2016_winter_lab_6 - BBio 351: Principles of Anatomy &...

This preview shows page 1 - 3 out of 15 pages.

BBio 351: Principles of Anatomy & Physiology IWinter 2016Lab 6: Earthworm action potentialscreated by Doug Wacker with materials provided by ADInstruments;revised by Greg CrowtherToday’s objectivesMake extracellular recordings of action potentials from anesthetized earthworms.Use these recordings to explore four core concepts of neurophysiology: threshold, “all-or-none” responses, nerve conduction velocity, and refractory period.Supplies/equipmentLabChart 7.1 softwarePowerLab Data Acquisition Unit with Bio AmpStimulator Cable (BNC to Alligator Clips)5 Lead Shielded Bio Amp CableShielded Lead Wires (3 Alligator Clips)Three silver wires, chlorided at one endModeling clayPetri dishMillimeter rulerTissuesBlunt probeDissection tray with wax or padDissection pinsEyedropper or Pasteur pipetteOne earthworm (Lumbricusspp.), at least 60 mm in length10% ethanol in earthworm salinePre-lab assignmentBy the start of your lab section (Thursday at 8:45am, or Thursday at 1:15pm) you should (1)print or download this lab handout, read it over, and bring it to lab; and (2) complete the pre-labassignment posted to Canvas.Background(see also sections 4.1 to 4.4 of your textbook)A characteristic of the nervous system is that signals are conducted from place to place bynerve impulses – action potentials that travel along a nerve fiber, or axon.All sensation,thought, and movement is mediated by coded patterns of nerve impulses.The properties ofaction potentials in single fibers are therefore of fundamental physiological importance.Annelids, such as the common earthworm (Lumbricusspp.), and arthropods have a ventralnerve cord that is analogous to the dorsal spinal cord of chordates.The earthworm possessesa medial giant nerve fiber and two lateral giant nerve fibers (that lie on either side of the medialone) that run the length of the animal.The earthworm also has a multitude of small nerves thatdo notrun the length of the animal (there are about 500-1000 neurons per segment, or about100,000 neurons altogether).Each giant fiber is actually made up of multiple large cells (oneper segment) that are electrically coupled to each other throughgap junctions.This results inthe rapid conduction of action potentials from cell to cell so that each giant fiber behaves almost1
We have textbook solutions for you!
/Process-Technology-Equipment-and-Systems-4th-Edition-9781285444581-715/
The document you are viewing contains questions related to this textbook.
Chapter 10 / Exercise 15
Process Technology Equipment and Systems
Thomas
Expert Verified
BBio 351: Principles of Anatomy & Physiology IWinter 2016

Upload your study docs or become a

Course Hero member to access this document

Upload your study docs or become a

Course Hero member to access this document

End of preview. Want to read all 15 pages?

Upload your study docs or become a

Course Hero member to access this document

Term
Spring
Professor
Steve
Tags
median giant fiber, Alligator Clips, Stimulator Panel, lateral giant
We have textbook solutions for you!
The document you are viewing contains questions related to this textbook.
Process Technology Equipment and Systems
The document you are viewing contains questions related to this textbook.
Chapter 10 / Exercise 15
Process Technology Equipment and Systems
Thomas
Expert Verified

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture