Nervous System Chapter 49
Organization correlates w/ lifestyle – Sessile molluscs w/ simple – Complex molluscs w/ complex Nerve net is connected nerve cells – Cnidarians to regulate gastrovascular cavity Nerves are bundles of nerve cells – Echinoderms w/ branched nerve nets – Bilateral animals w/ cephalization – Platyhelminthes w/ CNS – Arthropods and annelids w/ ganglia – Vertebrates w/ CNS and PNS Comparative Nervous Systems
Vertebrate Nervous Systems Nervous System Central Nervous System (CNS) BrainSpinal Cord Peripheral Nervous System (PNS) Motor (efferent) Autonomic (involuntary) SympatheticParasympathetic Somatic (voluntary) Sensory (afferent)
Cerebral Hemispheres Demonstrate lateralization – Left: math, speech, concrete processing, logic – Right: creativity, facial and pattern recognition Contralateral control Corpus callosum communicates 4 lobes dler/split.html
Cerebral Lobes Frontal – Reasoning, planning, personality, problem solving – Process emotional and painful info – Voluntary mov’t – Learned planned activities Parietal (2) – Sensory information – Integrating sensory and motor Temporal (2) – Auditory senses and memory – Broca’s and Wernicke’s area (left) Occipital – Visual information
Other Brain Anatomy Olfactory bulb Brainstem – Hindbrain Basic life processes – Respiration – Heart rate – Emesis Cerebellum – Coordination and balance – Proprioceptive input – Midbrain React to visual and auditory stimuli Optic lobes in non-mammal vertebrates – Reticular formation
Relative brain size – Animals – Male/female Cerebral cortex – Cortical folding – Mammals increase association areas Complex behavior and learning Cerebellum – Cat/dog Olfactory bulb Limbic system w/avoidance Comparative Brain Anatomy
Arousal and Sleep Reticular formation – Sensory filter for info into cerebral cortex More info = more alert Selective attention – LSD, sleep, alcohol inhibits Pineal gland w/ melanin – From 5-HT from tryptophan – Peak at night – Signal sleep stimulate areas Essential for survival Dolphins 1 hemisphere at a time