13 HUMAN ANATOMY fifth edition MARIEB MALLATT WILHELM

13 HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM Power. Point® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham PART 1 The Central Nervous System Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Central Nervous System § Central nervous system § § The brain and spinal cord Directional terms unique to the CNS § Rostral – toward the nose § Caudal – toward the tail Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Spinal Cord § Functions of the spinal cord § Spinal nerves attach to it § Provides two-way conduction pathway § Major center for reflexes § Location of the spinal cord § Runs through the vertebral canal § Extends from the foramen magnum to the level of the vertebra L 1 or L 2 Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Spinal Cord § Conus medullaris § Filum terminale § Cervical and lumbar enlargements § Cauda equina § The inferior end of the spinal cord § Long filament of connective tissue § Attaches to the coccyx inferiorly § Where nerves for upper and lower limbs arise § Collection of spinal nerve roots Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Spinal Cord Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Spinal Cord § Spinal cord segments § Indicate the region of the spinal cord from which spinal nerves emerge § Designated by the spinal nerve that issues from it § T 1 is the region where the first thoracic nerve emerges Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Spinal Cord Segments Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Spinal Cord § Two deep grooves run the length of the cord §

White Matter of the Spinal Cord § White matter § Outer region of the spinal cord § Composed of myelinated and unmyelinated axons § Allow communication between spinal cord and brain § Fibers classified by type § Ascending fibers § Descending fibers § Commisural fibers Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Gray Matter of the Spinal Cord and Spinal Roots § Shaped like the letter “H” § Gray commissure – contains the central canal § Dorsal horns § Consist of interneurons § Ventral and lateral horns § Contain cell bodies of motor neurons Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Anatomy of the Spinal Cord Copyright © 2008 Pearson Education, Inc. , publishing as

Organization of the Gray Matter of the Spinal Cord § Gray matter § Divided according to somatic and visceral regions § SS – somatic sensory § VS – visceral sensory § VM – visceral motor § SM – somatic motor Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Gray Matter of the Spinal Cord and Spinal Roots Copyright © 2008 Pearson Education,

Protection of the Spinal Cord § Protected by vertebrae, meninges, and CSF § Meninges § Dura mater – a single layer surrounding spinal cord § Arachnoid mater – lies deep to the dura mater § Pia mater – innermost layer § Delicate layer of connective tissue § Extends to the coccyx § Denticulate ligaments – lateral extensions of pia mater Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Cerebrospinal Fluid § § § Fills the hollow cavities of the brain and spinal cord Provides a liquid cushion for the spinal cord and brain Other functions § Nourishes brain and spinal cord § Removes wastes § Carries chemical signals between parts of the CNS Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Diagram of Lumbar Puncture Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin

13 HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM Power. Point® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham PART 2 The Central Nervous System Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Brain § Performs the most complex neural functions § Intelligence § Consciousness § Memory § Sensory-motor integration § Involved in innervation of the head Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Embryonic Development of the Brain § § Brain arises from rostral part of the neural tube Three primary brain vesicles in four-week old embryo § Prosencephalon – the forebrain § Mesencephalon – the midbrain § Rhombencephalon – the hindbrain Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Embryonic Development of the Brain § Secondary brain vesicles § Prosencephalon § Divides into telencephalon and diencephalon § Mesencephalon – remains undivided § Rhombencephalon § Divides into metencephalon and myelencephalon Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Embryonic Development of the Brain § Structures of the adult brain § Develop from secondary brain vesicles § Telencephalon the cerebral hemispheres § Diencephalon thalamus, hypothalamus, and epithalamus § Metencephalon pons and cerebellum § Myelencephalon medulla oblongata Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Embryonic Development of the Brain § Brain stem includes § The midbrain, pons, and medulla oblongata § Ventricles § Central cavity of the neural tube enlarges Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Embryonic Development of the Brain Copyright © 2008 Pearson Education, Inc. , publishing as

Embryonic Development of the Brain § Brain grows rapidly, and changes occur in the relative position of its parts § Cerebral hemispheres envelop the diencephalon and midbrain § Wrinkling of the cerebral hemispheres § More neurons fit within limited space Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Brain Development from Week 5 to Birth Copyright © 2008 Pearson Education, Inc. ,

