Download This guided reading is a hybrid of two chapters: chapter 40, section

GUIDED READING - Ch. 40.1 & 48 – ANIMAL TISSUES & THE NERVOUS SYSTEM
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NAME: ________________________
Please print out these pages and HANDWRITE the answers directly on the printouts. Typed work or answers on
separate sheets of paper will not be accepted.
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READ FOR UNDERSTANDING and not merely to complete an assignment. Though all the answers are in your textbook,
you should try to put answers in your own words, maintaining accuracy and the proper use of terminology, rather than blindly copying the
textbook whenever possible.
This guided reading is a hybrid of two chapters: chapter 40, section 1 and chapter 48.
Though we will cover all of chapter 40, we will return to sections 2-4 at a later date.
Animal form and function are correlated at all levels of organization. [2]
1. Animals need to exchange materials with their environment. This process occurs as substances dissolved in an
aqueous medium move across the plasma membrane of each cell. For each of the following organisms, explain
how this is possible. [2]
a. amoeba
b. hydra
c. tapeworm
d. whale
2. What is interstitial fluid?
3. Study Figure 40.4. In what sense is the exchange surface such as the lining of the digestive system both internal
and external? [1]
4. What the difference between a tissue and an organ?
5. a. What is an organ system?
b. Study Table 40.1. List the 11 organ systems of mammals and explain their main functions.
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
6. There are four types of tissues. For each, give examples, the general functions, and where it is found. [2]
Tissue & General Info
1. ___________________
Tissue Description
Cuboidal:
Simple Columnar:
Simple Squamous:
Stratified Squamous:
2. ___________________
Cartilage:
Adipose:
Blood:
Bone:
Fibrous Connective:
Loose Connective:
3. ___________________
Skeletal:
Smooth:
Cardiac:
4. ___________________
Neuron Cell:
Glial Cells:
General Function(s)
Locations
7. a. Explain the difference in the signaling of the endocrine system and the nervous system. Discuss the type of
signaling, transmission method, speed, and duration of the signaling.
Endocrine System
Nervous System
b. Though both the endocrine and nervous systems are involved in communication and coordination of
activities and responses in the body, they are each adapted to different functions. What is each of these
systems best suited for?
Next, please proceed to chapter 48: Neurons, Synapses, and Signaling.
Lines of Communication. [1]
8. a. What is a neuron?
b. What creates the electrical currents that are used by neurons to transmit information through the body?
c.
What is the function of the brain or ganglia in more complex animals?
Neuron organization and structure reflect function in information transfer. [2]
9. What are the three stages of information processing performed by the nervous system?
1.
2.
3.
10. a. Neurons can be placed into three groups, based on their location and function. [2]
Detect external stimuli or internal body conditions.
Analyze & Interpret sensory input &
initiate a response.
b. Where are each of the three types of neurons listed above located in the body?
c. Distinguish between the Central and Peripheral Nervous System divisions.
CNS
PNS
11. a. Label the following elements of this figure showing two neurons: cell body, dendrites, axon, axon hillock,
synapse, presynaptic cell, postsynaptic cell, synaptic vesicles, synaptic terminal, and neurotransmitter. [2]
b. Now, describe the functions of the terms used above
Cell body
Dendrite
Axon
Axon hillock
Synapse
Presynaptic cell
Postsynaptic cell
Synaptic vesicle
Synaptic terminal
Neurotransmitter
c.
What is indicated by the red arrows in the illustration of 11.a.?
12. Contemplate for a bit and then describe the basic pathway of information flow through neurons that cause you to
turn your head when someone calls your name? [1]
13. What is the role of glial cells?
Ion pumps and ion channels maintain the resting potential of a neuron. [2]
In this section you will need to recall information about the structure and function of the plasma membrane.
Recall that ions are not able to diffuse freely through the membrane, because they are charged
and so must pass through protein channels specific for each ion.
14. a. All cells have a membrane potential across their plasma membrane. [2] What is a membrane potential?
b. Neurons send signals by rapidly changing their membrane potential along the length of their body. What is
the typical resting potential of a neuron?
15. a. On the sketch below label the outside and inside of the cell. Show where the concentrations of Na+ and
K+ are highest. [2]
b. How are the concentration gradients of Na+ and K+ maintained? [2] Explain.
c.
Suppose you treated a neuron with ouabain, an arrow poison and rug that specifically disables the sodiumpotassium pump. What change in the resting potential would you expect to see? Explain. [1].
16. What generates the voltage across the neural membrane?
17. a.
While at rest, which ion channels are open and which are closed in a neuron?
b. How does this selective leakiness of the neuron’s plasma membrane allow for the formation of the resting
potential?
c.
Suppose a cell’s membrane potential shifts from –70 mV to –50mV. What changes in the cell’s permeability to
Na+ could cause such a shift? [1]
Axon potentials are the signals conducted by axons. [2]
18. As you see, in a resting neuron, the outside of the membrane is positively charged relative to the inside of the
membrane. If positively charged ions flow out (or negative ions were to flow in), the difference in charge between
the two sides of the membrane becomes greater, the inside increasing in negativity. What is the increase in the
magnitude of the membrane potential called? [2]
19. When a stimulus is applied, ion channels will open. [2] If positively charged ions flow in, the magnitude of
membrane potential is reduced. What is this called?
20. If depolarization causes the membrane potential to drop to a critical value of –55 mV, a wave of depolarization
will follow. What is this critical value called? [2]
21. a.
When threshold is reached, a wave of depolarization or an action potential results. What is an action
potential and what role to voltage gated channels play in helping generate it?
b. How long does a localized action potential last?
c.
What information is conveyed to the brain by the frequency of action potentials?
22. Just like toppling dominoes in a row, either the threshold of depolarization will be reached and an action
potential will be generated, or the threshold will not be reached and no wave will occur. What is this response
to stimulus called? [2]
23. The action potentials that occur along the length of a neuron represent the nerve impulses. Figure 48.10 below
contains almost all you need to know about nerve impulse transmission, so it is worth some careful study time.
Let’s approach it in steps. [2]
a.
Label Na+, K+, and their respective Na+ and K+ ion channels.
b.
Label the Resting state figure.
i.
Are the Na+ and K+ voltage-gated channels open or closed?
ii. What about the non-voltage gated Na+ and K+ channels?
c.
Label the Depolarization figure
i.
What triggers depolarization?
ii. What channels open when depolarization takes place and depolarization threshold is reached?
d. Label Stage 3, the rising phase, and then label Stage 4 in the figure, Repolarization. How is the charge on
the membrane reestablished?
e. Label Stage 5, Undershoot. Why does the neuron experience a temporary state of hyperpolarization and
what causes it to return to its normal Resting Potential.
f. Finally, label these regions of the graph: x- and y-axes, threshold, resting potential, depolarization, action
potential, undershoot, and repolarization.
g. Let’s see if you really understand this concept. Draw in another line on the graph to show what the change in
membrane potential would look like if a stimulus were applied that did not reach the depolarization
threshold.
24. What causes the refractory period during which another action potential around that same part of the membrane
cannot occur?
25. Here is a closer look at what is happening along the membrane as a wave of depolarization (an action potential)
travels along the length of the axon. First, label the key elements of the figure, then, to the right, explain how the
action potential is conducted. [2]
26. Suppose now that a mutation caused gated sodium channels to remain inactivated for a longer time following an
action potential. How would such a mutation affect the maximum frequency at which action potentials could be
generated? [1]
27. a.
Wider axons conduct action potentials more rapidly because they result in less resistance to current flow.
Vertebrate have axons 40x narrower yet they can propagate a nerve impulse faster than even the widest
axons of mollusks that can conduct signals at speeds of 30m/s. This is due to vertebrate axons being coated
in myelin sheaths. What is a myelin sheath?
b.
What are the two types of glial cells that produce myelin sheaths and how do they produce these sheaths?
28. How does a myelin sheath speed impulse transmission? Label the figure below and use it in a discussion of
saltatory conduction and nodes of Ranvier2. [2]
29. In the disease multiple sclerosis, the myelin sheaths harden and deteriorate. How would this affect nervous
system function? [1]
Neurons communicate with other cells at synapses. [2]
30. When the wave of depolarization arrives at the synaptic terminal, calcium ion channels open. What occurs to
the synaptic vesicles as the Ca2+ level increases? [2]
31. What is contained within the synaptic vesicles?
32. a.
b.
Label the figure. Include the synaptic vesicle, synaptic cleft, neurotransmitters, voltage-gated calcium ion
channel, presynaptic membrane, postsynaptic membrane, ligand-gated ion channels, and synapse. [2]
Explain how an action potential is transmitted from one cell to another across a synapse by summarizing
what is shown above in six steps. [2]
1.
2.
3.
4.
5.
6.
33. If all the Ca2+ in the fluid surrounding a neuron were removed, how would this affect the transmission of
information within and between neurons? [1]
34. There are many different types of neurotransmitters. Each neuron secretes only ONE neurotransmitter type. [2]
a.
Some neurotransmitters hyperpolarize the postsynaptic membrane. [2] How does this occur?
b. Are these excitatory or inhibitory neurotransmitters? [2]
c.
Some neurotransmitters depolarize the postsynaptic membrane. How doe this occur?
d. Are these excitatory or inhibitory neurotransmitters?
35. If neurotransmitters remained permanently in synaptic clefts, their effects would continue to be felt by
postsynaptic neurons indefinitely. What are four ways neurotransmitters are removed from synaptic clefts
following their release from synaptic terminals?
1.
2.
3.
4.
36. a. Define and explain summation.
b. A single postsynaptic neuron can be affected by neurotransmitter molecules released by many other
neurons, some releasing excitatory and some releasing inhibitory neurotransmitters. What will determine
whether an action potential is generated in the postsynaptic neuron?
37. You are not expected to know the actions or secretion sites of neurotransmitters, but you should recognize that
they are neurotransmitters! Go through the list in table 48.1, and say each aloud. Underline any that you have
heard mentioned before: acetylcholine, epinephrine, norepinephrine, dopamine, serotonin, GABA, glutamate,
glycine, substance P, endorphins, and nitric oxide. That’s all for this question! [2]
38. There is one neurotransmitter you absolutely MUST know however. It is the most common neurotransmitter in
both vertebrates and invertebrates, and it is released by the neurons that synapse with muscle
cells at the neuromuscular junction. In Figure 50.29, you will see a synapse between a neuron and a muscle
cell, resulting in depolarization of the muscle cell and its contraction. What is this neurotransmitter? [2]
39. Organophosphate pesticides work by inhibiting acetylcholinesterase, the enzyme that breaks down the
neurotransmitter acetylcholine. Explain how these toxins would affects EPSPs produced by acetylcholine. [1]
40. Please answer the Self-Quiz at the end of your chapter. Do your best to try it from memory first in order to
test how well you grasped the material.
1. ______
2. ______
3. ______
4. ______
5. ______
References
1.
Campbell et al. (2008). AP* Edition Biology. 8th Ed. San Francisco: Pearson Benjamin Cummings.
2.
Adapted from Fred and Theresa Holtzclaw
6. _______