Transcript File - Rogers` Anatomy and Physiology

7
PART C
IV. Central Nervous
System: Spinal Cord
PowerPoint® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University
ESSENTIALS
OF HUMAN
ANATOMY
& PHYSIOLOGY
EIGHTH EDITION
ELAINE N. MARIEB
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
A. Spinal Cord Location
1. Enclosed within the vertebral
column
2. Extends from the medulla
oblongata to the region of T12
3. Below T12 is the cauda equina
“horses tail” (a collection of
spinal nerves)
 Enlargements occur in the cervical
and lumbar regions
Figure 7.18
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Cause of Spina Bifida
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Spina Bifida
 At 21 days after conception (left drawing),
folds of tissue on the back of a developing
embryo are rapidly growing together (see
lines) to form the neural tube. Just a day later
(center drawing), the growth is almost
complete. If the tissue fails to close
completely (right drawing), development of
the spine, muscle and skin in this region is
affected and the baby will be born with spina
bifida.
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Spinal Cord Anatomy
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Spina Bifida Surgery
 http://www.youtube.com/watch?feature=play
er_detailpage&list=FLw79wcj2687CXBNNa
SAdOdQ&v=E080qJuHWdQ
Uploaded by mayoclinic on Oct 30, 2008
Every year, thousands of babies are born with spina bifida. It's a birth
defect where the spinal column does not close properly, exposing nerves
to the environment.
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
B. Spinal Cord Anatomy
 Exterior white mater – conduction tracts
Figure 7.19
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
B. Spinal Cord Anatomy
 Internal gray matter - mostly cell bodies
 Dorsal (posterior) horns- contain association neurons,
or interneurons
 Anterior (ventral) horns – contain cell bodies of motor
neurons of somatic (voluntary) nervous system
Figure 7.19
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
B. Spinal Cord Anatomy
1. Central canal filled with cerebrospinal fluid
Figure 7.19
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
B. Spinal Cord Anatomy
2. Meninges cover the spinal cord to cushion and protect
3. Nerves leave at the level of each vertebrae
 Dorsal root – sensory neurons
 Associated with the dorsal root ganglia – collections of
cell bodies outside the central nervous system
 Ventral root – motor neurons
4. The dorsal and ventral roots fuse to form spinal nerves
5. 31 pairs of spinal nerves arise from the cord and exit
from vertebral column
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
B. Spinal Cord Anatomy
 31 spinal nerves
 8 pairs cervical nerves
 12 pairs thoracic nerves
 5 pairs lumbar nerves
 5 pairs sacral nerves
 1 pair coccyx nerve
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings