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Welcome to the APPL601, Biological Bases of Behavior!. Your Host for the Semester. Jim McConkey MS/PMAC Biomedical Engineering from Johns Hopkins Specialties in neuroscience, medical imaging and computer-guided surgery JMcConkey@UBalt.edu. Tonight. Details about the course
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Your Host for the Semester • Jim McConkey • MS/PMAC Biomedical Engineering from Johns Hopkins • Specialties in neuroscience, medical imaging and computer-guided surgery • JMcConkey@UBalt.edu
Tonight • Details about the course • What are we studying? • Organization of the nervous system • Anatomy of the nervous system
Development of Psychology • Ideopathic model • Spirits, demons, etc. cause pathologies. • Mental model • Cognitive defects or faulty thinking cause psychopathologies. • Medical (biological) model • Psychopathologies are biologically driven. • They can be treated with drugs. • Integrated model • The real world is somewhere in between.
Biological Bases of Behavior aka Biopsychologyaka Physiological Psychology • The study of behavior and other psychological phenomena in terms of the development, functioning, and pathologies of the nervous system.
Biological Psychology • How are behaviors controlled by the brain? • What parts of the brain control which behaviors? • How much control do humans have? • How do psychoactive drugs work?
Neuroscience Neuroanatomy (structure) Neurophysiology (function) Biopsychology (behaviors) Neuropathology (disease) Neuropharmacology (drugs) Neurochemistry
Methods of Biopsychology • Historical techniques: dissection, staining • Surgical methods • Electrical stimulation and measurement • Pharmacological methods • Genetic engineering • Neuropsychological tests • Non-invasive imaging techniques
Introduction to the Nervous System • Nervous System • A system of nerves. • Cells specialized for the translation and processing of information. • Produce electrical and chemical activity. • Connects and coordinates all parts of the body. • A collection of specialized subsystems.
Divisions of the Nervous System • Central Nervous System • Brain • Spinal Cord • Peripheral Nervous System • Everything else
Divisions of the Peripheral NS • Somatic • Receives sensory input from periphery • Conscious control of peripheral muscles • Autonomic • Receives unconscious sensory input from organs • Unconscious control of movement and organs
Divisions of the Autonomic NS • Parasympathetic • Mostly inhibitory • Controls “housekeeping” functions • Sympathetic • Mostly excitatory • Controls “fight or flight” responses
Anatomy of the PNS • Autonomic nerves • Parasympathetic nerves leave the spinal cord at the cervical and sacral levels. • Sympathetic nerves leave the thoracic and lumbar vertebrae. • Somatic nerves • Enter and leave the spinal cord at every vertebra. • Sensory nerves have bodies in the dorsal root ganglia and ascend in the dorsal horns. • Motor nerves descend in the ventral horns.
Recap of NS Organization Nervous System Central NS Peripheral NS Somatic NS Autonomic NS Parasympathetic Sympathetic
Organization of Nerves • Nerves are organized in a tree-like fashion • Solitary neurons in the outermost periphery, protected by an endoneurium. • Solitary neurons gather in small bundles called fascicles, bound by a perineurium. • Fascicles gather with blood vessels in larger bundles, bound by an epineurium.
Organization of Nerves • Endoneurium wraps each neuron w/myelin. • Perineurium wraps several neurons into a fascicle. • Epineurium wraps a bundle of fascicles plus blood vessels.
