Page 530 - Fundamentals of anatomy physiology

Chapter 14 The Brain and Cranial Nerves 517

Figure 14–18 Brain Waves. The four electrical patterns revealed

by electroencephalograms (EEGs). The heights (amplitudes) of the four
waves are not drawn to the same scale.

a Alpha waves are Patient being wired 14
characteristic of for EEG monitoring
normal resting adults
234
b Beta waves typically
accompany intense
concentration

c Theta waves are
seen in children and
in frustrated adults

d Delta waves occur in 0 Seconds 1
deep sleep and in
certain pathological
conditions

involve the thalamus. Asynchrony between the hemispheres Checkpoint
can indicate localized damage or other cerebral abnormalities.
For example, a tumor or injury affecting one hemisphere typi- 2 1. What name is given to fibers carrying information
cally changes the pattern in that hemisphere, and the patterns between the brain and spinal cord, and through which
of the two hemispheres are no longer aligned. brain regions do they pass?

A seizure is a temporary cerebral disorder accompanied 2 2. What symptoms would you expect to observe in an
by abnormal movements, unusual sensations, inappropriate individual who has damage to the basal nuclei?
behavior, or some combination of these symptoms. Clinical
conditions characterized by seizures are known as seizure dis- 2 3. A patient suffers a head injury that damages her
orders, or epilepsies. Seizures of all kinds are accompanied by a primary motor cortex. Where is this area located?
marked change in the pattern of electrical activity recorded in
an electroencephalogram. The change begins in one portion of 24. Which senses would be affected by damage to the
the cerebral cortex but may then spread across the entire corti- temporal lobes of the cerebrum?
cal surface, like a wave on the surface of a pond.
25. After suffering a stroke, a patient is unable to speak.
The nature of the signs and symptoms produced de- He can understand what is said to him, and he can
pends on the region of the cortex involved. If a seizure af- understand written messages, but he cannot express
fects the primary motor cortex, movements will occur. If it himself verbally. Which part of his brain has been
affects the auditory cortex, the individual will hear strange affected by the stroke?
sounds.
26. A patient is having a difficult time remembering facts
and recalling long-term memories. Which part of his
cerebrum is probably involved?

See the blue Answers tab at the back of the book.