2. The functional unit of the nervous system is the neuron. Identify the functions of the following parts of the neuron:
a. Cell body -
b. Dendrites -
c. Axon hillock -
d. Axon -
e. Synaptic terminals -

3. Which is more abundant in the nervous system, glial cells or neurons?

4. What are two ways that glial cells contribute to the nervous system?

5. What is membrane potential? What is the typical membrane potential?

6. Where are each of the following ions typically found? (Answers should be either inside or outside the neuron).
a. High concentration of K+ :
b. High concentration of Na+ :
c. Anions :
d. Cl- :

7. How do cells prevent the breakdown of the concentration gradient? How does it work? Is this an active or passive process?

8. Why do ions need channels to move through membranes?

9. What are 2 types of channels?

10. What are 2 types of signals generated by neurons?

11. a) Draw and label an AP. Use time on the x-axis and voltage on the y-axis. Show areas of depolarization, hyperpolarization, and repolarization.
b) Label the following on the above drawing:
A = voltage sensitive sodium gates open
B = membrane is unable to respond to any further stimulation, regardless of intensity
C = voltage sensitive potassium channels are open and voltage sensitive sodium channels are starting to close

12. As sodium rushes into the cell, more and more sodium follows it. Is this an example of positive or negative feedback? Give two reasons why this feedback cycle ends.

13. Define the following:
a) Nodes of Ranvier -
b) saltatory conduction -
c) temporal summation -
d) spatial summation -

14.
a) Muscle contraction is active or passive?
b) Muscle relaxation is active or passive?
c) Muscle is composed of ________________________ that contain bundles of ________________________ that run longitudinally and consist of ________________________ . The functional unit of contraction is the ________________________ .

15. Diagram a typical uncontracted sarcomere and label the following:
A band
I band
H zone
Z line
Actin
Myosin

16. During a muscle contraction, the release of ________________________ from a motor neuron signals an ________________________ in the muscle cells, allowing ________________________ to be released from the sarcoplasmic reticulum and to bind to the ________________________ component of tropomyosin which subsequently exposes ________________________________ on the actin. The globular head of ________________________ binds to the actin and pulls it in a sliding manner. Contraction is terminated when the head of the ________________________ hydrolyzes ________________________ allowing detachment from the actin. ________________________ is then pumped back into the sarcoplasmic reticulum.