Chapter 14 Brain and Cranial Nerves Meninges connective tissue membranes Protect provide structural framework Dura mater folds inward to separate major parts of the brain periosteal layer meningeal layer continues into spinal cord Arachnoid mater transparent Subarachnoid space below Pia mater Cerebral Hemispheres External structures Gyri thick folds Precentral Postcentral Sulci shallow grooves Central lateral Fissures very deep grooves Longitudinal b w right and left hemispheres Transverse b w cerebrum and cerebellum Lobes frontal parietal temporal occipital insula Internal structures Gray matter neurosomas dendrites synapses Forms cortex and basal nuclei nuclei masses of cerebral gray matter buried deep in white matter Basal nuclei involved in motor control Associated with extrapyramidal tracts White matter tracts bundles of axons Lateralization Left spoken written language science math analytical reasoning Right imagination insight artistic skill Emotions Areas Motor control Frontal lobes premotor cortex motor association area patterned motor skills Where we plan our behavior Precentral gyrus primary motor cortex Its neurons send signals for muscle contractions Somatotopically mapped Forms pyramidal tracts Frontal lobe left Broca s area motor speech Generates motor program for the muscles that produce speech Sensation Postcentral gyrus primary somatosensory cortex awareness of stimulation sensory Parietal lobe somatosensory association area integration and analysis of sensory input from skin and muscles input Parietal lobe primary gustatory cortex Temporal lobe auditory cortex and association area olfactory cortex Wernike s area understanding of language Association areas Prefrontal cortex intelligence personality higher thought process Parietal association cortex with Wernike s perceiving stimuli Temporal association cortex identifying recognizing stimuli Cerebral White Matter Projection tracts extend vertucally b w higher and lower brain and spinal cord centers Carry information b w the cerebrun amd the rest of the body Commissural tracts cross from one hemisphere to the other through commissures bridges mostly in the large corpus callosum Communication b w hemispheres Association tracts connect different regions within the same hemisphere Link perceptual and memory centers etc Cranial nerves Name Innervation Olfactory Optic Oculomotor Trochlear Trigeminal Olfactory mucosa in nasal cavity olfactory bulb Smell Retina thalamus and midbrain Vision Midbrain intrinsic and some extrinsic eye muscles Midbrain superior oblique muscle of the eye Eye movements Face pons Abducens Inferior pons lateral rectus muscle of the eye Lateral eye movement Facial Sensory taste buds of tongue thalamus Motor pons muscles and glands of face 1 2 3 4 5 6 7 8 9 Vestibulocochlear Inner ear medulla pons Glossopharyngeal Sensory pharynx ear tongue medulla oblongata Motor medulla oblongata glands muscles of tongue 10 Vagus Sensory thoracic and abdominopelvic viscera Tongue throat ear medulla oblongata Motor Medulla oblongata tongue throat viscera 11 Accessory Spinal cord S1 S6 palate pharynx trapezius sternocleidomastoid muscles 12 Hypoglossal Medulla oblongta muscles if tongue Function Eye movements opening of the eyelid pupillary constriction Touch temperature pain sensation of face S Taste M Facial expressions Secretion of tears saliva mucus Hearing Equilibrium S Taste touch pain t from tongue and ear M Salivation swallowing gagging S Taste hunger fullness discomfort M Swallowing speech motility Swallowing Head neck and shoulder movements Tongue speech swallowing Diencephalon Thalamus Collection of nuclei forms lateral wall of the third ventricle Hypothalamus Collection of nuclei from optic chiasm to mamillary bodies Pituitary gland is connected to it by infindibulum Nearly all input has to pass through thalamus on the way to cereblum olfaction can bypass Processes and sorts the information Major control center of edocrine and autonomic nervous systems Plays essential role in homeostatic regulation Epithalamus Composed mainly of pineal glans Biological rhythms roof of the third ventricle and habenula choroid plexus Cerebral aqueduct Cerebral peduncles Corpora quadrigemina superior inferior culliculi Red nucleus Relay station for descending motor tracts Visual and auditory reflex centers Fine motor control Brainstem Midbrain Pons Anterior wall of 4th ventricle Medulla oblongata Pyramids Decussation of pyramids Connects the cerebellum to the pons and midbrain to cortex according to lab manual Centers for subconscious function cardiac vasomotor respiratory All nerve fibers connecting spinal cord to the brain pass through Cerebellum Hemispheres cerebellar peduncles arbor vitae white matter Function coordination of muscle function motor coordination Functional brain systems Limbic system Ring of structures on the medial side of cerebral hemisphere encircling corpus callosum and thalamus Hippocampus amygdala hypothalamus Important center of emotion and learning Reticular formation A loosely organised web of gray matter that runs vertically through all levels of brainstem Connected to diencephalon and cortex Maintains state of lertness in the cortex Tother with cerebellum coordinates muscle movement