1. Honors Anatomy & Physiology Spring 2005
Nervous System
Honors Anatomy & Physiology
Spring 2005

2. The Function
To act as the master _____________________________ system for the body

3. Structural Classifications
Central Nervous System (CNS)
Includes _________ and spinal cord
Acts as integrating and ___________
______________
Peripheral Nervous System (PNS)
Includes nerves outside of CNS
________________
Cranial nerves
Links all parts of body by _______________
impulses

4. PNS Assignment Quiz to be announced!!
There are 12 cranial nerves (pgs )
You are responsible for knowing their
number, name and function.
For example:
Cranial nerve I: olfactory, sense of
smell
Quiz to be announced!!

5. Subdivisions of PNS
1.) ________________________: voluntary nervous system
Contains __________ and motor nerves
Makes you aware of the world around you & allows you conscious control

6. Subdivisions of PNS 2.) Autonomic System: involuntary nervous system
Consists of motor nerves that carry impulses to _______________, blood vessels and glands
The unconscious or “_____________________________”

7. Subdivisions of Autonomic System
A. Sympathetic division
Active during stress
 heart rate, respiratory rate and rate of __________ breakdown
B. Parasympa-thetic Division
Active during conditions of ______________
______________

8. Cells of the Nervous System
1. _________________
Acts to support neurons
Makes up ~ _____% of brain and spinal
cord (s.c.)
There are 5 different types of neuroglial cells

9. Assignment
Using page 194 in your text, draw the different types of neuroglia and list their location and function within the nervous system below each drawing
DO NOT draw Schwann cells but do list its location and function

10. Cells of the Nervous System
2. Neurons
The conducting nerve cell
Senses ___________________ environment, integrates information, carries out motor responses
Structure: each _______________ varies in shape and size, but all have 3 main parts (dendrite, axon and cell body)

11. Neuron Anatomy
A. _________________: a process off of the cell body; receives impulses from adjacent neurons & conducts _______________ impulses TOWARD the cell body; ~1000/neuron

12. Neuron Anatomy
B. Axon: aka ______________; acts to transmit impulses AWAY from the cell body; 1 axon/neuron
C. Cell Body: contains the nucleus and _______________ center of the cell

13. Neuron Anatomy
D. Myelin sheath: made by __________________ in PNS and oligodendrocytes in CNS; encloses the ____________ & speeds up the rate of nervous conduction
i. Gray matter: non-myelinated
nerve fiber
ii. White matter: myelinated nerve
fiber

14. Neuron Anatomy
E. Nodes of ________________: gaps in regular intervals; aids in increasing speed of nervous conduction

15. 3 Types of Neurons
1. Afferent (_____________) Neurons: transmit impulses from PNS to CNS
i.e. pain receptors and proprioceptors
2. Efferent (motor) Neurons: transmit impulses _____________ to muscles or glands

16. 3 Types of Neurons
3. _______________________ (association neurons): located within CNS and conducts impulses between _______________ and _______________ neurons

17. Nervous System Ongoing Assignment
Based on notes and class discussion, you should be able to answer the following questions. This is an on-going assignment:
1. What are the organs of the CNS?
2. What body structures receive their nerve supply from the autonomic system?

18. Assignment Continued 3. Which neuroglial cells are found in the CNS?
4. What 3 structural features do all neurons have in common?
5. In what direction do impulses travel as they pass through the axon?
6. What are the 3 functional distinctions of neurons?

19. Central Nervous System
Left Brain
Language
Logic
_______________
Scientific Skill
Numbers
R hand control
Right Brain
Visual/spatial info.
_______________
Insight
3-D forms
Musical Awareness

20. Assignment Go to http://www.mindmedia.com/
and take the right brain/left brain quiz
Print out your results and bring to
class

21. CNS: Spinal Cord
A _________________ of the brain running from base of brain to 1st or 2nd lumbar vertebrae
Is enclosed within spinal column
Is ~ size of ____________ except at enlarged cervical and lumbar plexuses (spinal nerve distribution to upper and lower limbs)

22. CNS: Spinal Cord
Provides a _______________ pathway to and from the brain
Serves as a reflex center
Has _______ linear segments giving way to 31 spinal nerves (relay info. from PNS to CNS and vice versa)
________________: collection of spinal nerves at the inferior end of the vertebral column

23. Spinal Cord Cross-Section
Gray Matter: unmyelinated
Located in center of cord forming an “H”
_______________________: upper “arms” of H; contains terminal ends of sensory neurons
Anterior Horn: lower “legs” of H; contain cell bodies of motor neurons
Lateral Horn: between post. & ant. horns; contain cell bodies of _____________________ found within autonomic nervous system

24. Spinal Cord Cross-Section
___________ Commissure: horizontal bar connecting right and left sides of the “H”
Central Canal: in center of gray commissure; carries __________________________ throughout canal

25. Spinal Cord Cross-Section
White Matter: myelinated fibers
Surrounds central gray matter
Divided into __________________, posterior and lateral columns
Each column holds longitudinal nerve tracts
_______________________: carry sensory info to brain
Descending tracts: carry motor info. away from brain

26. Reflex Center
_______________: an extremely rapid response to an emergency situation
Occurs in spinal cord or ________________; does not require thinking
The Reflex Arc:
Receptor: at end of sensory neuron; can generate an action potential to ____________
Association neurons: receive info. from sensory neuron and routes response to motor neuron
Motor neurons: conduct impulses to effectors

27. Protections of CNS ____________: skull and vertebral column
_________________ (CSF):
Made from the blood
Forms a watery cushion that protects tissue from trauma
Changes in composition indicates brain pathology

28. Protections of CNS ___________________: connective tissue membranes
A. Dura mater: tough outer covering of brain and s.c.
B. Arachnoid mater: middle layer
C. _________________: inner surface which clings tightly to surface of brain and s.c.
_________________________: separates the arachnoid and pia maters; filled with CSF

29. Protections of CNS _________________________
Composed of least permeable capillaries in body
Brain depends on a very constant internal environment
Allows: water, glucose, and essential amino acids
Disallows: ________________________________
_________________________________________
Cannot block: fats, respiratory gases and fat soluble molecules (alcohol, nicotine and anesthetics)

30. Nervous System Ongoing Assignment
7. How is the high sodium ion concentration maintained on the outside of the plasma membrane?
8. The rapid movement of which ions into the cell leads to depolarization?
9. What two changes in the plasma membrane lead to repolarization?
10. What is the chemical that carries an impulse between the synaptic cleft between neurons?

31. Nervous System Ongoing Assignment
11. What is the outermost meningeal layer?
12. How does the posterior gray horn differ functionally from the anterior gray horn in the spinal column?
13. What are the conduction tracts in the spinal column?
14. What are the components of a reflex arc?