Cell bodies of interneurons found in the human brain. You are born with approximately twice as many neurons as you have now. The die-off of neurons occurs early in life, and with more room, the remaining neurons make many connections with other existing neurons. The degree of interconnectedness apparently determines our intelligence and memory. It is estimated that the human brain contains
100 billion (10 11 ) interneurons averaging 1000 synapses on each; that is, some
10 14 connections. If you had 10 14 pennies, how much money would you have?

SVHS ADVANCED BIOLOGY 2014-2015
OUTCOMES: A) Be able to explain how the body has two systems of communication; a fast nervous system and a slow endocrine system. (Page 252)
B) Be able to describe how an impulse is created and why it moves along an axon or dendrite.
(Pages 259-262)
C) Be able to explain how the nervous system is composed of two types of cells; neurons and neuroglial cells. Explain the different types of neuroglial cells and their functions.
(Pages 257-259)
D) Be able to describe the structure of a typical neuron. (Pages 256)
E) Be able to explain what saltatory conduction is and the role of the myelin sheath.
(Pages 262)
F) Be able to contrast an action potential and resting potential in terms of charges on the membranes and the ion concentrations. (Pages 259-262)
G) Be able to explain how an impulse bridges the gap between two neurons. (Pages 263-264)
H) Explain what factors determine if neurons can regenerate. (Page 259)
Monday 1/5 Discussion: Introduction to Nervous System
Lab: packet Activity A, begin Activity B
Homework: Read text 252-259, D.R. #9.1
Wednesday 1/7 Discussion: Structure of neurons.
Lab: Complete Activity C
Homework: Read Conduction of nerve impulses: text pgs 259-262
Thursday 1/8 Discussion: Conduction of nerve impulses.
Homework: Complete D.R. #9.2
Monday 1/12 Discussion: Conduction across a synapse & regeneration of nerve tissue
Homework: D.R. # 9.3 complete Study guide, study for test
Wednesday 1/14 Unit #7 Test: Nervous System: Neurons
Lab packet due
Thursday 1/15 Begin Biotech unit- Intro lecture lab: micropipette use
Monday 1/20 Martin Luther King Holiday

SVHS ADVANCED BIOLOGY
PART “A”: Neuron Types ( pg 257 ) Label each type of neuron shown below. See notes regarding types of neurons. Describe where each type might be found. Explain how each type differs in structure and function.
Neuron Type:
Found:
Differences:
Neuron Type:
Found:
Differences:
Neuron Type:
Found:
Differences:
Explain what this picture might be showing. Label structures using arrows.

Using page 256 of Tortora, label the structures of the neuron shown below. (Use each of the names listed in the table on the next page.)
Identify the structures being pointed to in the diagram of the axon cross section. Below, briefly describe the role played by that structure.
#1:
#2:
#3:
#4:
PART "B": OBSERVATION OF NEURONS FOUND IN THE SPINAL CORD.

Activity C Using the sample of cow spinal cord, diagram 3 neurons and their associated structures.
Also diagram the neuroglial cells found in the sample. Label all structures observed.
Spinal Cord Neurons (400X)
In the space below name and describe the role of the different types of neuroglial cells. Refer to Table 9.1
Figure 9.2
Structure of Neuron Function
Cell Body
Dendrite
Axon
Axon Collateral
Axon Terminals
Synaptic end bulbs
Myelin Sheath
Node of Ranvier
Schwann Cell

name:_________________ per: _______
In this lab you will use a “reaction time ruler” to measure your lab partner’s reaction time. After a predetermined number of practice runs an average of ten trials will determine the reaction time. We will then compare a “caffeine” reaction time with a “non-caffeine” reaction time. Only willing participants who regularly use caffeine will be involved in the comparison portion of the lab.
The procedure described below must be followed exactly as stated in order to get reliable results.
TEST PROCEDURE:
1) The subject to be tested must sit in a chair.
2) The releaser stands facing the subject and holds the release end of the ruler at his/her eye level.
3) The subject positions the thumb and first finger over the “thumb line”. The distance between the thumb and the first finger should be 1inch.
4) when ready the subject tells the releaser to “start”.
5) Once told to start, the releaser must release the ruler within a 10 sec time frame. The releaser must not look at the subject until after the subject has caught the ruler.
6) The subject must catch the ruler as quickly as possible after the release.
7) The line under the middle of the subjects thumb is used to determine the reaction time.
8) After 10 practice trials the actual 10 test trials are performed.
9) Record each test result.
Trial Practice Test w/o caffeine
Test with caffeine
4
5
6
7
1
2
3
8
9
10
Average

1) From pages 252-258, be able to
A) Name the system that responds quickly and the system that responds slowly to the body’s needs.
B) Name the three basic functions of the nervous system.
C) Name the two types of cells found in the nervous system.
D) Contrast neurons and neuroglial cells as to size, numbers, and types.
E) Identify and give a function for the following structures of a neuron; cell body, axon, dendrite, axon collaterals, axon terminals, synaptic end bulbs, synaptic vesicles.
F) Describe the structure and role of the myelin sheath.
G) Contrast white and gray matter as to myelin sheath.
2) From pages 259-262, be able to
A) List two striking characteristics of neurons.
B) Characterize a nerve impulse.
C) Explain how ions play a role in creating an impulse.
D) Explain how ion channels play a role in nerve impulses.
E) Characterize a neuron that is resting regarding charges, ion concentrations.
F) Explain the role of the sodium – potassium pump in a neuron.
G) Explain what a resting potential means in terms of a neurons membrane.
H) Explain when a neuron’s membrane said to be “polarized”.
I) Explain what is meant by the term “excitability”.
J) Explain what is meant by “depolarization” and “repolarization”.
K) Explain the term “threshold” regarding a stimulus to a neuron’s membrane.
L) Explain what happens when the “threshold’ is reached.
M) Define “action potential”.
N) Explain how the “refactory period” impacts the neuron.
3) From page 259-262, be able to
A) Define threshold stimulus.
B) Explain the “all-or-none” principle.
C) Explain how a sub-threshold stimulus is different compared to a threshold stimulus.
D) Explain what is meant by the term “summation”.
E) Define and contrast continuous and saltatory conduction.
F) Describe three factors that determine the speed of the impulse along a neuron.
G) Explain how size of the nerve fiber determines speed and which size is myelinated and which is not.
4) From pages 262-264 titled “Conduction Across a Synapse”, be able to
A) Explain what a synapse is and where it would be found.
B) Contrast pre-synaptic and post-synaptic neurons.
C) Explain the role of a neural transmitter.
D) Describe the structure and role of synaptic vesicles.
E) Explain how an impulse bridges a synapse.
F) Explain why impulses can only travel in one direction.
G) Explain the three possible results of a postsynaptic neuron receiving an impulse.
5) From page 259, be able to
A) Explain what types of neurons can regenerate themselves after injury.
B) Explain what factors determine if a neuron will regenerate.