Unit 5 Lecture 3 I Memory a Functions stores info ability to recall when needed Memory traces i Chemical and structural changes that encode memory OCCURS IN CHANGES b Immediate memory temporary storage Information probably held reverberating circuits in the frontal lobe i ii Small amounts of info 7 12 bits of information iii Brief periods of time iv v Hippocampus vi Amygdala If quickly recalled it may be moves it long term memory form new memories emotional memory c Long term Memory information or sensory experiences most stable form from repeated recall of new i Memory consolidation classify info and associate new with what is already known ii Processing over large areas of cerebral cortex 1 Brain vast capacity to store and recall info II Cerebral Hemispheres a Basal Nuclei masses of gray matter i Lentiform nucleus 1 Putamen and globus pallidus ii One of two subcortical motor areas cerebellum is the other iii Receive input from entire cerebral cortex iv Input from subcortical nuclei subthalmic nucleus substantia nigra red nucleus v Project into premotor areas but no direct connection with motor pathways e g corticospinal tracks etc vi Motor Control 1 Starting stopping monitoring movements executed by the cortex a Slow sustained or stereotyped movements e g arm swinging while walking eating etc Inhibit antagonistic or unnecessary ovements 2 3 Enhances ability to perform multiple tasks 4 Impairments disturbances in muscle tone tremors abnormally slow movements b Diencephalon i Develops from posterior forebrain surrounds 3rd ventricle and consists mostly of nuclei ii Thalamus 8 of diencephalon 1 Right and left sides are connected by intermediate mass commissural fiber track 2 Major sensory relay station except smell 3 Gateway to cerebral cortex 4 Afferent neurons synapse at least once in thalamic nuclei 5 some integration occurs Impulses for similar functions relayed vis internal capsule to sensory areas 6 Other imput to cortex passes through thalamus regulating emotions and visual function from hypothalamus a Motor impulses from cerebellum and basal nuclei 7 Separate groups of nuclei each receive and project specific information to a particular cortical region a Lateral Nuclei b Ventral Nuclei receive general somatic sensory touch pressure pain and relays to sensory cortex cerebellum to motor cortex c Medial and lateral Geniculate Bodies thalamus visual and auditory relay motor relay station from BN and posterior end of i Medial Geniculate auditory relay from ear to ii Lateral Geniculate Visual relay from eye to auditory cortex occipital cortex iii Hypothalamus below thalamus sits ontop of brain stem Interconnected to cerebral cortex thalamus other brain stem 1 2 Collection of functionally different nuclei 3 Role in maintaining total body homeostasis 4 Main visceral control center 5 Functions a Control and integration of ANS b Regulation of heart rate blood pressure respiration hunger and body weight water and electrolyte balance c Body temperature regulation d Sleep regulation biological clock e Controls movements and secretions in digestive track f Controls emotional responses and behavior pleasure g pain fear rage Initials physical expressions of emotion sweating dry mouth increases heart rate h Control of endocrine system pituitary hormone iv Other diencephalon structures secretions 1 Optic tracks and optic chiasm fibers of optic tracks cross on 2 3 Mammillary bodies the way to visual cortex Infundibulum relay hormones that function with endocrine system 4 Pineal Gland connects pituitary gland to hypothalamus posterior to infundibulum Olfactory extends from rood of diencephalon secrets III Limbic System a Functional organization of structures in medial aspect of cerebral hemispheres and diencephalon encircles upper brain stem b Structures i Hippocampus mammillary bodies hypothalamus anterior nuclei of thalamus amygdaloid body and other gyri and fiber tracts c Functions of emotional behavior emotional brain i Extensive connections with higher and lower brain regions ii Allows integration and response to a variety of stimuli iii Interacts with prefrontal lobes and produces relationship between feelings and thoughts iv Explains why emotions can override thoughts reason can override responses IV Brain Stem Midbrain Pons and Medulla a Midbrain i Most superior brain stem segment ii Contains bundles of myelinated fibers that join brain stem and cord with cerebrum iii Cerebral peduncles fibers of corticospinal tracts 1 Peduncle stem like connector or stalk iv Medial Lemniscus Cuneatus proprioception touch pressure etc to thalamus carries fibers from Nucleus gracilis and Nucleus connect midbrain and cerebellum connects 3rd and 4th ventricles superior and inferior colliculi visual reflex centers coordinate head and eyes to auditory relay from hearing receptors to auditory 1 Lemniscus ribbon or band v Superior Cerebellar Peduncles vi Cerebral Aqueduct vii Doral surface two pairs of round knobs viii Corpora Quadrigemina ix Superior Colliculi follow moving object Inferior Colliculi cortex turns head towards sound reflexes for posture x xi Red nucleus communicates with BN Cerebellum cord function xii Substantia Nigra nucleus functions in regulation of movement 1 Has connections similar to Red Nucleus i Appears as rounded bulge on ventral side of brain stem 1 Large bundles of transverse fibers that transmit impulses to and from cerebellum 2 Middle cerebellar peduncles ii Dorsal pons contains longitudinal fiber tracts e g Lateral Lemniscus b Pons carries auditory info iii Ventral pons contain corticospinal tracts iv Part of reticular formation c Medulla enlarged continuation of spinal cord i Medulla Oblongata most inferior brain stem structure appears 1 Dorsal surface flattened floor of 4th ventricle at superior end of central canal of cord 2 Ventral end contains pyramids where lateral corticospinal tracts cross of decussate Inferior cerebellar peduncles connect medulla to cerebellum 3 4 Nuclei of Medulla olive relays proprioceptive information to cerebellum Nucleus Gracilis and Cuneatus a Nuclei control centers for visceral motor activities i Cardiac control center heart rate ii Vasomotor Center vasoconstriction and vasodilation of blood vessels iii Respiratory center regulates breathing also in d Reticular Formation i RAS Reticular Activating System pons 1 Nuclei scattered in medulla pons and midbrain 2 Connected to centers in hypothalamus BN cerebellum cerebrum and al major ascending and