1. NERVOUS SYSTEM REVIEW

2. Be able to explain the 3 necessary functions of the nervous system

3. Identify the components of the CNS and the PNS
2 big initial divisions:
Central Nervous System CNS
The brain + the spinal cord
The center of integration and control
Peripheral Nervous System PNS
The nervous system outside of the brain and spinal cord
Consists of:
31 Spinal nerves
Carry info to and from the spinal cord
12 Cranial nerves
Carry info to and from the brain

4. Distinguish between the sensory (afferent) and motor (efferent) divisions
Can be divided into:
1. Sensory Division
Afferent division
Conducts impulses from receptors to the CNS
Informs the CNS of the state of the body interior and exterior
Sensory nerve fibers can be somatic (from skin, skeletal muscles or joints) or visceral (from organs w/i the ventral body cavity)
2. Motor Division
Efferent division
Conducts impulses from CNS to effectors (muscles/glands)
Motor nerve fibers

5. Somatic nervous system and the autonomic (ANS) nervous system
Somatic- conscious, voluntary control of skeletal muscles
ANS- automatic, involuntary

6. Sympathetic / Parasympathetic nervous system
These 2 systems are antagonistic.
Typically, we balance these 2 to keep ourselves in a state of dynamic balance.

7. Functional differences of supporting cells and neurons
Supporting cells (Neuroglia) insulate/protect neuron; do not transmit nor do they lose ability to divide
Neurons transmit messages impulse

8. Types of supporting cells

9. Supporting cells
Astrocytes – control the chemical environment of the brain; BBB
Are star-shaped
Microglia – dispose of debris, dead cells
Are spider-shaped

10. Supporting cells
Oligodendrocytes – create the myelin sheath only in the CNS
Ependymal cells – are ciliated to spread cerebrospinal fluid (CSF)

11. Axons and dendrites

12. Axons and dendrites Dendrites – conduct impulses toward the cell body
Axons – conduct impulses away from the cell body

13. Synapse/Synaptic cleft/synaptic membrane (pre and post)
Synapse – where neurons meet
Synaptic Cleft - space between neurons
Synaptic Membrane – pre is for sending neurotransmitters, post is for receiving neurotransmitters for an AP

14. Myelin and relationship to Schwann cells
Myelin insulates axon to speed up rate of transmission; Schwann is only in PNS

15. Cutaneous sense organs and proprioceptors
Cutaneous sense organs (CSO) – are found in skin and have sensory receptors;
Proprioceptors – sensory receptors in muscles and tendons to detect stretch and tension

16. Association or interneurons
Between; connect sensory to motor neurons

17. Polarization/Depolarization/ and Repolarization
Polarization – at rest, Na out/K in
Depolariozation – Na rush in to generate an action potential (AP)
Repolarization – returns to rest and has a refractory period

18. Irritability and conductivity of neurons
Irritability – ability to respond to a stimulus and disrupt the threshold to produce an AP
Conductivity – ability to transmit and spread an AP

19. Electrochemical nerve impulse
Is positive charge and is sent along axon to terminal then becomes chemical as neurotransmitters get released to produce another AP

20. Elements of a reflex arc
ALL REFLEX ARCS HAVE A MINIMUM OF 5 ELEMENTS:
1. A sensory receptor (which reacts to a stimulus)
2. An effector organ (muscle or gland to be stimulated)
3 and 4. Afferent and Efferent neurons to connect the two (interneuron or association)
5. CNS integration center

21. Autonomic and Somatic Reflexes
Autonomic – regulates smooth muscles, heart and glands
Somatic regulates activity of skeletal muscles
Both are still reflexes, automatic, involuntary responses

22. The Brain diagram