BIOL 1F25 Lecture Notes - Tetraodontidae, Patellar Reflex, Plantar Reflex
1 Oct 2013
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*when dendrites connect to the axon this is a synapse. Signalling within one brain cell: electrical in nature (action potentials) Signalling between most brain cells: chemical in nature. (neurotransmitters) Nerve cells are signalling units for behavioural responses. Example of a spinal reflex (150-151 of text) Most spinal reflexes are polysynaptic (more than one synapse) Plantar reflex: stroke foot- normal response is downward response (curling toes inwards) Infant reflex- hidden as we age but can reappear from brain trauma or excessive alcohol use. In summary: four general features of the nervous system: stereotyped electronically signals (action potentials, connections (chemical synapse, specific connection patterns, connections can be modified by experience. Ion channels in the nerve cell membrane and neurotoxins act on them. The nerve cell membrane has ion channels (pores that allow ions to move across the membrane). The movement of these ions across the membrane creates electricity. Without this we would be unable to signal properly.
