Grading: All questions are worth 2pts. each unless otherwise stated.
Submission instructions
If an assignment is submitted incorrectly, you will be contacted and the assignment will not be graded unless resubmitted properly. Late penalties may apply.
Type your answers and copy all pictures directly into this Word document. Submit it via the blackboard submission link in Word format (docx).
Answers typed into a blank document or submitted in the incorrect format will not be accepted.
Pictures will not be accepted as stand-alone files.
Assignments may not be submitted via email without express permission from the instructor.
Introduction
You will complete a series of activities to help you better understand how messages are transmitted via our brain and spinal cord to our peripheral nervous system. You will need to find someone to help you complete this lab.
Activity 1: Divisions of the Nervous System
1-7: Identify the divisions of the nervous system (A-G). Each letter will only be used once.
1. Central nervous system (CNS) C
2. Peripheral nervous system (PNS) G
3. Somatic B
4. Autonomic E
5. Enteric D
6. Sympathetic F
7. Parasympathetic A
Rest and digest
Voluntary
Brain and spinal cord
Brain of the gut
Involuntary
Fight or flight
Nerves and ganglia
Activity 1: Nervous Tissue
Nervous tissue consists of 2 main groups of cells. Neurons conduct impulses and are assisted by various types of supporting cells called neuroglia.
Neurons can either be classified by structure or function. Neuroglia are organized by function and location.
8-18: Identify the neurons and neuroglia from their descriptions:
Description
Cell
Description
Cell
8. Sensory neurons
AFFERENT NEURONS
9. Immune in CNS
ASTROCYTES
10. Motor neurons
EFFERENT NEURONS
11. Myelin in CNS
OLIGODENDROCYTES
12. 1 axon and 1 dendrite
BIPOLAR NEURONS
13. Cerebrospinal fluid
EPENDYMAL CELLS
14. 1 axon and many dendrites
MULTIPOLAR NEURON
15. Myelin in PNS
SCHWANN CELLS
16. Single cell process
UNIPOLAR NEURON
17. Support in PNS
SATELITE GLIAL CELL
18. Support in CNS
GLIAL CELLS
Activity 3: Meninges
The spinal cord and brain are surrounded by several connective tissue membranes called meninges. Between these are spaces that contain fluid, fat, or other substances.
19-26: Put the structures in order from superficial to deep:
19. Subdural space 3
20. Subarachnoid space 5
21. Dura mater 4
22. Pia mater 7
23. Vertebrae 1
24. Arachnoid mater 6
25. Spinal cord 8
26. Epidural space 2
Activity 4: Spinal Cord Structure
The spinal cord is the major relay center to and from the body and brain. It has sections of both white matter (myelinated axons for sending) and gray matter (cell bodies, dendrites, etc.—basically “thinking matter”). It is connected to the spinal nerves for transmission.
27-36: Label the spinal cord
27. Posterior gray horn D
28. Dorsal white column H
29. Anterior gray horn E
30. Lateral gray horn B
31. Central canal F
32. Ventral white column G
33. Lateral white column B
34. Posterior root A
35. Posterior root ganglion J
36. Anterior root C
Activity 5: Parts of a Reflex Arc
Label the 5 parts of a Reflex Arc (Place answers into table below)
Complete the chart below by adding in the function of the 5 parts of a typical reflex arc
Table Worth Up To 25 Points (5pts each part)
Number
Function
37. #1
Receptor:
Dendrites or other sensory structures responds to changes in the environment
38. #2
Sensory neuron:
Conducts an impulse from receptor to its axon terminal
39. #3
Integration center,
Made of interneuron
some region in the central nervous system
40. #4
Motor neuron:
Impulses from the integration center to an effector
41. #5
Effector muscle:
Responds to motor nerve impulse
Activity 6: Reaction Time
Introduction
Reaction time is a measure how quickly organism responds to a stimulus. Reflexes and reactions, while seeming similar, are quite different. Reflexes are involuntary, used to protect the body, and are faster than a reaction. Reflexes are usually a negative feedback loop and act to help return the body to its normal functioning stability, or homeostasis. Reactions are actually a symphony of hundreds of thousands of neurons working together to produce a conscious decision. We have to decide what we would like to do regarding this stimulus. Furthermore, the quickness of reaction times can differ depending on what type of stimulus you are reacting to and what kind of task you are doing.
Test 1- Visual Response
Procedures:
1. You will need one 12-inch ruler (that can read cm) to complete this test.
2. Have your subject sit at a table with their dominant hand over the edge.
3. Hold the ruler at the 30 cm mark so that the 0 cm end is just at your subject’s index finger.
4. Tell your subject that when you release the ruler, they are to grab it as fast as possible.
a. DO NOT MAKE ANY SOUNDS OR GESTURES THAT INDICATE WHEN YOU WILL DROP IT!
b. They will need to only react to the visual stimulus of seeing the ruler being released.
5. Record the cm mark above the index finger in the chart below.
6. Repeat the experiment 3 more times.
7. Switch with your subject and you do the visual only catch 4 times as well.
Test 2- Auditory Response
Procedures:
1. Have your subject sit back at a table as they did during the first test. We will still be using the dominant hand
2. Blindfold your subject.
3. Tell the subject that you will say “RELEASE” as you release the ruler.
4. Once they grab it, record the centimeter mark and repeat 3 times.
5. Switch with your subject and complete 4 times
Test 3- Tactile Responses
1. Have your subject sit back at the table with their dominant hand once again over the edge.
2. Blind fold subject again.
3. Tell the subject that you will touch the shoulder of their non-dominant arm as you release the ruler.
a. Give NO AUDITORY CUES- SIMPLY TOUCH
4. Record the centimeter mark and repeat 3 times
5. Switch with your subject and complete 4 times.
42. Table is worth up to 8 points if fully filled out with UNITS (cm and sec as needed
Visual (cm)
Auditory (cm)
Tactile (cm)
1.
1.
1.
Subject
2.
2.
2.
1
3.
3.
3.
4.
4.
4.
Average (cm)
Reaction time (sec)
1.
1.
1.
Subject
2.
2.
2.
2
3.
3.
3.
4.
4.
4.
Average (cm)
Reaction time (sec)
Average distance (cm)
Reaction time (sec)
1
0.045
2
0.064
3
0.078
4
0.090
5
0.101
6
0.111
7
0.120
8
0.128
9
0.136
10
0.143
11
0.150
12
0.156
To determine your reaction time, use the table above.
Conclusion Questions
Insert 2 pictures of you and your subject completing the activity.
43.
44.
45. Which of your senses had the fastest reaction time?
Tactile Response
46. The average reaction time for humans is 0.25 seconds to a visual stimulus, 0.17 for an audio stimulus, and 0.15 seconds for a touch stimulus. A) How did your subject and you compare to these norms? The response agrees with this stimulus norm since the tactile was fastest then auditoria then followed by visual response
B) Explain why you think you are faster or slower than the norms.
47. What is different regarding the neural pathways of reflexes vs reactions to cause reflexes to occur faster than our reactions?
Sources
*Reaction Time Table Source: Top End Sports (opens in new window)
*All images in this lab are copyright of McGraw-Hill
