The document discusses the back and autonomic nervous systems. It begins by covering the anatomy of the vertebral column, including its embryology, functions, typical vertebrae structure, intervertebral disks, and spinal meninges. It then discusses the autonomic nervous system, including that it innervates smooth muscle, cardiac muscle and glands. The autonomic nervous system consists of the sympathetic and parasympathetic divisions, each involving a two-neuron pathway from the CNS to target organs. The sympathetic division prepares the body for fight or flight through spinal cord pathways from T1-L2. The parasympathetic division conserves energy at rest through cranial nerve and sacral spinal cord pathways.

1. BACK AND AUTONOMIC
NERVOUS SYSTEM
DANIEL ORTIZ .D.D.S 21/05/2019

2. LEARNING OBJECTIVES
 Demonstrate understanding of vertebral column and spinal meninges
 Use knowledge of spinal nerves
 Use knowledge of autonomic nervous system

3. VERTEBRAL COLUMN
 EMBRYOLOGY
 During week 4, Slerotome cells of the
somites ( mesoderm) migrate medially
to surround the spinal cord and
notochord
 WHAT IS A SOMITE?
 masses of mesoderm distributed along
the sides of the neural tube that will
eventually become dermis, skeletal
muscle, or vertebrae

4. SCLEROTOME
 Sclerotome cells
Surrounding NEURAL
TUBE.
 After proliferation of the
caudal portion of the
sclerotomes, the
vertebrae are formed,
each consisting of the
caudal part of one
sclerotome and the
cephalic part of the next.

5. VERTEBRAL COLUMN
FUNCTIONS:
• Muscle attachment
• Movements
• Articulations of the head and trunk
• Protection for the spinal cord
• The vertebral column is composed of
32-33 vertebrae
• ( 7 cervical, 12 thoracic, 5 lumbar, the
fused 5 sacral and 3-4 coccygeal.
• Intervertebral disks
• Synovial articulations ( zygapophyseal
joints)
• ligaments
33 vertebrae
31 spinal nerves

6. TYPICAL VERTEBRA
 A Typical vertebra consist of
anterior body and a posterior
vertebral arch consisting of 2
pedicles and 2 laminae.
 Vertebral foramen-spinal chord
 The pedicle is a stub of bone that
connects the lamina to the
vertebral body to form the
vertebral arch
 Transverse processes provide
attachment sites for muscles and
ligaments.

7. TYPICAL VERTEBRA
 Vertebral notches
of adjacent
pedicles form
intervertebral
foramen:
provides for the
exit of the spinal
nerves.

8. INTERVERTEBRAL DISKS
 The intervertebral disk contribute to
about 25% of the length of the
vertebral column. They form the
cartilaginous joints between the
vertebral bodies and provide limited
movements between the individual
vertebrae.
 GENERAL RULE : each intervertebral
disk is numbered by the vertebral
body above the disk
 Each intervertebral disk is composed
of the following

9. INTERVERTEBRAL DISKS
 Annulus fibrosus: consist of the outer
concentric rings of fibrocartilage and
fibrous connective tissue. The annuli
connect the adjacent bodies and
provide limited movement between
the individual vertebrae.
 NUCLEUS PULPOSUS. Is a inner soft,
elastic, compressible material that
functions as a shock absorber for
external forces. IS THE POSTNATAL
REMMANT OF THE NOTOCHORD

10. LIGAMENTS OF THE VERTEBRAL COLUMN
 The vertebral bodies are strongly supported
by two ligaments. Both ligaments are firmly
attached to the intervertebral disks and to
the bodies of vertebrae.
 Anterior longitudinal ligament
 Posterior longitudinal ligament

11. INTERVERTEBRAL FORAMEN
 The intervertebral foramina are formed by
successive intervertebral notches and provide
for the passage of the SPINAL NERVE. The
boundaries of the foramina are:
 Anterior: Bodies of the vertebrae and
intervertebral disks
 Posterior: Zygapophyseal joint and articular
processes
 Superior and inferior : pedicles of the
vertebrae

12. SPINAL MENINGES
 The spinal cord
is protected and
covered by three
connective tissue
layers within the
vertebral canal:
The Pia mater,
Dura mater,
and arachnoid.

13. PIA MATER
 The Pia mater is tightly attached to the surface of the spinal cord and provides a
delicate covering of the cord.
The spinal cord, with its covering of pia mater.
Terminates at the L1 or L2
vertebral levels in the
adult.

14. Pia Mater
 The denticulate ligaments are
bilateral thickenings of pia mater that
run continuously on the lateral sides
of the midpoint of the cord. They
separate the ventral and dorsal roots
of the spinal nerves and anchor to
the Dura mater.
 The filum terminale is a
continuation of the pia mater distal
to the lower end of the spinal cord.
The filum terminale is part of the
CAUDA EQUINA, which is composed
of ventral and dorsal roots of lumbar
and sacral nerves that extend below
the inferior limited of the spinal
chord

15. DURA MATER
 The Dura mater is a tough,
cylindrical covering of connective
tissue forming a Dural sac, which
envelops the entire spinal cord
and cauda equina.
 ITS + RESISANT OF THE 3 LAYERS
MENINGEAS

16. DURA MATER
The Dura mater and Dural sac terminate inferiorly at
the second sacral vertebral level
Superiorly, the Dura mater continues through the
foramen magnum, and is continuous with the
meningeal layer of the cranial Dura.

