* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Neurons
Brain Rules wikipedia , lookup
Types of artificial neural networks wikipedia , lookup
Donald O. Hebb wikipedia , lookup
Neuromuscular junction wikipedia , lookup
Environmental enrichment wikipedia , lookup
Artificial general intelligence wikipedia , lookup
Neuropsychology wikipedia , lookup
Node of Ranvier wikipedia , lookup
Endocannabinoid system wikipedia , lookup
Neural oscillation wikipedia , lookup
Neuroeconomics wikipedia , lookup
Cognitive neuroscience wikipedia , lookup
Axon guidance wikipedia , lookup
Aging brain wikipedia , lookup
Activity-dependent plasticity wikipedia , lookup
Human brain wikipedia , lookup
Caridoid escape reaction wikipedia , lookup
Nonsynaptic plasticity wikipedia , lookup
Neuroplasticity wikipedia , lookup
Neural engineering wikipedia , lookup
Neural coding wikipedia , lookup
Mirror neuron wikipedia , lookup
Central pattern generator wikipedia , lookup
Holonomic brain theory wikipedia , lookup
Neurotransmitter wikipedia , lookup
Single-unit recording wikipedia , lookup
Pre-Bötzinger complex wikipedia , lookup
Synaptogenesis wikipedia , lookup
Biological neuron model wikipedia , lookup
Clinical neurochemistry wikipedia , lookup
Chemical synapse wikipedia , lookup
Neuroregeneration wikipedia , lookup
Molecular neuroscience wikipedia , lookup
Metastability in the brain wikipedia , lookup
Optogenetics wikipedia , lookup
Premovement neuronal activity wikipedia , lookup
Development of the nervous system wikipedia , lookup
Feature detection (nervous system) wikipedia , lookup
Channelrhodopsin wikipedia , lookup
Circumventricular organs wikipedia , lookup
Stimulus (physiology) wikipedia , lookup
Synaptic gating wikipedia , lookup
Neuropsychopharmacology wikipedia , lookup
Neurons and the Nervous System Nervous System – Central nervous system (CNS): • Brain • Spinal cord – Peripheral nervous system (PNS): • Sensory neurons • Motor neurons (somatic and autonomic) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The Nervous System The Nervous System Central Nervous System (CNS) Brain Peripheral Nervous System (PNS) Spinal Cord • Motor Neurons Somatic Nervous System voluntary movements via skeletal muscles Sympathetic - “Fight-or-Flight” responses • Sensory Neurons Autonomic Nervous System organs, smooth muscles Parasympathetic - maintenance Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Divisions of the autonomic nervous system The Nervous System • A physical organ system like any other • The main cell of the nervous system are: –Neurons The Neuron • The basic functional unit of the nervous system. • Function: Send impulses to and from the CNS and PNS Neuron Structure • Dendrite Fine hair-like extensions on the end of a neuron. –Function: receive incoming stimuli. • Cell Body or Soma The control center of the neuron. –Function: Directs impulses from the dendrites to the axon. • Nucleus Control center of the Soma. –Function: Tells the soma what to do. • Axon Pathway for the nerve impulse (electrical message) from the soma to the opposite end of the neuron. • Myelin Sheath An insulating layer around an axon. Made up of Schwann cells. • Nodes of Ranvier Gaps between schwann cells. – Conduction of the impulse. (Situation where speed of an impulse is greatly increased by the message ‘jumping’ the gaps in an axon). Types of Neurons • There are 3 types of neurons. 1. Sensory Neurons Neurons located near receptor organs (skin, eyes, ears). Function: receive incoming stimuli from the environment. 2. Motor Neurons Neurons located near effectors (muscles and glands) Function: Carry impules to effectors to initiate a response. 3. Interneurons Neurons that relay messages between other neurons such as sensory and motor neurons. (found most often in Brain and Spinal chord). Types of Neurons Sensory vs. Motor sensory nerve e.g., skin Neurons that send signals from the senses, skin, muscles, and internal organs to the CNS motor nerve Neurons that transmit commands from the CNS to the muscles, glands, and organs Gray’s Anatomy 38 1999 e.g., muscle Nerves • Nerves Collections of neurons that are joined together by connective tissue. • Responsible for transferring impulses from receptors to CNS and back to effectors. Neuron Anatomy and Neural Communication Neurons Dendrites Cell Body Myelin Sheath Axon of another neuron Axon Dendrites of another neuron Neural Anatomy and communication Synapse junction between the axon tip of the sending neuron and the dendrite or cell body of the receiving neuron tiny gap at this junction is called the synaptic gap or cleft Specific Parts: The Neuron Structure Specific Parts: The Neuron Function 1. 3. 2. Neurons = 3 functions: Reception, Conduction, Transmission Communication • Impulse releases neurotransmitter from vesicles • Neurotransmitter enters synaptic gap • Neurotransmitter binds to receptors on the receiving neuron Place of the PNS in the structural organization of the nervous system CNS PNS Motor division Sensory division Sympathetic division Parasympathetic division Human Anatomy and Physiology, 7e by Elaine Marieb & Katja Hoehn Autonomic nervous system Somatic nervous system Copyright © 2007 Pearson Education, Inc., publishing as Benjamin Cummings. Central Nervous System The Brain • cerebral cortex: the covering, where most mental processes take place • The brain is divided into two halves (cerebral hemispheres) separated by a deep fissure – hemispheres control opposite side of body (e.g. right-handers’ writing is controlled by the left hemisphere) Our Divided Brain • cerebral hemispheres connected by the: – corpus callosum, a large band of neural fibers that transmits messages between hemispheres Structure of the Cortex • cerebral cortex divided into lobes, or regions of the brain – Each lobe is (roughly) responsible for different higher-level functions, but remember that they do not work merely in isolation. Structure of the Cortex • occipital lobe: brain lobe at the back of the head – responsible primarily for vision Structure of the Cortex • temporal lobe: the brain lobe under the temples, in front of the ears – many functions, including receiving and processing sounds, comprehending language committing information to long term memory, emotion Structure of the Cortex • parietal lobe: brain lobe at the top and center/rear of the head –involved in registering spatial location, body awareness, touch and pressure, taste Structure of the Cortex • frontal lobe: the brain lobe located behind the forehead – Movement of body, personality, concentration, planning, problem solving, meaning of words, emotional reactions, speech and smell. – In many ways, the frontal lobe is what makes us uniquely human. Our Divided Brain • cerebral hemispheres connected by the: – corpus callosum, a large band of neural fibers that transmits messages between hemispheres