Test 4: Chapter 13 Flashcards
A small bundle or cluster, especially of nerve or muscle fibers
Fascicle
Polio is another word for this. Caused by a virus called poliovirus
Poliomyelitis
The constriction of the pupils that occur when a bright light is flashed in the eye is a protective response
Pupillary Light Reflex
One of the thirty one pairs of nerves that originate on the spinal cord from posterior and anterior roots
Spinal Nerve
Corresponds with the attachments of the large nerves which supply the upper limbs. It extends from about the third cervical to the second thoracic vertebra, its maximum circumference (about 38 mm.) being on a level with the attachment of the sixth pair of cervical nerves
Cervical Enlargement
The structure compsed of axons of motor 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
Area where axons cross from one side of spinal cord to the other
Anterior White Commisure
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
A network formed by nerve axons from the anterior rami of the first four cervical nerves and receiving gray rami communicantes from the superior cervical ganglion
Cervical Plexus
A network of nerves, veins, or lymphatic vessels
Plexuses
A space between the spinal dura matter and the vertebral canal, containing areolar connective tissue and a plexus of veins
Epidural Space
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 of mature compact bone, containing blood and lymphatic vessels and nerves.
Central Canal
The inntermost of the three meninges (coverings) of the brain and spinal cord
Pia Mater
Paralysis of four limbs: two upper and two lower
Quadriplegia
A space between the arachnoid mater and the pia mater that surrounds the brain and spinal cord and through which cerebrospinal fluid circulates
Subarachnoid Space
A network of nerve axons of the anterior rami of spinal nerves C5, C6, C7, C8, and T1. The nerves that emerge from this supply the upper limb
Brachial Plexus
A network formed by the anterior branches of spinal nerves L1 through L4
Lumbar Plexus
Deeper groove that separates the right and left portions of the anterior white matter
Anterior Median Fissure
Injection of anesthetic drug in the epidural space to cause temporary loss of sensation
Epidural Block
Innervation so that the contraction of a muscle or set of muscles is accompanied by the simultaneous inhibition of an antagonistic muscle or set of muscles
Reciprocal Innervation
A shallow vertical groove dividing the spinal cord throughout its whole length in the midline posteriorly
Posterior Median Sulcus
Motor response is on the opposite side as the sensory input
Contralateral Reflex Arc
A group of cell bodies of sensory neurons and their supporting cells located along the posterior root of a spinal nerve
Posterior Root Ganglion
Flexion of ankle, knee, and hip when the foot is painfully stimulated; the crossed extension reflex occurs in association with it
Flexor Reflex
A partial transection of the cord on either the right of left side
Hemisection
An area of gray matter (anterior, lateral, or posterior) in the spinal cord
Horns
The procedure of taking fluid from the spine in the lower back through a hollow needle, usually done for diagnostic purposes
Spinal Tap (Lumber Puncture)
No interneuron involved
When a reflex arc consists of only two neurons
Monosynaptic Reflex Arc
Paralysis of the upper limb, trunk, and lower limb on one side of the body
Hemiplegia
A reflex action that involves an electrical impulse being transferred from a sensory neuron to a motor neuron via at least one connecting neuron (interneuron) in the spinal cord
Polysynaptic Reflex Arc
The middle of the three meninges (coverings) of the brain and spinal cord
Arachnoid
A reflex induced by stimulation of somatic sensory nerve endings
Somatic Reflex
Motor response is on the same side as the sensory input
Ipsilateral Reflex Arc
Infection of the PNS by herpes zoster, causes pain, discoloration, and blisters
Shingles
An organ of the body, either a muscle or a gland, that is innervated by somatic or autonomic motor neurons
Effector
Inferior to the lumbar enlargement, the spinal cord terminates as a tapering, conical structure, which ends at the level of the intervertebral disc between the first and second lumbar vertebrae in adults
Conus Medullaris
Inflammation of the nerves due to a direct blow, bone fracture, or poisons
Neuritis
The most basic conduction pathway through the nervous system, connecting a receptor and an effector and consisting of a receptor, a sensory neuron, an integrating center in the central nervous system, a motor neuron, and an effector
Reflex Arc
Inflammation of the spinal cord
Myelitis
Paralysis of one limb only
Monoplegia
Stroke the abdomen with a blunt object to the side of the umbilicus. Normal response is movement of the umbilicus toward stimulation. No response indicates possible damage to lower thoracic spinal cord nerves, may also be present with multiple sclerosis.
