Functions of Major Brain Regions Pages 239-252

Cerebrum: General Functions Speech, memory, logical/emotional response Consciousness, interpretation of sensation Voluntary movement Speech

Cerebrum: Primary Somatic Sensory Area Receives impulses from the body’s sensory receptors Pain, temperature, light touch Located in parietal lobe posterior to central sulcus Sensory homunculus is a spatial map showing locations of specifics sensations Left side of the primary somatic sensory area receives impulses from right side or body(and vice versa) © 2015 Pearson Education, Inc.

Figure 7.13c Left lateral view of the brain. Central sulcus Primary motor area Primary somatic sensory area Premotor area Anterior association area Gustatory area (taste) Working memory and judgment Speech/language (outlined by dashes) Posterior association area Problem solving Language comprehension Visual area Broca’s area (motor speech) Olfactory area Auditory area (c)

Figure 7.14 Sensory and motor areas of the cerebral cortex. Posterior Motor Sensory Anterior Motor map in precentral gyrus Sensory map in postcentral gyrus Shoulder Hip Trunk Neck Head Arm Forearm Trunk Leg Hand Wrist Elbow Arm Hip Knee Elbow Hand Fingers Fingers Knee Thumb Thumb Neck Foot Eye Brow Nose Eye Toes Face Lips Genitals Face Primary motor cortex (precentral gyrus) Primary somatic sensory cortex (postcentral gyrus) Teeth Lips Gums Jaw Jaw Tongue Pharynx Tongue Intra- abdominal Swallowing

Special Senses Specific lobes of the cerebral hemispheres are responsible for impulses of specific senses: Visual area (occipital lobe) Auditory area (temporal lobe) Olfactory area (temporal lobe) © 2015 Pearson Education, Inc.

Cerebrum: Primary Motor Area Sends impulses to skeletal muscles (efferent pathway) Located in frontal lobe anterior to central sulcus Motor neurons form corticospinal (pyramidal) tract, which descends to spinal cord Motor homunculus is a spatial map showing specific locations responsible for respective body areas © 2015 Pearson Education, Inc.

Figure 7.13c Left lateral view of the brain. Central sulcus Primary motor area Primary somatic sensory area Premotor area Anterior association area Gustatory area (taste) Working memory and judgment Speech/language (outlined by dashes) Posterior association area Problem solving Language comprehension Visual area Broca’s area (motor speech) Olfactory area Auditory area (c)

Figure 7.14 Sensory and motor areas of the cerebral cortex. Posterior Motor Sensory Anterior Motor map in precentral gyrus Sensory map in postcentral gyrus Shoulder Hip Trunk Neck Head Arm Forearm Trunk Leg Hand Wrist Elbow Arm Hip Knee Elbow Hand Fingers Fingers Knee Thumb Thumb Neck Foot Eye Brow Nose Eye Toes Face Lips Genitals Face Primary motor cortex (precentral gyrus) Primary somatic sensory cortex (postcentral gyrus) Teeth Lips Gums Jaw Jaw Tongue Pharynx Tongue Intra- abdominal Swallowing

Cerebrum: Specialized Areas Broca’s area Involved in our ability to speak Usually in left hemisphere Anterior and posterior association areas Involved in multiple capabilities including: Reasoning Behavior Visual recognition Speech © 2015 Pearson Education, Inc.

Figure 7.13c Left lateral view of the brain. Central sulcus Primary motor area Primary somatic sensory area Premotor area Anterior association area Gustatory area (taste) Working memory and judgment Speech/language (outlined by dashes) Posterior association area Problem solving Language comprehension Visual area Broca’s area (motor speech) Olfactory area Auditory area (c)

Figure 7.12b Development and regions of the human brain. Cerebral hemisphere Diencephalon Cerebellum Brain stem (b) Adult brain Structures of the Diencephalon

Diencephalon Thalamus Surrounds the third ventricle Relay station for sensory impulses Sends impulses to cortex for interpretation Distinguishing pleasant vs. unpleasant sensations begins here (pg. 246) Involved in memory © 2015 Pearson Education, Inc.

