Block 1 Mini 1 Epithelia
Questions and Answers
- 1.
Plasma cells are derived from which of the following?
- A.
Macrophages
- B.
Fibroblast
- C.
T-lymphocytes
- D.
Monocytes
- E.
B-lymphocytes
Correct Answer
E. B-lymphocytesExplanation
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.Rate this question:
-
- 2.
Which of the following statements BEST describes basal folds?
- A.
They possess cilia
- B.
They function in exocytosis
- C.
They are involved in lipid transport
- D.
They are associated with cells involved in active transport
- E.
They make up part of the terminal web
Correct Answer
D. They are associated with cells involved in active transportExplanation
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.Rate this question:
-
- 3.
Which of the following statements is CORRECT for epithelia?
- A.
They are incapable of performing absorptive functions
- B.
Certain types may contain apical specializations
- C.
They are surrounded by an abundance of extracellular matrix
- D.
They demonstrate weak adhesion between cells
- E.
They are highly vacularized
Correct Answer
B. Certain types may contain apical specializationsExplanation
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.Rate this question:
-
- 4.
Which of the following is found primarily in the lamina densa of the basement membrane?
- A.
Entactin
- B.
Type IV collagen
- C.
Microfibrils
- D.
Laminin
- E.
Reticular fibers
Correct Answer
B. Type IV collagenExplanation
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.Rate this question:
-
- 5.
Which of the following contributes to epithelial polarity?
- A.
Presence of an intact basal lamina
- B.
Gap junctions
- C.
Membrane fluidity
- D.
Presence of desmosomes
- E.
Location of golgi apparatus near the nucleus
Correct Answer
A. Presence of an intact basal laminaExplanation
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.Rate this question:
-
- 6.
Which one of the following statements about stratified squamous epithelium is FALSE?
- A.
The surface layer of cells may be keratinized
- B.
The cells in its most superficial layer are squamous
- C.
All cells are supported by a basal lamina
- D.
Its cells possess desmosomes
- E.
Some cells may show pigmentation
Correct Answer
C. All cells are supported by a basal laminaExplanation
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.Rate this question:
-
- 7.
Which of the following junctions allows the cytoskeleton of the cell to bind to Ca++ dependent cadherins?
- A.
Zonula occludens
- B.
Zonula adherens
- C.
Hemidesmosomes
- D.
Focal adhesions
- E.
Gap Junction
Correct Answer
B. Zonula adherensExplanation
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.Rate this question:
-
- 8.
Which of the following cell types is found lining blood vessels of the skin?
- A.
Stratified cuboidal epithelium
- B.
Loose connective tissue
- C.
Transitional epithelium
- D.
Ciliated pseudostratified columnar
- E.
Simple squamous epithelium
Correct Answer
E. Simple squamous epitheliumExplanation
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.Rate this question:
-
- 9.
Which of the following cell types is found lining the epididymis ?
- A.
Stratified cuboidal epithelium
- B.
Ciliated pseudostratified epithelium with goblet cells
- C.
Transitional epithelium
- D.
Pseudostratified columnar epithelium with stereocilia
- E.
Simple columnar epithelium with striated border and goblet cells
Correct Answer
D. Pseudostratified columnar epithelium with stereociliaExplanation
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.Rate this question:
-
- 10.
Which of the following junctions allows the cell to bind to the basal lamina?
- A.
Zonula occludens
- B.
Zonula adherens
- C.
Hemidesmosomes
- D.
Macula adherens
- E.
Gap Junction
Correct Answer
C. HemidesmosomesExplanation
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.Rate this question:
-
- 11.
On the basal side of the cell, the cytoskeleton of the cell communicates with the extracellular matrix across the plasma membrane by means of
- A.
Cadherins
- B.
Integrins
- C.
Proteoglycans
- D.
Microtubules
- E.
Tonofilaments
Correct Answer
B. IntegrinsExplanation
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.Rate this question:
-
Back to top