KIN 1223 Unit 5 Lecture 3 Memory Storage of information ability to recall when needed Memory traces o Chemical and structural changes that encode memory o Occurs in stages Immediate memory o Temporary storage o Information probably held reverberating circuits frontal lobe o Small amounts of information for brief periods of time 7 12 bits telephone s o If immediate memory quickly may be moved to long term memory o Hippocampus o Amygdala forms new memories emotional memory Long term memory Most stable form o From repeated recall of new information or sensory experiences o Memory consolidation associate new information with what is already known o Processing over large areas of cerebral cortex Brain has vast capacity to store recall information Cerebral Hemispheres In Cerebrum o Basal Nuclei masses of gray matter Structures Putamen Globus Pallidus Functions One of two subcortical motor areas cerebellum is other Receive input from entire cerebral cortex Input from subcortical nuclei o Subthalmic Nucleus o Substantia Nigra o Red Nucleus BN project to premotor areas No direct connection with motor pathways e g Corticospinal tracks etc Motor control important in o Starting stopping monitoring movements executed by the cortex Slow sustained or stereotyped movements e g arm swinging while walking eating o Inhibit antagonistic or unnecessary movements o Enhances ability to perform multiple tasks o Impairment Disturbances in muscle tone Tremors Abnormally slow movements o Diencephalon Develops from posterior forebrain Surrounds 3rd ventricle Consists mostly of nuclei Major structures Thalamus o 80 of Diencephalon o Right and left sides connected by Intermediate mass a commissural fiber track o Major sensory relay station all except smell o Gateway to cerebral cortex o Afferent neurons synapse at least once in thalamic nuclei o Some integration occurs o Impulses for similar functions relayed via internal capsule to sensory areas o Other input to cortex passes through thalamus Regulating emotion visual function from hypothalamus Motor impulses from cerebellum basal nuclei o Consists of many separate groups of nuclei each receiving and projecting specific info to a particular cortical region Lateral N Ventral N Receives general somatic sensory touch pressure pain Relays to sensory cortex Motor relay station From BN and cerebellum motor cortex Medial Geniculate In posterior end of thalamus Auditory relay from ear to auditory cortex Lateral Geniculate In posterior end of thalamus Visual relay from eye to occipital cortex Hypothalamus o Below thalamus sits atop brain stem o Interconnected to Cerebral cortex Thalamus Other brain stem o Collection of functionally different nuclei o Key role in maintaining total body homeostasis o Main visceral control center o Functions Control and integration of ANS Regulation of Heart rate Blood pressure Respiration Body temperature Hunger body weight Water and electrolyte balance Sleep biological clock Controls Movements and secretions in digestive track Emotional responses and behavior pleasure pain fear rage Endocrine function produces releasing hormones which in turn control pituitary hormone secretion The emotional part of the brain located at the heart of the limbic system With ANS it initiates physical expressions of emotion sweating dry mouth increased heart rate Optic tracks and optic chiasm fibers of optic tracks cross on way to visual cortex Infundibulum Connects pituitary gland to hypothalamus Mammillary bodies Olfactory relay posterior to infundibulum Pineal Gland o Extends from roof of diencephalon o Secretes hormones functions with Endocrine system Limbic System Limbus means ring In medial aspect of cerebral hemispheres and diencephalon Encircles upper brain stem Structures o Hippocampus o Mammillary bodies o Hypothalamus o Anterior Nuclei of Thalamus o Amygdaloid body o Other gyri and fiber tracts Functions in emotional aspects of behavior o Called the emotional brain o Extensive connections with higher lower brain regions o Allows integration response to a variety of stimuli o Interacts with prefrontal lobes o Produces relationship between feelings and thoughts o Explains why emotions can override thoughts o Reason can override reponses Brain Stem o Midbrain Most superior brain stem segment Contains bundles of myelinated fibers joining brain stem and cord with cerebrum Cerebrum peduncles Fibers of Corticospinal tracts Peduncle stem like connector or stalk Superior Cerebellar Peduncles Connect midbrain and cerebellum Medial Lemniscus Lemniscus ribbon or band touch pressure etc to thalamus Cerebral Aqueduct Connects 3rd and 4th ventricles Dorsal surface with two pairs of rounded knobs Corpora Quadrigemina o Superior Colliculi Carries fibers from N Gracilis and N Cuneatus proprioception Visual reflex centers Coordinate head and eyes to follow moving object o Inferior Colliculi Auditory relay From hearing receptors to auditory cortex Turns head toward sound Red Nucleus Communicates with BN Cerebellum Cord Functions reflexes for posture Substantia Nigra Nucleus functions in regulation of movement Has connections similar to Red Nucleus o Pons Appears as rounded bulge on ventral side of brain stem Large bundles of transverse fibers Transmits impulses to and from cerebellum Middle cerebellar peduncles Dorsal pons contains longitudinal fiber tracts e g Lateral Lemniscus carries auditory info Ventral pons contains Corticospinal tracts Part of the Reticular formation o Medulla Oblongata Most inferior brain stem structure Appears as enlarged continuation of spinal cord Dorsal surface flattened floor of 4th ventricle at superior end of central canal of cord Ventral surface contains pyramids where lateral Corticospinal tracts cross over Decussate Inferior cerebellar peduncles connect medulla to cerebellum Nuclei of Medulla Olive Relays proprioceptive information to cerebellum N Gracilis and N Cuneatus control centers for visceral motor activities o Cardiac Control Center heart rate o Vasomotor Center vasoconstriction and vasodilation of blood vessels o Respiratory Center regulates breathing also in Pons Reticular Formation RAS Reticular Activating System o Nuclei scattered in medulla pons and midbrain o Connected to centers in hypothalamus BN cerebellum cerebrum and all major ascending and descending tracts o Responds to sensory input by signaling cerebral cortex activates cortex to wake up o Without this arousal cortex unaware of stimulation o Can t