What is the stratum spinosum composed of?

keratinocytes
The stratum spinosum (or spinous layer/prickle cell layer) is a layer of the epidermis found between the stratum granulosum and stratum basale. This layer is composed of polyhedral keratinocytes. These are joined together with desmosomes.

What type of cells are in the stratum spinosum?

Stratum spinosum, 8-10 cell layers, also known as the prickle cell layer contains irregular, polyhedral cells with cytoplasmic processes, sometimes called “spines”, that extend outward and contact neighboring cells by desmosomes. Dendritic cells can be found in this layer.

Which layer is the stratum spinosum?

The stratum spinosum is a Latin term, which literally means spinous layer. This layer is found in in between the stratum basale and the stratum granulosum. The keratinocytes in the stratum spinosum are referred to as prickle cells. These keratinocytes are polyhedral in shape and with large pale-staining nuclei.

What is the epidermis layer of skin composed of?

keratinized
The epidermis is composed of keratinized, stratified squamous epithelium. It is made of four or five layers of epithelial cells, depending on its location in the body. It does not have any blood vessels within it (i.e., it is avascular).

What makes the stratum spinosum spiny?

As the name suggests, the stratum spinosum is spiny in appearance due to the protruding cell processes that join the cells via a structure called a desmosome. The desmosomes interlock with each other and strengthen the bond between the cells.

How is the stratum spinosum formed?

The stratum spinosum is composed of eight to 10 layers of keratinocytes, formed as a result of cell division in the stratum basale (Figure 4).

Why is the stratum spinosum called Spinosum?

From the stratum basale, the keratinocytes move into the stratum spinosum, a layer so called because its cells are spiny-shaped cells. The stratum spinosum is partly responsible for the skin’s strength and flexibility.

What is stratum granulosum?

The granule cell layer (stratum granulosum) is the next layer (3-5 layers of cells). As the cells move up into this layer, they start to lose their nuclei and cytoplasmic organelles, and turn into the keratinised squames of the next layer. The granules contain a lipid rich secretion, which acts as a water sealant.

What are the layers of the epidermis and what do they do?

The epidermis provides a protective waterproof barrier that also keeps pathogens at bay and regulates body temperature. The main layers of the epidermis are: stratum corneum, stratum lucidium, stratum granulosm, stratum spinosum, stratum germinativum (also called stratum basale).

What is the definition stratum spinosum?

Medical Definition of stratum spinosum : the layers of prickle cells over the layer of the stratum basale capable of undergoing mitosis. — called also prickle cell layer.

What is special about stratum spinosum?

The prickle cell layer (stratum spinosum) is the next layer (8-10 layers of cells). The cells in these layers have lots of desmosomes, which anchor the cells to each other, and contain thick tufts of intermediate filaments (keratin).

How keratin is formed in the stratum spinosum and stratum Granulosum?

As the stratum basale continues to produce new cells, the keratinocytes of the stratum spinosum are pushed into the stratum granulosum. The cells become flatter, their cell membranes thicken, and they generate large amounts of the proteins keratin and keratohyalin.