* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Title of Presentation
Embodied language processing wikipedia , lookup
Functional magnetic resonance imaging wikipedia , lookup
Donald O. Hebb wikipedia , lookup
Neuroscience and intelligence wikipedia , lookup
Activity-dependent plasticity wikipedia , lookup
Environmental enrichment wikipedia , lookup
Neuroeconomics wikipedia , lookup
Clinical neurochemistry wikipedia , lookup
Neuroinformatics wikipedia , lookup
Neurophilosophy wikipedia , lookup
Dual consciousness wikipedia , lookup
Lateralization of brain function wikipedia , lookup
Limbic system wikipedia , lookup
Blood–brain barrier wikipedia , lookup
Emotional lateralization wikipedia , lookup
Neuroesthetics wikipedia , lookup
Neurolinguistics wikipedia , lookup
Intracranial pressure wikipedia , lookup
Time perception wikipedia , lookup
Selfish brain theory wikipedia , lookup
Neuropsychopharmacology wikipedia , lookup
Cognitive neuroscience wikipedia , lookup
Cognitive neuroscience of music wikipedia , lookup
Brain morphometry wikipedia , lookup
Brain Rules wikipedia , lookup
Circumventricular organs wikipedia , lookup
Haemodynamic response wikipedia , lookup
Neuroplasticity wikipedia , lookup
Neural correlates of consciousness wikipedia , lookup
Neuropsychology wikipedia , lookup
History of neuroimaging wikipedia , lookup
Human brain wikipedia , lookup
Metastability in the brain wikipedia , lookup
Aging brain wikipedia , lookup
Sports-related traumatic brain injury wikipedia , lookup
Neuroanatomy wikipedia , lookup
Anatomy & Physiology I Chapter 10 Cerebrum Cerebral hemispheres Diencephalon Thalamus Hypothalamus Brain stem Midbrain Pons Medulla oblongata Cerebellum Corpus callosum Thalamus Hypothalamus Midbrain Pons Medulla oblongata Cerebellum Cerebral cortex – outer layer of gray matter Gyri – elevated ridges Sulci – shallow grooves Fissures – deep grooves Five Lobes Frontal Parietal Temporal Occipital Insula (within the hemisphere) External surface of the brain, superior view. The division into two hemispher es and into lobes is visible. Surface markings Central sulcus Separates the frontal lobe and the parietal lobe Longitudinal fissure Separates the two hemispheres Lateral sulcus Separates the temporal lobe from the frontal and parietal Transverse cerebral fissure Separates the cerebrum and the cerebellum Precentral gyrus Immediately anterior to the central sulcus Postcentral gyrus Immediately posterior to the central sulcus Precentral gyrus Frontal lobe Central sulcus Postcentral gyrus Parietal lobe Lateral sulcus Occipital lobe Temporal lobe Transverse cerebral fissure Cerebellum Fissure Gyrus Cortex (gray matter) Sulcus White matter Frontal lobe Central sulcus Gyri of insula Temporal lobe (pulled down) Figure 12.6b Anterior Longitudinal fissure Frontal lobe Cerebral veins and arteries covered by arachnoid mater Parietal lobe Right cerebral hemisphere Occipital lobe Left cerebral hemisphere Posterior Figure 12.6c three connective tissue membranes that envelop the brain and spinal cord lies between the nervous tissue and bone protect the brain and provide structural framework for its arteries and veins Dura mater – outer layer Dural sinuses - collect blood circulating through brain Arachnoid mater – middle layer Pia mater – innermost layer (adheres to brain) Skull Dura mater Subdural space Subarachnoid space Arachnoid mater Pia mater Cerebrum: Gray matter White matter Terminology: What’s The Meaning? • Epidural • Subdural • Subarachnoid inflammation of the meninges serious disease of infancy & childhood; especially between 3 months and 2 years of age caused by bacterial and virus invasion of the CNS by way of the nose and throat bacterial meningitis can cause swelling the brain, enlarging the ventricles, and hemorrhage signs include high fever, stiff neck, drowsiness, and intense headache and may progress to coma – death within hours of onset diagnosed by examining the CSF for bacteria lumbar puncture (spinal tap) draws fluid from subarachnoid space between two lumbar vertebrae 14-14 Clear fluid found in and around the brain and spinal cord Formed by choroid plexus in ventricles Absorbed into bloodstream by arachnoid villi CSF provides these functions: Buoyancy Protection Chemical stability buoyancy allows brain to attain considerable size without being impaired by its own weight if it rested heavily on floor of cranium, the pressure would kill the nervous tissue protection protects the brain from striking the cranium when the head is jolted shaken child syndrome and concussions do occur from severe jolting chemical stability flow of CSF rinses away metabolic wastes from nervous tissue 14-16 Path of CSF through ventricles: Lateral ventricles Interventricular foramen 3rd ventricle Cerebral aqueduct 4th ventricle CSF then continues through the central canal (spinal cord) and outside the brain and spinal cord About 500ml of CSF is produced and drained from the CNS daily What happens if production and drainage are not balanced? Arachnoid villus 8 Superior sagittal sinus Arachnoid mater 1 CSF is secreted by choroid plexus in each lateral ventricle. 2 CSF flows through Interventricular foramina into third ventricle. 