Sensory input Integration Sensory receptor Motor output Brain

Central Nervous System (brain and spinal cord) Peripheral Nervous System (cranial and spinal nerves) Motor (efferent) Sensory (afferent) Sense organs Somatic (voluntary) Skeletal muscles Parasympathetic © 2018 Pearson Education, Inc. Autonomic (involuntary) Cardiac and smooth muscle, glands Sympathetic 2

Capillary Neuron Astrocyte (a) Astrocytes are the most abundant and versatile neuroglia. © 2018

Neuron Microglial cell (b) Microglial cells are phagocytes that defend CNS cells. © 2018

Fluid-filled cavity Ependymal cells Brain or spinal cord tissue (c) Ependymal cells line cerebrospinal

Myelin sheath Process of oligodendrocyte Nerve fibers (d) Oligodendrocytes have processes that form myelin

Satellite cells Cell body of neuron Schwann cells (forming myelin sheath) Nerve fiber (e) Satellite cells and Schwann cells (which form myelin) surround neurons in the PNS. © 2018 Pearson Education, Inc. 7

Dendrite Mitochondrion Cell body Nissl substance Axon hillock Neurofibrils Nucleus Nucleolus Axon Collateral branch One Schwann cell Axon terminal Node of Ranvier Schwann cells, forming the myelin sheath on axon (a) © 2018 Pearson Education, Inc. 8

Cell body Central process (axon) Sensory Spinal cord neuron (central nervous system) Ganglion Dendrites Peripheral process (axon) Afferent transmission Interneuron (association neuron) Receptors Peripheral nervous system Efferent transmission Motor neuron To effectors (muscles and glands) © 2018 Pearson Education, Inc. 9

(a) Free nerve endings (pain and temperature receptors) © 2018 Pearson Education, Inc. 10

(b) Meissner’s corpuscle (touch receptor) © 2018 Pearson Education, Inc. 11

(c) Lamellar corpuscle (deep pressure receptor) © 2018 Pearson Education, Inc. 12

(d) Golgi tendon organ (proprioceptor) © 2018 Pearson Education, Inc. 13

(e) Muscle spindle (proprioceptor) © 2018 Pearson Education, Inc. 14

Slide 2 [Na+ ] [K+] © 2018 Pearson Education, Inc. 1 Resting membrane is polarized. In the resting state, the external face of the membrane is slightly positive; its internal face is slightly negative. The chief extracellular ion is sodium (Na+), whereas the chief intracellular ion is potassium (K+). The membrane is relatively impermeable to both ions. 15

Slide 3 Na+ © 2018 Pearson Education, Inc. 2 Stimulus initiates local depolarization. A stimulus changes the permeability of a local “patch” of the membrane, and sodium ions diffuse rapidly into the cell. This changes the polarity of the membrane (the inside becomes more positive; the outside becomes more negative) at that site. 16

Slide 4 Na+ © 2018 Pearson Education, Inc. 3 Depolarization and generation of an action potential. If the stimulus is strong enough, depolarization causes membrane polarity to be completely reversed, and an action potential is initiated. 17

Slide 5 4 Propagation of the action potential. Depolarization of the first membrane patch causes permeability changes in the adjacent membrane, and the events described in step 2 are repeated. Thus, the action potential propagates rapidly along the entire length of the membrane. © 2018 Pearson Education, Inc. 18

Slide 6 K+ K+ © 2018 Pearson Education, Inc. 5 Repolarization. Potassium ions diffuse out of the cell as the membrane permeability changes again, restoring the negative charge on the inside of the membrane and the positive charge on the outside surface. Repolarization occurs in the same direction as depolarization. 19

Slide 7 Na+ – K+ pump Na+ Diffusion K+ Diffusion Cell exterior Cell interior © 2018 Pearson Education, Inc. 6 Initial ionic conditions restored. The ionic conditions of the resting state are restored later by the activity of the Plasma membrane sodium-potassium pump. Three sodium ions are ejected for every two potassium ions carried back into the cell. 20

Slide 2 Axon of transmitting neuron Receiving neuron Dendrite Axon terminal © 2018 Pearson

Slide 5 2 Vesicle Transmitting neuron fuses with 4 Neurotransplasma 3 Neurotrans- mitter binds membrane. mitter is to receptor released into on receiving synaptic cleft. neuron’s membrane. Synaptic cleft Ion channels Neurotransmitter molecules Receiving neuron © 2018 Pearson Education, Inc. 22

Slide 6 5 Ion channel opens. Neurotransmitter Receptor Na+ Receiving neuron © 2018 Pearson

Slide 7 6 Ion channel closes. Neurotransmitter is broken down and released. Na+ Receiving

Precentral gyrus Frontal lobe Central sulcus Postcentral gyrus Parietal lobe Parieto-occipital sulcus (deep) Lateral sulcus Occipital lobe Cerebral cortex (gray matter) Gyrus Sulcus Fissure (a deep sulcus) (a) © 2018 Pearson Education, Inc. Temporal lobe Cerebellum Pons Medulla oblongata Spinal cord Parietal lobe Left cerebral hemisphere Frontal lobe Occipital lobe Temporal lobe Superior Inferior (b) Brain stem Cerebellum Cerebral white matter 25

