Block 1 Mini 1 Epithelia

Simple squamous epithelium is the correct answer because it is the type of cell lining that is found in the blood vessels of the skin. Simple squamous epithelium is a single layer of flat cells that allows for easy diffusion of substances and is well-suited for lining blood vessels where exchange of gases and nutrients occurs.

Hemidesmosomes are junctions that allow cells to bind to the basal lamina. They are specialized cell adhesion structures found in epithelial tissues. Hemidesmosomes anchor the basal surface of epithelial cells to the underlying extracellular matrix, specifically the basal lamina. This anchoring is important for maintaining the structural integrity and stability of the epithelial tissue.

Type IV collagen is found primarily in the lamina densa of the basement membrane. The basement membrane is a thin, specialized extracellular matrix that separates epithelial and endothelial cells from underlying connective tissue. Type IV collagen is a major component of the basement membrane and provides structural support and stability to the membrane. It forms a mesh-like network in the lamina densa, contributing to the barrier function of the basement membrane and regulating the passage of molecules between the epithelial/endothelial cells and the underlying tissue.

The correct answer is pseudostratified columnar epithelium with stereocilia. This type of epithelium is found lining the epididymis, which is a coiled tube located on the posterior surface of the testis. Pseudostratified columnar epithelium is characterized by cells of varying heights, giving the appearance of multiple layers, although all cells are attached to the basement membrane. Stereocilia are long, non-motile microvilli that increase the surface area for absorption and secretion. This lining helps in the maturation, storage, and transportation of sperm cells.

Zonula adherens is the correct answer because it is a type of junction that allows the cytoskeleton of the cell to bind to Ca++ dependent cadherins. Zonula adherens is a belt-like junction found in epithelial tissues, and it plays a role in cell-cell adhesion by connecting adjacent cells through cadherin proteins. These cadherins bind to the cytoskeleton of the cell, providing structural support and stability to the tissue.

Plasma cells are derived from B-lymphocytes. B-lymphocytes are a type of white blood cell that play a crucial role in the immune response. When B-lymphocytes encounter an antigen, they differentiate into plasma cells, which produce and secrete antibodies specific to that antigen. These antibodies help to neutralize or eliminate the antigen, thereby protecting the body against infection.

Certain types of epithelia may contain apical specializations. Epithelial tissues are one of the four main types of tissues in the human body and they line the surfaces of organs, glands, and cavities. They serve various functions including protection, secretion, absorption, and transportation. Apical specializations refer to specific structures or modifications found on the apical surface of certain epithelial cells, such as microvilli or cilia, which increase the surface area or aid in movement. Therefore, it is correct to say that certain types of epithelia may contain apical specializations.

Integrins are transmembrane proteins that connect the cytoskeleton of a cell to the extracellular matrix. They act as bridges between the inside and outside of the cell, allowing for communication and signaling. Integrins play a crucial role in cell adhesion, migration, and tissue organization. They are involved in various cellular processes such as wound healing, immune response, and development. Therefore, integrins are the correct answer for the given question.

Epithelial polarity refers to the asymmetrical distribution of proteins and lipids within epithelial cells, which is essential for their proper function. The basal lamina is a thin layer of extracellular matrix that provides structural support to epithelial cells. It helps in maintaining the integrity and organization of the cells, contributing to their polarity. Therefore, the presence of an intact basal lamina is a crucial factor in establishing and maintaining epithelial polarity.

Stratified squamous epithelium is a type of tissue that consists of multiple layers of squamous (flat) cells. The surface layer of cells may be keratinized, meaning it contains a tough protein called keratin. The cells in the most superficial layer are indeed squamous in shape. The statement that is FALSE is "All cells are supported by a basal lamina." A basal lamina is a thin layer of extracellular matrix that underlies epithelial cells, but in stratified squamous epithelium, not all cells are in contact with the basal lamina. Some cells may show pigmentation, meaning they contain pigments that give color to the tissue. The cells in stratified squamous epithelium are held together by desmosomes, which are specialized cell junctions.

Basal folds are associated with cells involved in active transport. This means that these folds are found in cells that actively transport substances across their membranes. These folds increase the surface area of the cell, allowing for more transport proteins to be present and therefore increasing the efficiency of active transport.