Neurobiology, Part 1. Overview of the nervous system.

Slides:



Advertisements
Similar presentations
Topic Nerves.
Advertisements

Mean = 75.1 sd = 12.4 range =
The Electrical Nature of Nerves
Figure 48.1 Overview of a vertebrate nervous system.
Propagation of the Action Potential The Central Dogma Of Excitable Tissues.
Neural Condition: Synaptic Transmission
Chapter 11-Part II Biology 2121
Nervous systems. Keywords (reading p ) Nervous system functions Structure of a neuron Sensory, motor, inter- neurons Membrane potential Sodium.
Neurophysiology Chapters Control and Integration Nervous system –composed of nervous tissue –cells designed to conduct electrical impulses –rapid.
Nervous System Neurophysiology.
Synaptic Signaling & The Action Potential
Action Potentials and Conduction. Neuron F8-2 Axons carry information from the cell body to the axon terminals. Axon terminals communicate with their.
Biology 41.1 nervous System
The Nervous System AP Biology Unit 6 Branches of the Nervous System There are 2 main branches of the nervous system Central Nervous System –Brain –Spinal.
David Sadava H. Craig Heller Gordon H. Orians William K. Purves David M. Hillis Biologia.blu C – Il corpo umano Neurons and Nervous Tissue.
Neurons The two principal cell types of the nervous system are:
Top Score = 101!!!! Ms. Grundvig 2nd top score = 99 Mr. Chapman 3rd top score = Ms. Rodzon Skewness = -.57.
1 Psychology 304: Brain and Behaviour Lecture 11.
1 Neuron structure fig Myelin sheath fig 6-2a Peripheral nervous system: Schwann cells Central nervous system: oligodendrocytes.
Nervous System.
Neurons, Synapses and Signaling
Chapter 48 Neurons, Synapses, and Signaling. Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Overview: Lines of Communication.
CHAPTER 48  NEURONS, SYNAPSES, & SIGNALING 48.1  Neuron organization & Structure I. Intro to information processing A. Processing 1. Sensory input a.
P. Ch 48 – Nervous System pt 1.
Action Potential: Overview The action potential (AP) is a series of rapidly occurring events that change and then restore the membrane potential of a cell.
Quick Review What’s another name for neurons? Can you name the parts of a neuron?
The Nervous System Components Brain, spinal cord, nerves, sensory receptors Responsible for Sensory perceptions, mental activities, stimulating muscle.
Chapter 44: Neurons and Nervous Systems CHAPTER 44 Neurons and Nervous Systems.
Nerve Impulse Every time you move a muscle & every time you think a thought, your nerve cells are hard at work. They are processing information: receiving.
Nervous System IB Biology. Nervous System In order to survive and reproduce an organism must respond rapidly and appropriately to environmental stimuli.
Galvanism 1790 Luigi Galvani & “animal electricity” Contraction of a muscle that is stimulated by an electric current.
Biology 211 Anatomy & Physiology I Electrophysiology.
Nervous System Reflexes and Action Potential How do cells detect and respond to changes in their internal and external environment to successfully survive.
How neurons communicate ACTION POTENTIALS Researchers have used the axons of squids to study action potentials The axons are large (~1mm) and extend the.
Neurons & Nervous Systems. nervous systems connect distant parts of organisms; vary in complexity Figure 44.1.
8.2 Structures and Processes of the Nervous System
Copyright © 2008 Pearson Education, Inc., publishing as Pearson Benjamin Cummings Ch 48 – Neurons, Synapses, and Signaling Neurons transfer information.
Structures and Processes of the Nervous System – Part 2
Nerve Impulses.
Neural Communication: Action Potential Lesson 10.
THE NERVE IMPULSE. Cells and membrane potentials All animal cells generate a small voltage across their membranes This is because there is a large amount.
AP Biology Nervous Systems Part 3. Synapse and Neurotransmitter.
What you should know The parts of the nerve What an action potential is How nerve cells are insulated and the function of this How nerve cells communicate.
Nerve Impulses. Neuron Physiology Action Potentials- nerve impulses which are sent by a change in electrical charge in the cell membrane. Depends on ions.
Action Potentials. Membrane Potential Electrical charge inside a neuron is different than interstitial space Resting membrane potential (RMP) is -70mV.
Neural Communication Signaling within a neuron. Postsynaptic Potentials n E m changes dendrites & soma n Excitatory: + n Inhibitory: - ~
3.E.2 Nervous System Animals have nervous systems that detect external and internal signals, transmit and integrate information, and produce responses.
CAMPBELL BIOLOGY IN FOCUS © 2014 Pearson Education, Inc. Urry Cain Wasserman Minorsky Jackson Reece Lecture Presentations by Kathleen Fitzpatrick and Nicole.
Do Now 1/9/15 1.Name 3 glial cells and describe their function and location. 2.Which neural pathway transmits a signal when the internal body temperature.
Chapter 28 Nervous system. NERVOUS SYSTEM STRUCTURE AND FUNCTION © 2012 Pearson Education, Inc.
Electrical Properties of the Nervous System Lundy-Ekman, Chapter 2 D. Allen, Ph.D.
Neurons and Synapses 6.5. The Nervous System Composed of cells called neurons. These are typically elongated cells that can carry electrical impulses.
Chapter 11 Outline 12.1 Basic Structure and Functions of the Nervous System A. Overall Function of the N.S. & Basic Processes Used B. Classification.
A NERVE CELL?.
Chapter 48: Nervous System
Synaptic Signaling & The Action Potential
What is the part of the neuron that receives signals? Sends them?
Action Potentials and Conduction
Action Potential Lesson 11
Cell Communication: Neuron.
Neural Condition: Synaptic Transmission
The cone snail is a deadly predator. Why?
Nerve Impulses.
Neural Signaling: Postsynaptic Potentials
Action Potentials Department of Biology, WCU.
Neural Communication: Action Potential
Nerve Impulse (pp ).
Saltatory conduction in nerve impulses
Neural Condition: Synaptic Transmission
Presentation transcript:

Neurobiology, Part 1

Overview of the nervous system

Structure of neurons and associated cells

Examples of neurons

Glial cells  10:1  50:1 glial cell:neuron ratio  Known functions   Creates myelin sheath (in the vertebrates only)   Why important?   Creates a matrix that connects neurons   Helps guide development of neural pathways   Blood-brain-barrier (tight junctions)   Provides metabolic support for neurons   NEW: appear to communicate chemically with other glial cells and neurons

Membrane potentials: the key to electrical signals   What is meant by the membrane potential?   Charge difference between the inside and ouside of the membrane   An “electrical signal” of the nervous system is a change in the memrane potential.   Example: Action potential…   What determines the value of the membrane potential?   Chemical gradients   Electrical gradients   Selective permeability of the membrane

Chemical and electrical gradients  Chemical gradients (“chalk talk”)

Na+-K+-pump: maintains the gradients  Think of it as operating in the background. It is no way involved in individual action potentials!

Chemical and electrical gradients  Electrical gradients (“chalk talk”)

Selective permeability   The membrane potential at any time is based on the permeability of the membrane to particular ions.   Impermeable ions cannot move and thus cannot influence the membrane potential.

Neuron at rest: ~ -70 mV  Why is the resting membrane potential negative?

Resting potential   At rest, the membrane is ~25 times more permeable to K+ than Na+, thus K+ is nearly solely responsible for the RP of neurons.   Relatively large number of K+ channels open at rest   These are “resting” or “passive” channels (always open)   Very few Na+ channels open at rest.

Action potentials  A rapid, transient change in the membrane potential from negative to positive and back again!  This is the nerve impulse!  What allows the changes in membrane potential to occur during an AP?  Changes in membrane permeability due to opening and closing of voltage-gated channels  Resultant movement of ions.

Action potentials  Follow the bouncing professor and make your own custom drawing!

Action potentials (cont.)  Know what is meant by the threshold  For each stage of the AP: Ask yourself:  What change in permeability occurred?  What type of channel opened or closed and why?  Which ion moved, and in which direction (in or out of cell?)  Understand why you see the direction you do.  What change in membrane potential occurred as a result of the ion movement?  What stopped the movement of the ion?

Propagation of the action potential  Passive spread of positive charge   Depolarization of next segment of the axon   Threshold reached  AP in next section

Myelin sheath  Cell type: Schwann cell

Saltatory conduction  Ions only able to move at the Nodes of Ranvier  AP “jumps” from node to node

The synapse: Write out steps in your own words!  NOTE: See diagram in text: Newer diagram clearly shows the voltage-gated calcium channels!

How is neurotransmitter activity stopped?  Three different ways… Know them!

Neural integration

 Summation: graded potentials (EPSPs and IPSPs) are summed to either depolarize or hyperpolarize a post-synaptic neuron