3 Choroid plexus in third ventricle adds more CSF. 4 CSF flows down cerebral aqueduct to fourth ventricle. Subarachnoid space Dura mater 1 2 Choroid plexus Third ventricle 3 7 4 5 Choroid plexus in fourth ventricle adds more CSF. 6 CSF flows out two lateral apertures and one median aperture. 7 CSF fills subarachnoid space and bathes external surfaces of brain and spinal cord. 8 At arachnoid villi, CSF is reabsorbed into venous blood of dural venous sinuses. Cerebral aqueduct Lateralaper ture Fourth ventricle 6 5 Median aperture 7 Centralcanal of spinal cord Subarachnoid space of spinal cord Frontal lobe Motor area Speech centers Parietal lobe Sensory area Estimation of distances, sizes, shapes Temporal lobe Auditory area Olfactory area Occipital lobe Visual receiving area Visual association area ZOOMING IN • What cortical area is posterior to the central sulcus? What area is anterior to the central sulcus? Auditory areas Auditory receiving Auditory association Speech comprehension (Wernicke area) Motor areas Motor speech (Broca area) Written speech center Visual areas Visual language images receiving Short-term memory Information retain for few seconds to minutes; lost unless reinforced Long-term memory Transfer of short term memory to long term memory requires rehearsal (repetition) Information stored for later recall Requires mental alertness Procedural Memory Motor (physical) memory of movements Tying shoes, typing, playing instruments, sports Thalamus Sorts sensory impulses Directs impulses within cerebral cortex Hypothalamus Maintains homeostasis Controls sympathetic and parasympathetic divisions of autonomic nervous system Influences heartbeat, blood flow, hormone secretion Regions of the diencephalon. The figure shows the relationship among the thalamus, hypothalamus, and pituitary gland (hypophysis). ZOOMING IN • To what part of the brain is the pituitary gland attached? Networks of neurons that work together and span wide areas of the brain Limbic system – Emotional Brain Includes the amygdala, cingulate gyrus and hippocampus Reticular formation – Consciousness Mass of gray matter extending through the entire brainstem Thalamic Nuclei Corpus callosum •Hypothalamus •Cingulate gyrus •Amygdala •Hippocampus Olfactory bulb Includes centers for both gratification and aversion gratification – sensations of pleasure or reward aversion – sensations of fear or sorrow Emotional or affective brain Amygdala—recognizes angry or fearful facial expressions, assesses danger, and elicits the fear response Cingulate gyrus—plays a role in expressing emotions via gestures, and resolves mental conflict Hippocampus – plays a significant role in learning and memory formation Puts emotional responses to odors Example: skunks smell bad Hippocampus and amygdala—play a role in memory plays central role in states of consciousness, such as alertness and sleep Consciousness is a state of wakefulness Very sensitive to the effects of certain drugs and alcohol Combination of tranquilizers and alcohol can damage the reticular formation, causing permanent unconsciousness Consciousness depends on the reticular activating system (RAS) Reticular Formation Visual impulses Radiations to cerebral cortex Auditory impulses Reticular formation Ascending general sensory tracts (touch, pain, temperature) Descending motor projections to spinal cord RAS (reticular activating system) Sends impulses to the cerebral cortex to keep it conscious and alert Filters out repetitive and weak stimuli (~99% of all stimuli!) Severe injury results in permanent unconsciousness (coma) Nuclei that control cranial nerves III and IV Superior part of brain stem Reflexes involving eyes and ears substantia nigra dark gray to black nucleus pigmented with melanin motor center that relays inhibitory signals to thalamus & basal nuclei preventing unwanted body movement degeneration of neurons leads to tremors of Parkinson disease Forms part of the anterior wall of the fourth ventricle Fibers of the pons Connect higher brain centers and the spinal cord Relay impulses between the motor cortex and the cerebellum Origin of cranial nerves V, VI, VII and VIII Nuclei that help maintain normal rhythm of breathing reticular formation in pons contains additional nuclei concerned with: sleep, respiration, and posture cardiac center adjusts rate and force of heart vasomotor center adjusts blood vessel diameter respiratory centers control rate and depth of breathing reflex centers for coughing, sneezing, gagging, swallowing, vomiting, salivation, sweating Location of cranial nerves - IX, X, XI, XII Three parts Vermis Left hemisphere Right hemisphere Functions Help coordinate voluntary muscles Help maintain balance Help maintain muscle tone (A) Posterior view showing the two hemispheres. (B) Midsagittal section showing the distribution of gray and white matter. The three parts of the brain stem (midbrain, pons, and medulla oblongata) are also labeled. Cerebellum receives impulses from the cerebral cortex of the intent to initiate voluntary muscle contraction Signals from proprioceptors and visual and equilibrium pathways continuously “inform” the cerebellum of the body’s position and momentum Cerebellar cortex calculates the best way