Midbrain (mesencephalon)

Cerebellum Subconscious skeletal muscle mvmt

Equilibrium and balance

Functions Evaluate how cerebrum initiated movements are being executed Coordinates skeletal muscle contractions Posture & balance Cognition and language processing See table 14.2

Diencephalon Surrounds third ventricle

Thalamus Internal medullary lamina = Y-shaped (white matter) Divides lobes of gray matter Thalamus

Hypothalamus Composed of a dozen nuclei REGULATES: ANS activities Production and release of hormones (oxytocin & ADH) Emotional and behavioral patterns (with limbic system) Feeding center, satiety center, thirst center Body temperature Circadian rhythms Hypothalamus

Epithalamus

Cerebrum Read, write, memory, imagine, emotions, math, music etc. Gray matter / white matter

Cerebrum The Seat of Intelligence Longitudinal fissure Corpus callosum 5 lobes Cerebrum The Seat of Intelligence

Brain Lobes Folded deep within lateral sulcus Believed to play a role in emotion, consciousness and regulating homeostasis

Corpus Callosum Callosal commissure Tough body Broad band of nerve fibers Hemispheric communication Largest white matter area

Cerebrum Functional Areas Sensory, Motor, Association

Cerebral Cortex

Brain Folds of Cerebral Cortex Gyri – convolutions Sulci – shallow grooves Fissures – deeper grooves Longitudinal fissure (most prominent)  separates the cerebral hemispheres. Falx cerebri  in the longitudinal fissure

Cerebral White Matter Connections between parts of brain and to rest of NS Myelinated axons – 3 directions

Cerebral White Matter 3 types of fibers: Association – gyri in same hemisphere Commissural (3 groups) – corresponding gyri between hemispheres Projection

Cerebral White Matter Commissural Fibers Corpus Callosum – largest Anterior Commissure Posterior Commissure

Projection fibers: Internal Capsule  thick band of white matter containing ascending and descending tracts Runs through basal nuclei

Basal Ganglia or Basal Nuclei NOTE  no longer called ganglia b/c that is a group of cell bodies in the PNS. 3 large nuclei deep within white matter Globus pallidus Putamen Caudate nucleus

Basal Nuclei (Ganglia) Globus pallidus + putamen = lentiform nucleus Lentiform nucleus + caudate nucleus = corpus striatum

Initiate and terminate body movements FUNCTIONS: Initiate and terminate body movements Suppress unwanted movements Regulate muscle tone Sensory, limbic, cognitive and linguistic functions GABA Gamma-Amino Butyric acid

Limbic System Emotional Life, Memory, Motivation, Epinephrine (adrenaline) flow CURRENT structures include: Hippocampus – spatial memory and learning Amygdala – Cognitive, emotional and social processes Mammillary bodies of hypothalamus – limbic circuits Olfactory bulbs Fornix Stria terminalis Stria medullaris Medial forebrain bundle Mammillothalamis tract Linked by bundles of interconnected myelinated axons

Limbic System