Chapter 9b The Central Nervous System 2013 Pearson Education Inc Figure 9 12 SIMPLE AND COMPLEX PATHWAYS IN THE BRAIN A simple neural reflex Behavioral state and cognition influence brain output Cognitive system voluntary Feedback CNS behavioral state system Sensory system reflex Motor system output Physiological response or behavior Sensory input Integration Output Response Brain Function Cerebral Cortex From a functional viewpoint it can be divided into three specializations Sensory areas Motor areas Sensory input translated into perception awareness Direct skeletal muscle movement Association areas Integrate information from sensory and motor areas Can direct voluntary behaviors 2013 Pearson Education Inc FUNCTIONAL AREAS OF THE CEREBRAL CORTEX The cerebral cortex contains sensory areas for perception motor areas that direct movement and association areas that integrate information FRONTAL LOBE Primary motor cortex Motor association area premolar cortex Skeletal muscle movement PARIETAL LOBE Primary somatic sensory cortex Sensory association area Figure 9 13 Coordinates information from other association areas controls some behaviors Sensory information from skin musculoskeletal system viscera and taste buds OCCIPITAL LOBE Visual association area Visual cortex Vision Prefrontal association area Taste Gustatory cortex Smell Olfactory cortex Auditory Auditory cortex association area Hearing TEMPORAL LOBE Figure 9 14 CEREBRAL LATERALIZATION The distribution of functional areas in the two cerebral hemispheres is not symmetrical LEFT HAND Prefrontal cortex Speech center Writing Auditory cortex right ear General interpretive center language and mathematical calculation Visual cortex right visual field C O R P U S C A L L O S U M LEFT HEMISPHERE RIGHT HEMISPHERE RIGHT HAND Prefrontal cortex Analysis by touch Auditory cortex left ear Spatial visualization and analysis Visual cortex left visual field FIGURE QUESTIONS 1 What would a person see if a stroke destroyed all function in the right visual cortex 2 What is the function of the corpus callosum 3 Many famous artists including Leonardo da Vinci and Michelangelo were left handed How is this related to cerebral lateralization Brain Function Sensory Information Primary somatic sensory cortex Termination point of pathways from skin musculoskeletal system and viscera Somatosensory pathways Touch Temperature Pain Itch Body position 2013 Pearson Education Inc Brain Function Sensory Information Special senses have devoted regions Visual cortex Auditory cortex Olfactory cortex Gustatory cortex Neural pathways extend from sensory areas to association areas which integrate stimuli into perception 2013 Pearson Education Inc Figure 9 15 PERCEPTION The brain has the ability to interpret sensory information to create the perception of a shapes or b three dimensional objects What shape do you see What is this object Brain Function Motor System Three major types Skeletal muscle movement Somatic motor division Neuroendocrine signals Hypothalamus and adrenal medulla Visceral responses Autonomic division Voluntary movement Primary motor cortex Motor association areas 2013 Pearson Education Inc Brain Function Behavioral State Modulator of sensory and cognitive processes Neurons collectively known as diffuse modulatory systems Originate in reticular formation in brain stem Project axons to large areas of the brain Reticular activating system controls consciousness 2013 Pearson Education Inc Figure 9 16a 1 of 4 Noradrenergic Norepinephrine Hypothalamus Locus coeruleus Thalamus Cerebellum Functions Attention arousal sleep wake cycles learning memory anxiety pain and mood Neurons originate Neurons terminate Locus coeruleus of the pons Cerebral cortex thalamus hypothalamus olfactory bulb cerebellum midbrain spinal cord Figure 9 16b 2 of 4 Serotonergic Serotonin To basal nuclei Raphe nuclei Functions 1 Lower nuclei Pain locomotion 2 Upper nuclei Sleep wake cycle mood and emotional behaviors such as aggression and depression Neurons originate Raphe nuclei along brain stem midline Neurons terminate 1 Lower nuclei project to spinal cord 2 Upper nuclei project to most of brain Figure 9 16c 3 of 4 Dopaminergic Dopamine Prefrontal cortex Ventral tegmental area Functions 1 Motor control 2 Reward centers linked to addictive behaviors To basal nuclei Substantia nigra Neurons originate 1 Substantia nigra in midbrain 2 Ventral tegmentum in midbrain Neurons terminate 1 Cortex 2 Cortex and parts of limbic system Figure 9 16d 4 of 4 Cholinergic Acetylcholine Cingulate gyrus Fornix Pontine nuclei Functions Sleep wake cycles arousal learning memory sensory information passing through thalamus Neurons originate Base of cerebrum pons and midbrain Neurons terminate Cerebrum hippocampus thalamus Figure 9 17a 1 of 2 Figure 9 17b 2 of 2 Brain Function Sleep Four stages with two major phases Slow wave sleep Adjusts body without conscious commands REM sleep Brain activity inhibits motor neurons to skeletal muscle paralyzing them Dreaming takes place Circadian rhythm Suprachiasmatic nucleus 2013 Pearson Education Inc Figure 9 18 EMOTIONS AFFECT PHYSIOLOGY The association between stress and increased susceptibility to viruses is an example of an emotionally linked immune response Sensory stimuli Cerebral cortex Integration occurs within the association areas of the cerebral cortex Integrated information Feedback creates awareness of emotions Limbic system creates emotion Hypothalamus and brain stem KEY Interneuron initiate Somatic motor responses both voluntary and unconscious Autonomic responses Endocrine responses Immune responses Brain Function Motivation Defined as internal signals that shape voluntary behaviors Some states known as drives Work with autonomic and endocrine responses Motivated behaviors stop when a person has reached a certain level of satiety 2013 Pearson Education Inc Brain Function Moods Similar to emotions but longer lasting Mood disorders Fourth leading cause of illness worldwide today Depression Sleep and appetite disturbances Alterations of mood and libido May affect function at school or work or in personal relationships Antidepressant drugs alter synaptic transmission 2013 Pearson Education Inc Brain Function Learning and Memory Learning has two broad types Associative learning Nonassociative learning Habituation and sensitization Memory has several types Short term and long term Working memory and consolidation Reflexive and declarative Stored in memory