Difference Between Tonofibrils and Tonofilaments

The key difference between tonofibrils and tonofilaments is that tonofibrils are cytoplasmic fibrils found in epithelial cells that converge at desmosomes and hemidesmosomes, providing a framework to the cell while tonofilaments are keratin intermediate filaments that combine as bundles to make tonofibrils.

1. What are Tonofilaments?
2. Where are Tonofilaments located?
3. What is cytokeratin a marker for?
4. Where are Hemidesmosomes found in the body?
5. Is stratum Granulosum dead?
6. What specialized cells are responsible for human skin color?
7. What does stratum Granulosum produce?
8. What is vimentin a marker for?
9. What is CK7 positive?
10. What is Pan cytokeratin?

What are Tonofilaments?

Tonofilaments are keratin intermediate filaments that makes up tonofibrils in the epithelial tissue. In epithelial cells, tonofilaments loop through desmosomes. ... The protein filaggrin is believed to have an important role in holding them together as tonofibrils.

Where are Tonofilaments located?

ton·o·fil·a·ment. A structural cytoplasmic protein, bundles of which together form a tonofibril; tonofilaments are made up of a variable number of related proteins, keratins, and are found in all epithelial cells.

What is cytokeratin a marker for?

A type of protein found on epithelial cells, which line the inside and outside surfaces of the body. Cytokeratins help form the tissues of the hair, nails, and the outer layer of the skin. ... A cytokeratin is a type of tumor marker. Also called keratin.

Where are Hemidesmosomes found in the body?

Hemidesmosomes are found in epithelial cells connecting the basal epithelial cells to the lamina lucida, which is part of the basal lamina. Hemidesmosomes are also involved in signaling pathways, such as keratinocyte migration or carcinoma cell intrusion.

Is stratum Granulosum dead?

The filaments are made of tonofilaments of the Stratum Spinosum and the granules of the Stratum Granulosum. Remember that there are no blood vessels in the epidermis so the cells get their nutrients by diffusion from the connective tissue below, therefore the cells of this outermost layer are dead.

What specialized cells are responsible for human skin color?

The basal cell layer contains cells called melanocytes. Melanocytes produce the skin coloring or pigment known as melanin, which gives skin its tan or brown color and helps protect the deeper layers of the skin from the harmful effects of the sun.

What does stratum Granulosum produce?

Stratum Granulosum

The cells (three to five layers deep) become flatter, their cell membranes thicken, and they generate large amounts of the proteins keratin, which is fibrous, and keratohyalin, which accumulates as lamellar granules within the cells (see Figure 3).

What is vimentin a marker for?

Vimentin, a major constituent of the intermediate filament family of proteins, is ubiquitously expressed in normal mesenchymal cells and is known to maintain cellular integrity and provide resistance against stress. ... In recent years, vimentin has been recognized as a marker for epithelial-mesenchymal transition (EMT).

What is CK7 positive?

For example, a CK7-negative/CK20-positive phenotype is often associated with carcinomas of colorectal origin, whereas a CK7-positive/CK20-negative phenotype is seen in a wide variety of carcinomas, including carcinomas of the lung, breast, thyroid, pancreas, and female genital tract.

What is Pan cytokeratin?

Pan Cytokeratin [AE1/AE3] antibody recognizes the acidic and basic (Type I and II) subfamilies of cytokeratins. The cocktail of these two antibodies has been shown to detect in human epithelia. The acidic cytokeratins have molecular weights of 56.5, 55, 51, 50, 50, 48 46, 45 and 40 kDa.