Organization of Nerves • Collections of neurons, grouped by function • CNS: tracts • PNS: nerves • Neuron cell bodies tend to clump together: • CNS: nuclei (nucleus) • PNS: ganglia (ganglion)
Protection of the CNS • The CNS is very important and very sensitive and is therefore well protected by: • Thick bones • 3 layers of meninges • Cerebrospinal Fluid (CSF) • Blood-Brain Barrier • Circle of Willis – redundant blood supply
Protection of the CNS • Skull • Thick, hard bone • Over 1 cm thick in places • Totally surrounds and protects the brain
Protection of the CNS • Meninges • Thick, fibrous layers • Dura mater • Periosteal • Meningeal • Arachnoid mater • Pia mater
Protection of the CNS • Cerebrospinal Fluid (CSF) • Mostly water • Shock absorber • Produced in choroid plexus
Protection of the CNS • Blood-Brain Barrier • Tight junctions • pass O2, CO2, OH • Carrier-mediated transport of • glucose, AAs, ions • Blocks • large molecules • many drugs and toxins
Organization of the CNS • The lower the brain level, the more primitive the more instinctive, and the less brain control. • Pure reflexes occur in the spinal cord with no intervention from the brain. • The older/lower parts of the brain have 2 layers of neurons. The newer parts of the brain (neocortex) have 6 layers.
Organization of the CNS • Myelencephalon • Medulla oblongata (or just medulla) • Contains nuclei which are part of the reticular formation and control: • Arousal and attention • Heart rate • Respiration rate • Cardiovascular smooth muscle tone • Skeletal muscle tone
Organization of the CNS • Metencephalon • Pons (=“bridge”) • Part of reticular formation responsible for sleep and arousal • Relay nuclei between cortex and cerebellum • Cerebellum • Primarily responsible for coordinated movements • Receives all sensory input except olfactory • Connected to pons via cerebellar peduncles
Organization of the CNS • Mesencephalon • Tectum (=“roof”) • Inferior (auditory) and Superior (visual) colliculi • Responsible for audiovisual reactions • Tegmentum (=“covering”) • Contains nuclei of the reticular formation • Controls eye movements • Red Nucleus – sends motor info from cortex and cerebelum to spinal cord • Substantia Nigra – communicates with caudate and basal ganglia
Organization of the CNS • Diencephalon (“2 brains”) • Surrounds the 3rd ventricle • Thalamus • Two lobes • Major sensory transfer station • Many sensory nuclei • Hypothalamus (=“beneath thalamus”) • Autonomic control center, four F’s • Hormonal control, direct and thru pituitary
Organization of the CNS • Telencephalon • Cerebral cortex • Two cerebral hemispheres • Lateral ventricles (two) • Corpus callosum/anterior commisure • Limbic cortex • Involved in motivation and emotion • Basal ganglia • Caudate nucleus, globus pallidus, putamen • Involved in planned movement
Organization of the CNS • Cerebral hemispheres • Lateralization, specialization per side • Left • Verbal abilities • Analysis and serial behaviors • Right • Spatial abilities • Synthesis • Music, arts, emotions
Anatomical Directions Superior (top) Dorsal = back Ventral = front Caudal = tail Rostral = head Lateral = side Medial = center Posterior (rear) Anterior (front) Inferior (bottom)
Anatomical Terminology • Brain topography terminology • A gyrus (gyri) is a bump • A sulcus (sulci) is a shallow groove • A fissure (fissures) is a deep groove Fissure Gyrus Gyrus Sulcus Sulcus
Anatomy of the Cortex • Major anatomical landmarks • Longitudinal Fissure separates hemispheres • Central Sulcus • Lateral (Sylvian) Fissure • Parieto-Occipital Sulcus (internal)
Anatomy of the Cortex • Major lobes of the cortex • Demarcated by fissures and sulci • Frontal lobe - anterior to central sulcus • Thinking, planning, executive function • Parietal lobe - posterior to the central sulcus • Association area • Temporal lobe - inferior to the lateral fissure • Auditory function • Occipital lobe - posterior of cortex • Vision
Anatomy of the Cortex White Matter – has myelin sheath. Gray Matter – no myelin. Cell bodies are here.
Spinal Pathways • Spinal cord has two gray matter horns which contain cell bodies. The two sides are connected by the gray commissure, and are surrounded by white matter, which carries tracts. • Dorsal horns receive sensory afferents. • Afferent somas external in dorsal root ganglia • Ventral horns carries somatic motor efferents. • Efferent somas in ventral horns