The Integrative Action of the Nervous System (Hardcover)

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: LECTURE IV INTERACTION BETWEEN REFLEXES Argument: The simple reflex a convenient but artificial abstraction. Compounding of reflexes. The principle of the common path. Relative aperiodicity of the final common path. Afferent arcs which use the same final common path to different effect have successive but not simultaneous use of it. Allied reflexes. Allied reflexes act harmoniously, are capable of simultaneous combination, and in many cases reinforce one another's action on the final common path. Antagonistic reflexes. Alliance or coalition occurs between (1) individual reflexes belonging to the same type-reflex, (2) certain reflexes originated by receptors of different species but situate in the same region of surface, (3) certain reflexes belonging to propriocep- tive organs secondarily excited by reflexes initiated at the body- surface (the three fields of reception, extero-ceptive, intero-ceptive, and proprio-ceptive), (4) certain reflexes initiated from widely separate but functionally interconnected body-regions. Alliance between reflexes exemplif1ed in inhibitory actions as well as in excitatory. An- tagonisitc reflexes interfere, one reflex deferring, interrupting, or cutting short another, or precluding the latter altogether from taking effect on the final common path. Intraspinal seat of the interference. Compound reflexes may interfere in part. The place (? synapse) where convergent afferent paths impinge on a common path constitutes a mechanism of co-ordination. The convergence of afferent paths to form common paths occurs with great frequency in the central nervous system. A question whether any reflexes are in the intact organism wholly neutral one to another. We have hitherto dealt with reflex reactions under the guise of a convenient but artific...