SSB Histology Lab I
Nerve Cells and Skin
SSB Week 1
The following suggestions are intended to guide your "seeing" in lab, and also to prime your attention for further reading.
Please don't let these exercises limit your experience. On any slide, there is always more to see than seems apparent at first.
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Slide 24, spinal cord smear.
(Note: This specimen was prepared by smearing, or
squashing, a bit of gray matter onto the slide. It is not a
tissue slice like most other specimens in your slide set.)
(EASY) Find the nucleus of a nerve cell body.
Slide 2, scalp
Slide 3, skin
(EASY) Find epidermis. Question: What kind of tissue
is epidermis?
(EASY) Find a dendrite. Question: Where is the end of
the dendrite? (Is it likely to be on the slide?)
(HARDER) Find the stratum corneum of the epidermis.
Question: What does the presence of keratohyalin
granules reveal about the tissue?
(VERY HARD) Find an axon. Question: How long is
the axon? (Is it likely to fit on the slide?)
(EASY) Find the dermis. Question: What kind of tissue
is dermis?
(EASY) Find the nucleus of a glial cell. Question: How
can you tell the difference between nuclei of nerve cells
and nuclei of glial cells?
(HARDER) Distinguish between papillary and reticular
layers of the dermis.
(THOUGHTFUL) Find the biggest nerve cell body on
this slide. Question: Is this cell most probably a sensory
neuron, a motor neuron, or an interneuron? Why?
(EASY) Find a hair follicle. Question: What kind of
tissue is the hair follicle? Question: Why do hair follicles
present so many different appearances?
(EASY) Find a sebaceous gland.
(HARD) Find an arrector pili muscle.
Slide 23, spinal cord
Repeat the exercises above.
(Look at this slide again in a couple weeks, when you
know more about pathways in the spinal cord.)
Slide 16, peripheral nerve section
Slide 55, artery, vein, nerve
(EASY) Find the epineurium. Question: What kind of
tissue is epineurium? (Can you see fibroblasts?)
(EASY) Find a Schwann cell nucleus.
(IMPOSSIBLE) Find a nerve cell body. Question: Why
is this impossible?
(HARDER) Distinguish axons from myelin. Distinguish
axons of different sizes.
(IMPOSSIBLE) Distinguish sensory from motor axons.
Question: Why is this impossible?
(EASY) Distinguish cross section from longitudinal
section.
(HARDER) On a longitudinal section, find a node of
Ranvier.
(THOUGHTFUL) Count the nodes of Ranvier visible in
one high-magnification field of view of a longitudinal
section of nerve. Question: How could you use this
number to estimate the length of a typical internode?
Why should a clinician care about the length of an
internode?
(HARD) Find a nerve on some other slide.
(EASY) Find an artery and a vein. Hint: Look deep.
(HARDER) Find some capillaries. Hint: There should
be lots, especially in the papillary layer (but they may be
extremely inconspicuous).
(EASY) Find a sweat gland. What kind of tissue is the
hair follicle?
(HARDER) Distinguish the secretory portion of a sweat
gland from its duct.
(EASY) Find a keratinocyte Question: In what layer
should you look?
(HARDER) Find an epidermal cell that is not a
keratinocyte. Question: What other cell type might it be
(list at least three possibilities)?
(EASY) Find collagen. Question: In what layer should
you look?
(EASY) Find adipocytes. Question: Where should you
look?
(EASY) Find any other connective tissue cell. List the
types of connective tissue cells which may occur in skin.
Question: Which ones are typically more common?
(EASY) Find a dying cell with a pyknotic (shrunken)
nucleus. Hint: Look in sebaceous glands.
(HARDER) Find a nerve. Hint: Look deep. Question:
Do the axons in this nerve belong to sensory or motor
nerve cells? Explain why.
(THOUGHTFUL) Compare / contrast skin with
specimens of cornea (slide 25), esophagus (slide 34) and
vagina (slide 77), tongue (slide 29).