Chapter 6 Nervous System Flashcards
Nervous System divison
CNS, PNS, ANS
CNS
Brain and spinal cord
PNS
Cranial nerves, Brachial plexus, Spinal nerves, Lumbosacral plexus
ANS
Sympathetic NS, Parasympathetic NS
Dendrites
Bring info to the cell body
Axons
Take info away from cell body
White matter
mostly myelinated, increases speed of impulses in spinal cord and fiber systems by containing ascending (sensory) and descending (motor) fiber pathways. Pathways cross from one side of the body to the other at diff areas
Gray matter
mostly unmyelinated, in cerebral cortex and central portion of spinal cord, contains neurons and synapses
Myelin sheath
Fatty substance around axon that insulates nerve and electrical impulses and increases nerve conduction speed
Synapse
Where a nerve ends and transmission of impulses occur
Sensory Neuron Pathway
Dendrites arise in skin, run to its cell body in the POSTERIOR root ganglion of spinal nerve and into the spinal cord, sends AFFERENT impulses
Motor Neuron Pathway
Axon leaves ANTERIOR horn through white matter, continue down peripheral nerve to its termination in a motor end plate of a muscle fiber, then conducts EFFERENT impulses
Efferent
Motor = away = anterior
Afferent
Sensory = towards = posterior
What does the brain stem and cerebellum do
basic functions in the brain stem, movement coordination in the cerebellum
Posterior Horn of gray matter
Transmits sensory impulses
Anterior Horn of gray matter
Transmits motor impulses
Upper Motor Neuron and lesion location
Synapse above the anterior horn. Lesion located between the brain and spinal cord, proximal to the anterior horn.
Lower Motor Neurons and lesion location
Synapse at or below the anterior horn. Lesion located between anterior horn of the spinal cord and the periphery
UMN Clinical signs
Spastic paralysis, Hyperreflexia, Babinski reflex and clonus
LMN Clinical signs
Flaccid paralysis, muscle atrophy and hyporeflexia
Cranial Nerves
12 pairs located in the brain. Odor Of Orangutans Terrified Tarzan After Forty Voracious Gorillas Attacked Him
Trigeminal
V, sensation to the face
Facial
VII, motor to the face
Spinal Accessory
XI, motor for sternocleidomastoid and trapezius
Dermatone
Area of skin innervated by a specific spinal nerve root, use them to diagnose spinal nerve conditions
Cervical Plexus
C1 - C4 (Innervates neck muscles)
Brachial Plexus
C5 - T1 (motor/sensory for entire upper extremity)
Lumbosacral Plexus
L1 - S5 (motor/sensor for entire lower extremity) L1-4 is mostly thigh, L5-S5 is mostly leg and foot
