27 Post-Lab for Spinal Cord and Spinal Nerves
Gillian Backus; Heidi W. Wangerin; and Paula Rodgers
Post-Lab: Spinal Cord and Spinal Nerves Lab
Name: ________________________
Lab Checkout:
When you finish the lab, please clean up your lab space and put away your materials neatly in the tray. Once you have thoroughly cleaned, washed, and dried your lab table, please get your instructor’s initials to check-out of lab.
- Lab bench clean, washed, and dried
- Materials put away properly and organized in trays
- Microscope properly put away
Lab completed (% completed = ______ %) Instructor initials: ______________
Activity 1: The Structure of the Spinal Cord
1. Match the structure of the spinal cord with its description.
| a. filum terminale
b. conus medullaris c. central cana d. subarachnoid space e. denticulate ligaments f. cauda equina |
___ space within the grey matter of the spinal cord that contains CSF
___ extension of neurons beyond the spinal cord ___ end of the spinal cord ___ extension of pia matter that anchors the spinal cord to the coccyx ___ extensions of pia matter that anchor the spinal cord laterally ___ space within the meninges where CSF circulates |
2. Motor signals are integrated in the (circle one): grey matter or white matter and sensory signals are integrated in the (circle one): grey matter or white matter of the spinal cord.
3. What structure(s) make-up the posterior root ganglion?
4. Given the terminology of a cross-section of the spinal cord, which anatomical part is most likely affected in each scenario.
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- The patient is unable to process sensory information.
- Motor signals do not reach the peripheral nervous system.
- Signals are unable to travel from the right side of the spinal cord to the left, resulting in weakness on both the affected side and the non-affected side.
- Cerebrospinal fluid is leaking out of the central canal, due to rifts (spaces) in these cells.
Activity 3: Spinal Nerve Structure and Function
5. Trace the pathway of the sensory information from the sensory receptors (#1) in the fingertip into the spinal cord by correctly numbering the steps below:
_______ dorsal/posterior root
___1___ sensory receptors in the fingertip
_______ dorsal/posterior horn
_______ spinal nerve
_______ ventral ramus
6. Plexuses are composed of (posterior, anterior, or meningeal) rami. Circle one.
7. Trace the pathway of motor information to the fingertip starting in the spinal cord (#1) and extending to the muscles in the finger by correctly numbering the steps below:
_________ ventral ramus
____1____ ventral horn
_________ spinal nerve
_________ muscles of the fingertip
_________ ventral root
Activity 4: Identification of the Major Spinal Nerves and Plexuses
8. Identify which nerve(s) is/are most likely damaged given the description below. You will need to use muscle action innervation tables from the muscle lab and you’re in-lab activities from this lab to help you answer these questions. as well as Table 1 in this lab.
- weak leg extension at the hip: ______________________________________
- weak dorsiflexion of foot: __________________________________________
- unable to sense touch on the medial thigh: ____________________________
- weak flexion of fingers: ___________________________________________
- weak plantar sensation: ___________________________________________
- difficulty flexing forearm: __________________________________________
Activity 5: Somatic and Autonomic Reflexes
9. Explain the difference between a somatic reflex and an autonomic reflex.
10. In the patellar reflex, name the receptor and the effector.
Receptor: _____________________ Effector: _____________________
11. Explain why the reflex above is called an “ipsilateral reflex”.
12. In a normal pupillary light reflex, name the type of receptor (stretch receptor, photoreceptor, mechanoreceptor, or chemoreceptor) that is stimulated and the brain region (frontal lobe, thalamus, or occipital lobe) that serves as the integration center.
Receptor: __________________ Integration Center: ___________________
Activity 6: Spinal Nerve Pathways
13. You have a lesion (damage) in the thalamus. Explain how you predict this will affect sensation by filling out the information below:
-
- Would this lesion primarily affect the ascending or descending pathway?
- Name the neuron that will not be able to send the signal circle one (1st order, 2nd order, 3rd order, upper motor neuron, lower motor neuron).
14. You have a lesion (damage) in the pyramidal cells of the medulla. Explain how you predict this will affect motor movement by filling out the information below:
-
- Does this lesion primarily affect the ascending or descending pathway
- Name the neuron that will not be able to send the signal circle one (1st order, 2nd order, 3rd order, upper motor neuron, lower motor neuron).
Putting it All Together
15. You diagnose your patient with sciatica (inflammation of the sciatic nerve) and femoral neuropathy. Connect what you learned about the anatomy of spinal cord and spinal nerves to explain why she is experiencing the sensation of pain as well as having motor difficulty with her leg.
