BBio 351 – November 10, 2015 Outline for this week Finish Hasuwa (2013) Start neurophysiology – review/extend knowledge of… Membrane potential Ion distributions.

Slides:

Advertisements

Similar presentations

Outline Neuronal excitability Nature of neuronal electrical signals Convey information over distances Convey information to other cells via synapses Signals.

Advertisements

Membrane at Rest Selectively Permeable Channels Ion Concentration Differences Nernst Relationship Ion Pumps.

The Electrical Nature of Nerves

Membrane Potentials and Action Potentials

PHYSIOLOGY 1 Lecture 11 Membrane Potentials. n Objectives: Student should know –1. The basic principals of electricity –2. Membrane channels –3. Electrical-chemical.

Bioelectricity Provides basis for “irritability” or “excitability Fundamental property of all living cells Related to minute differences in the electrical.

Monday April 7, Introduction to the nervous system and biological electricity 1. Pre-lecture quiz 2. A word about prelecture readings 3. Introduction.

Neurophysiology Opposite electrical charges attract each other

Structure and Control of Movement

Neurophysiology Opposite electrical charges attract each other In case negative and positive charges are separated from each other, their coming together.

Chapter 11-Part II Biology 2121

Nervous Systems. What’s actually happening when the brain “learns” new information? 3. I’m too old to learn anything new anymore; I hire people do that.

General Organization - CNS and PNS - PNS subgroups The basic units- the cells - Neurons - Glial cells Neurophysiology - Resting, graded and action potentials.

Ion Pumps and Ion Channels CHAPTER 48 SECTION 2. Overview  All cells have membrane potential across their plasma membrane  Membrane potential is the.

Nervous systems. Keywords (reading p ) Nervous system functions Structure of a neuron Sensory, motor, inter- neurons Membrane potential Sodium.

Electricity & Chemistry Our Nervous System only works thanks to electricity!

Neural Signaling: The Membrane Potential Lesson 9.

ECF and ICF show no electrical potential (0 mV).

The central nervous system consists of ______.

Ion Channels are membrane-bound proteins Involved in communication 3 types, voltage, ligand and mechanically-sensitive Nerves: They rely on “batteries”—constant.

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.

Nervous System. Mosby items and derived items © 2008 by Mosby, Inc., an affiliate of Elsevier Inc. The nervous system is the communication and control.

Chapter 9.2: Electrochemical Impulse Pages

Learning Objectives Organization of the Nervous System Electrical Signaling Chemical Signaling Networks of Neurons that Convey Sensation Networks for Emotions.

Membrane Potentials All cell membranes are electrically polarized –Unequal distribution of charges –Membrane potential (mV) = difference in charge across.

Agenda Membrane potentials – what they are Formation of membrane potentials Types and uses of membrane potentials The significance of membrane potentials.

BME 6938 Mathematical Principles in Neuroscience Instructor: Dr Sachin S. Talahthi.

Announcements:. Last lecture 1.Organization of the nervous system 2.Introduction to the neuron Today – electrical potential 1.Generating membrane potential.

NERVOUS TISSUE Chapter 44. What Cells Are Unique to the Nervous System? Nervous systems have two categories of cells: Neurons generate and propagate electrical.

Neurons, Synapses and Signaling

Warm-Up 5/8 1.The sympathetic nervous system has what effect on the body? 2.What portion of the nervous system is responsible for voluntary movement? 3.Support.

Transmission 1. innervation - cell body as integrator 2. action potentials (impulses) - axon hillock 3. myelin sheath.

The Nervous System The nervous system controls and coordinates functions throughout the body and responds to internal and external stimuli.

 Consists of circuits of neurons and supporting cells › A Neuron is a nerve cell; the fundamental unit of the nervous system, having structure and properties.

The Nervous System Ch. 36.

Major communication systems coordinate parts of animals body 1.Neuronal system: Rapid & Short Burst 2.Endocrine system: Slow & Persistent The Physical.

How Neurons Generate Signals The Neuron at Rest. Stepping on a Thumbtack  Reflexive withdrawal of the foot – a simple behavior controlled by a circuit.

Equilibrium Potential E x (where x is an ion) Membrane potential with an electrical driving force equal but opposite to the driving force of the concentration.

Nervous communication.  Nervous system provides fast communication and coordination  Mammalian nervous system:  Central nervous system (CNS): brain.

8.2 Structures and Processes of the Nervous System

Do Now: 1.Syllabus update: Today (Th 11/3) OUT: cell size lab; IN: Nervous system (cross OUT on W 11/25). I will add the cell size back later… How does.

Structures and Processes of the Nervous System – Part 2

Sgs-psychology.org.uk Structure and Function of the Nervous System An introduction to Physiological Psychology.

Transmission of Nerve Impulses GHB 2004 Information is carried along a neurone as an electrical impulse.

Action Potential revisited When a stimulus reaches threshold level, Sodium channels open up and Sodium rushes into the axon along the concentration gradient.

Topics covered 1.Organization of the nervous system 2.Regions / specialization of the neuron 3.Resting membrane potential Especially ionic basis- Nernst,

Neuron Structure and Function. Nervous System  Nervous system is composed of specialized cells called neurons.  Neurons have long “arms” called axons.

