BIO 121 Study Guide - Quiz Guide: Auditory Cortex, Neocortex, Cephalization
25 Apr 2017
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Peripheral nervous system (pns): made up of sensory receptors; neurons outside the cns. Response to stimulus: stimulus receptor messenger effector response. Neurons: receive stimuli; transmit electrical and chemical signals. Dendrites: extend from cell body; receive stimuli and sends signals to cell body. Axons: extend from body; forms branches; transmits signals into terminal branches (which end in synaptic terminals: myellin sheath surrounds and insulates axons, schwann cells form myelin sheath in the pns. In cns sheath is formed by other glial cells: nodes of ranvier gaps in sheath between successive schwann cells. Nerves and ganglia: nerve several hundred axons, wrapped in connective tissue, ganglion mass of neuron cell bodies in the pns. Glial cells support/nourish neurons; important in neural communication. Neural signals: electrical signals transmit info (along axons, plasma membrane of resting neuron (not transmitting an impulse) is polarized inner surface of plasma membrane is ( ) charged (relative to extracellular fluid)