Basic Parts and Organization of the Brain § Divided into four regions § Cerebral hemispheres § Diencephalon § Brain stem § Midbrain, pons, and medulla § Cerebellum Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Basic Parts and Organization of the Brain Copyright © 2008 Pearson Education, Inc. ,

Basic Parts and Organization of the Brain § Organization § Centrally located gray matter § Externally located white matter § Additional layer of gray matter external to white matter § Due to groups of neurons migrating externally § Cortex – outer layer of gray matter § Formed from neuronal cell bodies § Located in cerebrum and cerebellum Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Ventricles of the Brain § § § Expansions of the brain’s central cavity Filled with cerebrospinal fluid Lined with ependymal cells Continuous with each other Continuous with the central canal of the spinal cord Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Ventricles of the Brain § Lateral ventricles – located in cerebral hemispheres § Horseshoe-shaped from bending of the cerebral hemispheres § Third ventricle – lies in diencephalon § Connected with lateral ventricles by interventricular foramen Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Ventricles of the Brain § § Cerebral aqueduct – connects 3 rd and 4 th ventricles Fourth ventricle – lies in hindbrain § Connects to the central canal of the spinal cord Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Ventricles of the Brain Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin

The Brain Stem § Includes the § Midbrain § Pons § Medulla oblongata Copyright

The Brain Stem § Several general functions § Produces automatic behaviors necessary for survival § Passageway for all fiber tracts running between the cerebrum and spinal cord § Heavily involved with the innervation of the face and head § 10 of the 12 pairs of cranial nerves attach to it § Which CN do NOT attach to brain stem? Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Ventral View of the Brain Copyright © 2008 Pearson Education, Inc. , publishing as

The Brain Stem – The Medulla Oblongata § Most caudal level of the brain stem § Is continuous with the spinal cord § Choroid plexus lies in the roof of the fourth ventricle § External landmarks of medulla § Pyramids of the medulla § Lie on its ventral surface § Decussation of the pyramids § Crossing over of motor tracts Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Brain Stem – The Medulla Oblongata § External landmarks of medulla (continued) § Inferior cerebellar peduncles § Fiber tracts connecting medulla and cerebellum § Olive (olive of the medulla) § Contains inferior olivary nucleus Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Brain Stem – The Medulla Oblongata § Cranial nerves VIII–XII attach to the medulla § VIII – Vestibulocochlear § IX – Glossopharyngeal nerve § X – Vagus nerve § XI – Accessory § (Spinal Accessory – a branch of the vagus nerve) § XII – Hypoglossal nerve Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Brain Stem – Medulla Oblongata Copyright © 2008 Pearson Education, Inc. , publishing

The Brain Stem – The Medulla Oblongata § The core of the medulla contains § Much of the reticular formation § Nuclei influence autonomic functions § Visceral centers of the reticular formation include § Cardiac center § Vasomotor center § The medullary respiratory center § Centers for hiccupping, sneezing, swallowing, and coughing Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Brain Stem – The Medulla Oblongata Copyright © 2008 Pearson Education, Inc. ,

The Brain Stem – The Pons § § A “bridge” between the midbrain and medulla oblongata Pons contains the nuclei of cranial nerves § V – Trigeminal nerve § VI – Abducens nerve § VII – Facial nerve Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Brain Stem – The Pons § The pons contains § Motor tracts coming from the cerebral cortex § Pontine nuclei § Connect portions of the cerebral cortex and cerebellum § Send axons to cerebellum through the middle cerebellar peduncles Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Brain Stem – The Pons Copyright © 2008 Pearson Education, Inc. , publishing

The Brain Stem – The Midbrain § § Lies between the diencephalon and the pons Cerebral aqueduct § The central cavity of the midbrain § Cerebral peduncles located on the ventral surface of the brain § Contain pyramidal (corticospinal) tracts § Superior cerebellar peduncles § Connect midbrain to the cerebellum Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Brain Stem and Diencephalon Copyright © 2008 Pearson Education, Inc. , publishing as

