1. Nervous System Structure

2. The Nervous System Central Nervous System (CNS)
Peripheral Nervous System (PNS)

3. Neuraxis
The imaginary line drawn through the CNS, from the base of the spinal cord to the front of the brain.

4. Nervous system directions, in relation to the neuraxis
Anterior / Rostral
Toward the nose
(rOstral  nOse)
Dorsal
Toward the back
Superior
Above
Lateral
Away from the midline
Ipsilateral
Same side
Posterior / Caudal
Toward the tail
(cAudal  tAil)
Ventral
Toward the belly
Inferior
Below
Medial
Toward the midline
Contralateral
Opposite side

5. Contralateral
Ipsilateral

6. Nervous system planes Transverse Sagittal Horizontal Cross section
Sagittal section
Horizontal
Horizontal section

7. Meninges Three protective layers surrounding the brain and spinal cord
Layers of the meninges
Brain
Pia mater
Arachnoid trabeculae
Subarachnoid space
Arachnoid membrane
Dura mater
Three protective layers surrounding the brain and spinal cord
Dura Mater
Arachnoid membrane
Pia mater

8. Ventricles
Openings in the brain that contain cerebrospinal fluid (CSF)

9. Cerebrospinal fluid CSF is made in the choroid plexus
CSF flows through the ventricles into the subarachnoid space, where it surrounds the CNS.

10. Neural development Neural tube
Develops into the CNS
Neural tube forms 3 ventricles at the rostral end
Tissue surrounding ventricles = ventricular zone

11. Neural development Forebrain Midbrain (Mesencephalon) Hindbrain
Telencephalon
Diencephalon
Midbrain (Mesencephalon)
Tectum
Tegmentum
Hindbrain
Metencephalon
Myelencephalon

12. Cellular development Founder cells - in developing brain
Initial cells in the ventricular zone
Symmetrical division
Increases size of the ventricular zone
Asymmetrical division
Creates neurons while maintaining ventricular zone
Stem cells - in the adult brain

13. Cellular development Radial glia
Radial glia ensure development of systematic pathways in the brain.

14. Cellular development Cortical development ends with apoptosis
Neurons grow into adult form with dendrites, axons & terminal buttons
Neurons that do not connect with other neurons die

15. Forebrain - Telencephalon
Cortex
Limbic system
Basal ganglia

16. Telencephalon Cerebral cortex – surrounds the cerebral hemispheres
Gyri (singular: Gyrus)
Sulci (Sulcus)
Fissures
Cortex consists of densely packed glia and neurons
Four lobes of the brain
Frontal
Parietal
Temporal
Occipital

17. Cortex - Frontal lobe Prefrontal Cortex
Involved in organization of thought, planning actions, and higher cognitive functions.

18. Cortex - Frontal lobe Primary motor cortex (PMC)
Directly controls motor output
Somatotopic organization
Motor Association Cortex
Involved in planning movement

19. Cortex - Parietal lobe Primary Somatosensory Cortex
Receives sensory information
Somatotopic organization
Somatosensory Association Cortex
Somatosensory perception and memories

20. Cortex - Temporal lobe Primary Auditory Cortex
Receives auditory input
Auditory Association Cortex
Analyzes auditory information
Auditory perception and memory storage

21. Coretex - Occipital lobe
Primary Visual Cortex
Receives input from the visual system
Input comes from the contralateral visual field
Visual Association Cortex
Analyzes information received in the PVC
Involved in visual perception

22. Cortical connections
Corpus Callosum – large bundle of axons connecting corresponding regions of each hemisphere

23. Telencephalon – Limbic system
Located within the telencephalon
Includes:
Limbic cortex
Amygdala
Hippocampus
Mammillary bodies of the hypothalamus
Fornix

24. Limbic system
Major role in emotion, learning and memory

25. Telencephalon – Basal ganglia
Motivation and generation of movement
Include:
Caudate nucleus
Putamen
Globus pallidus

26. Forebrain - Diencephalon
Located between the telencephalon and the midbrain
Includes:
Thalamus
Hypothalamus

27. Diencephalon Thalamus
Composed of nuclei that relay information to the proper cortical regions
Projection fibers

28. Diencephalon Hypothalamus
Controls the autonomic nervous system and the endocrine system
Two major structures control endocrine function
Anterior pituitary gland
Posterior pituitary gland

29. Midbrain (Mesencephalon)
Structurally and evolutionarily between the diencepalon and the hindbrain
Only two major structures
Tectum
Tegmentum

30. Midbrain - Tectum Located on the dorsal mesencephalon
Superior colliculi
Inferior colliculi

31. Midbrain - Tegmentum Located on the ventral mesencephalon
Reticular formation
Periaqueductal grey area
Red nucleus
Substantia nigra

32. Hindbrain
Most primitive brain structure; responsible for basic survival functions
Consists of the metencephalon and myelencephalon

33. Hindbrain - Metencephalon
Cerebellum (dorsal brainstem)
Attached to the pons by the cerebellar peduncles
Coordinates movement
Pons (ventral brainstem)
Projects information from cortex to cerebellum
Role in sleep and arousal

34. Hindbrain - Myelencephalon
Caudal-most region of the brain
Contains the medulla oblongata
Cardiovascular & respiratory functions, muscle tone, arousal

35. Spinal cord Cells of the spinal cord Grey matter White matter
Cell bodies and unmyelinated axons
Dorsal horns
Ventral horns
White matter
Myelinated axons
web.lemoyne.edu/.../graphics/spinal_cord.jpg

36. Spinal cord Spinal nerves
31 pairs of spinal nerves attach to the spinal cord
Each spinal nerve consists of a motor efferent (output) and a sensory afferent (input)
As each nerve approaches the spinal cord, it splits into a dorsal and ventral root

37. Spinal cord Dorsal root – carries the sensory axon
Cell body is in the dorsal root ganglion
Axon enters the spinal cord
Ventral root – carries the motor axon
Cell body is in the ventral horn of the spinal cord
Axon exits to the periphery

38. Cranial nerves
12 pairs of cranial nerves attach to the ventral surface of the brain.
Sensory & motor functions of the face, head, neck and throat.

39. Peripheral Nervous System
Somatic Nervous System
Autonomic Nervous System
Sensory input
Motor control
Sympathetic Nervous System
Parasympathetic Nervous System
“Fight or Flight” Response
Utilization of energy resources
“Rest & Digest” Response
Conservation of energy resources