Objectives Basics of electrophysiology 1. Know the meaning of Ohm’s Law 2. Know the meaning of ionic current 3. Know the basic electrophysiology terms.

The Electrochemical Impulse Action Potential Threshold Level All-or-None Response.

PHYSIOLOGY OF THE NERVOUS SYSTEM Neurons are IRRITABLE Ability to respond to a stimulus! (What’s a stimulus?)

The Action Potential. Four Signals Within the Neuron  Input signal – occurs at sensor or at points where dendrites are touched by other neurons.  Integration.

Neural and Hormonal Systems Will Explain Why We FEEL…… Pain Strong Sick Nervous.

Objectives 31.1 The Neuron -Identify the functions of the nervous system. -Describe the function of neurons. -Describe how a nerve impulse is transmitted.

Principles of Bioelectricity. Key Concepts The cell membrane is composed of a phospholipid bilayer The cell membrane may have transport channels (made.

Chapter 44 Lecture 15 Neurons and Nervous System Dr. Alan McElligott.

Afferent Nerves Efferent Nerves cell body: cell body: central part of cell; contains the nucleus axon: axon: long slender extension from cell body; used.

The Neuron Functions of the nervous system Two parts to the nervous system: Peripheral nervous system – nerves and supporting cells that collects.

Neurons and Synapses 6.5. The Nervous System Composed of cells called neurons. These are typically elongated cells that can carry electrical impulses.

Sci 2 Lect. 2 Membrane Potential ©Dr Bill Phillips 2002

Nerve cell membrane Electrochemical message is created by the movement of ions across the nerve cell membrane The resting nerve membrane has a electrical.

Biological Psychology: Micro Level - Neural Communication

Structures & Processes of the Nervous System

Neurons, Synapses & Signalling

Do Now: 1. What is 1 of the characteristics of nerve signals that you defined from the “dominos” lab? 2. What is the role of the axon? 3. What creates.

Changes in electrical gradients

Do Now: 1. What is 1 of the characteristics of nerve signals that you defined from the “dominos” lab? 2. What is the role of the axon? 3. What creates.

Presentation transcript:

BBio 351 – November 10, 2015 Outline for this week Finish Hasuwa (2013) Start neurophysiology – review/extend knowledge of… Membrane potential Ion distributions Electrochemical gradients Nernst equation Action potential Synapses Post-synaptic potentials Summation

Overall course flow How will we tackle the nervous system? How neurons fire and communicate (this week) Neural circuits and integration Nervous system evolution Central nervous system (brain & spinal cord) SENSORY systems: intro, mechanical, taste/smell, vision Review: endocrine system vs. nervous system?

Mini-meta-POGIL from Brown A&P workbook 1. Place a large plus sign on the side of the membrane with the most positive charges and a large minus sign on the side of the membrane with the fewest positive charges. Patrick J.P. Brown (2016)

2. Where are most of the sodium ions – inside the cell, or outside the cell? 3. If the channel were to open, which way would sodium travel through the channel? 4. What effect would this have on the membrane potential (the difference in charge across the membrane)? Patrick J.P. Brown (2016)

5. This chart shows the resting membrane potential of a nerve cell. Notice that the line is running at around -70 millivolts. a. The resting membrane potential has a negative value. Based on what we’ve already learned – is this measuring the inside or the outside of the cell? Patrick J.P. Brown (2016)

b. If a sodium channel opens, will the inside of the cell become more positive or more negative as the sodium ions come in along their concentration gradient? c. Based on your answer to A and B, extend the line in the chart to show what might happen to the potential when sodium channels open. d. Before the sodium channel opened, the membrane was polarized, like a battery (a positive and negative side). After opening the sodium channel, is the cell going to be polarized anymore? Patrick J.P. Brown (2016)

Misleading aspects of this POGIL exercise?

Draft of a potential jingle Is this at all helpful? Can you supply a catchy melody or otherwise make it better? “Potential” means that something just might happen; That something always needs a driving force…. That force could be a gradient, And a gradient is a difference, And a difference is a potential – yes, of course! Crowther, unpublished

What are electrochemical gradients? IonChemical gradientElectrical gradient Electrochemical gradient Na + K+K+

The Nernst equation shows how 1 ion would balance its electrical and chemical potentials. “…At the voltage you have found [said Walther Nernst], There’s no flux in or out [said Walther Nernst]!”

Nernst equation: example

There is 0 net flux at the Nernst potential (E). Which way does the flux go at OTHER membrane potentials? Example 1 Note: chemical concentrations & gradient remain constant.

There is 0 net flux at the Nernst potential (E). Which way does the flux go at OTHER membrane potentials? Example 2 Note: chemical concentrations & gradient remain constant.

There is 0 net flux at the Nernst potential (E). Which way does the flux go at OTHER membrane potentials? General rule?

Why is the membrane potential what it is (about -70 mV at rest)?

From 1 ion to many: from the Nernst equation to the Goldman-Hodgkin-Katz equation