Primary motor area Premotor area Anterior association area • Working memory and judgment • Problem solving • Language comprehension Broca’s area (motor speech) Olfactory area Central sulcus Primary somatic sensory area Gustatory area (taste) Speech/language (outlined by dashes) Posterior association area Visual area Auditory area (c) © 2018 Pearson Education, Inc. 26

Posterior Motor b Toes Genitals Face Jaw Swallowing © 2018 Pearson Education, Inc. s er Fi ng se o N ce Fa s Lip h Teet s Gum Jaw Tongue Lips Tongue Sensory map in postcentral gyrus Th um b Ey e Nec Bro k w Eye Knee Foot Knee m Leg Hip Trunk Neck Head Arm Elb ow Fo r Ha earm nd Anterior Hip Trunk nd Ha s er ng Fi Th u der Shoul Arm ow Elb t s Wri Motor map in precentral gyrus Sensory Primary motor cortex (precentral gyrus) Primary somatic sensory cortex (postcentral gyrus) Pharynx Intraabdominal 27

Posterior Motor b Toes Genitals Face Jaw Swallowing © 2018 Pearson Education, Inc. s er Fi ng se o N ce Fa s Lip h Teet s Gum Jaw Tongue Lips Tongue Sensory map in postcentral gyrus Th um b Ey e Nec Bro k w Eye Knee Foot Knee m Leg Hip Trunk Neck Head Arm Elb ow Fo r Ha earm nd Anterior Hip Trunk nd Ha s er ng Fi Th u der Shoul Arm ow Elb t s Wri Motor map in precentral gyrus Sensory Primary motor cortex (precentral gyrus) Primary somatic sensory cortex (postcentral gyrus) Pharynx Intraabdominal 28

Longitudinal fissure Superior Association fibers Lateral ventricle Commissural fibers (corpus callosum) Basal nuclei Corona radiata Fornix Thalamus Internal capsule Third ventricle Pons Medulla oblongata © 2018 Pearson Education, Inc. Projection fibers 29

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 Pituitary gland Cerebral peduncle Mammillary body Pons Fourth ventricle Choroid plexus (part of epithalamus) Medulla oblongata (a) © 2018 Pearson Education, Inc. Spinal cord Midbrain Cerebellum 30

Lateral ventricle Anterior horn Septum pellucidum Inferior horn Lateral aperture Interventricular foramen Third ventricle Cerebral aqueduct Fourth ventricle Central canal (a) Anterior view © 2018 Pearson Education, Inc. 31

Lateral ventricle Anterior horn Interventricular foramen Posterior horn Third ventricle Inferior horn Cerebral aqueduct Median aperture Fourth ventricle Central canal Lateral aperture (b) Left lateral view © 2018 Pearson Education, Inc. 32

4 Superior sagittal sinus Arachnoid granulation Subarachnoid space Arachnoid mater Choroid plexuses of lateral and third ventricles Meningeal dura mater Corpus callosum Periosteal dura mater 1 Interventricular foramen Third ventricle Right lateral ventricle (deep to cut) 3 Choroid plexus of fourth ventricle Cerebral aqueduct Lateral aperture Fourth ventricle Median aperture Central canal of spinal cord 2 1 CSF is produced by the choroid plexus of each ventricle. 2 CSF flows through the ventricles and into the subarachnoid space via the median and lateral apertures. Some CSF flows through the central canal of the spinal cord. 3 CSF flows through the subarachnoid space. 4 CSF is absorbed into the dural venous sinuses via the arachnoid granulations. (c) CSF circulation © 2018 Pearson Education, Inc. 33

Axon Myelin sheath Endoneurium Perineurium Epineurium Fascicle Blood vessels © 2018 Pearson Education, Inc.

III Oculomotor IV Trochlear VI Abducens I Olfactory II Optic V Trigeminal VII Facial Vestibular branch Cochlear branch VIII Vestibulocochlear X Vagus IX Glossopharyngeal XII Hypoglossal © 2018 Pearson Education, Inc. XI Accessory 35

Cervical nerves Thoracic nerves Lumbar nerves Sacral nerves C 1 2 3 4 5 6 7 8* T 1 2 3 4 5 6 7 8 9 10 11 12 L 1 2 3 4 5 (a) S 1 2 3 4 Ventral rami form cervical plexus (C 1 – C 5) Ventral rami form brachial plexus (C 5 – C 8; T 1) No plexus formed (intercostal nerves) (T 2 – T 12) Ventral rami form lumbar plexus (L 1 – L 4) Ventral rami form sacral plexus (L 4 – L 5; S 1 – S 4) *Note that the cervical nerve C 8 emerges inferior to the C 7 vertebra, while the other seven cervical nerves emerge superior to the vertebrae for which they are named. © 2018 Pearson Education, Inc. 36

Central nervous system Peripheral nervous system Effector organs Acetylcholine Somatic nervous system Skeletal muscle Norepinephrine Acetylcholine Autonomic nervous system Sympathetic division Smooth muscle (e. g. , in stomach) Ganglion Epinephrine and norepinephrine Acetylcholine Blood vessel Adrenal medulla Glands Acetylcholine Cardiac muscle Parasympathetic division Ganglion KEY: Preganglionic axons (sympathetic) © 2018 Pearson Education, Inc. Postganglionic axons (sympathetic) Myelination Preganglionic axons (parasympathetic) Postganglionic axons (parasympathetic) 37