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Introduction To The Nervous System Notes

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This is an extract of our Introduction To The Nervous System document, which we sell as part of our Neurology Notes collection written by the top tier of Bristol University students.

The following is a more accessble plain text extract of the PDF sample above, taken from our Neurology Notes. Due to the challenges of extracting text from PDFs, it will have odd formatting:

Lecture 1 Introduction to the Nervous System





Basic organisation of the NS o SENSORY PNS (all lead to CNS)
? Sensory NS

* Somatic and special sensory receptors on neurons
? Afferent NS

* Autonomic sensory receptors and neurons
? Efferent NS

* Sensory receptors in GI tract and enteric plexus

* leads to motor neurons too o MOTOR PNS? EFFECTORS
? Somatic motor neurons (voluntary)? Skeletal muscle
? Autonomic motor neurons (involuntary) SNS & PSNS divisions

* ? Smooth muscle, cardiac muscle, glands and adipose tissue

* ? Enteric motor neurons (involuntary) in enteric plexuses (MOTOR PNS) o ?Smooth muscle, glands, and endocrine cells of GI tract Synaptic transmission (sequence of events) o Action potential at axon terminal o Ca2+ channels openIncrease intracellular Ca2+ conc.= Neurotransmitter released o Neurotransmitter diffuses across synaptic cleft and binds to specific receptors o Postsynaptic potential generated
? Na+= depolarisation= EPSP (Excitatory PostSynaptic Potential)
? Cl-= hyperpolarisation= IPSP (Inhibitory PostSynaptic Potential) o Local currents spread along cell membrane Comparison of nervous and endocrine systems o Mediator molecules
? NS= Neurotransmitters released in response to nerve impulses
? ES= Hormones delivered to tissues throughout body by blood o Cells affected
? NS= Muscles, glands, other neurons
? ES= Virtually all body cells o Time of onset of action
? NS= Typically milliseconds
? ES= Seconds to hours to days o Duration of action
? NS= Generally brief
? ES= Generally longer Heterogeneity of chemical signals in the NS o Msec-Sec
? Impulse conduction
? Transmitter release
? Fast synaptic transmission o Sec-Min
? Slow synaptic transmission
? Neuromodulation o Min-Hour-Day
? Synaptic plasticity
? Delayed pharmacological effects

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