The Nervous System Cells Neurons Organization Generate and conduct electric impulses Can be very long or very short Basic Structure Cell body Dendrites Axon Synaptic Knobs also called terminals or pre synaptic terminals Form connections with other neurons called synapses Presynaptic neuron Postsynaptic neuron Can form large complex circuits especially in the brain About 100 billion neurons in brain 5000 synapses per neuron 500 trillion synapses in brain Circuits make function of brain possible Central Nervous System CNS Brain Spinal Cord Peripheral Nervous System PNS Everything Else Afferent Sensory Neurons Efferent Neurons Autonomic Neurons generally involuntary Innervate heart smooth muscle glands cells Sympathetic Parasympathetic Division Division Somatic motor neurons generally voluntary Innervate skeletal muscle The Central Nervous System Made up of the brain and spinal cord The Brain Telencephalon cerebrum vocabulary speech thought judgement voluntary control sensory perception memory and dreams The Central Nervous System Made up of the brain and spinal cord The Brain Telencephalon cerebrum Diencephalon thalamus hypothalamus epithalamus gateway to cerebral cortex thalamus control involuntary autonomic functions food and water intake thermoregulation cardiovascular regulation hormone secretion sleep wake cycle basic emotions The Central Nervous System Made up of the brain and spinal cord The Brain Telencephalon cerebrum Diencephalon thalamus hypothalamus epithalamus Mesencephalon midbrain cerebral peduncles corpora quadrigemina relays information to higher brain centers The Central Nervous System Made up of the brain and spinal cord The Brain Telencephalon cerebrum Diencephalon thalamus hypothalamus epithalamus Mesencephalon midbrain cerebral peduncles corpora quadrigemina Metencephalon cerebellum and pons coordinates movement of skeletal muscle aids in learning motor skills The Central Nervous System Made up of the brain and spinal cord The Brain Telencephalon cerebrum Diencephalon thalamus hypothalamus epithalamus Mesencephalon midbrain cerebral peduncles corpora quadrigemina Metencephalon cerebellum and pons Myelencephalon medulla oblongata cardiac center heart vasomotor center vessels respiratory center breathing others sneezing vomiting hiccuping swallowing sweating The Central Nervous System Made up of the brain and spinal cord The Brain Telencephalon cerebrum Diencephalon thalamus hypothalamus epithalamus Mesencephalon midbrain cerebral peduncles corpora quadrigemina Metencephalon cerebellum and pons Myelencephalon medulla oblongata Spinal Cord carries most nerves to and from rest of body integration center for spinal reflexes them don t have to think about APs go from sensor to integration center to effector before brain is even conscious of stimulus The Central Nervous System The CNS receives information in the form of action potentials All of the action potentials are identical How does the CNS interpret information such as hard and soft sweet and sour red and green etc The Central Nervous System The CNS receives information in the form of action potentials All of the action potentials are identical How does the CNS interpret information such as hard and soft sweet and sour red and green etc Neural coding APs from different neurons mean different things Different neurons only fire under specific conditions eye rods shades of gray green light neurons red light neurons blue light neurons pain neurons light touch neurons hard touch neurons skin The Central Nervous System The CNS receives information in the form of action potentials All of the action potentials are identical How does the CNS interpret information such as hard and soft sweet and sour red and green etc Neural coding APs from different neurons mean different things Different neurons only fire under specific conditions One neuron can fire a little or a lot Weak stimulus just a few APs per second Strong stimulus many APs per second Trends in Brain New slide inserted Myelencephalon medulla Basic body fxn Metencephalon cerebellum Coordinate body mvt Predict sensations caused by mvt and then filter that info before it is sent to telenceph Mesencephalon Initial visual and auditory F r o g s R a t s P e o p e l i s m i l a r processing Diencephalon temp Telencephalon Hormones hunger thirst body Trend 1 Trend 2 Lowest fxns located in myelencephalon at base Highest fxns located it top front portion Built like an ice cream cone old circuits never disappeared still in there Trend 3 Basic fxns have specific locations Sensory processing pretty straight forward Higher fxns distributed over many places memory decision making and may change over time memory R a t s P e o p e l i s m i l a r Conscious thought dreams vocabulary personality Smaller in rats than people MUCH smaller in frogs Vision Retina Layer of cells at back of eye Photoreceptors Send electric impulses to brain via optic nerve Almost right away electric impulses distributed to different areas of brain Mesencephalon reflexes blind sightedness Amygdala emotion memory Primary visual cortex Initial and higher level processing of image Saccades Vision Retina Layer of cells at back of eye Photoreceptors Send electric impulses to brain via optic nerve Almost right away electric impulses distributed to different areas of brain Mesencephalon reflexes blind sightedness Amygdala emotion memory Primary visual cortex Initial and higher level processing of image Saccades chronostasis Hearing Organ of Corti Cells deep inside ear Convert vibration sound to electric impulses Send electric impulses to brain via vestibulocochlear nerve Almost right away electric impulses distributed to different areas of brain Mesencephalon reflexes Amygdala emotion memory Auditory cortex Initial and higher level processing of sound Saccades possible here too Dead phone illusion
View Full Document
Unlocking...