Nervous System Lecture 2 PDF
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This document is a lecture presentation about the electrical properties of a resting nerve cell. It includes diagrams and text explaining various aspects, including ion channels, membrane potentials, and the action of ion pumps.
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NERVOUS SYSTEM LECTURE 2 The Electrical Properties of a Resting Nerve Cell CHEMICAL COMMUNICATION AXON CELL BODY DIRECTION OF ELECTRICAL IMPULSE MICRO- ELECTRODES NERVE CELL RESTING MEMBRANE POTENTIA...
NERVOUS SYSTEM LECTURE 2 The Electrical Properties of a Resting Nerve Cell CHEMICAL COMMUNICATION AXON CELL BODY DIRECTION OF ELECTRICAL IMPULSE MICRO- ELECTRODES NERVE CELL RESTING MEMBRANE POTENTIAL -70mV -70mV REST, THE INSIDE OF A NERVE CE IS 70mV ORE NEGATIVE THAN THE OUTSID -70mV REST, THE OUTSIDE OF A NERVE C IS 70mV MORE POSITIVE THAN THE INSIDE WHY DOES THE INSID OF A RESTING NERVE CELL HAVE A NEGATIVE LECTRICAL CHARGE? 3 REASONS PHOSPHOLIPID MOLECULE OUTSIDE CELL Cell membrane INSIDE CELL REASON 1 LOTS OF NEGATIVEL CHARGED PROTEINS INSIDE THE NERVE CEL OUTSIDE CELL Cell membrane - PROTEIN PROTEIN - INSIDE CELL - - PRO TEIN PROTEIN - PROTEIN - PROTEIN - PROTEIN PROTEIN - REASON 2 ACTION OF THE Na+ / K+ ION EXCHANGE PUMPS Na+ / K+ ION EXCHANGE PUMP *ADENOSINE TRIPHOSPHAT USES ATP* - PROTEIN PROTEIN - - - PRO TEIN PROTEIN - PROTEIN - PROTEIN - PROTEIN PROTEIN - Na + Na+ Na+ + Na+ Na Na+ Na+ / K+ ION EXCHANGE PUMP *ADENOSINE TRIPHOSPHAT USES ATP* - PROTEIN PROTEIN - - - PRO TEIN PROTEIN - PROTEIN - Na + PROTEIN - PROTEIN PROTEIN - Na + Na+ Na+ + Na+ Na K+ Na+ Na+ / K+ ION EXCHANGE PUMP *ADENOSINE TRIPHOSPHAT USES ATP* - PROTEIN PROTEIN - TEIN - K+ K+ PROTEIN - PRO - PROTEIN - K+ K + Na + PROTEIN - PROTEIN PROTEIN - Na + Na + Na + OUT IN K + K + REASON 2 DUE TO PUMP ACTIO POSITIVE CHARGE IS PUMPED OUT OF THE CELL REASON 3 BEHAVIOUR OF ION CHANNELS ION ION CHANNEL + ION CHANNELS ARE ION-SPECIFIC ION CHANNEL + ION CHANNELS ARE ION-SPECIFIC ION CHANNEL + ION CHANNELS ARE ION-SPECIFIC ION CHANNEL ION CHANNELS + ARE ION-SPECIFIC THERE ARE FFERENT TYPES O ION CHANNEL UNGATED ION CHANNEL GATED ION CHANNEL CAN BE OPEN ALWAYS OPEN OR CLOSED UNGATED ION CHANNEL GATED ION CHANNEL “LEAKAGE” CHANNEL ELECTRICALLY-GATED CHEMICALLY-GATED MECHANICALLY-GATED ION CHANNEL ION CHANNEL ION CHANNEL Na CHANNELS: + LECTRICALLY-GATE Na + Na+ Na+ Na+ Na + Na + Na + Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ Na+ SODIUM CHANNEL AT REST: CHANNELS ARE CLO Na + PROTEIN - Na+ K CHANNELS: + OME ELECTRICALLY-GATE SOME UNGATED K+ ALWAYS OPEN POTASSIUM CHANNEL UNGATED K+ K+ K+ K+ K + K + PROTEIN - K+ K + K+ K+ K+ K+ ALWAYS OPEN POTASSIUM CHANNEL UNGATED K+ K+ K+ K+ K+ K+ K + K + K + PROTEIN - K+ REASON 3POSITIVELY-CHARGE POTASSIUM IONS LEAK OUT THROUG UNGATED CHANNEL WHAT HAPPENS WHEN THE NERVE CELL IS ACTIVATED?