The Brain Stem – The Midbrain § Periaqueductal gray matter surrounds the cerebral aqueduct § Involved in two related functions § Fright-and-flight § reaction Mediates response to visceral pain Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 13. 21

The Brain Stem – The Midbrain § Corpora quadrigemina (quad-ri-gemina) § The largest nuclei § Divided into the superior and inferior colliculi § Superior colliculi – nuclei that act in visual reflexes § Inferior colliculi – nuclei that act in reflexive response to sound Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Brain Stem – Dorsal View Copyright © 2008 Pearson Education, Inc. , publishing

The Brain Stem – The Midbrain § Imbedded in the white matter of the midbrain § Two pigmented nuclei § Substantia nigra – neuronal cell bodies contain melanin § Functionally linked to the basal nuclei § Red nucleus – lies deep to the substantia nigra § Largest nucleus of the reticular formation Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Cerebellum § Located dorsal to the pons and medulla § Smoothes and coordinates body movements § Helps maintain equilibrium Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Cerebellum § § Consists of two cerebellar hemispheres Surface folded into ridges called folia § Separated by fissures § Hemispheres each subdivided into § Anterior lobe § Posterior lobe § Flocculonodular lobe (tiny) Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Cerebellum Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings Figure

The Cerebellum § Composed of three regions § Cortex – gray matter § Arbor vitae § Internal white matter § Deep cerebellar nuclei – deeply situated gray matter Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Cerebellum § Cerebellum receives information from the cerebral cortex § On equilibrium § On current movements of § Limbs, neck, and trunk Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Cerebellum – Cerebellar Peduncles § Thick tracts connecting the cerebellum to the brain stem are § Superior cerebellar peduncles § Middle cerebellar peduncles § Inferior cerebellar peduncles § Fibers to and from the cerebellum are ipsilateral § Run to and from the same side of the body Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

13 HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM Power. Point® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham PART 3 The Central Nervous System Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Diencephalon § § § Forms the center core of the forebrain Surrounded by the cerebral hemispheres Composed of three paired structures § Thalamus § Hypothalamus § Epithalamus § § Border the third ventricle Primarily composed of gray matter Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Diencephalon and Brainstem Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin

The Diencephalon – The Thalamus § § Makes up 80% of the diencephalon Contains approximately a dozen major nuclei § Act as relay stations for incoming sensory message § Every part of brain communicating with cerbral cortex relays signals through thalamic nuclei! § § Send axons to regions of the cerebral cortex See figure 13. 18 b for nuclei Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Diencephalon – The Thalamus § Afferent impulses converge on the thalamus § Synapse in at least one of its nuclei § § Is the “gateway” to the cerebral cortex Nuclei organize and amplify or tone down signals Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Diencephalon Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings Figure

Relationship of Thalamus to Cerebrum Copyright © 2008 Pearson Education, Inc. , publishing as

The Thalamus (note nuclei) Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin

The Diencephalon – The Hypothalamus § § Lies between the optic chiasm and the mammillary bodies Pituitary gland projects inferiorly Contains approximately a dozen nuclei Main visceral control center of the body § The master gland’s master!! Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Diencephalon – The Hypothalamus § Functions include the following § Control of the ANS § Control of emotional responses § Regulation of body temperature § Regulation of hunger and thirst sensations § Control of behavior § Regulation of sleep-wake cycles § Control of the endocrine system § Formation of memory Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Nuclei of the Hypothalamus Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin

The Diencephalon – The Epithalamus § § § Forms part of the “roof” (top) of the third ventricle Consists of a tiny group of nuclei Includes the pineal gland (pineal body) § Secretes the hormone melatonin § Under influence of the hypothalamus § Aids in control of circadian rhythm Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Cerebral Hemispheres § Account for 83% of brain mass § Fissures – deep grooves, which separate major regions of the brain § Transverse fissure – separates cerebrum and cerebellum § Longitudinal fissure – separates cerebral hemispheres Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Cerebral Hemispheres § Sulci § Grooves on the surface of the cerebral hemispheres § Gyri § Twisted ridges between sulci § Prominent gyri and sulci are similar in all people Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Cerebral Hemispheres § § § Deeper sulci divide cerebrum into lobes Lobes are named for the skull bones overlying them Central sulcus separates frontal and parietal lobes § Bordered by two gyri § Precentral gyrus § Postcentral gyrus Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Cerebral Hemispheres Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Cerebral Hemispheres § Parieto-occipital sulcus § Separates the occipital from the parietal lobe § Lateral sulcus § Separates temporal lobe from parietal and frontal lobes § Insula – deep within the lateral sulcus Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Cerebral Hemispheres § Frontal section through forebrain § Cerebral cortex § Cerebral white matter § Deep gray matter of the cerebrum (basal ganglia) Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Cerebral Cortex § § Home of our conscious mind Enables us to § Be aware of ourselves and our sensations § Initiate and control voluntary movements § Communicate, remember, and understand Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Cerebral Cortex § Composed of gray matter § Neuronal cell bodies, dendrites, and short axons § § § Folds in cortex – triples its size Approximately 40% of brain’s mass Brodmann areas § 52 structurally distinct areas Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Cerebral Cortex § Functional regions § Traditionally – studied brain-injured people and animals § New discoveries – PET and f. MRI § Regions of the cerebral cortex § Perform distinct motor and sensory functions § Memory and language spread over wide area Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Functional and Structural Areas of the Cerebral Cortex Copyright © 2008 Pearson Education, Inc.

13 HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM Power. Point® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham PART 4 The Central Nervous System Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Cerebral Cortex § Three general kinds of functional areas § Sensory areas § Association areas § Motor areas PLAY Rotatable Brain Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Cerebral Cortex § Each of the major senses § Has a specific brain region called a primary sensory cortex § Has an association area to process information § These are multimodal association areas Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory Areas § Cortical areas involved in conscious awareness of sensation § Located in § Parietal lobes § Temporal lobes § Occipital lobes § PLAY Distinct regions of each lobe interpret each of the major senses Rotatable Sectioned Brain Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory Areas – Primary Somatosensory Cortex § § § Located along the postcentral gyrus Involved with conscious awareness of general somatic senses Spatial discrimination § Precisely locates a stimulus § Certain regions are more adept at distinguishing precise stimili Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory Areas – Primary Somatosensory Cortex § Projection is contralateral § Cerebral hemispheres § Receive sensory input from the opposite side of the body § Sensory homunculus § A body map of the sensory cortex Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory Areas – Primary Somatosensory Cortex Copyright © 2008 Pearson Education, Inc. , publishing

Sensory Areas – Somatosensory Association Cortex § § Lies posterior to the primary somatosensory cortex Integrates different sensory inputs § Touch § Pressure § Draws upon stored memories of past sensory experiences § You are able to recognize keys or coins in your pocket without looking at them Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory Areas – Visual Areas § Primary visual cortex § Location is deep within the calcarine sulcus § On medial part of the occipital lobe § Largest of all sensory areas § Receives visual information that originates on the retina § Exhibits contralateral function § First of a series of areas processing visual input Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory Areas – Visual Areas § Visual association area § Surrounds the primary visual area § Continues the processing of visual information § Analyzes color, form, and movement § Complex visual processing extends into § Temporal and parietal lobes Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory Areas – Visual Areas § Visual association area § Approximately 30 cortical areas have been identified § Visual information proceeds in two streams Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory Areas – Visual Areas § Ventral stream § Passes information into inferior part of the temporal lobe § Responsible for recognizing objects, words, and faces § Dorsal stream § Extends to the post-central gyrus § Perceives information about spatial relationships § Ventral and dorsal streams § The “what” and “where” pathways for vision Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Ventral and Dorsal Streams Copyright © 2008 Pearson Education, Inc. , publishing as