Abdominal Reflex
Paralysis of both lower limbs
Paraplegia
Loss fo reflex function
Areflexia
A polsynaptic, ipsilateral reflex that protects tendons and their associated muscles from damage that might be brought about by excessive tension
Tendon Reflex
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
Inflammation of the meninges due to an infection, usually caused by a bacterium or virus
Meningitis
A muscle contraction in response to stretching within the muscle. It is a monosynaptic reflex which provides automatic regulation of skeletal muscle length. When a muscle lengthens, the muscle spindle is stretched and its nerve activity increases
Stretch Reflex
Any reflex action mediated through a center of the spinal cord
Spinal Reflex
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 eighteen months of age and indicative of damage ro descending motor pathways such as the corticospinal tracts after that age
Babinski Sign
Inflammation and pain along the sciatic nerve; felt along the posterior aspect of the thigh extending down the inside of the leg
Sciatica
Nonnervous fibrous tissue of the spinal cord that extends inferiorly from the conus medullaris to the coccyx
Filum Temrinale
Pralysis of both arms or both legs
Diplegia
Connective tissue wrapping around individual nerve axons
Endoneurium
Start in the brain and end in the spinal cord, convey motor information.
Descending Tract
Unconscious motor reflexes relayed from organs and glands to the CNS through visceral afferent signaling
Autonomic Reflex
Lateral extensions of pia mater that pass through the arachnoid layer and attach to the internal surface of the dura mater.
Function to anchor the spinal cord
Denticulate Ligaments
Connective tissue wrapping around fascicles in a nerve
Perineurium
Three membranes covering the brain and spinal cord, called the dura mater, arachnoid, and pia mater
Meninx/Meninges
The outermost of the three meninges (coverings) of the brain and spinal cord
Dura Mater
The cord is severed from one side to the other, thus cutting all sensory and motor tracts. It results in a loss of all sensations and voluntary movement below the level of transection
Complete Transection
Brain involvement, but not under conscious control
Cranial Reflex
The strucute composed of sensory axons lying between a spinal nerve and the dorsolateral aspect of the spinal cord
Posterior Root
Using the flat side of the reflex hammer strike below the patellar. Normal response: extension, straightening of the leg. No response indicates possible damage of lumbar segments of spinal cord. May also indicate diabetes, mellitus, or alcoholism
Patellar Reflex
Thickening in the spinal cord that supplies nerves to lower limbs
Lumbar Enlargement
A tail-like array of roots of spinal nerves at the inferior end of the spinal cord
Cauda Equina
A space between the duar mater and the arachnoid materof the brain and spinal cord that contains a small amount of fluid
Subdural Space
A narrow strip of gray matter connecting the two lateral gray masses within the spinal cord
Gray Commissure
Start in the spinal cord and end in the brain, convey sensory information
Ascending Tract
A specialized cell or a distal portion of a neuron that responds to a specificsensory modality, such as touch, pressure, cold, light, or sound, and converts it to an electrical signal. A specific molecule or cluster of molecules that recognizes and binds a particular ligand
Receptor
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 proprioceptive receptor, sensitive to changes in muscle tension and force of contraction, found chiefly near the junctions of tendons and muscles
Tendon (Golgi Tendon) Organ
Motor response is through a spinal nerve at a different level than the sensory input
Intersegmental Reflex Arc
Group of white matter tracts in the spinal cord
Columns
The superficial connective tissue covering around an entire nerve
Epineurium
Hold the foot and strike the achilles tendon with the flat side of the reflex hammer. Normal response is plantar flexion (extension) of the foot. NO response or an exaggerated response indicates injury to sacral segments of the spinal cord. Exaggerated response may be present with a compression of the cervical spine
Achilles Reflex
Crossing of sensory impulses within the reflex center to produce an opposite effect; ex: when you step on a tack and the opp. leg reacts to keep you balanced
Crossed Extensor Reflex
A network formed by the anterior rami branches of spinal nerves L4 through S3
Sacral Plexus
