Anatomy Histology of Connective Tissues Questions and Answers — Questions and Answers
Question 1: A pathologist examining a biopsy from a torn Achilles tendon would primarily observe which histological feature?
- Chondrocytes situated within lacunae in a glassy matrix
- A meshwork of fine, branching reticular fibers supporting lymphocytes
- Densely packed, parallel bundles of type I collagen fibers with flattened fibroblasts (Correct answer)
- A loose arrangement of collagen and elastic fibers with abundant ground substance
Correct answer: Densely packed, parallel bundles of type I collagen fibers with flattened fibroblasts
Tendons connect muscle to bone and must withstand strong, unidirectional tensile forces. This function is served by dense regular connective tissue, which is characterized by densely packed, parallel arrays of type I collagen fibers. Flattened fibroblasts (tenocytes) are aligned between these fiber bundles.
Question 2: In the stroma of a lymph node, which type of connective tissue forms a delicate, three-dimensional framework that supports the organ's cells, such as lymphocytes and macrophages?
- Dense irregular connective tissue
- Reticular connective tissue (Correct answer)
- Elastic connective tissue
- Areolar connective tissue
Correct answer: Reticular connective tissue
Reticular connective tissue is composed of type III collagen fibers, also known as reticular fibers, which form a fine, branching network or 'stroma'. This mesh-like framework is ideal for supporting the cell populations within lymphoid organs like the spleen, liver, and lymph nodes.
Question 3: A histology slide of the articular surface of the femur shows a smooth, glassy matrix with cells residing in small cavities (lacunae). This tissue is avascular and lacks a perichondrium. Which type of cartilage is being observed?
- Fibrocartilage
- Elastic cartilage
- Hyaline cartilage (Correct answer)
- Osseous tissue
Correct answer: Hyaline cartilage
Hyaline cartilage is characterized by its smooth, glassy, and translucent matrix, which is rich in type II collagen fibrils that are not easily visible with standard staining. Chondrocytes are found within lacunae. It is the most common type of cartilage and is found on the articular surfaces of bones, where it provides a low-friction surface for joint movement.
Question 4: Which resident cell of connective tissue proper is responsible for synthesizing the protein fibers and amorphous ground substance of the extracellular matrix?
- Macrophage
- Mast cell
- Adipocyte
- Fibroblast (Correct answer)
Correct answer: Fibroblast
The fibroblast is the principal cell of connective tissue proper. Its primary function is to produce and maintain the extracellular matrix by secreting its components, including collagen, elastic, and reticular fibers, as well as the glycosaminoglycans and proteoglycans of the ground substance.
Question 5: A student observes a tissue sample under a microscope that shows large, closely packed cells, each with a single, large lipid droplet that pushes the nucleus to the periphery, creating a 'signet ring' appearance. What is the primary function of this tissue?
- Forming a supportive framework for lymphoid organs
- Providing flexible, stretchable support
- Energy storage, insulation, and physical protection (Correct answer)
- Resisting tension from multiple directions
Correct answer: Energy storage, insulation, and physical protection
The described histology is characteristic of unilocular (white) adipose tissue. The large cells, called adipocytes, are specialized for storing energy in the form of triglycerides within a single large lipid droplet. This tissue also serves to insulate the body and cushion organs.
Question 6: Which of the following components of the extracellular matrix is a viscous, clear substance that fills the space between cells and fibers, and is composed primarily of glycosaminoglycans (GAGs), proteoglycans, and glycoproteins?
- Ground substance (Correct answer)
- Interstitial fluid
- Reticular lamina
- Collagen fibers
Correct answer: Ground substance
Ground substance is the amorphous, gel-like component of the extracellular matrix that surrounds the cells and fibers. It is highly hydrated and composed of proteoglycans, glycosaminoglycans (like hyaluronic acid), and multiadhesive glycoproteins, which allows it to act as both a lubricant and a barrier.
Anatomy Histology of Connective Tissues Questions and Answers
A pathologist examining a biopsy from a torn Achilles tendon would primarily observe which histological feature?