Sensory Areas – Auditory Areas § Primary auditory cortex § Function § Conscious awareness of sound § Sound waves excite receptors in the inner ear § Impulses transmitted to primary auditory cortex § Location § Superior edge of the temporal lobe Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory Areas – Auditory Areas § Auditory association area § Lies posterior to the primary auditory cortex § Permits evaluation of different sounds § Lies in the center of Wernicke’s area § Involved in recognizing and understanding speech Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory Areas – Vestibular Cortex § Responsible for § Conscious awareness of sense of balance § Located in the posterior part of the insula § Deep to the lateral sulcus Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory Areas – Gustatory Cortex § Function § Involved in the conscious awareness of taste stimuli § Location § On the “roof” of the lateral sulcus Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory Areas – Olfactory Cortex § Lies on the medial aspect of the cerebrum § Located in a the piriform lobe § Olfactory nerves transmit impulses to the olfactory cortex § Provides conscious awareness of smells Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory Areas – Olfactory Cortex § § Part of the rhinencephalon – “nose brain” Includes § The piriform lobe, olfactory tracts, and olfactory bulbs § Connects the brain to the limbic system § Explains why smells trigger emotions § Involved with consciously identifying and recalling specific smells Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Visceral Sensory Areas § Location § Within the lateral sulcus § On the insula lobe § Receives general sensory input § Pain § Pressure § Hunger Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Multimodal Association Areas § Large areas of the cerebral cortex § Receive sensory input from § Multiple sensory modalities § Sensory association areas § Make associations between kinds of sensory information Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Multimodal Association Areas § Three multimodal association areas § Posterior association area § Anterior association area § Limbic association area Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Posterior Association Area § Located at interface of visual, auditory, and somatosensory association areas § Integrates sensory information into unified perception § Allows awareness of spatial location of body § “Body sense” § Related to language comprehension and speech Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Posterior Association Area § Multiple language areas in left cerebral cortex § Wernicke’s area functions in § Speech comprehension § Coordination of auditory and visual aspects of language § Initiation of word artiucltion § Recognition of sound sequences Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Posterior Association Area § Areas in right cerebral hemisphere act in § Creative interpretation of words § Emotional overtones of speech Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Anterior Association Area § A large region of the frontal lobe § The prefrontal cortex § § Receives information from posterior association area Integrates information with past experience Initiates and plans motor movements Has links to the limbic system Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Anterior Association Areas § More complex functions include all aspects of § Thinking, perceiving, intentionally remembering § Processing abstract ideas, reasoning, judgment § Impulse control, mental flexibility, social skills § Humor, empathy, conscience Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Anterior Association Area § Functional neuroimaging techniques § Reveal functions of specific parts of the prefrontal cortex § Anterior pole of frontal cortex § Active in solving the most complex problems § More complex problems, emotions, cognition at anterior part of frontal lobe. Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Anterior Association Area § Additional functions § Stores information for less than 30 seconds § Three working memory areas § Visual working memory § Auditory working memory § Executive area Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Limbic Association Areas § Located on medial side of frontal lobe § Involved with memory and emotions § Integrates sensory and motor behaviors § Aids in the formation of memory § Processes emotions Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Motor Areas – Premotor Cortex § § § Located anterior to the precentral gyrus Controls more complex movements Receives processed sensory information § Visual, auditory, and general somatic sensory § § Controls voluntary actions dependent on sensory feedback Involved in the planning of movements Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Motor Areas – Primary Motor Cortex § Controls motor functions § Primary motor cortex (somatic motor area) § Located in precentral gyrus (Brodmann area 4) § Pyramidal cells § Large neurons of primary motor cortex Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Motor Areas – Primary Motor Cortex § Corticospinal tracts descend through brainstem and spinal cord § Axons signal motor neurons to control skilled movements § Contralateral § Pyramidal axons cross over to opposite side of the brain Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Motor Areas § Specific pyramidal cells control specific areas of the body § Face and hand muscles are controlled by many pyramidal cells § Motor homunculus § Somatotopy § Body map of the motor cortex § Body is represented spatially in many parts of the CNS Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Motor Areas Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings Figure

