Cerebral Cortex II

Question 1

Describe the location of the language center in the brain

Answer 1

Left cerebral hemisphere is usually dominant language center in most people with Broca’s and Wernicke’s around lateral sulcus.

Question 2

What is the location and function of Broca’s area?

Answer 2

In frontal lobe, does motor component of language.

Question 3

What is the location and function of Wernicke’s area?

Answer 3

In parietotemporal area, does language comprehension.

Question 4

What connects Broca’s and Wernicke’s areas?

Answer 4

Arcuate fasciculus

Question 5

What are the clinical manifestations of Broca’s and Wernicke’s aphasia?

Answer 5

Broca’s: inability/difficulty in speech production.

Wernicke’s: loss of language comprehension, speaking incomprehensible words.

Question 6

What is the function and anatomy of the reticular formation?

Answer 6

RF exists within brainstem and is the coordination network for the brainstem. Its unique cytoarchitecture allows convergence of somatosensory information and divergence of efferent outputs. Pulls together specific neurons to make them work together. Exists between midbrain-medulla, in bands.

Question 7

What are the midline, lateral, and paramedian zones of the reticular formation?

Answer 7

Midline -> diffuse modulatory system.
Lateral -> sensory zone
Paramedian -> effector zone.

Question 8

Where do RF afferents from lateral group come from?

Answer 8

Cortex, tectum, cranial nerves, cerebelloreticular and spinoreticular tracts.

Question 9

Where do RF efferents from medial groups go?

Answer 9

Spinal cord (posture and locomotion) and brainstem (central tegmental tract) terminations.

Question 10

Where are diffuse modulatory systems?

Answer 10

Lie around borders of reticular formation.

Question 11

Describe Ascending Reticular Activating System (ARAS)

Answer 11

Type of diffuse modulatory system. Role in level of alertness, sleep-wake rhythms, and startle reactions. Plays role in activation of cerebral cortex.

Question 12

What is the principle neurotransmitter in diffuse modulatory systems?

Answer 12

Serotonin. Largest territorial distribution of any CNS neurons.

Question 13

What is consciousness?

Answer 13

State of self-awareness

Question 14

What does the diffuse modulating system maintain and where to neuromodulators go?

Answer 14

Maintains consciousness. Raphe nuclei (serotonin) -> thalamus and cortex. Locus ceruleus (norepinephrine) -> cortex and thalamus. Midbrain reticular formation (acetylcholine) -> thalamus

Question 15

What are the functions of sleep?

Answer 15

Restoration and recovery, consolidation of memory and daily experiences, brain growth and development.

Question 16

Compare and contrast REM and non-REM sleep

Answer 16

REM=highest arousal level, increased sympathetic activity, vivid dreaming, abolished muscle tone, and low amplitude, high frequency EEG. Non-REM = lower arousal level, increased parasympathetic activity, vague dreams, decreased muscle tone, and high amplitude, low frequency EEG.

Question 17

Describe sleep cycle regulation

Answer 17

SCN is circadian rhythm pacemaker. It interacts with preoptic area (hypothalamus) and medullary reticular formation to get you asleep.

Question 18

Describe the role of neurotransmitters in narcolepsy.

Answer 18

Narcoleptics have loss of orexin neurons. Narcoleptics enter REM sleep quickly, act out their dreams, and have cataplexia (i.e. lose motor tone when very excited, e.g. fall over paralyzed).