17. ARACHNOID
 The arachnoid is a delicate membrane which completely lines the inner surface of
the Dura mater and Dural sac. It continues inferiorly and terminates and the
second sacral vertebral.

18. TWO SPACES RELATED TO THE
MENINGES
 The epidural space is located between the inner walls of the vertebral canal and
the Dura mater. It contain fat and the internal vertebral venous plexus.

19. TWO SPACES RELATED TO THE
MENINGES
 The subarachnoid space is pressurized space located between the arachnoid
and pia mater layers. It contains cerebrospinal fluid( CSF), which bathes the
spinal cord and spinal nerve roots within the Dural sac, and terminates at the
second sacral vertebral level.

20. IMPORTANT
 L1 OR L2 vertebrae.
Inferior limit of the spinal
cord in adult ( conus
medullaris )
 S2 vertebra: inferior limit
of the Dural sac and the
subarachonoid space (
cerebrospinal fluid)

21. IMPORTANT TO KNOW
 In vertebrates it consists of two main parts, the central nervous system (CNS) and the
peripheral nervous system (PNS). The CNS consists of the brain and spinal cord. The
PNS consists mainly of nerves, which are enclosed bundles of the long fibers or axons,
that connect the CNS to every other part of the body. Nerves that transmit signals from
the brain are called motor or efferent nerves, while those nerves that transmit
information from the body to the CNS are called sensory or afferent. Spinal nerves serve
both functions and are called mixed nerves. The PNS is divided into three separate
subsystems, the somatic, autonomic, and enteric nervous systems. Somatic nerves
mediate voluntary movement. The autonomic nervous system is further subdivided into
the sympathetic and the parasympathetic nervous systems. The sympathetic nervous
system is activated in cases of emergencies to mobilize energy, while the
parasympathetic nervous system is activated when organisms are in a relaxed state. The
enteric nervous system functions to control the gastrointestinal system. Both autonomic
and enteric nervous systems function involuntarily. Nerves that exit from the cranium are
called cranial nerves while those exiting from the spinal cord are called spinal nerves.

22. Diagram

23. AUTONOMIC NERVOUS SYSTEM (ANS)
 The autonomic nervous system is concerned the motor innervation of SMOOTH
MUSCLE, CARDIAC MUSCLE, and GLANDS OF THE BODY
 Anatomically and functionally, the ANS is composed of two motor divisions:
 1) Sympathetic and 2) Parasympathetic. In both divisions. Two neurons
form and autonomic pathway.

24. AUTONOMIC NERVOUS SYSTEM (ANS)
Preganglionic neurons have their neuronal
cell bodies in the CNS (formed by
neuroectoderm); their axons exit in cranial
and spinal nerves
Postganglionic neurons have cell bodies in
autonomic ganglia in the peripheral nervous
system ( PNS) ( formed by neural crest cell)

25. SYMPATHETIC NERVOUS SYSTEM
 ALSO CALL ¨ FIGHT OR FLIGTH”
 ¨¨E¨¨ DIVISSION: EXERCISE. EXCCITMENT, EMERGENCY, EMBARRASMENT
 The preganglionic cell bodies of the sympathetic nervous system are found in
the LATERAL HORN gray matter of spinal cord segments T1-L2 ( 14 segments).
 The postganglionic cell bodies of the sympathetic system are found in one of
two types of motor ganglia in the PNS:
 1)Chain or Paravertebral
 2)Collateral or Prevertebral (found only in abdomen or pelvis)

26. Sympathetic nervous system (
thoracolumbar outflow)

27. Parasympathetic Nervous System
 Responsable for mainting your body and conserving enery for later
 “ REST AND REPOSE” System
 The preganglionic cell bodies of the parasympathetic nervous system are found in
the CNS in orne of 2 places.
1. Gray matter of brain stem associated with cranial nerves III. IV.IX.X
2. Spinal cord gray in sacral segments S2. S3. S4 ( PELVIC SLANCHNICS)
 The postganglionic cell bodies of the parasympathetic nervous system are found
in terminal ganglia in the PNS that usually located near the organ innerrvated or
in the Wall of the organ.

28.  POSTGANGLIONAR FIBERS OF SYMPATHETIC
NERVOUS SYSTEM ARE LONGER TOWARD
TARGET ORGAN IN COMPARISSION WITH
PARASYMPATHETIC FIBERS OF
PARASYMPATHETIC NERVOUS SYSTEM.

29. Comparison of Autonomic and somatic
motor Systems

30. Difference
between
sympathetic
and
parasympath
etic