Chapter 3 lec 1 by pengxiang

VIEWS: 3 PAGES: 15

									Mind and
 Brain



           Structure of the Nervous
           System
           Chapter 3
Chapter Preview
 Basic Features of the Nervous System
 The Central Nervous System
 The Peripheral Nervous System
Basic Features of the Nervous
System
   An Overview (see Figure 3.1)
    ◦ Directions in the Nervous System
        Anterior/Rostral = Front
        Posterior/Caudal = Back
        Dorsal = Top
        Ventral = Bottom
        Lateral = Toward the Side
        Medial = Toward the Middle
        Ipsilateral = Same Side
        Contralateral = Opposite Side
Directions in the Vertebrate
Nervous System
Directions in the Vertebrate
Nervous System
Basic Features of the Nervous
System
 ◦ Brain Slices and Planes
    Cross Section or Frontal Section
      Transverse section at right angles to the neuraxis.
      Also called coronal section
    Horizontal Section
      Section made through the brain parallel to the ground.
    Sagittal Section
      Section parallel to neuraxis and perpendicular to the
       ground.
      Midsagittal Plane – special type of sagittal section through
       the corpus callosum separating the hemispheres.
Figure 3.2 Brain Slices and Planes
Basic Features of the Nervous
System
 ◦ Central Nervous System (CNS)
    Brain and spinal cord
      Encased in bone
 ◦ Peripheral Nervous System (PNS)
    Cranial nerves, spinal nerves, and peripheral ganglia
Figure 3.3 The Nervous System
Basic Features of the Nervous
System
   Meninges
    ◦ Dura Mater – tough, flexible outermost meninx.
    ◦ Arachnoid Membrane – middle layer of the
      meninges.
      Subarachnoid Space – space between arachnoid
       membrane and pia mater filled with cerebrospinal fluid
       (CSF)
    ◦ Pia Mater – last layer of the meninges, which
      adheres to the surface of the brain.

    ◦ The PNS is covered by only 2 layers
      The dura mater and pia mater fuse to form a sheath
Basic Features of the Nervous
System
   Ventricular System and Production of CSF
    ◦ Ventricles – a set of holes within the brain
      filled with CSF. These include:
      Lateral Ventricles
      Third Ventricle
      Cerebral Aqueduct – connects third and fourth
       ventricles
      Fourth Ventricle
    ◦ Choroid Plexus – highly vascular tissue that
      protrudes into the ventricles and
      manufactures CSF.
CSF
   CSF is produced by the choroid plexus.
   Continuously
   Total volume = 125ml
   Half-life ~3 hours
   CSF flows from lateral ventricles, into 3rd ventricle, then
    flows through cerebral aqueduct to 4th ventricle, then
    flows through subarachnoid space around CNS.
   CSF gets reabsorbed into the blood supply through the
    arachnoid granulations.
Figure 3.4 Ventricular System of the
Brain
Figure 3.6 Hydrocephalus in an
Infant
Terminology Note
              CNS              PNS
Myelin-       Oligodendrocytes Schwann
providing                      Cells
glia
Clusters of Nuclei               Ganglia
cell bodies (singular nucleus)   (singular
                                 ganglion)
Bundles of Tracts                Nerves
axons

								
To top