. Practical anatomy of the rabbit : an elementary laboratory textbook in mammalian anatomy . Rabbits; Anatomy, Comparative. 38 Anatomy of the Rabbit. In the non-medullated nerve fibres the myelin sheath is lacking. This type of fibre is chiefly distributed in connection with the sympathetic system. A nerve is an association of nerve fibres, the latter being disposed in a parallel fashion and united together into bundles of larger or smaller size by connective tissue, which also forms a general peripheral investment, the epineurium. The dead-white coloration of a nerve is due to the fatt
. Practical anatomy of the rabbit : an elementary laboratory textbook in mammalian anatomy . Rabbits; Anatomy, Comparative. 38 Anatomy of the Rabbit. In the non-medullated nerve fibres the myelin sheath is lacking. This type of fibre is chiefly distributed in connection with the sympathetic system. A nerve is an association of nerve fibres, the latter being disposed in a parallel fashion and united together into bundles of larger or smaller size by connective tissue, which also forms a general peripheral investment, the epineurium. The dead-white coloration of a nerve is due to the fatty materials of the myelin sheaths, but nerves are commonly found imbedded in a fatty con- nective tissue which is associated with the epineurium and is also of white coloration. Nerve fibres, and also nerves, are distinguished functionally as afferent and efferent. They are organs of conduction, which carry impulses either from the peri- pheral parts of the body to the central nervous system, or in the oppo- site direction. Sensory nerves are afferent, while motor nerves aro efier- ent. Nerves, however, usually contain both afferent and efferent fibres and are hence described as mixed. In the distribution of afferent and efferent fibres chere is a marked difference between the external or somatic portions of the body and the internal or visceral portions. Con- sequently, both somatic and visceral kinds of afferent and efferent fibres are conveniently distinguished. On account of certain differences in coloration, the cellular and white fibrous constituents of the central nervous system produce characteristic patterns where either one is concentrated. Thus the cellular material is greyish, and is hence distinguished as the grey SUl)Stance, while white fibrous material produces when concen-. FlG. icf. Section of the spinal cord of the rabbit: c, central canal; , anteiior median fissure; , posterior median sulcus; , , and , anterior, lateral, and posterior
Size: 1787px × 1398px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectanatomy, bookyear1921
