THE NERVOUS SYSTEM

Lab Objectives

Students should be able to:

1. identify the microscopic structures of the neuron using a slide and model of a neuron.

2. identify the microscopic and macroscopic anatomy of the spinal cord.

3. identify the microscopic anatomy of a nerve.

4. identify various anatomical structures on whole and sagittal section brain models.

5. identify various anatomical structures on preserved sheep brain.


I. HISTOLOGY:  Use the microscope and prepared slides to study the structures listed.

          A. Using the slides labeled "Motor Neuron", learn to recognize the following: Picture 1 and Picture 2
              1. neuroglia cells
              2. multipolar neuron
                      a. cell body (soma)
                      b. nucleus (and nucleolus)
                      c. nerve cell processes (axon and dendrites)

         B.   Study of the neuron model.  Picture 1, Picture 2, Picture 3, Picture 4
    1.  dendrites
    2.  axon (with axon hillock)
    3.  nodes of Ranvier
    4.  cell body
    5.  nucleus
    6.  endoneurium
    7.  myelin sheath
    8.  nissl bodies

             9.  schwann cell with nucleus

             10. axon terminals

             11. neurilemma

          C. Identify the following structures on the model and the slide labeled "Spinal Cord" cross-section (c.s.) Picture 1, Picture 2, Picture 3, Picture 4
              1.   central canal
              2.   anterior median fissure
              3.   posterior median sulcus
              4.   anterior and posterior horns of gray
              5.   dorsal root ganglia (if attached)
              6.   gray matter containing cell bodies of neurons
              7.   white matter containing cross-sections of myelinated fibers                

          D. Using the slide labeled "Peripheral Nerve, c.s", learn to recognize the following:  Picture 1, Picture 2
              1. epineurium, perineurium, fascicles, and endoneurium
              2. cross-section of myelinated axon                   

 II. GROSS ANATOMY:  Use available sketches, photographs, and written descriptions in your textbook and lab atlas to help you with the following tasks  BLANK DIAGRAMS.

              A. Study the life-sized spinal cord model and learn to recognize the following structures: Picture 1, Picture 2

                  1. Brain stem structures
                         a. pons
                         b. medulla oblongata

        2. Other brain structures visible

               a.  Optic nerve and optic chiamsa

               b.  Frontal lobe and olfactory nerve (and bulb)

        3.  Spinal cord in vertebral canal
                 a. conus medullaris
                 b. cauda equina

                 c. filum terminal

        4.  Spinal nerve roots, spinal nerves, plexuses, and peripheral nerves
                 a. cervical plexus
                 b. brachial plexus
                 c. intercostal nerves
                 d. lumbar plexus
                 e. sacral plexus
                 f. sciatic nerve

        5.  Sympathetic trunk with sympathetic chain ganglia

 

    B. Study the peripheral nerve model and learn to recognize the following structures:  Picture 1, Picture 2, Picture 3

         1. Cervical Plexus

         2. Brachial Plexus

                a.  Suprascapular nerve

                b.  Radial nerve

                c.  Median nerve

                d.  Ulnar nerve

                e.  Palmar digital nerve

         3.  Intercostal nerves

         4.  Lumbar plexus

                a.  Femoral nerve

                b.  Saphenous nerve

                c.  Obturator nerve (looks like its coming off the sciatic but does not!!)

         5.  Sacral plexus

                a.  Sciatic nerve

                b.  Tibial nerve

                c.  Fibular nerve

                d.  Sural nerve

                e.  Medial and lateral plantar nerve

         6. Sympathetic trunk 

 

    C. Study the model of the brain ventricles. Picture 1, Picture 2

         1. lateral ventricles (right and left)
         2. third ventricle (with interventricular foramen/foramen of Monro)
         3. cerebral aqueduct
         4. fourth ventricle
         5. choroid plexus
 
    D. Study the models of the entire brain.
         1. cerebral hemisphere  Picture 1, Picture 2, Picture 3
                 a. Parietal lobe, frontal lobe, occipital lobe, and temporal lobe
                 b. optic chiasma
                 c. olfactory bulbs
                 d. central sulcus
                 e. precentral gyrus
                 f. postcentral gyrus
                 g. lateral sulcus

                 h. white and grey matter 
         2. longitudinal fissure and transverse fissure
         3. cerebellum (with folia and vermis)
         4. pons
         5. medulla oblongata

         6. all twelve cranial nerves

                a.  Olfactory Nerve (I)

                b.  Optic Nerve (II)

                c.  Oculomotor (III)

                d.  Trochlear (IV)

                e.  Trigeminal (V)

                f.   Abducens (VI)

                g.  Facial (VII)

                h.  Vestibulocochlear (VIII)

                i.   Glossopharyngeal (IX)

                j.   Vagus (X)

                k.  Accessory (XI)

                l.   Hypoglossal (XII)

         7. pitutary gland
       

     E. Study any sagittal section of plastic imbedded human brains.  In addition to the above structures, learn to recognize the following structures: Picture 1, Picture 2
          1.  corpus callosum
          2.  septum pellucidum
          3.  thalamus
          4.  massa intermedia  

          5. anterior and posterior commisure
          6.  third and fourth ventricles
          7.  midbrain (composed of corpora quadrigemina and cerebral aqueduct)
          9.  gray matter (cortex) and white matter
          10.  arbor vitae
          11.  hypothalamus
          12.  pituitary gland
          13.  pineal gland

          14.  pia mater

          15.  fornix

 

      F. Study the preserved sheep brain.  Find the following parts using these photos for aid:

1. meninges (dura and pia mater)
2. cerebrum and the various lobes

3. longitudinal fissure

4. transverse fissure

5. cerebellum

6. optic nerve and optic chiasma

7. olfactory bulb

8. spinal cord

9. corpus callosum (septum pellucidum if visible)

10. ventricles

11. cerebral aqueduct

12. pons

13. medulla oblongata

14. arbor vitae

     

III. USEFUL WEBSITES