Nervous system 3

Neuron synapsesNeurotransmitters

Effects of drugs on synapses

One direction

No that’s not what I meant.

SynapseA structure that permits a neuron (nerve cell) to pass an electrical or chemical signal to another cell.

Excitatory post synaptic potential

Inhibitory post synaptic potential

Types of synapses

Electrical v. Chemical synapse

Types of synapsesSynapse with another neuron

Junction between two nerve cells

NeuroeffectorNeuromuscular: synapse of motor neuron and

muscleNeuroglandular: synapse of neuron and endocrine

or exocrine gland.

NeurotransmittersExcitatory – can cause next cell to initiate a new impulse– ACh (acetylcholine) – neuromuscular junction– NE (norepinephrine)– DA (dopamine)

NeurotransmittersInhibitory– can cause hyperpolarization of next cell, reduce chance of a new impulse– Serotonin– GABA (gamma aminobutyric acid)– Glycine

Convergence and Divergence

Synapse functionEssential for homeostasisA problem with communication between nerves at synapses is often the basis for disease

Examples: Parkinsons, Azheimers, depression, anxiety, schizophrenia

Drug effects Can increase permeability of nerve cell membrane to Na+ makes impulses more likelyCan decrease permeability of nerve cell membrane to Na+ makes impulses less likelyCan block / compete for receptor site binding

Aspirin, Morphine, CurareCan inhibit secretory vesicle formation / release

Botulism / Tetanus