Module 08 The Brain Lower Level Brain Structures

Module 08 The Brain

Lower - Level Brain Structures l brainstem: l l l oldest, most basic part of brain medulla – controls life-support functions like breathing & the cardiovascular system reticular formation – nerve network that controls wakefulness and arousal l thalamus – brain’s sensory switchboard l cerebellum – controls balance, muscle coordination, memories for using body

Lower-Level Brain Structures cerebellum

The Limbic System l hypothalamus – helps regulate hunger, thirst, body temp. “flight or fight reaction, linked to emotion (aggression, pleasure, stress reactions, and mating) l hippocampus – helps process new memories l amygdala – linked to emotions like fear & anger

The Limbic System

The Cerebral Cortex l longitudinal fissure – divides brain into hemispheres l corpus callosum – connects brain hemispheres & carries messages between l lobes: l frontal – judgment & planning, organizing, voluntary movement, language processing l parietal – association areas, math reasoning, processing touch information (sensation) l occipital – vision l temporal – auditory & language processing (hearing & speaking)

Longitudinal Fissure & Corpus Callosum

Lobes of the Cerebral Cortex

Cerebral Cortex

Cerebral Cortex

Cerebral Cortex

Cerebral Cortex

Motor Cortex l controls voluntary movement (back strip of the frontal lobes) l different parts of the motor cortex control different parts of the body l cross-wired pattern (ex. left cortex controls right side of body) l parts requiring more intricate movement have more brain tissue than larger parts of body

Somatosensory Cortex l registers and processes body senses (front strip of the parietal lobes) l gives more brain tissue to parts of body that are more sensitive to touch (fingertips) than those that are less sensitive (arms)

Brain Diagrams Label & color each of the following brain structures. Diagram 1 Frontal Lobe Parietal Lobe Occipital Lobe Temporal Lobe Somatosensory Cortex Motor Cortex Cerebellum Diagram 2 Thalamus Medulla Corpus Callosum Cerebellum Frontal Lobe Parietal Lobe Occipital Lobe Refer to pages 144 -146

Hemispheric Differences

Hemispheric Differences l two hemispheres but they work as a single entity l both sides continually communicate via the corpus callosum

Hemispheric Differences

Left Hemisphere l language functions (for most people) l two important language regions: l Broca’s Area (frontal lobe) l responsible for muscle movements of speech l Damage (strokes): can form ideas but not express them l Wernicke’s Area (temporal lobe) l responsible for language comprehension and expression; our ability to understand what is said to us

Damage to Broca’s Area This is the brain of “Tan” from whom Broca discovered the area for speech. Note the damage to Broca’s Area.

PET Scan of Broca’s & Wernicke’s Areas

Right Hemisphere l spatial abilities - perceive or organize things in a given space, judge distance l helps in making connections between words l Example: What word goes with painting, ring, and nail?

Brain Plasticity

Plasticity l ability of the brain tissue to take on new functions l greatest in childhood l important if parts of the brain are damaged or destroyed

The Split Brain l read pages 150 – 151 (explain this photo)