________________
Glossary
109 Pons : The band of tissue bridging the left and right balves of the cerebellum, containing many important groups of nerve-cells. Prefrontal cortex: The most anterior part of the cortex; may be related to the ability to plan and to make choices. Purpose : The aim or objective of a living system (or artifact). Raphe : The region where the two halves of the medulla oblongata are joined. The name literally means 'a seam'.
Reflex (action): An inherited program for performing a single action in response to an external stimulus. Reticular formation and RAS : A dense network of neurons in the brainstem that regulates consciousness and channels the brain's attention. It and its pathways running from the spinal cord to the cortex are known as the 'reticular activating system' (RAS). Reticular System : A network of short neurons running up and down near the center of the brain and responsible for the programs of arousal to action and sleep.
Somatosensory cortex: The part of brain that deals with signals sent from the skin; e.g. for touch. Spinal Cord : It constitutes the central nervous system together with brain. It is body's main nerve circuit, carrying out reflex actions and sending nerve impulses to and from the brain through its nerve tracts; it extends from the base of the brain-stem to the second lumbar vertebra and is enclosed by the spinal column. Standard : Goal, set-point, reference-point. Hereditary standards are basically defined by the genetic program. Synapse : The microscopic gap between two adjacent nerve-cells. The terminal knob (bouton) by which the end of a presynaptic axon comes into contact with the dendrite of a post-synaptic nerve-cell; the joint effect of many of these knobs activates the post-synapatic cell, usually by releasing a chemical transmitter.
