Lab: Part 1:
Practice applying knowledge from Ch11 (functional
organization of nervous tissue, neuron signaling)
Part 2:
Spinal Cord and Spinal nerves anatomy
To do prior to lab:
1.
Study for the Lab Quiz
. Remember, the lab quiz this week will include pictures of nerves and cells
of nervous system covered in previous exercise. You will need to identify neurons by structure,
function and location. You will also need to identify locations and functions of glial cells.
2.
Check your understanding of nervous system (covered in lecture) by answering critical questions
below.
You will need to upload the entire exercise as a single PDF (30% penalty if not
incorrect format).
Make sure all answers are in your own words.
Failing to answer the questions
in your own words violates academic integrity.
Be as specific and detailed as possible in your
answers to showcase your understanding of muscle physiology. Don’t give one word responses,
explain how you came to this conclusion.
A.
List two differences between white matter & gray matter.
Give an example of each in the CNS and
PNS. (
2pts
)
B.
Mature neurons are unable to give rise to brain tumors.
Explain why this is so.
However, as you
know, people do get brain tumors.
If neurons are unable to give rise to tumors of the nervous
system, what cells do form brain tumors?
(
2pts
)
C.
In multiple sclerosis, there is progressive and intermittent damage to the myelin sheath of
peripheral nerves.
This results in poor motor control of the affected area.
Why does destruction of
the myelin sheath affect motor control? (
3pts
)
D.
Let’s apply our knowledge of action potentials to understand the general mechanisms of anesthesia.
Read the simplified explanation of anesthesia and answer the questions 1-8 below:
“
Specific
neurons
maintain state of consciousness when depolarized
, but
we enter the state of unconsciousness when
anesth
etics
hyperpolarize them. The anesthetic binds to and opens a certain kind of
K
+
channel,
which increases
K
+
“leak” current
, while
voltage-gated potassium channels
are unaffected
. This
inhibits the neurons, and therefore you aren’t conscious of the surgeons performing the
procedure.”
1.
At resting membrane potential, does sodium leak in or out of the cell? Why is it leaking in/out?
Mention the
role of electrochemical gradients in your answer.
(
2pts
)
2.
In your own words, compare depolarization and hyperpolarization and explain how each of them would
relate the threshold potential.
(
2pts
)
3.
When person is conscious, certain neurons conduct action potentials. Describe in detail depolarization of a
neuron to threshold. Make sure to mention graded potential, chemically and voltage gated channels in your
answer
(
2pts
)
4.
What is meant by the statement
“anesthesia inhibits the neurons?”
(
1pts
) (Hint: mention membrane
potential and threshold in your answer).