to smoothly coordinate a muscle contraction A “blueprint” of coordinated movement is sent to the cerebral motor cortex and to brain stem nuclei Record electric currents given off by brain nerve cells Study sleep patterns Diagnose disease Locate tumors Study drug effects Determine brain death Scalp electrodes are used to record brain wave activity (EEG). Alpha waves (8–13 Hz)—regular and rhythmic, lowamplitude, synchronous waves indicating an “idling” brain Beta waves (14–30 Hz)—rhythmic, less regular waves occurring when mentally alert Theta waves (4–7 Hz)—more irregular; common in children and uncommon in adults Delta waves (4 Hz or less)—high-amplitude waves seen in deep sleep and when reticular activating system is damped, or during anesthesia; may indicate brain damage 1-second interval Alpha waves—awake but relaxed Beta waves—awake, alert Theta waves—common in children Delta waves—deep sleep (b) Brain waves shown in EEGs fall into four general classes. Figure 12.20b Change with age, sensory stimuli, brain disease, and the chemical state of the body EEGs used to diagnose and localize brain lesions, tumors, infarcts, infections, abscesses, and epileptic lesions A flat EEG (no electrical activity) is clinical evidence of death Hydrocephalus Abnormal CSF accumulation within brain Causes Congenital malformation Tumor Inflammation Hemorrhage Encephalitis Inflammation of the brain Viral causes Toxic substances causes Viral vaccine causes Stroke (Cerebrovascular Accident; CVA) Most common brain disorder sudden death of brain tissue caused by ischemia atherosclerosis, thrombosis, ruptured aneurysm effects range from unnoticeable to fatal blindness, paralysis, loss of sensation, loss of speech common recovery depends on surrounding neurons, collateral circulation Tumors Gliomas – tumor arising from glial cells Neuroma – tumor arising from nerves Meningioma – tumors arising from meninges Cerebral palsy (CP) Group of neuromuscular disorders that result from injury to an infant before, during or shortly after delivery. All forms cause impairment of skeletal muscle activity Mental retardation and speech difficulty may accompany CP Epilepsy Disorder in which neurons of the brain fire suddenly and unpredictably May be caused by brain tumors, toxins, trauma, or fever. Grand mal seizure - motor areas fire repeatedly causing convulsive seizures and loss of consciousness Petit mal seizure - sensory areas affected; not accompanied by convulsions or prolonged unconsciousness brain is only 2% of the adult body weight, and receives 15% of the blood 750 mL/min neurons have a high demand for ATP, and therefore, oxygen and glucose, so a constant supply of blood is critical to the nervous system 10 second interruption of blood flow may cause loss of consciousness 1 – 2 minute interruption can cause significant impairment of neural function 4 minutes with out blood causes irreversible brain damage 14-45 Injury Head trauma can lead to injury within skull Epidural hematoma Subdural hematoma Intracerebral hematoma Cerebral concussion the brain must communicate with the rest of the body most of the input and output travels by way of the spinal cord 12 pairs of cranial nerves arise from the base of the brain exit the cranium through foramina lead to muscles and sense organs located mainly in the head and neck 14-47 some cranial nerves are classified as motor, some sensory, others mixed sensory (I, II, and VIII) motor (III, IV, VI, XI, and XII) stimulate muscle but also contain fibers of proprioception mixed (V, VII, IX, X) sensory functions may be quite unrelated to their motor function facial nerve (VII) has sensory role in taste and motor role in facial expression 14-48 Cranial Nerves 12 pairs Remember: all nerves (cranial and spinal) carry signals toward or away from the CNS Four categories Special sensory impulses General sensory impulses Somatic motor impulses Visceral motor impulses Cranial nerves. The 12 pairs of cranial nerves are seen from the base of the brain. The Cranial Nerves (functions) I. Olfactory – sense of smell II. Optic – vision III. Oculomotor – eye movement (innervates most eye muscles) IV. Trochlear – eye movement (innervates one eye muscle; so) V. Trigeminal – facial sensation VI. Abducens – eye movement (innervates one eye muscle; lr) The Cranial Nerves (functions) VII. Facial – facial movement (expressions), taste sensation, saliva and tear secretion VIII. Vestibulocochlear – sense of hearing and equilibrium IX. Glossopharyngeal – tongue and throat movement (swallowing), saliva secretion X. Vagus – regulation of viscera; muscles of larynx & pharynx XI. Accessory – Swallowing, head, neck and shoulder movement XII. Hypoglossal – tongue movement Trigeminal neuralgia (tic douloureux) recurring episodes of intense stabbing pain in trigeminal nerve area (near mouth or nose) pain triggered by touch, drinking, washing face treatment may require cutting nerve Bell palsy degenerative disorder of facial nerve causes paralysis of facial muscles on one side may appear abruptly with full recovery within 3 - 5 weeks 14-53 Decreased brain size and weight Decreased speed of information processing Slowed movements Diminished memory Reduced blood flow to brain