NERVOUS SYSTEM

Central nervous system (CNS) Peripheral nervous system (PNS) Figure 49.4 Central nervous system (CNS) Peripheral nervous system (PNS) Brain Cranial nerves Spinal cord Ganglia outside CNS Spinal nerves Figure 49.4 The vertebrate nervous system.

Peripheral nervous system (PNS) Central nervous system (CNS) Figure 48.3 Sensory input Integration Sensor Motor output Figure 48.3 Summary of information processing. Effector Peripheral nervous system (PNS) Central nervous system (CNS) 3

Basic Neuron Structure

Dendrites Stimulus Axon hillock Nucleus Cell body Presynaptic cell Figure 48.4 Dendrites Stimulus Axon hillock Nucleus Cell body Presynaptic cell Axon Signal direction Synapse Synaptic terminals Figure 48.4 Neuron structure and organization. Synaptic terminals Postsynaptic cell Neurotransmitter 7

Depolarized region (node of Ranvier) Figure 48.14 Schwann cell Depolarized region (node of Ranvier) Cell body Myelin sheath Axon Figure 48.14 Saltatory conduction. 10

Presynaptic cell Synaptic cleft Figure 48.15 Presynaptic cell Postsynaptic cell Axon Synaptic vesicle containing neurotransmitter 1 Postsynaptic membrane Synaptic cleft Presynaptic membrane 3 Figure 48.15 A chemical synapse. K Ca2 2 Voltage-gated Ca2 channel Ligand-gated ion channels 4 Na 12

Table 48.2 Table 48.2 Major Neurotransmitters 13

Table 48.1 Table 48.1 Ion Concentrations Inside and Outside of Mammalian Neurons 14

Sodium- potassium pump Figure 48.7 Key Na K Sodium- potassium pump OUTSIDE OF CELL Potassium channel Sodium channel Figure 48.7 The basis of the membrane potential. INSIDE OF CELL 15

Membrane potential (mV) Figure 48.11-1 Key Na K 50 Membrane potential (mV) Threshold 50 1 Resting potential 100 Figure 48.11 The role of voltage-gated ion channels in the generation of an action potential. Time OUTSIDE OF CELL Sodium channel Potassium channel INSIDE OF CELL Inactivation loop 1 Resting state 16

Membrane potential (mV) Figure 48.11-2 Key Na K 50 Membrane potential (mV) Threshold 2 50 1 2 Depolarization Resting potential 100 Figure 48.11 The role of voltage-gated ion channels in the generation of an action potential. Time OUTSIDE OF CELL Sodium channel Potassium channel INSIDE OF CELL Inactivation loop 1 Resting state 17

Rising phase of the action potential Membrane potential (mV) Figure 48.11-3 Key Na K 3 Rising phase of the action potential 50 Action potential 3 Membrane potential (mV) Threshold 2 50 1 2 Depolarization Resting potential 100 Figure 48.11 The role of voltage-gated ion channels in the generation of an action potential. Time OUTSIDE OF CELL Sodium channel Potassium channel INSIDE OF CELL Inactivation loop 1 Resting state 18

Falling phase of the action potential 3 Figure 48.11-4 Key Na K 4 Falling phase of the action potential 3 Rising phase of the action potential 50 Action potential 3 Membrane potential (mV) Threshold 4 2 50 1 2 Depolarization Resting potential 100 Figure 48.11 The role of voltage-gated ion channels in the generation of an action potential. Time OUTSIDE OF CELL Sodium channel Potassium channel INSIDE OF CELL Inactivation loop 1 Resting state 19

Falling phase of the action potential 3 Figure 48.11-5 Key Na K 4 Falling phase of the action potential 3 Rising phase of the action potential 50 Action potential 3 Membrane potential (mV) Threshold 4 2 50 1 1 5 2 Depolarization Resting potential 100 Figure 48.11 The role of voltage-gated ion channels in the generation of an action potential. Time OUTSIDE OF CELL Sodium channel Potassium channel INSIDE OF CELL Inactivation loop 1 Resting state 5 Undershoot 20

Membrane potential (mV) Figure 48.11a 50 Action potential 3 Membrane potential (mV) 2 4 Threshold 50 1 Figure 48.11 The role of voltage-gated ion channels in the generation of an action potential. 1 5 Resting potential 100 Time 21

Axon Plasma membrane Action potential 1 Cytosol Action potential 2 Figure 48.12-3 Axon Plasma membrane Action potential 1 Cytosol Na Action potential K 2 Na Figure 48.12 Conduction of an action potential. K Action potential K 3 Na K 22

Figure 49.9a Figure 49.9 Exploring: The Organization of the Human Brain

Diencephalon Thalamus Pineal gland Brainstem Hypothalamus Midbrain Figure 49.9d Diencephalon Thalamus Pineal gland Brainstem Hypothalamus Midbrain Pituitary gland Pons Figure 49.9 Exploring: The Organization of the Human Brain Medulla oblongata Spinal cord

Left cerebral hemisphere Right cerebral hemisphere Figure 49.9c Left cerebral hemisphere Right cerebral hemisphere Cerebral cortex Corpus callosum Cerebrum Basal nuclei Figure 49.9 Exploring: The Organization of the Human Brain Cerebellum Adult brain viewed from the rear

Motor cortex (control of skeletal muscles) Figure 49.15 Motor cortex (control of skeletal muscles) Somatosensory cortex (sense of touch) Frontal lobe Parietal lobe Prefrontal cortex (decision making, planning) Sensory association cortex (integration of sensory information) Visual association cortex (combining images and object recognition) Broca’s area (forming speech) Figure 49.15 The human cerebral cortex. Temporal lobe Occipital lobe Auditory cortex (hearing) Visual cortex (processing visual stimuli and pattern recognition) Cerebellum Wernicke’s area (comprehending language)

Central Nervous System (information processing) Figure 49.7 Central Nervous System (information processing) Peripheral Nervous System Afferent neurons Efferent neurons Autonomic nervous system Motor system Sensory receptors Control of skeletal muscle Figure 49.7 Functional hierarchy of the vertebrate peripheral nervous system. Internal and external stimuli Sympathetic division Parasympathetic division Enteric division Control of smooth muscles, cardiac muscles, glands

Parasympathetic division Sympathetic division Figure 49.8 Parasympathetic division Sympathetic division Action on target organs: Action on target organs: Constricts pupil of eye Dilates pupil of eye Inhibits salivary gland secretion Stimulates salivary gland secretion Sympathetic ganglia Constricts bronchi in lungs Relaxes bronchi in lungs Cervical Slows heart Accelerates heart Stimulates activity of stomach and intestines Inhibits activity of stomach and intestines Thoracic Stimulates activity of pancreas Inhibits activity of pancreas Stimulates gallbladder Stimulates glucose release from liver; inhibits gallbladder Figure 49.8 The parasympathetic and sympathetic divisions of the autonomic nervous system. Lumbar Stimulates adrenal medulla Promotes emptying of bladder Inhibits emptying of bladder Promotes erection of genitalia Sacral Promotes ejaculation and vaginal contractions Synapse