Fig. 8.1

Fig. 8.2

Fig. 8.3

Fig. 8.4

Gray vs White Matter

• CNS composed of gray and white matter.– Gray matter consists

of neuron cell bodies and dendrites.

– White matter (myelin) consists of axon tracts.

Fig. 8.5

Fig. 8.6

Fig. 8.7

Masses of gray matter composed of neuronal cell bodies located deep within white matter. Contain:

Corpus striatum:Caudate nucleus.Lentiform nucleus:

Putaman and globus pallidus.

Functions in the control of voluntary movements.

Basal Nuclei (basal ganglia)

Fig. 8.11

Cerebral dominance:Specialization of one hemisphere.

Left hemisphere: More adept in language and analytical abilities.Damage:

Severe speech problems.

Right hemisphere: Most adept at visuospatial tasks.Damage:

Difficulty finding way around house.

Cerebral Lateralization

Fig. 8.12

Language• Broca’s area:

– Involves articulation of speech.– In damage, comprehension of speech in unimpaired.

• Wernicke’s area:– Involves language comprehension.– In damage, language comprehension is destroyed, but speech is rapid without any

meaning.

• Angular gyrus:– Center of integration of auditory, visual, and somatosensory information. – Damage produces aphasias.

• Arcuate fasciculus:– To speak intelligibly, words originating in Wernicke’s area must be sent to Broca’s

area.• Broca’s area sends fibers to the motor cortex which directly controls the musculature of

speech.

Fig. 8.13

Limbic system:Group of forebrain nuclei and fiber tracts that form a ring around the brain stem.

Center for basic emotional drives.

Emotion and Motivation

Fig. 8.14

Areas of the hypothalamus and limbic system are involved in feelings and behaviors.Aggression:

Amygdala and hypothalamus.Fear:

Amygdala and hypothalamus.Feeding:

Hypothalamus (feeding and satiety centers).Sexual drive and behavior:

Hypothalamus and limbic system.Goal directed behavior (reward and punishment):

Hypothalamus and frontal cortex.

Emotion and Motivation

Fig. 8.16

Fig. 8.17

Functions of Hypothalamus• Contains neural centers for hunger, thirst,

and body temperature.• Contributes to the regulation of sleep,

wakefulness, emotions, sexual arousal, anger, fear, pain, and pleasure.

• Stimulates hormonal release from anterior pituitary.

• Produces ADH and oxytocin.• Coordinates sympathetic and

parasympathetic reflexes.

Fig. 8.19

Midbrain

Midbrain– Corpora quadrigemina:

• Superior colliculi:– Involved in visual reflexes.

• Inferior colliculi:– Relay centers for auditory information.

– Cerebral peduncles:• Composed of ascending and descending fiber tracts.

– Substantia nigra:• Required for motor coordination.

– Red nucleus:• Maintains connections with cerebrum and

cerebellum.– Involved in motor coordination.

Fig. 8.18

Fig. 8.19

Cerebellum, Pons, & Medulla

Fig. 8.21

Fig. 8.23

Fig. 8.24