1. 1 Chapter 2a CNS Gross Anatomy Chris Rorden University of South Carolina Norman J. Arnold School of Public Health Department of Communication Sciences and Disorders University of South Carolina

2. 2 Multiple choice What is the image plane? A.Axial. B.Coronal. C.Oblique. D.Sagittal.

3. 3 Multiple choice What is unusual about this brain? A.Too much gray matter B.Too much white matter C.Too much cerebral spinal fluid D.Too much bone

4. 4 Roles of the CNS Functions of neurons in the CNS (brain and spinal cord) include: –Sensor: Receives environmental and body stimuli –Integrator: Combines information received –Effector: Initiates body movements –Regulator: Maintains homeostatic state for body function

5. 5 Nervous System The CNS is protected and isolated. –Bone offers protection from injury Skull covers brain Vertebral Column covers spinal cord –The is encased in soft-tissue membranes –The brain’s blood vessels stop many subastances from entering the brain (blood-brain barrier) Protects from contamination/infection –The brain floats in cerebral spinal fluid Offers protection from impact

6. 6 The Meninges Dura Mater: Tough outer covering Arachnoid Mater: Middle layer Pia Mater: Inner closely formed layer Latin - English Dura – strong Arachnoid – spider Pia – tender Mater -mother

7. 7 Cerebrospinal Fluid (CSF) Located between the meninges and in the ventricular cavities of the brain Produced in the ventricular cavities by the choroid plexus Functions –mechanical buffer –fluid for metabolic functions "Copyright © 2005 by Thompson Delmar Learning, a division of Thomson Learning, Inc. ALL RIGHTS RESERVED"

8. 8 CSF CSF is in ventricles, subarchnoid space, interventricular foramens, and around the spine. Circulates from ventricles around brain and spinal column Is finally absorbed by venous system Replenishes at ventricles every 7 hours

9. 9 Divisions of the PNS Somatic Nervous System (under voluntary control) –Sensory and Motor –Skin and Muscles Autonomic Nervous System (can not be voluntarily controlled). –Sensory and Motor –Visceral organs and glands –Two main subdivisions: –Sympathetic: Fight, Flight, Fear Prepare to expend energy –Parasympathetic: Regulates normal function Prepare to conserve energy

10. 10 Major Structures of the Brain Longitudinal Fissure –Separates Two Hemispheres of the Brain –Aka ‘Interhemispheric Fissure’

11. 11 The folds of your brain are like a fingerprint – there are a few general patterns, with individual variability. Two main folds –Central Sulcus Fissure of Rolando Rolandic sulcus –Lateral sulcus Sylvian fissure The central sulcus separates the frontal and parietal lobes. The lateral sulcus separates the temporal lobe from frontal, parietal, insula

12. 12 The major cortical lobes Insular Lobe – Tucked away, but often injured in patients seen by speech pathologists

13. 13 Major medial sulci Central Sulcus Preoccipital Notch Calcarine Sulcus Parieto-occipital Sulcus

14. 14 Landmarks of the frontal lobe Frontal Pole Precentral Gyrus Precentral Sulcus Premotor Cortex Speech, Fine Motor Prefrontal Cortex

15. 15 Frontal Lobe Functions Motor Function Cognitive Functions Reasoning, Abstract Thinking, Self- Monitoring, Decision Making, Planning, Inhibition Organization of Spoken Language Frontal Motoric Areas

16. 16 Broca’s Area – speech production Pars opercularis (Inferior frontal gyrus) Pars triangularis (Inferior fronal gyrus) Pars orbitalis (Inferior frontal gyrus)

17. 17 Parietal Lobe Landmarks Post Central Gyrus (PoCG) –Primary Sensory Cortex Superior and Inferior Parietal Lobules (SPL, AnG,SmG) –Perceptual Synthesis, Spatial Orientation, Memory Angular Gyrus (AnG) Supramarginal Gyrus (SMG) – In Dominant Hemisphere: Reading, Writing and Calculation

18. 18 The homunculus (little man) The motor strip (red, frontal cortex) and primary sensory cortex (green, parietal) spatially map corresponding portions of the contralateral hemisphere.

19. 19 Temporal Lobe – Major External Gyri Superior Temporal Gyrus Middle Temporal Gyrus Inferior Temporal Gyri Temporal Pole

20. Temporal Operculum Dorsal surface of STG is called the ‘Temporal Operculum’ (Lip) –Middle section: Heschel’s Gyri (Brodmann Areas 41 + 42) Auditory Reception Cortex –Posterior section: Wernicke’s Area (Brodmann 22) Auditory Association Cortex

21. 21 Heschl’s Gyrus Primary auditory cortex found in Heschl’s gyrus This is organized tonotopically – a high pitched sound excites a different region than low pitched sounds.

22. Superior Temporal Gyrus Auditory Cortex lies inside the Superior Temporal Sulcus Part of the superior temporal gyrus that is imperative for the perception of speech is Heschl’s gyrus Heschl’s gyrus (primary AC) planum temporale (nonprimary AC) planum polare (nonprimary AC)

23. 23 Ventral-Medial Structures Temporal Lobe –Fusiform gyrys (Face Recognition) –Hippocampal Gyrus (places, memory) –Uncus (smell) Occipital lobe –Cuneus and Lingual gyrus (primary vision) Medial View

24. 24 Ventral-Medial Structures Uncus Parahippocampal Gyrus Fusiform Gyrus Lingual Gyrus Cerebellum and Brainstem removed

25. 25 Occipital Lobe Occipital Pole (medial) –Medially: cuneus and lingual gyrus: primary visual cortex –Clinically: field cuts, blindsight Lateral occipital structures: –Superior, Lateral and Superior Occipital Gyris: Secondary Visual Cortex (Association)

26. 26 Language Areas

27. Insular Lobe (Isle of Reil) Deep in Lateral Fissure –Functions: Language(?), taste, disgust, cravings (e.g. smoking)

28. 28 Midsagittal Surface Corpus Callosum –Connects Hemispheres Limbic System –Emotions Cingulate Gyrus Fornix Thalamus Hypothalamus

29. 29 Midsagittal Surface Uncus Fornix Septum Corpus Callosum Cingulate Gyrus

30. 30 Transverse Slice Fornix ThalamusPutamen Caudate Nucleus Globus Pallidus Claustrum

31. 31 Brain Stem Midbrain Pons Medulla Optic Nerve Optic Chiasm Optic Tract Pituitary Stalk Pes Pedunculi

32. 32 Basal Ganglia Caudate Nucleus Putamen Globus Pallidus (Pallidum) Caudate Nucleus +Putamen = Striatum Putamen + Globus Pallidus = Lenticular Nucleus

33. 33 Striatum Cleft for Internal Capsule Head of Caudate Nucleus Thalmus Putamen Amygdaloid Nucleus Tail of Caudate Nucleus Lateral View