Page 225 - Critical Care Nursing Demystified

210 CRITICAL CARE NURSING DeMYSTIFIED

KEY WORDS

Anisocoria DTRs – deep tendon reflexes
AVM – arteriovenous malformation Dysconjugate
AVPU – awake, verbal, pain, Dysmetria
unconscious GCS – Glasgow Coma Scale
Babinski’s reflex Halo’s sign
Battle’s sign (periauricular Hemianopsia
ecchymoses) Kernig’s sign
Brudzinski’s sign Oculocephalic – doll’s eyes movements
Consensual pupillary response PERRLA – Pupils equal round and reac-
Contrecoup/coup tive to light accommodation
Cushing’s triad/syndrome Raccoon’s eyes (periorbital
Decerebrate posturing ecchymoses)
Decorticate posturing Romberg’s sign

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The brain and nervous system has often been compared to a computer; they
both rely heavily on one’s knowledge of the diverse, intricate functioning and
integration of internal circuits. Computers, just like the nervous system, func-
tion to obtain, analyze, and transmit innumerable signals and responses to the
correct recipients. Numerous issues that can lead to computer meltdowns can
also in the human being lead to compromises in neurological functioning, such
as cerebrovascular accidents (CVAs), seizures, and traumatic injuries or inci-
dents. Much is also expected of critical care nurses who are required to be
computer literate as well as knowledgeable about the nervous system and
accompanying neurological disorders.

Anatomy and Physiology of the Nervous System

The Neuron

The most basic cellular structure of the nervous system is the neuron. The
organ that most predominantly affects the nervous system is the brain. The
neuron consists of axons, dendrites, neuroglia, synapses, and a myelin sheath.
Axons carry impulses away from the cell body and dendrites conduct impulses
toward the cell body. Neuroglia is the “glue” or supportive tissue that binds