Motor Areas – Frontal Eye Field § Lies anterior to the premotor cortex § In Brodmann area 8 § Controls voluntary movement of the eyes § Especially when moving eyes to follow a moving target Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Motor Areas – Broca’s Area § Located in left cerebral hemisphere § Manages speech production § Connected to language comprehension areas in posterior association area § A corresponding region in the right cerebral hemisphere § Controls emotional overtones to spoken words Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Lateralization of Cortical Functioning § The two hemispheres control opposite sides of the body § Contralateral = opposite side § Hemispheres are specialized for different cognitive functions Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Lateralization of Cortical Functioning § Left cerebral hemisphere – control over § Language abilities, math, and logic § Right cerebral hemisphere – involved with § Visual-spatial skills § Reading facial expressions § Intuition, emotion, artistic, and musical skills Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

13 HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM Power. Point® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham PART 5 The Central Nervous System Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Cerebral White Matter § Different areas of the cerebral cortex § Communicate with each other § Communicate with the brainstem and spinal cord § Fibers communicating are § Usually myelinated and bundled into tracts Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Cerebral White Matter § Types of tracts § Commissures – composed of commissural fibers § Allows communication between cerebral hemispheres § Corpus callosum – the largest commissure § Association fibers § Connect different parts of the same hemisphere § Parts of Wernike’s and Broca’s areas are connected by association fibers Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Cerebral White Matter Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Cerebral White Matter § Types of tracts (continued) § Projection fibers – run vertically § Descend from the cerebral cortex § Ascend to the cortex from lower regions § Corticospinal tracts begin with pyramidal cells Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Projection Tracts § Internal capsule – projection fibers form a compact bundle § Passes between the thalamus and basal nuclei § Corona radiata – superior to the internal capsule § Fibers run to and from the cerebral cortex Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Projection Tracts Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings Figure

13 HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM Power. Point® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham PART 6 The Central Nervous System Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Deep Gray Matter of the Cerebrum § Consists of § Basal ganglia § Involved in motor control § Basal forebrain nuclei § Associated with memory § Claustrum § A nucleus of unknown function § Amygdala § Located in cerebrum but is considered part of the limbic system Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Basal Ganglia § § A group of nuclei deep within the cerebral white matter Formed from § Caudate nucleus – arches over thalamus § Putamen § Globus pallidus Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Basal Ganglia § Complex neural calculators § Cooperate with the cerebral cortex in controlling movement § § Receive input from many cortical areas Substantia nigra also influences basal ganglia Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Basal Ganglia Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings Figure

Basal Ganglia § Corpus striatum – combination of the lentiform and caudate nuclei Copyright

Basal Ganglia § Evidence shows that they § Start, stop, and regulate intensity of voluntary movements § In some way estimate the passage of time Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Basal Forebrain Nuclei § Structures composing basal forebrain nuclei § Septum § Diagonal band of Broca § Horizontal band of Broca § Basal nucleus of Meynert Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Basal Forebrain Nuclei § Part of cholinergic system § Location § Functions related to § That is, they synthesize and release acetylcholine § Anterior and dorsal to hypothalamus § Arousal § Learning § Memory § Motor control Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Structures and Functions of the Cerebrum Copyright © 2008 Pearson Education, Inc. , publishing

13 HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM Power. Point® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham PART 7 The Central Nervous System Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Functional Brain Systems § Networks of neurons functioning together § Limbic system § Spread widely in the forebrain § The reticular formation § Spans the brain stem Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Functional Brain Systems – The Limbic System § Location § Composed of § § Medial aspect of cerebral hemispheres § Also within the diencephalon § Septal nuclei, cingulate gyrus, and hippocampal formation § Part of the amygdala The fornix and other tracts link the limbic system together Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Functional Brain Systems – The Limbic System § The “emotional brain” § Cingulate gyrus § Allows us to shift between thoughts § Interprets pain as unpleasant § Hippocampal formation § Hippocampus and the parahippocampal gyrus Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Functional Brain Systems – The Reticular Formation § § Runs through the central core of the medulla, pons, and midbrain Forms three columns § Midline raphe nuclei § Medial nuclear group § Lateral nuclear group Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Functional Brain Systems – The Reticular Formation § Widespread connections § Ideal for arousal of the brain as a whole § Reticular activating system (RAS) § Maintains consciousness and alertness § Functions in sleep and arousal from sleep § Malfunctions in those with narcolepsy Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Functional Brain Systems – The Reticular Formation Copyright © 2008 Pearson Education, Inc. ,

