1. Dividing the Nervous System
actually a single uniform structure
divisions may be made on the basis of
structural continuity
function
developmental homology

3. Communication from the CNS to the PNS is via
Spinal Nerves
begin at the junction of the dorsal and ventral roots of spinal cord
innervate muscles and sensory receptors

5. Cranial Nerves attached to the ventral surface of the brain
innervate muscles and sensory receptors of the head
exception: the vagus nerve or CN X innervates the thoracic and abdominal cavity

8. Meninges
three layers of connective tissue which cover the nervous system

9. three layers
Dura Mater
Arachnoid Membrane
Pia Mater

10. Dura Mater Arachnoid Membrane Pia Mater "hard mother" outermost layer
thick, tough, and flexible but not stretchable
Arachnoid Membrane
"spider" membrane
soft and spongy
covers only the CNS - not found in the PNS
Pia Mater
"pious mother"
closely attached to the brain and spinal cord
follows every surface convolution

12. Subarachnoid Space space between the arachnoid membrane and pia mater
filled with CSF
cushions and protects the brain

13. note: The PNS is covered with only two layers of meninges
note: The PNS is covered with only two layers of meninges. The arachnoid membrane covers only the brain and spinal cord; it does not extend to the peripheral system.

14. The Blood Brain Barrier

15. What constitutes a BBB? (tight junction) endothelial cells
flat cells that line blood vessels particularly
densely packed (tight junction) in the blood vessels that transport oxygen and nutrients to the brain.

18. How do nutrients get into the brain?
small lipophilic (fat loving) molecules enter readily
hydrophilic (water loving) molecules are restricted
e.g. morphine is hydrophilic and does not easily enter the brain while heroin, a morphine derivative is lipophilic and enters readily

19. active transporters
there are systems which operate to specifically transport some hydrophilic molecules into the brain
e.g. the amino acids phenylalanine and tryptophan must be actively carried into the brain by these transport mechanisms

20. Peripheral Nervous System (PNS)

21. Somatic Division receives sensory information from the sensory organs
cell bodies located in dorsal root ganglia
afferent neuron
controls movements of the skeletal muscles
cell bodies located in the gray matter of the spinal cord
efferent neurons

25. Spinal Reflexes rapid, automatic response to stimuli
monosynaptic or polysynaptic

26. Autonomic Division regulates smooth muscle, cardiac muscle, and glands
smooth muscle is found in skin, blood vessels, eyes, gut, bladder, and gall bladder
two subdivision
sympathetic division
parasympathetic division

27. Sympathetic Division of ANS
fight or flight system
involved in activities that expend energy
increase HR, BP, RPM
dilate pupils
cause piloerection in animals
responsible for the 4 Fs

28. Parasympathetic Division of ANS
supports activities that increase the body's store of energy
controls salivation, intestinal motility, secretion of digestive juices
the "LDHN" (lye down and have a nap) system (I made that up)

29. The Central Nervous System (CNS)

30. Divide the Brain into 3 Major Sections:
Forebrain
Cortex
subcortical structures
Midbrain
Tectum
Tegmentum
Hindbrain
Pons
Cerebellum
Medulla Oblongata

31. Structures of the Forebrain
cerebral cortex
basal ganglia
limbic system
thalamus
hypothalamus

32. Structures of the Midbrain
Tectum
Tegmentum

33. Structures of the Hindbrain
pons
cerebellum
medulla oblongata

34. Cortex & Subcortical Structures
The Forebrain
Cortex
&
Subcortical Structures

35. Subcortical Structures

36. Limbic System consists of mediates emotion and memory
the limbic cortex or cingulate gyrus
hippocampus
fornix
mammillary bodies
olfactory bulbs
amygdala
mediates emotion and memory
"old" part of the mammalian brain

38. The Basal Ganglia subcortical nuclei
anterior and inferior to the lateral ventricles
consists of
caudate (tail)
putamen (shell)
globus pallidus (pale globe)
involved in the control of movement
damage or loss of particular components may yield
Parkinson's like symptoms
uncontrollable movements

39. Thalamus "inner chamber"
immediately medial and caudal to the basal ganglia
most neural input to the cerebral cortex comes from the thalamus
a relay station

40. Hypothalamus
lies at the base of the brain inferior and anterior to the thalamus
largely responsible for homeostasis
regulates eating, drinking, sexual drive and other species specific behaviors
regulates hormones via anterior and posterior pituitary

41. The Midbrain

43. The Tectum means "roof" includes superior colliculus
responsible for visual/vestibular reflexes
inferior colliculus
responsible for auditory/vestibular reflexes

44. The Tegmentum means "floor" or covering as in a rug
ventral to the tectum
includes:
rostral end of reticular formation
periaqueductal gray matter
high concentration of endogenous opiate receptors

47. Substantia Nigra or Dark Substance
sends informtion to the basal ganglia (caudate and putamen)
loss of these DA neurons results in Parkinson's Disease

48. The Hindbrain

50. Cerebellum "little brain" two hemispheres covered by cerebellar cortex
receives variety of sensory information
visual
auditory
vestibular
somatosensory
kinestetic
proprioceptive
largely responsible for smooth volitional movement
damage results in
impaired standing, walking, coordinated movement
produces jerky, poorly coordinated and/or exaggerated movements

52. Pons Pons = bridge the "bulgy" part of the brainstem
rostral to medulla
ventral to cerebellum

53. contains a portion of the reticular formation
occupies core of the brainstem
responsible for
sleep and arousal
attention
muscle tone
movement

54. Medulla most caudal portion of the brainstem
most caudal portion is rostral border of the spinal cord
responsible for
arousal
reticular formation
vital functions
damage coma or death

55. Reticular Formation