View
224
Download
0
Category
Tags:
Preview:
Citation preview
BIO 240 HISTOLOGY REVIEWBIO 240 HISTOLOGY REVIEWThe SkinThe Skin
Dr. Tim BallardDr. Tim Ballard
Department of Biology and Marine BiologyDepartment of Biology and Marine Biology
Human skin – H&E – 10x objective
The arrowheads indicate the position of the basement membrane, separating the keratinized stratified squamous epithelium from the dermis below.
Skin – general featuresSkin – general features
epidermis
dermis
Human skin – H&E – 40x objective
This is a section of thin skin, so the stratum lucidum is not present.
Skin (thin) - epidermisSkin (thin) - epidermis
stratum basale
stratum spinosum
stratum granulosum
stratum corneum
Human skin – H&E – 40x objective
To identify a melanocyte in the stratum basale, look for granules of brown-black pigments in and around cells in this layer.
Skin (thin) - epidermisSkin (thin) - epidermis
stratum basale – mitotic cells giving rise to the keratinizing system with melanocytes scattered about
stratum spinosum – cells receiving melanin from melanocytes and moving towards the surface
stratum granulosum – several layers of living cells accumulating granules of keratohyaline
stratum corneum – multiple layers of dead squamous cells filled with keratin
Pig skin – H&E – 10x objective
The reticular dermis has a looser arrangement of fibers than does the papillary dermis.
Skin - dermisSkin - dermis
epidermis
dermis
papillary dermis
reticular dermis
dermal papilla
Human skin – H&E – 4x objective
In this section the coiled tubular portions of eccrine sweat glands are seen in the reticular dermis.
Skin – dermisSkin – dermis
epidermis
dermis
papillary dermis
reticular dermis
dermal papilla
sweat glands
Human skin – H&E – 4x objective
Skin – eccrine sweat glandsSkin – eccrine sweat glands
secretory portions of sweat
glands
sweat gland duct moving towards the
surface
Eccrine sweat glands are simple coiled tubular glands. The secretory portion lies deep in the dermis. The duct is a straight tube that opens on the surface.
Lip – H&E – 4x objective
Sebaceous glands are oil (sebum) glands of mammalian skin, always associated with hair follicles.
Skin – sebaceous glandsSkin – sebaceous glands
sebaceous glands
epidermis
hair follicles
Lip – H&E – 20x objective
The gland is formed as a sac of cells that opens into a hair follicle. The secretion is called sebum.
Skin – sebaceous glandsSkin – sebaceous glands
sebaceous gland
hair follicles
Recommended