Anatomy of the Nervous System Central nervous system (CNS) Spinal cord Brain Peripheral nervous system (PNS) Nerve outside the brain and spinal cord

Brain

Regions of the Brain Telencephalon Diencephalon Brain stem Cerebellum

Brain Stem Parts of the brain stem Medulla oblongata Pons Midbrain

Medulla oblongata Fig. 12.9 A sagittal section of the brain. (Photograph by Kevin Fitzpatrick on behalf of GKT School of Medicine, London.) 8

Pons Fig. 12.9 A sagittal section of the brain. (Photograph by Kevin Fitzpatrick on behalf of GKT School of Medicine, London.) 9

functions Major Components of Brainstem Cranial nerve nuclei & related structures Long fiber tracts ascending and descending Cerebellar paths and circuits Reticular formation & related structures Functional Divisions Cranial nerve abnormalities Long tract deficits (motor & sensory) Ataxia (cerebellar origin) Impaired level of consciousness (RF)

Midbrain Fig. 12.9 A sagittal section of the brain. (Photograph by Kevin Fitzpatrick on behalf of GKT School of Medicine, London.) 11

Cerebellum Fig. 12.9 A sagittal section of the brain. (Photograph by Kevin Fitzpatrick on behalf of GKT School of Medicine, London.) 13

Functions Balance Motor Skill

Regions of the Brain Telencephalon Diencephalon Brain stem Cerebellum

Diencephalon Thalamus Hypothalamus Epithalamus

Ventricles and Location of the Cerebrospinal Fluid

Ventricles and Location of the Cerebrospinal Fluid

Regions of the Brain Telencephalon Diencephalon Brain stem Cerebellum

Cerebral gray and white matter Corpus callosum

Lobes of the Cerebral Cortex (lateral surface) Frontal lobe Parietal lobe Temporal Lobe Occipital lobe

Basal ganglia

The 12 pairs of cranial nerves

Cranial Nerve 1: Olfactory Nerve

Spinal Nerves 31 pairs

Spinal Nerves

Dorsal ramus

Ventral ramus

Fig. 57.23 The approximate segmental distribution of the cutaneous nerves on the front of the trunk. The contribution from the first thoracic spinal nerve is not shown and the considerable overlap that occurs between adjacent segments is not indicated.

The segmental innervation of anterior surface of trunk

Spinal nerve plexus

The Cervical Plexus Deep in the neck under the sternocleidomastoid muscle Formed by first 4 cervical nerves (C1 – C4) Most are cutaneous nerves Phrenic nerve – major nerve

The Cervical Plexus (C1 – C4)

Brachial plexus (C5 -T1)

Lumbar Plexus

Sacral Plexus

The Lumbar Plexus The Sacral Plexus