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

Ascending (Sensory) v v Figure 16.1 v

Descending (motor) v v v

Brain

CNS Development

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.) 11

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

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.) 16

Cerebellum and surrounding regions A: Midbrain . B: Pons. C: Medulla. D: Spinal cord. E: 4th ventricle. F: Arbor vitae. G: Tonsil. H: Anterior lobe. I: Posterior lobe. Cerebellum and surrounding regions; sagittal view of one hemisphere. A: Midbrain. B: Pons. C: Medulla. D: Spinal cord. E: Fourth ventricle. F: Arbor vitae. G: Tonsil. H: Anterior lobe. I: Posterior lobe.

Functions Balance Motor Skill

Regions of the Brain Telencephalon Diencephalon Brain stem Cerebellum

Ventricles and Location of the Cerebrospinal Fluid

Ventricles and Location of the Cerebrospinal Fluid

Diencephalon Thalamus Hypothalamus Epithalamus

Regions of the Brain Telencephalon Diencephalon Brain stem Cerebellum

Basal ganglia

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

Specialized Area of the Cerebrum

Cerebral White Matter Corpus callosum

Cerebral White Matter Internal capsule

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

The 12 pairs of cranial nerves

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