Diencephalon Hypothalamus Important autonomic nervous system center Helps regulate: body temperature, water balance, metabolism Houses limbic center which is responsible for: emotions (pleasure, fear, anger) drives (hunger, sex, parenting, dominance) Regulates pituitary gland (which produces ADH and oxytocin) Houses mammillary bodies for olfaction (smell) These are reflex centers for smell © 2015 Pearson Education, Inc.

Diencephalon Epithalamus Houses the pineal body an endocrine gland which produces melatonin, a hormone involved in regulating sleep cycles and reproductive behaviors Includes the choroid plexus of the 3rd ventricle Capillaries within the ventricles which form CSF Regulates motor pathways and emotions © 2015 Pearson Education, Inc.

Figure 7.16a Diencephalon and brain stem structures. Cerebral hemisphere Corpus callosum Third ventricle Choroid plexus of third ventricle Occipital lobe of cerebral hemisphere Thalamus (encloses third ventricle) Anterior commissure Pineal gland (part of epithalamus) Hypothalamus Corpora quadrigemina Optic chiasma Cerebral aqueduct Midbrain Pituitary gland Cerebral peduncle Mammillary body Fourth ventricle Pons Choroid plexus Medulla oblongata Cerebellum Spinal cord (a)

Figure 7.16a Diencephalon and brain stem structures. Structures of the Brain Stem Cerebral hemisphere Corpus callosum Third ventricle Choroid plexus of third ventricle Occipital lobe of cerebral hemisphere Thalamus (encloses third ventricle) Anterior commissure Pineal gland (part of epithalamus) Hypothalamus Corpora quadrigemina Optic chiasma Cerebral aqueduct Midbrain Pituitary gland Cerebral peduncle Mammillary body Fourth ventricle Pons Choroid plexus Medulla oblongata Cerebellum Spinal cord (a)

Brain Stem Midbrain Composed mostly of tracts of nerve fibers Two bulging fiber tracts, cerebral peduncles, convey ascending and descending impulses Four rounded protrusions, corpora quadrigemina, are the visual and auditory reflex centers called “colliculi” © 2015 Pearson Education, Inc.

Brain Stem Pons The anteriorly bulging center part of the brain stem Mostly composed of fiber tracts Includes nuclei involved in the control of breathing © 2015 Pearson Education, Inc.

Brain Stem Medulla oblongata The lowest part of the brain stem Merges into the spinal cord Includes important fiber tracts from the cerebrum These tracts cross to opposite sides at this location Contains important homeostatic control centers: Heart rate control Blood pressure regulation Breathing Swallowing Vomiting © 2015 Pearson Education, Inc.

Brain Stem Reticular formation Diffuse mass of gray matter along the entire brain stem Involved in motor control of visceral (internal) organs Reticular activating system (RAS) Plays a role in awake/sleep cycles and consciousness Filter for incoming sensory information © 2015 Pearson Education, Inc.

Figure 7.16b Diencephalon and brain stem structures. Radiations to cerebral cortex Auditory impulses Visual impulses Descending motor projections to spinal cord Reticular formation Ascending general sensory tracts (touch, pain, temperature) (b)

Cerebellum Two hemispheres with convoluted surfaces Controls balance and equilibrium Provides precise timing for skeletal muscle activity and coordination of body movements Balance, posture Alcohol affects coordination via the cerebellum © 2015 Pearson Education, Inc.

Figure 7.16a Diencephalon and brain stem structures. The Cerebellum Cerebral hemisphere Corpus callosum Third ventricle Choroid plexus of third ventricle Occipital lobe of cerebral hemisphere Thalamus (encloses third ventricle) Anterior commissure Pineal gland (part of epithalamus) Hypothalamus Corpora quadrigemina Optic chiasma Cerebral aqueduct Midbrain Pituitary gland Cerebral peduncle Mammillary body Fourth ventricle Pons Choroid plexus Medulla oblongata Cerebellum Spinal cord (a) This midsagittal section shows the gray matter outlining the arbor vitae (white)