1. ANATOMY Unit 2 Notes: Cells & Organization

2. (1) Neurons Neuron = Nerve Cell Types: Multipolar + Unipolar
Basic Structural Components:
Dendrites (Incoming)
Cell Body (Integrate + Process)
Axon (Outgoing)
Myelin Sheath (Insulation + Speed)
Axon Terminal (Final Destination)

5. (2) Unipolar Neurons Use: Afferent Input (Sensory Input) Main Job:
Get message to CNS
Let CNS process and decide
(NO need to have cell body right by dendrites)
Process:
Dendrites connected to sensory organ
Message sent to cell body  Out Axon
Message sent out of axon terminal

7. (3) Multipolar Neurons Use: Efferent Output (Motor Output) Main Job:
Organize messages by importance
Make organs do things
(Important to have cell body right next to dendrites)
Process:
Cell body directly connected to dendrites
Dendrites coming from CNS / Efferent path  effected organ

9. (4) Neuroglia Function: Support, insulate and protect neurons. Types:
Cannot transmit nerve impulses
Can continuously divide through mitosis
Types:
Astrocytes
Microglia
Ependymal
Oligodendrocytes
Schwann Cells & Satellite Cells

10. (5) Astrocytes Connect neurons to capillaries
Transfer blood-nutrients to neurons (and neuron waste to blood)

13. (6) Microglia
Phagocytize neuron debris and infectious agents.

15. (7) Ependymal Cells Pillow-Shaped cells
Line brain and spinal cord cavities
Beat cilia + Circulate cerebrospinal fluid
Provide Shock Absorption

17. (8) Oligodendrocytes Flat, Straw-Shaped cells
Wrap around a neuron’s axon
Fatty insulation for axon (myelin sheath)

19. (9) Schwann & Satellite Cells
Schwann Cell:
Form Myelin Sheath around axons
Cover Oligodendrocytes
Satellite Cell:
Protective Cushioning
Surround Cell body of neurons

20. (10) Junctions Junction = Meeting of Neuron + Neuron or Neuron + Organ
A.K.A.  Synapse, Synaptic Cleft
Nerve Impulse  Axon  Axon Terminal  Release Neurotransmitter
Neurotransmitter = Chemical Message
Causes an effect
Binds with cell membrane on other side

22. (11) Nervous System Organization
CENTRAL NERVOUS SYSTEM
PERIPHERAL NERVOUS SYSTEM
(SENSORY / AFFERENT INPUT)
PERIPHERAL NERVOUS SYSTEM
(MOTOR / EFFERENT OUTPUT)
BODY
(INITIAL STIMULUS
/ IMBALANCE)
AUTONOMIC
(INVOLUNTARY)
SOMATIC
(VOLUNTARY)
SYMPATHETIC
(FIGHT / FLIGHT)
PARASYMPATHETIC
(REST & DIGEST)

23. (12) Defining the Levels Sensory = Afferent = Going to the CNS
Motor = Efferent = Going away from the CNS
Somatic = Voluntary
Autonomic = Involuntary
Sympathetic = Emotional
Parasympathetic = Non-Emotional

24. (13) Voluntary Responses
Voluntary = You consciously choose to move a body part / respond.
Pathway:
Motor / Efferent
Division
Central Nervous System
Somatic Division
Sensory / Afferent
Division
Stimulus
Effector Organ

25. (14) Involuntary Emotional Responses
Involuntary = Without control.
Emotional = Scared, Anxious, Angry, Happy, Excited
Pathway:
Motor / Efferent
Division
Autonomic
Division
Central Nervous System
Sensory / Afferent
Division
Sympathetic
Division
Stimulus
Effector Organ

26. (15) Involuntary Non-Emotional Responses
Involuntary = Without control.
Non-Emotional = Every day homeostatic mechanisms.
Pathway:
Motor / Efferent
Division
Autonomic
Division
Central Nervous System
Sensory / Afferent
Division
Parasympathetic
Division
Stimulus
Effector Organ