. Comparative zoology, structural and systematic. For use in schools and colleges. Zoology. 172 COMPARATIVE ZOOLOGY, is fatal. Of the twelve pairs of nerves issuing from the contents of the skull {encej^halon), ten come from the me- dulla obloiiejata. Among these are the nerves of hearing and taste, and those that control the lungs and heart. ^ Respiration ceases im- '•' \\ mediately when the medulla is injured. The spinal cord can of itself generate nerve- force; but it is mainly a conductor—propaga- ting through its central gray matter the impres- sions received by the nerves to the brain, a
. Comparative zoology, structural and systematic. For use in schools and colleges. Zoology. 172 COMPARATIVE ZOOLOGY, is fatal. Of the twelve pairs of nerves issuing from the contents of the skull {encej^halon), ten come from the me- dulla obloiiejata. Among these are the nerves of hearing and taste, and those that control the lungs and heart. ^ Respiration ceases im- '•' \\ mediately when the medulla is injured. The spinal cord can of itself generate nerve- force; but it is mainly a conductor—propaga- ting through its central gray matter the impres- sions received by the nerves to the brain, and taking back through its fibrous part the im- pulses of the brain. In Man, thirty-one pairs of nerves arise from the cord to supply the whole body, except the head. Each nerve has Fig. 144.—Relation of the Sympathetic and Spinal r^jj anterior and pOStC- Nerves: c, fissure of spinal cord; a, anterior of _ ^ ^ a dorsal spinal nerve; 2h posterior root, with rior rOOt : itS pOWCr of its ganglion; o', anterior branch ; j)'i posterior branch; s, ; f, its double junction CailSlUg mUSCUlar COU- by white and gray filaments. ^^.^^^j^^^ .^ ^^^^^^^ .^ the former (hence called motor), and the power of giv- ing rise to sensation resides in the latter {sensory). The fibres leading from the brain to the cord cross one anoth- er in the medulla oblongata, so that if the right cerebral hemisphere be diseased, the left side of the body loses the power of voluntary motion. The sym/pathetic nervous system is a double cliain of knots, or ganglia, lying along the sides of the vertebral. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Orton, James, 1830-1877. New York, Harper and brothers
Size: 1295px × 1930px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, bookpublishe, booksubjectzoology
