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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 [email protected]. Tonight. Details about the course - PowerPoint PPT Presentation
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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
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 Biopsychology
aka 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?
Neuroanatomy(structure)
Neurophysiology(function)
Biopsychology(behaviors)
Neuropharmacology(drugs)
Neuropathology(disease)
Neurochemistry
Neuroscience
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
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
Parasympathetic Sympathetic
Somatic NS Autonomic NS
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
Posterior
(rear)
Anterior
(front)
Superior (top)
Inferior (bottom)
Dorsal = back
Ventral = front
Caudal = tail
Rostral = head
Lateral = side
Medial = center
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
Gyrus GyrusFissure
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
Anatomy of the Cortex
White Matter – has myelin sheath.
Gray Matter – no myelin. Cell bodies are here.
Cranial Nerves - 12 pairs
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
Sensory Pathway
R
