BIOL 112 Lecture 24

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Animals

Neurons

• Function: Propagates electrical signals
• Polarized morphology: one side looks very different from other side.
• Input end: dendrite
• Cell body (contains nucleus and organelles
• Output end: axon

Sensory Cells

Specialized receptor proteins

recognize different stimuli (light, touch, heat, etc.)

converts stimulus to electrical charge

Interneuron

just passes on information to next neuron cell.

Motor neuron

activates muscle target

Junction between axon of one cell and dendrites of another cell form a synapse:

• electrical: physically, electrically coupled by protein channels called gap junctions
• chemical: pre-synaptic cell axon releases #neurotransmitters into space between cells.

Neurotransmitters

• acetylcholine - muscles
• dopamine - tyrosine derivative
• serotonin - tryptophan
• noradenalin - tyrosine derivative
• gaba - amino acid
• glutamine - amino acid