Lab 5

Agenda

  1. Turn in Lab 4 by the staplers on the North bench.
    1. Needs a name and group number
  2. ~10 min.: Q&A on Lab 4 material
  3. 20 min.: Quiz 4
  4. ~2 hrs.: Lab 5: Action Potentials and Neurons
  5. ~30 min.: Next lab reminders/questions/review

Lab 4 Q&A

Core principles

What is diffusion?

  • How is it affected by:
    • Temperature
    • Molecule size

How to calculate osmolarity

Osmolarity = Molarity \times n

n is the number of particles the solute dissociates into when dissolved

\% solution = grams/milliliter

Osmotic Pressure

\pi = 19,300 mmHg \times \Delta C
\Delta C = Osm_{solution_1} - Osm_{solution_2}

Normal Osmolarity of Human Plasma

  • 0.9% NaCl
  • 5.0% Glu

The Effect of Tonicity

Quiz 4

Action Potentials & Neurons

Lab 5

Lab Purpose

To allow students to experiment with principles of neuron function, the generation of action potentials and nerve potentials and how they may be modified.

Lab objectives

  • Explain the location of the major parts and channels of a neuron.
  • Understand the parts of an action potential and what causes them.
  • Define the electrical properties of a nerve, including threshold.
  • Observe the relationship between stimulus intensity and action potential strength in a nerve and how
    this may or may not differ from the activity of a single neuron.
  • Be able to explain refractory periods and what causes them.

Lab Safety

  • Half the lab is computer based.  Just be patient with the software and follow the instructions and you'll be fine.

Experiment 1-3

Experiment 4 & 5

Core Principles

Neuron Anatomy

Ion Channels and Pumps

Action Potentials

  • What is an action potential (AP)?
  • Can you label/define the parts?
  • Define threshold.
  • Describe the action of these ions during an AP.
    • Na+
    • K+
    • Ca++
    • Cl-
  • How are APs similar to nerve potentials? How are they different?

Summation

  • What kinds are there?
    • Temporal
    • Spatial
  • Can you define them?

Drug Effects

  • Monosodium Glutamate (MSG) - glutamate is an excitatory neurotransmitter
  • Nicotine - activates nicotinic ACh receptors
  • Calcium chloride - increases voltage dependence of Na and K channels, increasing threshold.

Lab 6: Sensory Physiology

  • Read:
    • Stanfield pgs. 256-299
    • Silverthorn pgs. 291-294, 314-353
  • Bring:
    • Calculator

Lab 5 - Action Potentials & Neurons

By Ben Carter

Lab 5 - Action Potentials & Neurons

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