* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Nervous System Basics: Neurons
Donald O. Hebb wikipedia , lookup
Types of artificial neural networks wikipedia , lookup
Cognitive neuroscience wikipedia , lookup
Neural engineering wikipedia , lookup
Biochemistry of Alzheimer's disease wikipedia , lookup
Convolutional neural network wikipedia , lookup
Neural modeling fields wikipedia , lookup
Neuroplasticity wikipedia , lookup
Artificial general intelligence wikipedia , lookup
Neural oscillation wikipedia , lookup
Apical dendrite wikipedia , lookup
Endocannabinoid system wikipedia , lookup
Action potential wikipedia , lookup
Electrophysiology wikipedia , lookup
Multielectrode array wikipedia , lookup
Microneurography wikipedia , lookup
Activity-dependent plasticity wikipedia , lookup
Neuroregeneration wikipedia , lookup
Node of Ranvier wikipedia , lookup
Clinical neurochemistry wikipedia , lookup
Central pattern generator wikipedia , lookup
Metastability in the brain wikipedia , lookup
Optogenetics wikipedia , lookup
Caridoid escape reaction wikipedia , lookup
Neural coding wikipedia , lookup
Premovement neuronal activity wikipedia , lookup
Axon guidance wikipedia , lookup
Mirror neuron wikipedia , lookup
Circumventricular organs wikipedia , lookup
Development of the nervous system wikipedia , lookup
Neuromuscular junction wikipedia , lookup
Holonomic brain theory wikipedia , lookup
Pre-Bötzinger complex wikipedia , lookup
Feature detection (nervous system) wikipedia , lookup
End-plate potential wikipedia , lookup
Channelrhodopsin wikipedia , lookup
Synaptogenesis wikipedia , lookup
Chemical synapse wikipedia , lookup
Neurotransmitter wikipedia , lookup
Nonsynaptic plasticity wikipedia , lookup
Molecular neuroscience wikipedia , lookup
Single-unit recording wikipedia , lookup
Neuroanatomy wikipedia , lookup
Neuropsychopharmacology wikipedia , lookup
Biological neuron model wikipedia , lookup
Stimulus (physiology) wikipedia , lookup
Book Slam Nervous System Basics: Neurons Ch. 40 I. Neuron Structure A. Neuron- Basic unit of nervous system 1. AKA Nerve Cell 2.Conduct impulses B. Consists of a cell body, dendrites and an axon I. Neuron Structure C. Dendrites 1. Branch off the cell body 2. Receives impulses and sends them to the cell body a. “Sensors/Feelers” D. Cell Body (Soma) 1. Contains nucleus 2. Contains other organelles 3. Interprets impulse and sends it to the axon I. Neuron Structure E. Axon 1. Conducts the impulses 2. AKA “Nerve Fiber” 3. Myelin Sheath- White, fatty tissue layer that covers the axon a. Insulates & aides in relaying impulses faster I. Neuron Structure E. Types of Neurons 1. Sensory Neurons a. Takes nerve impulses from sensory receptors in the skin, eye, ear, etc to the brain & spinal cord I. Neuron Structure 2. Motor Neuron a. Takes nerve impulses from the brain & spinal cord to muscles or glands I. Neuron Structure 3. Interneurons a. Lie in between other neurons b. Ex: Between a sensory neuron & a motor neuron c. Located in spinal cord and brain II. Relaying an Impulse A. Shoulder Tap 1. Sensors in the skin “feel” the tap. 2. Sensory neurons send an impulse to the brain. 3. The brain interprets the message. II. Relaying an Impulse A. Shoulder Tap (cont.) 4. The brain sends a response down a motor neuron to neck muscle. 5. The muscles contracting in the neck cause the head to turn. II. Relaying an Impulse B. A Resting Neuron 1. Potassium ions (K+) and sodium ions (Na+) inside and around the axon membrane are involved in transmitting impulses II. Relaying an Impulse 2. Na+/K+ Pump a. Uses active transport to move 3 Na+ out for every 2 K+ that goes in. b. This causes the inside of the neuron axon to be slightly more negative than the outside. II. Relaying an Impulse c. The membrane is said to be polarized. R est N P eace = = = Resting neuron Negative charge “Poloarized” II. Relaying an Impulse C. Transmitting the Impulse 1. When a stimulus excites an neuron, gates in the axon membrane open and let Na+ move in. a. This causes the inside to change to a slightly positive charge II. Relaying an Impulse b. This change in charge is called depolarization. c. As depolarization occurs, the Na+/K+ pump works to return the axon to its resting state 1) This is called repolarization 2) See website II. Relaying an Impulse d. The gates don’t open at the same time, they open as the impulse moves down the axon. 1) Wave-like 2) See website II. Relaying an Impulse D. Speed of Impulses 1. Myelinated neurons are much faster a. myelinated: 100 m/sec b. nonmeyelinated: 10 m/sec 2. The impulse actually jumps from one node of ranvier to the next III. Connecting Neurons A. Neurons lie axons to dendrites (end of one to beginning of the next), but they don’t actually touch. 1. Synaptic Cleft- The gap between two neurons III. Connecting Neurons B. When the impulse reaches the axon terminal (end), neurotransmitters are released into the synaptic cleft. 1. Acetylcholine (muscle) 2. Norepinephrine (neurons) III. Connecting Neurons C. When the neurotransmitter reaches the dendrites of the next neuron, it signals it to open the Na gates and send the impulse down the axon. RECAP -What is a neuron? -What are the main parts of a neuron? -What are the types of neurons? -What is the charge of the inside when a neuron is resting RECAP -What are the steps in transmitting an impulse? -How does the message of the impulse get across the synaptic cleft?