(4) Functional Areas of the Brain

Primary motor cortex

• Known as the somatic motor area

• located in the precentral gyrus

• control skeletal muscle activities

Premotor cortex

• Plans and coordinate motor movements

• receive information from sensory cortex

Frontal eye field

– Allow both eyes to move together

– Following objects

– Sometimes included in the premotor cortex

Broca’s area

– Speech initiation

– Motor movements necessary for speaking

– Found in the left hemisphere

– Emotional overtone of speech found in the

corresponding right hemisphere

Primary somatosensory area (postcentral gyrus)

– Conscious awareness of general somatic senses (skin and muscles)

– Process stimuli received from skin and muscles

– Precisely localize the stimulus received (spatial discrimination)

– The location where the body is mapped on the cortex (sensory homunculus)

Somatosensory association area

– Allows comprehensive understanding of what is being felt

– Reaching to your pocket

Wernicke’s area

– Found also in temporal lobe

– Located in left hemisphere

– Recognizing of spoken or written language

Primary auditory cortex

– Conscious awareness of sound

– Gets information from ear about frequency and amplitude of sound

Auditory association area

– Allows evaluation of sound

– Stores memory of past sounds

Primary olfactory cortex

– Receives information from smell receptors in nasal cavity

Olfactory association area

– Allow us to interpret smell

– Connected to the limbic system and may trigger emotions

Primary visual cortex

– Largest of cortical areas

– Receive visual information from the retina of the eyes

Visual association area

– Process visual information by analyzing color, shapes, movement, form, etc…

Thalamus

• Makes up 80% of the diencephalon

• Made of about dozen nuclei

• Acts as a sensory relay station (except olfactation)

Hypothalamus

• Control of autonomic nervous system

• Control of emotional responses

• Regulation of body temperature

• Regulation of hunger and thirst

• Control of motivational behavior (reward)

• Regulation of sleep-wake cycle

• Control of endocrine functions

• Formation of memory

Epithalamus

• Contains the pineal gland

– Secretes melatonin which signal the body

to prepare for sleep

Midbrain

• Processes visual and auditory data; generates reflexive somatic motor responses

Pons

• Relays sensory information to cerebellum and thalamus; subconscious somatic and visceral motor centers

Medulla Oblongata

• Relays sensory information to thalamus; autonomic centers for regulation of visceral function (cardiovascular, respiratory, digestive)

Temporal lobe

• Auditory cortex and olfactory cortex; conscious perception of auditory and olfactory stimuli

Occipital lobe

• Visual cortex; conscious perception of visual stimuli

Frontal lobe

• Primary motor cortex; higher intellectual functions, planning, and decision-making

Parietal lobe

• Primary somatosensory cortex; conscious perception of touch, pressure, pain, and temperature

Cerebellum

• Adjusts postural muscles of body; programs and fine-tunes movements controlled at conscious and subconscious levels

Basal ganglia (cerebral nuclei)

• Direct subconscious control of skeletal muscle tone and coordination of learned movement patterns