Introduction to Neuroanatomy and Terminology

Main Regions of the Nervous System Two Main Divisions –Central Nervous System –Peripheral Nervous System

Parts of Central Nervous System Spinal Region Brainstem and Cerebellum –Medulla –Pons –Midbrain –Cerebellum Cerebral Area –Diencephalon –Cerebrum

Spinal Region Within vertebral column Nerve roots are considered to be part of the spinal region

Spinal Cord - Functions Conduct information between the periphery and the brain Process information Simple and complex reflex responses

Review of Anatomy Dorsal root Dorsal root ganglion Ventral Root Spinal nerve Conus medullaris Cervical, thoracic, lumbar and sacral levels (# levels in each)

Spinal cord internal anatomy Gray matter –Central location –H-shaped –Dorsal horn –Ventral horn –Lateral horn – sometime present

Gray matter contents Cell bodies –Motor neurons –Interneurons Nerve endings –Sensory neurons

White matter –Periphery of spinal cord –Dorsal, lateral and ventral columns –Axons ascending and descending in spinal cord

Brainstem Medulla oblongata Pons Midbrain Connects spinal cord to cerebrum Most cranial nerves exit from the brainstem

Cross-section of Brainstem Base (2 and 3) Tegmentum (4) Tectum (5) Periventricular region (light region in 5)

Cerebellum Attached to posterior part of brainstem

Cerebral Region - Diencephalon Diencephalon –Thalamus –Hypothalamus

Cerebral Region - Cerebrum Cerebral cortex White matter that connects the cerebral cortex with other areas Deep nuclei

Lobes of the cerebral cortex Frontal Parietal Temporal Occipital Limbic

Support Systems Two arteries supply the brain –Internal carotid artery –Vertebral Artery

Support Systems - Ventricles 4 fluid-filled ventricles Also fluid-filled space surrounding brain and spinal cord Cerebrospinal fluid Choroid plexus Cushions brain

Clinical Aspects of the Nervous System What can cause injury to the nervous system? What are some examples of each?

Clinical Aspects of the Nervous System Types of lesions based based on their distribution History Examination

Distribution of Lesions Focal Multifocal Diffuse

History Onset of symptoms (time to maximal S & S –Acute (minutes to hours) –Subacute (few days) –Chronic (weeks or years) What type of disease process is associated with each time course?

History Is the patient awake? Is the patient aware? Can the patient respond properly to questions?

Examination Specific tests –Motor systems –Sensory systems –Autonomic systems Tests for specific areas of the nervous system

Diagnosis Is the lesion in the central or peripheral nervous system? Is the lesion focal, multifocal or diffuse? Unless you have reasons to think otherwise, usually assume that the S & S are due to one specific injury!

Is the lesion acute, subacute or chronic? Does the pattern of S & S indicate a syndrome? What region or regions of the nervous system are involved? What is the probable etiology? What is the diagnosis?

Directions – Spinal Cord Dorsal Ventral Anterior Posterior Rostral Caudal Superior Inferior

Directions - Brain Dorsal Ventral Anterior Posterior Rostral Caudal Superior Inferior

Names for Gray Matter Nucleus Ganglion –One major exception Basal Ganglia – part of CNS

Names for White Matter Nerve Tract Lemniscus Capsule Column Funiculus Fascicle (Fasciculus) Peduncle

Commissure Decussation