Brain and Cranial Nerves

1. Brain and Cranial Nerves

2. Dura Mater tough outermost covering creates sinuses and ligaments Arachnoid closely associated with the dura subarachnoid space contains the CSF and cerebral vasculature arachnoid villi, transfers CSF from subarachnoid space to venous vasculature Pia Mater delicate tissue over brain attached by astrocytes blood vessels lie on top of it

5. Spaces within the brain filled with CSF 2 lateral ventricles 3rd ventricle 4th ventricle

6. CSF is created in the ventricles in structures called choroid plexi lateral ventricles connected through the interventricular foramina the third and fourth ventricles are connected through the cerebral aqueduct CSF gets into the subarachnoid space through the median and lateral apertures remember that CSF gets back into the blood through the arachnoid villi

7. Area of brain devoted to higher level functions gray matter (outside) neural cell bodies, dendrites, unmyelinated axons, support cells white matter (inside) tracts of information corpus callosum internal capsule nuclei islands of grey matter

8. Divided into right and left hemispheres Hemispheres divided into lobes: Frontal Lobe Parietal Lobe Temporal Lobe Occipital Lobe

9. Fissures: deep grooves in the cerebrum longitudinal fissure between hemispheres transverse fissure between cerebrum and cerebellum

10. Sulci: shallow depressions in gray matter Central Sulcus divides frontal and parietal lobes Lateral Sulcus divides the temporal from the parietal lobes Gyri: ridges in gray matter to increase surface area precentral gyrus primary motor cortex postcentral gyrus somatosensory area

11. Functions of the lobes Frontal Lobe motor, speech (l. lobe), personality Parietal Lobe sensation (except smell, language Temporal Lobe hearing, smell, language Occipital Lobe vision

12. Diencephalon Thalamaus Hypothalamus Epithalamus

13. Thalamus bulges into the 3rd ventricle paired, oval areas of grey matter and white matter tracts acts as a relay station for sensory input

14. Hypothalamus nuclei major regulation mamillary bodies process olfactory sensations pituitary hormonal regulation attached via the infundibulum

15. Functions of Hypothalamus controls somatic motor activities at the subconscious level controls autonomic function coordinates activities of the nervous and endocrine systems secretes hormones produces emotional and behavioral drive coordinates voluntary and autonomic functions regulates body temperature coordinates circadian cycles of activity

16. Epithalamus pineal gland

17. Basal Ganglia control motor movements that don’t require much thought: arm swinging, muscle tone, smiling. sets muscle tone defects in dopamine regulation in these structures results in Parkinson’s disease

18. Corpus Callosum area where axons cross over Caudate Nucleus Putamen Globus Pallidus Thalamus tail of caudate nucleus corpus callosum

19. fine tunes and coordinates motor movements people with cerebellar deficiencies have problems with balance and position Cerebellar Hemispheres Vermix

20. Arbor Vitae tracts of white matter in the cerebellum

21. Mesencephalon (midbrain) Pons Medulla Oblongata

22. Lies inferior to thalamus Corpora Quadrigemina superior colliculi reflexes for vision such as tracking and pupillary reflexes inferior colliculi auditory pathways to the thalamus responsible for startle reflex CV III and IV arise from midbrain Midbrain also acts as motor relay and does some processing of motor information Cerebral peduncles motor pathways on anterior side of midbrain

24. Pons “bridge” one of the first relay areas for motor information contains apneustic and pneumotaxic areas modify activity of medullar respiritory areas CN V, VI, VII and VIII

25. Medulla pyramids decussation of pyramids olivary nuclei cardiovascular center, rhythmicity area, embarrassing bodily functions area: vomiting, coughing, sneezing CN VIII-XII