Lab 11 Integumentary System: 1) Index 2) Introduction 3) Things to identify 4) Thick Skin 5) Thick Skin II 6) Thin Skin 7) Pigmented Epithelium 8) Lower Lip 9) Apocrine Sweat Glands 10) Nail Developement 11) Comparisons 12) Practical

 

Nail Development

 

# 12 - Nail development, h - e, l. s., Mallory stain

 

Compare the morphology of the epidermis on either side of the phalanx (finger bone). Identify the cells of the nail matrix. Note how the nail plate replaces the stratum corneum over the nail bed. Observe the insertion of skeletal muscle fibers onto the phalanx.

References: Gartner, p. 216, Fig. 1, 2 Ross, p. 403, Fig. 2 (nailbed) Wheater, p. 168, Fig. 9.1

 

Here is a an image of the Finger Nail. The actual Nail is made from cells that have hard keratin and is called the Nail Plate (yellow arrow). The red arrow is pointing to the Eponychium (cuticle). Cells from the stratum corneum extend outward into the nail plate to become this. The blue arrow is pointing to the Hyponychium, which is the skin under the free surface of the distal end of the nail plate.

Red arrow - Eponychium (cuticle)

Yellow arrow - Nail Plate

Blue arrow - Hyponychium

 

Here is a closer view of the nail. The white arrow is pointing to the Matrix. It is here were cells are proliferating to give rise to the Nail Plate (blue arrow), by gradually transforming into hard keratin. The Nail plate lies over the Nail Bed (yellow arrows). The red arrow is pointing to the Cuticle.

Red arrow - Cuticle (Eponychium)

Blue arrow - Nail Plate

White arrow - Matrix

Yellow arrow - Nail Bed

 

Finger Nail

Nail Plate