1. Chapter 11 Outline
12.1 Basic Structure and Functions of the Nervous System
A. Overall Function of the N.S. & Basic Processes Used
B. Classification of the Nervous System
Histology of Nervous System
A. Neuroglia Cells
B. Neurons
C. Types of Neurons
12.4 The Action Potential
A. Electrically Active Cell Membranes
B. Membrane Potentials That Act As Signals
C. Graded Potentials (See Text section 12.5)
D. Action Potentials
12.5 Communication Between Neurons
A. Basic Concepts and Terms
B. Synapses
C. Neurotransmitter Systems
12.3 The Functions of the Nervous System– How the Parts All Work Together

2. 11.1 The Nervous System: Receives, Integrates, and Responds to Information
A. Overall Function of the Nervous System & Basic Processes Used
Afferent =
INTEGRATION
Efferent =
Figure 7.1

3. B. Classification of the Nervous System
1. CNS =
Parts
Functions:
2. PNS =
Functions

4. 2. Functional Subdivisions of the Peripheral N.S.
Sensory
(Afferent)
Motor
(Efferent)
Figure 7.2

5. 2. Peripheral Nervous System … a. Afferent (Somatic) Division
Components

6. i) Somatic nervous system = ____________
2. Peripheral Nervous System … b. Motor division Functional Subdivisiions
i) Somatic nervous system = ____________
ii) Autonomic nervous system = ___________
Parasympathetic =
Peace
Sympathetic =
Stress

7. 11. 2 Neuroglia Support & Maintain Neurons A
11.2 Neuroglia Support & Maintain Neurons A. Neuroglia (Glial) Cells– 6 types
1. in CNS
1. Astrocytes –
2. Microglial

8. II-A
3. Ependymal –
4. Oligodendrocyte –

9. Neuroglia …
PNS
5. Satellite cells--
6. Schwann cells--

10. 11.3 Neurons are the Structural Units of the Nervous System

11. B. Neurons = _______________________
1. Neuron anatomy
a. Cell body
Function
Nissl Body
Nuclei & Ganglion
b. Neuron Processes:
i) Dendrites:
ii) Axons:
Functon
Axolemma
Axon Hillock
Nissl Body

12. Terminal Branches (telodendria): _____________ Axon terminals:
B-ii
Axon Collaterals =
Terminal Branches (telodendria): _____________
Axon terminals:
Synaptic Vessicles
Nuerotranmitters
Synapse & Synaptic Cleft
Terminal Branch

13. Which Axons Function: Process: Neurilemma: Nodes of Ranvier:
II-B c. Myelin sheath:
Which Axons
Function:
Process:
Neurilemma:
Nodes of Ranvier:
Schwann Cells

14. Nerve fiber myelination by Schwann cells in PNS.
sheath
Schwann
cell
cytoplasm
Axon
Neurilemma
(b) Cross-sectional view of a myelinated axon (electron micrograph 24,000X)

17. Neurons … C. Types of Neurons 1. Functional Classification
a. Motor b. Sensory c. Association (Interneuron)

18. a. Multipolar neurons: Abundance Functional Types:
Neurons … C. Types of Neurons … 2. Structural Classification of Neurons
a. Multipolar neurons:
Abundance
Functional Types:
Figure 7.8a

19. Structural Classification of Neurons …
Bipolar neurons: ______________
Abundance:
Functional Types:
Figure 7.8b

20. Structural Classification of Neurons …
Unipolar neurons:
Functional Types:
Figure 7.8c

21. 2. Functional Types of neurons Motor Sensory Association, Interneurons

22. 11.4 The Resting Membrane Potential
Neurotransmitter GP
ELECTRICAL AP
Neurotransmitter CHEMICAL GP
ELECTRICAL AP
Neurotransmitter
A. Nerve Impulse Components:
KEY
1) Graded Potential
2) Action Potential
1) Neurotransmitter at Synapse GP

23. 12.4 The Action Potential … B. Electrically Active Cell Membranes
1. Electricity across Membranes
a. Opposite charges
b. Separated charges
c. Voltage (V) =
Flow of charge
2. Role of IONS
3. Role of Transmembrane Proteins-REVIEW
a. Carrier Proteins
b. Channels
c. Pumps

