Department
of Zoology
Southern Illinois University at Carbondale
ZOOL 409, Lab Week 13
Lab notes offer a preview of upcoming labs and links to more information about tissues examined during lab.
- Week 13 lecture notes
- SYLLABUS (including links to all note pages)
- 409 Homepage (index of course resources)
- Dr. King's School of Medicine histology page
- Slide summary
TUESDAY primary objective: Examine slides featuring nerve cells and peripheral nerves.
Look for large cell bodies with round euchromatic nuclei and prominent nuclei. Other cells (those with smaller, more heterochromatic nuclei) are glial cells (in central nervous system) or Schwann cells (in peripheral nerves).
- Spinal cord smear: slide 29 -- This is a smear preparation (a bit of spinal gray matter, not sliced but simply spread out and pressed down on the slide). This may be our best slide to see some of the shape of nerve cells. Note texture of cytoplasm (with Nissl bodies), dendrites tapering away from cell bodies. Also note very numerous small nuclei belonging to glial cells. Some blood vessels may also be stretched across the specimen.
(You might also look on each neuron for a pale axon hillock and thin pale axon -- but be aware that this feature will not be visible on most nerve cells [depending on how the cells was flattened onto the slide] and may not be apparent anywhere on a given slide. Slides 29 in boxes 1 and 8 do have at least one visible axon hillock.)
- Spinal cord section: Slides with sections of spinal cord show nerve cell bodies prominently in the ventral horn (the shorter, broader arm of the "H" of gray matter): 27, 28 (silver stain), 69, 75 (with roots and dorsal root ganglion)
- Ganglia: Nerve cell bodies in ganglia may be seen on slides 44 (Golgi stain for Golgi bodies; look in dorsal root ganglia, beside the spinal cord) and 83. Nerve cell bodies may also be found in Auerbach's plexus, on any specimen of the GI tract (e.g., slides, 03, 05, 37, 47), between the circular and longitudinal layers of smooth muscle.
- Peripheral nerves may be found on many different slides. Look in connective tissue (often near larger blood vessels) for a bundle of fibers enclosed in a more-or-less distinct sheath.
Relatively large nerves cut in cross section appear on slide 74, "artery, vein, nerve". Nerves can sometimes be seen deep in dermis of skin (slides 43, 92), in tongue (slide 46), in vagina (slide 56), and in salivary gland (slide 42).
- Nerve spread: Slide 76 is a bit of nerve teased apart and flattened on the slide, not sliced. Myelin and nodes of Ranvier should be visible. Most of the thickness of each nerve fiber is myelin; nodes are the neat gaps that appear between one myelin segment and the next.
- Muscle spread, with motor nerve endings. Slide 79 is a bit of striated muscle at the site where a motor axons synapse with muscle fibers. Hunt for the long black nerve fibers, then try to follow them to motor end plates.
THURSDAY primary objective: Examine some regions of central nervous system.
- Spinal cord: slides 27, 28 (silver stain), 69, 75 (includes nerve roots and dorsal root ganglion). Identify dorsal horn and ventral horn (gray matter), also dorsal column, ventral column, and lateral column (white matter, axons travelling up and down the cord).
- Cerebral cortex: slides 25 (Golgi stain, for nerve cells and astrocytes), 26 (astrocytes?), 32, 33 (silver stain), 63 (Nissl stain), 86 (stained for microglia. probably frog brain). On all of these slides, find nerve cell bodies and note the associated volume of neuropil (consisting of dendrites and axons, where most synapses are located). Note many blood vessels.
- Cerebellar cortex: 31 (silver stain), 45. On these slides, note the distinct layers, with large cell bodies of Purkinje nerve cells in the Purkinje cell layer between the granule cell layer and the molecular layer.
Complete slide list:
01, 02, 03,
04, 05, 06,
07, 08, 09,
10, 11, 12,
13, 14, 15,
16, 17, 18,
19, 20, 21,
22, 23, 24,
25, 26, 27,
28, 29, 30,
31, 32, 33,
34, 35, 36,
37, 38, 39,
40, 41, 42,
43, 44, 45,
46, 47, 48,
49, 50, 51,
52, 53, 54,
55, 56, 57,
58, 59, 60,
61, 62, 63,
64, 65, 66,
67, 68, 69,
70, 71, 72,
73, 74, 75,
76, 77, 78,
79, 80, 81,
82, 83, 84,
85, 86, 87,
88, 89, 90,
91, 92, 93,
94, 95, 96,
97, 98, 99,
100