Chapter 14 The Brain and Cranial Nerves Lecture Outline Brain structure 1. Cerebrum Hemispheres: left & right Cerebral cortex Gyri Sulci Fissures Longitudinal fissure Corpus callosum Lobes Central sulcus Parietal lobes Frontal lobes Lateral sulcus Frontal lobes Temporal lobes Parieto-occipital sulcus Parietal lobes Occipital lobes Insula Lateral sulcus 2. Cerebrum Hemispheres: left & right Vermis Cerebellar cortex Folia Primary fissure Anterior & posterior lobes 3. Diencephalon Epithalamus Thalamus Hypothalamus 4. Brain stem Mesencephalon Pons Medulla oblongata 5. Ventricles Lateral ventricles Cerebral hemispheres Third ventricle Diencephalon Fourth ventricle Pons & cerebellum Central canal Brain protection 1. Cranial bones Occipital Frontal Sphenoid Ethmoid Parietals Temporals 2. Cranial meninges A. Dura mater Dural folds 1. Falx cerebri Longitudinal fissure 2. Tentorium cerebelli Cerebrum & cerebellum 3. Falx cerebelli Cerebellar hemispheres B. Arachnoid 1. Arachnoid membrane 2. Arachnoid trabeculae CSF C. Pia mater Astrocytes 3. Cerebrospinal fluid (CSF) Functions: -cushion -support -diffusion Choroid plexus Ependymal cells Capillaries Arachnoid granulations Hydrocephalus 4. Blood brain barrier Endothelial cells Tight junctions Astrocytes Inflammation Brain Anatomy: Functional regions Brainstem Medulla oblongata, Pons, Mesencephalon 1. Medulla oblongata Functions: -Sensory relay -Autonomic reflexes -Visceral motor White matter Ascending & descending tracts Gray matter 1. Sensory & motor nuclei Cranial nerves VIII - XII motor: pharynx, neck, back viscera sensory: inner ear 2. Autonomic nuclei A. Reticular formation 1. Cardiovascular centers A. Cardiac center B. Vasomotor center 2. Respiratory rhythmicity centers 3. Relay stations A. Nucleus gracilis & Nucleus cuneatus Amy Warenda Czura, Ph.D.1SCCC BIO130 Chapter 14 HandoutSomatic sensory to Thalamus B. Olivary nucleus Stretch and Somatic motor to Cerebellum C. Solitary nucleus Visceral sensory to Autonomic centers 2. Pons Functions: -Connection White matter Ascending tracts sensory: medulla to thalamus Descending tracts motor: cerebrum & cerebellum to nerves Gray matter 1. Relay centers to/from cerebellum 2. Sensory & motor nuclei Cranial nerves V - VII jaw, face, inner ear 3. Apneustic & pneumotaxic centers respiration 3. Midbrain / Mesencephalon Functions: -Process auditory & visual -Somatic motor reflexes -Consciousness White matter Cerebral peduncles Descending tracts voluntary somatic motor Ascending tracts sensory to thalamus Gray matter 1. Superior colliculi visual 2. Inferior colliculi auditory 3. Red nuclei & substantia nigra subconscious motor to upper limbs 4. Reticular formation Reticular Activating System (RAS) consciousness 5. Motor nuclei Cranial nerves III & IV eyes 4. Diencephalon Functions: -Integrate conscious and subconscious A. Epithalamus 1. Pineal gland Melatonin Day/Night 2. Choroid plexus CSF B. Thalamus Functions: -Relay -Filter Thalamic nuclei -relay sensory to cortex -relay motor to cortex -emotion awareness -memory -limbic system C. Hypothalamus Functions: -Autonomic functions -Pituitary hormones -Emotions Autonomic centers visceral activities Tuberal nuclei hormones to control pituitary Supraoptic nucleus Antidiuretic hormone (ADH) water retention Paraventricular nucleus Oxytocin smooth muscle Mammilary bodies feeding reflexes Preoptic areas thermostat Suprachiasmatic nuclei circadian rhythms 5. Cerebellum Functions: -Balance -Equilibrium White matter 1. Arbor vitae cortex & nuclei to peduncels 2. Superior peduncle to Midbrain, Diencephalon, Cerebrum 3. Middle peduncle to Pons 4. Inferior peduncle to Medulla and cord Gray matter: 1. Cerebellar cortex Purkinje cells 2. Cerebellar nuclei -maintain balance & equilibrium -coordination Ataxia Limbic system Cerebrum & diencephalon Amy Warenda Czura, Ph.D.2SCCC BIO130 Chapter 14 Handout1. Amygdala -fear response -link emotion with memory 2. Hippocampus -memory & learning 3. Cingulate gyrus -emotion gestures -resolve metal conflicts 6. Cerebrum Functions: -Interpret sensory info -Control voluntary motor -Intellectual & emotional processing White matter: 1. Association fibers same hemisphere 2. Commissural fibers between hemispheres 3. Projection fibers to lower brain Gray matter: 1. Basal nuclei (ganglia) -muscle tone -learned motor 2. Cerebral cortex A. Primary motor cortex precentral gyrus B. Primary somatosensory cortex postcentral gyrus C. Visual cortex occipital lobes D. Auditory cortex temporal lobes E. Olfactory cortex temporal lobes F. Gustatory cortex insula G. Association areas H. Integrative centers 1. Wernicke’s area / General interpretive