Protection of the Brain § The brain is protected from injury by § The skull § Meninges § Cerebrospinal fluid § Blood-brain barrier Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Protection of the Brain – Meninges § Functions of meninges § Cover and protect the CNS § Enclose and protect the vessels that supply the CNS § Contain the cerebrospinal fluid § Between pia and arachnoid maters Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Dura Mater § § Strongest of the meninges Composed of two layers § Periosteal layer § Meningeal layer § Two layers are fused except to enclose the dural sinuses Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Dura Mater Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Dura Mater § § Largest sinus – the superior sagittal sinus Dura mater extends inward to subdivide the cranial cavity Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings Figure 13. 31

The Arachnoid Mater § § Located beneath the dura mater Arachnoid villi § Project through the dura mater § Allow CSF to pass into the dural blood sinuses Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

The Pia Mater § § Delicate connective tissue Clings tightly to the surface of the brain § Follows all convolutions of the cortex Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

13 HUMAN ANATOMY fifth edition MARIEB | MALLATT | WILHELM Power. Point® Lecture Slides prepared by Leslie Hendon, University of Alabama, Birmingham PART 8 The Central Nervous System Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Protection of the Brain – Cerebrospinal Fluid (CSF) § Formed in choroid plexuses in the brain ventricles § Choroid plexus is § Located in all four ventricles § Composed of ependymal cells and capillaries § Arises from blood § 500 ml/day Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Protection of the Brain – Cerebrospinal Fluid (CSF) Copyright © 2008 Pearson Education, Inc.

Protection of the Brain – Blood-Brain Barrier § Prevents most blood-borne toxins from entering the brain § Impermeable capillaries § Not an absolute barrier § Nutrients such as oxygen pass through § Allows alcohol, nicotine, and anesthetics through Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Sensory and Motor Pathways in the CNS § § Multineuron pathways connect brain and body periphery Pathways are composed of tracts § Ascending pathways – carry information to more rostral areas of the CNS § Descending pathways – carry information to more caudal regions of the CNS Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Major Fiber Tracts in White Matter of the Spinal Cord Copyright © 2008 Pearson

Ascending Pathways § § Conduct general somatic sensory impulses Chains of neurons composed of § First-, second-, and third-order neurons § Four main ascending pathways § Dorsal column pathway § Spinothalamic pathway § Posterior spinocerebellar pathway § Anterior spinocerebellar pathway Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Ascending Pathways Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings Figure

Descending Pathways § Most motor pathways § Decussate at some point along their course § Consist of a chain of two or three neurons § Exhibit somatotopy § Tracts arranged according to the body region they supply § All pathways are paired § One of each on each side of the body Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Descending Pathways § § Deliver motor instructions from the brain to the spinal cord Divided into two groups § Pyramidal (corticospinal) tracts § Other motor pathways § Tectospinal tracts § Vestibulospinal tract § Rubrospinal tract § Reticulospinal tract Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Descending Pathways Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings Figure

Disorders of the Central Nervous System § Spinal cord damage § Paralysis – loss of motor function § Parasthesia – loss of sensation § Paraplegia – injury to the spinal cord is between T 1 and L 2 § Paralysis of the lower limbs § Quadriplegia – injury to the spinal cord in the cervical region § Paralysis of all four limbs Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Disorders of the Central Nervous System § Brain dysfunction § Degenerative brain diseases § Cerebrovascular accident (stroke) § Blockage or interruption of blood flow to a brain region § Alzheimer’s disease § Progressive degenerative disease leading to dementias Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Disorders of the Central Nervous System § Congenital malformations § Hydrocephalus § Neural tube defects § Anencephaly – cerebrum and cerebellum are absent § Spina bifida – absence of vertebral lamina § Cerebral palsy – voluntary muscles are poorly controlled § Results from damage to the motor cortex Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings

Postnatal Changes in the Brain § Brain structures complete development at different times § Critical periods in learning § Language § Some development occurs into early 20 s § Decline with age attributed to changes § In neural circuitry § Amount of neurotransmitters being released Copyright © 2008 Pearson Education, Inc. , publishing as Benjamin Cummings