between the arachnoid mater and the pia mater that surrounds the brain and spinal cord and through which the cerebrospinal fluid circulates
Subarachnoid space
A space between the dura mater and the arachnoid mater of the brain and spinal cord that contains a small amount of fluid
Subdural space
A polysynaptic, ipsilateral reflex that protects tendons and their associated muscles from damage that might be brought about by excessive tension. The receptors involved are called tendon organs (Golgi tendon organs)
Tendon reflex
A bundle of nerve axons in the central nervous system
Tract
The part of the body to which the upper and lower limbs are attached
Trunk
