Structure of the nervous system Neuroanatomy

Brain ~1.3 – 1.4 kg Men > Women

Some free brain atlases (apps and websites): BrainView: http://itunes.apple.com/us/app/isurf-brainview/id381072423?mt=8 Brain tutor 3D: http://www.brainvoyager.com/iOS/iphonebraintutor3d.html 3D brain: http://itunes.apple.com/us/app/3d-brain/id331399332?mt=8 http://www.med.harvard.edu/AANLIB/cases/caseNA/pb9.htm

Central vs. Peripheral nervous system Central Nervous System (CNS) Brain (in the skull) Spinal Cord (in the spine) Peripheral Nervous System (PNS) Located outside of the skull and spine Serves to bring information into the CNS and carry signals out of the CNS

Brain size by age & gender Alzheimer

Brain size by age & gender Alzheimer

Superior (dorsal) view Inferior (ventral) view Dorsal = Top Ventral = Bottom

Lateral view Medial view

Posterior/ Caudal Anterior/ rostral

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

Cross sections of the brain

Grey matter White matter Grey matter White matter

Brain Slices and Planes Cross Section or Frontal Section (also called coronal) Transverse section at right angles to the neuraxis. Horizontal Section (also called axial) 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.

Grey vs. White matter frontal section horizontal section ventricles White matter Grey matter Grey matter: neuron and glia cell bodies (between 1 – 4mm thick) White matter: axons

sulcus gyrus Total surface area of the cerebral cortex = 2,500 cm2 (mostly buried inside sulci)

Owl monkey

Comparative Neuroanatomy The complexity of sulci increased throughout evolution Source: Comparative Mammalian Brain Collection http://brainmuseum.org/

Cerebral Cortex Two Hemispheres

Two Hemispheres (lateral view) posterior anterior anterior posterior Right Hemisphere Left Hemisphere Cerebellum Cerebellum

Defining the lobes Lateral View central (rolandic) sulcus frontal lobe parietal lobe occipital lobe temporal lobe sylvyan (lateral) sulcus

Two hemispheres Medial view Lateral view Cerebellum Corpus Callosum posterior anterior anterior posterior Cerebellum Corpus Callosum Brain stem Cerebellum

Defining the lobes Medial View Frontal Parietal Cingulate gyrus Occipital Temporal

03-10b Cytoarchitecture Broadman’s areas Lateral

03-10c Cytoarchitecture Broadman’s areas medial

Grey vs. White matter frontal section horizontal section ventricles White matter Grey matter Grey matter: neuron and glia cell bodies (between 1 – 4mm thick) White matter: axons

Ventricular System and Production of CSF Ventricles – a set of holes within the brain filled with CSF (cerebro spinal fluid). These include: Lateral Ventricles Third Ventricles Cerebral Aqueduct Fourth Ventricle Choroid Plexus – manufactures CSF.

Four Ventricles Two laterals Third Fourth the brain "floats" in it. Filled with cerebrospinal fluid (CSF) CSF - surrounds the brain the brain "floats" in it. a "cushion" or buffer for the brain http://www.neuroanatomy.wisc.edu/ventricles/ventricles.html

Summary Directions Slices Grey/White matter Sulci & Gyri Cerebral cortex has two symmetrical hemispheres divided to 4 lobes (each!) The lobes are further subdivided by cytoarchitectonic features The ventricular system