24. Role of Transmembrane Proteins-REVIEW …
b. CHANNELS:
Allow:
Two main types:
1. Leakage (ungated) channels:
2. Gated channels (3 types):
Chemically gated (ligand-gated):
Voltage-gated:
Mechanically gated:

25. c. Pumps 1. Characteristics 2. Example: Na+/K+ Pump

26. 3. Resting Membrane Potential (RMP) a. Differences in Ionic Composition
Occurs at membrane surface
Chemical Gradient
i. INSIDE:
K+ most
Negative Proteins
& Amino Acids
ii. OUTSIDE:
Na+
b. Electrical
Gradient
Membrane Potential = _______
c. Membrane is polarized
Dendrites
Axon A- K+
Na+
Na+
Cell Body

27. 3. Resting Membrane Potential …
d. Maintenance of RMP
Differences in Plasma Membrane Permeability:
Impermeable to negative proteins
Leakage of Na+ and K+
Na+/K+ ATPase PUMP
Outside cell
Na+
(140 mM ) K+
(5 mM ) K+
(140 mM )
Na+
(15 mM )
Inside cell

28. Resting Membrane Potential (Vr)

29. C. Membrane Potentials That Act as Signals
Signal = Changes in membrane potential due to
a. Movement of ions through
b. Gated channels
2. Two types of signals
Graded potentials
Action potentials (APs) GP GP AP GP GP GP GP

30. Nerve Impulses– involve movement within and between neurons
Neurotransmitter
Nerve Impulses– involve movement within and between neurons GP AP
Neurotransmitter GP AP
Neurotransmitter GP

31. 3. Terms for Graded and Action Potentials Depolarization =
Repolarization =
Hyperpolarization =
Presynaptic Neuron & Postsynaptic Neuron
Synapse

32. 11.5 Graded Potentials Mechanism a. Voltage Moves in one direction:
b. Part of Neuron involved:
c. Where:
d. Initiated by Chemicals = Neurotransmitters  ions move:
e. Local Current generated– ions that enter or leave will then:

33. D. Graded Potentials (Local currents) …
Mechanism …
f. Membrane not myelinated so:
g. Distance traveled:
Short—But Depends on Strength of Stimulus GP GP GP AP GP GP GP

34. Plasma membrane 2. Characteristics a. Channels involved:
b. Ions Involved determine: Na+, Cl-
c. Result:
d. Naming Graded Potentials
i) Generator Potentials: Sensory Neurons only
ii) Post Synaptic Potentials (PSP) for other neurons
Excitatory– EPSP they help an action potential
Inhibitory– IPSP they inhibit
Stimulus
Plasma
membrane

35. * REVIEW OF MECHANISM & CHARACTERISTICS
Neurotransmitter  Chemical Gated Channel
 Ions move across membrane
 ions move along membrane
 reach Axon Hillock
Neurotransmitters
Synapse

36. Graded Potentials … 3. Affect of PSP on generation of AP
EPSP  Depolarization
Threshold:
Chance of AP:
Ion of Channel:
Depolarizing stimulus

37. b. IPSP  Hyperpolarization = Inside axon becomes: chance of AP
Graded Potentials …
b. IPSP  Hyperpolarization =
Inside axon becomes:
chance of AP
Ion of Gated Channel
Hyper-polarization

38. Different Neurotransmitters
Graded Potentials …
c. number of graded potentials per neuron
Different Neurotransmitters
Synapse
Synapse

39. 4. Summation of graded potentials at a neuron:
a. Spatial summation =
Temporal =
Inhibitory and Excitatory
together E1 E1
E1 + E2 1

40. 11.6 Action Potentials (AP) *** NEXT PPTGP AP

41. END

42. Review Questions sensory
The PNS is further divided into _________ (or afferent) nerves and motor (or ________) nerves. The ________ sheath surrounds the _______ of some neurons and is formed by _________________ in the CNS.
efferent
myelin
axons
oligodendrocytes

43. Review Questions
Depolarization
_______________ diminishes the magnitude of the membrane potential and increases the chance of an AP while ______________ does the opposite. What 2 types of leakage channels are always open in a neuron’s membrane? Which one above is leakier and is most responsible for resting potential?
hyperpolarization
Na+ and K+ K+