1. Cranial Fossa: Brain and Spinal Cord PA 544 Tony Serino, Ph.D. Clinical Anatomy

2. Central Nervous System (CNS) Gray vs. White matter Protection of CNS –Meninges –CSF flow Brain –Development –Selected structures Spinal cord –Selected structures

3. Cranial Fossa Anterior Middle Posterior

4. CNS (Central Nervous System) Brian and spinal cord Displays gray and white matter –Gray matter are areas of CNS with many cell bodies of neurons present (little myelinated nerve fibers) –White matter are area of CNS with few cell bodies but many myelinated nerve fibers Protected by bone and membranes

5. Gray and White Matter Since the cerebrum and cerebellum outgrow their cores, gray matter ends up on outside of both structures.

6. Meninges Dura Mater –outermost; tough, fibrous CT –In brain, divided into two layers (periosteal and meningeal) –In spine, only one layer with fat filled space above the layer called the epidural space Arachnoid –middle; web-like appearance –Potential space between Dura and arachnoid is the subdural space Pia Mater –innermost, delicate membrane fused with CNS surface –Space between Pia and Arachnoid is the subarachnoid space

7. Meninges of the Spinal Cord Pia mater Arachnoid Dura mater Meninges Centrum Epidural space Subdural space Subarachnoid space Dorsal Root Ganglion

8. Brain Meninges

9. Extensions of Dura Mater hold brain in cavity Sellar diaphragm (not shown)

10. Venous Sinuses of Cranium Superior Sagittal Inf. Sagittal Straight Cavernous Sigmoid Transverse

11. Lateral Venous Lacunae Arachnoid villi

12. Maxillary A. Middle Meningeal A. Middle Meningeal Artery

13. Brain Ventricles

14. Choroid Plexus

15. CSF (cerebral-spinal fluid) Flow

16. Hydrocephalus Blockage of CSF flow can lead to severe brain and/or head enlargement. In an adult, such swelling would be fatal.

17. Brain Development Structures Functional Areas

18. Neural Tube forming

19. Neural Tube

20. Brain Vesicles

21. Flexures and Cerebral Cortex Growth

22. Major Divisions of Brain Brain Stem = midbrain + pons + medulla

23. Brain Anatomy (req’d)

24. Projections vs. Commissures

25. Functional Areas of Cerebrum

26. Primary Motor and Somatosensory Gyri

27. Basal Nuclei: cerebral nuclei Putamen and Globus Pallidus Subthalamic nuclei and the Substantia nigra are usually included

28. Reticular Formation Extends along length of brain stem; used in maintaining alertness while awake; also includes motor nuclei such as centers for Cardiac, Respiratory and Vasomotor control.

29. RAS receives inputs from eye, ear and general sensation to maintain alertness

30. Limbic System: functional system; responsible for emotion and memory Cingulate Gyrus Fornix Mammillary body

31. Hypothalamus Control of Pituitary

32. Posterior Pituitary

33. Anterior Pituitary

34. Pineal Gland Plays a major role in circadian rhythm control through its sympathetic connection to the hypothalamus Melatonin increases at night and decreases during daylight Implicated in the control of major life changes (such as the onset of puberty and adulthood

35. Internal Carotid Artery

36. Blood Supply (Circle of Willis) Vertebral A. Internal Carotid A. Ant. Communicating Post. Communicating Ant. Cerebral Post. Cerebral Middle Cerebral Basilar A.