HOME

TheInfoList




The ''stratum basale'' (basal layer, sometimes referred to as ''stratum germinativum'') is the deepest layer of the five layers of the
epidermis The epidermis is the outermost of the three layers that comprise the skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate Vertebrates () comprise all species of animal Animals (also calle ...

epidermis
, the external covering of
skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate Vertebrates () comprise all species of animal Animals (also called Metazoa) are multicellular eukaryotic organisms that form the Kingdom (biolo ...

skin
in
mammal Mammals (from Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally spoken in the area around Rome, known as Latium. Through the power of the Roman Republ ...
s. The ''stratum basale'' is a single layer of
columnar or cuboidal
columnar or cuboidal
basal cells. The cells are attached to each other and to the overlying
stratum spinosum The stratum spinosum (or spinous layer/prickle cell layer) is a layer of the epidermis The epidermis is the outermost of the three layers that make up the skin, the inner layers being the dermis and Subcutaneous tissue, hypodermis. The epidermis ...
cells by
desmosome A desmosome (; #Etymology, "binding body"), also known as a macula adherens (plural: maculae adherentes) (Latin language, Latin for ''adhering spot''), is a cell (biology), cell structure specialized for cell-to-cell adhesion. A type of Cell juncti ...

desmosome
s and
hemidesmosomes Hemidesmosomes are very small stud-like structures found in keratinocyte Keratinocytes are the primary type of cell Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Closed spaces * Monast ...
. The
nucleus ''Nucleus'' (plural nuclei) is a Latin word for the seed inside a fruit. It most often refers to: *Atomic nucleus, the very dense central region of an atom *Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA ...

nucleus
is large, ovoid and occupies most of the cell. Some basal cells can act like
stem cell In multicellular organisms Multicellular organisms are organism In biology, an organism (from Ancient Greek, Greek: ὀργανισμός, ''organismos'') is any individual contiguous system that embodies the Life#Biology, properties ...
s with the ability to divide and produce new cells, and these are sometimes called basal
keratinocyte Keratinocytes are the primary type of Cell (biology), cell found in the epidermis (skin), epidermis, the outermost layer of the skin. In humans, they constitute 90% of epidermal skin cells. Basal cells in the stratum basale, basal layer (''st ...
stem cells. Others serve to anchor the epidermis
glabrous skin Hair is a protein filament In biology Biology is the natural science that studies life and living organisms, including their anatomy, physical structure, Biochemistry, chemical processes, Molecular biology, molecular interactions, Phy ...
(hairless), and hyper-proliferative epidermis (from a skin disease).McGrath, J.A.; Eady, R.A.; Pope, F.M. (2004). ''Rook's Textbook of Dermatology'' (Seventh Edition). Blackwell Publishing. Pages 3.7. . They divide to form the keratinocytes of the stratum spinosum, which migrate superficially. Other types of cells found within the ''stratum basale'' are
melanocyte Melanocytes are melanin Melanin (; from el, μέλας ''melas'', "black, dark") is a broad term for a group of natural pigments found in most organisms. Melanin is produced through a multistage chemical process known as melanogenesis, wher ...
s (pigment-producing cells) and
Merkel cell Merkel cells, also known as Merkel-Ranvier cells or tactile epithelial cells, are oval-shaped mechanoreceptors essential for light touch sensation and found in the skin of vertebrates. They are abundant in highly sensitive skin like that of the fi ...
s (touch receptors).


Clinical significance

Basal-cell cancer Basal-cell carcinoma (BCC), also known as basal-cell cancer, is the most common type of skin cancer Skin cancers are cancers that arise from the skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrat ...
s, also called basal-cell carcinomas, account for around 80 per cent of all
skin cancer Skin cancers are cancer Cancer is a group of diseases A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not due to any immediate external ...

skin cancer
s. Not all basal-cell cancers originate in the basal cells but they are so named because the cancer cells resemble basal cells when seen under a microscope.


Additional images

Image:Normal Epidermis and Dermis with Intradermal Nevus 10x.JPG, Epidermis and dermis of human skin Image:Skinlayers.png, Section of epidermis


See also

*
List of keratins expressed in the human integumentary system There are many different keratin proteins normally expressed in the human integumentary system. See also * List of cutaneous conditions caused by mutations in keratins * List of target antigens in pemphigoid * List of target antigens in pem ...


References

{{Integumentary system Skin anatomy Epithelial cells