1. NERVOUS
SYSTEM

2. TOPIC #5 Nervous System Notesheet Neuron Vocabulary
Nervous System Web Lab Day 1 and 2
Neurons Notes (includes spinal nerve notesheet)
Nervous System Crossword
Quiz 1
Central Nervous System
Blood-BrainBarrier Article & Summary

3. Neuron Vocabulary Cell body Nissl substance Neurofibrils Dendrites
Axons
Axonal terminals
Neurotransmitters
Synaptic cleft
Synapse
Myelin
Schwann cells
Myelin Sheath
Neurilemma
Nodes of Ranvier
Nuclei
Ganglia
Tracts

4. neurons

5. NEURAL IMPULSE Parts 2 and 3 Continuous conduction
Unmyelinated neurons
Saltatory conduction
Myelinated neurons
Impulse travels faster as it jumps from/to each Node of Ranvier
Video
Neurotransmitters carry impulses across the synapse from pre-synaptic neurons to post-synaptic neurons
Parts 2 and 3

6. Part 8 Resting Potential Inside neuron is negative relative to outside
Extracellulary: More Na+ ions
Intracellularly: More K+ ions
Action Potential when neurons start firing messages/impulses
A strong enough stimulus causes charge reversal!
Positive Na+ ions rushing into neuron and K+ out = DEPOLARIZATION!
Repolarization occurs when K+ ions diffuse out of cell after impulse passes restoring overall negativity intracellularly
Neuron cannot conduct another impulse until repolarization is restored
Part 8

7. TYPES of neurons
There are 12 pairs of cranial nerves in the PNS that serve the head and the neck.
Only one pair (the vagus nerve) extends to the thoracic and abdominal cavities.
There are 31 pairs of spinal nerves in the PNS.
Formed by ventral & dorsal roots of spinal cord.
Named by the region of cord from which they arise.
 What happens after a spinal nerve is formed?
It divides into dorsal & ventral rami
Dorsal rami serve skin and muscles of posterior trunk
Ventral rami form plexuses (complex nerve networks that serve the limbs, motor and sensory)
T1 – T12 spinal nerves – ventral rami form intercostal nerves
Serve muscles between ribs & skin and also anterior/lateral trunk.

8. Central Nervous System
Embryonic development
Starts out as simple neural tube along length
Anterior end expands by 4th week = brain
Posterior end becomes spinal cord
Central canal enlarges into four main regions

9. SPINAL CORD
17 inches long
Continuation of brain stem
2-way communication pathway to/from the brain
Major reflex center
Protected by vertebrae and meninges
31 pairs of spinal nerves arise from it
Cauda equina (page 227)

10. Diencephalon (interbrain)
4 main parts (page 215)
Cerebral Hemispheres
Divided into lobes each with its own function
Diencephalon (interbrain)
Thalamus
Epithalamus
Pineal Body
Choroid Plexus
Hypothalamus
Limbic System
Pituitary Gland
Mammillary Bodies

11. 3. Brain Stem – size of thumb, 3 inches long
Midbrain
Pons
Medulla Oblongata
Reticular Formation
4. Cerebellum – provides precise timing of voluntary muscle activity, controls balance and equilibrium
Draw sagittal suture of brain and color and label the parts we have talked about today (page 219)

12. Protection of CNS
Meninges – connective tissue membranes that cover/protect the brain
Dura Mater
Arachnoid Mater
Pia Mater
Cerebrospinal Fluid – continuously circulates in the brain maintaining normal pressure
What?
Formed from?
How can you test it?
Blood Brain Barrier (homework)

13. DISEASES OF THE CNS