Central Nervous System (CNS): Brain and Spinal Cord Comparative Anatomy Tony Serino, Ph.D. Biology Dept. Misericordia Univ.
Central Nervous System (CNS) Gray vs. White matter Protection of CNS Meninges CSF flow Brain Development Selected structures Spinal cord
CNS (Central Nervous System) Brian and spinal cord Displays gray and white matter Gray matter are areas of CNS with many cell bodies of neurons present (little myelinated nerve fibers) White matter are area of CNS with few cell bodies but many myelinated nerve fibers Protected by bone and membranes
Meninges Dura Mater –outermost; tough, fibrous CT In brain, divided into two layers (periosteal and meningeal) In spine, only one layer with fat filled space above the layer called the epidural space Arachnoid –middle; web-like appearance Potential space between Dura and arachnoid is the subdural space Pia Mater –innermost, delicate membrane fused with CNS surface Space between Pia and Arachnoid is the subarachnoid space
Brain Meninges
Brain Ventricles
Choroid Plexus
CSF (cerebral-spinal fluid) Flow
Hydrocephalus Blockage of CSF flow can lead to severe brain and/or head enlargement. In an adult, such swelling would be fatal.
Brain Development Structures Functional Areas
Brain Vesicles
Major Divisions of Brain Brain Stem = midbrain + pons + medulla
Brain Anatomy (req’d)
Projections vs. Commissures
Functional Anatomy of Brain
Functional Areas of Cerebrum
Primary Motor and Somatosensory Gyri
Basal Nuclei: cerebral nuclei Putamen and Globus Pallidus Subthalamic nuclei and the Substantia nigra are usually included
Limbic System: functional system; responsible for emotion and memory Cingulate Gyrus Fornix Mammillary body
Circle of Willis
Spinal Cord Receives and generates signals to body through the spinal nerves
Spinal Cord (X.S.)
Cord in Spinal Canal Posterior Median Sulcus Posterior Root Denticulate Ligament Dorsal Root Ganglion Anterior Root Spinal Nerve
Spinal Cord Segments 4 segments: Cervical, Thoracic, Lumbar, and Sacral (only 1 coccygeal nerve) 31 pairs of spinal nerves
Cauda Equina
Lumbar Puncture
Functional Arrangement of SC
Neurotransmission Scenario
ANS Divsions
Parasympathetic (Craniosacral)
Sympathetic (Thoracolumbar)
Sympathetic Ganglia