Connective Tissue Cells and Functions Quiz

Connective Tissue Overview

• Connective tissue differs from epithelium, characterized by scattered cells surrounded by an abundant extracellular matrix
• The matrix consists of ground substance (mainly water, glycosaminoglycans, and glycoproteins) and fibers (collagenous, reticular, and elastic).
• Connective tissue functions in support, defense, and nutrition.

Connective Tissue Constituents

• Matrix: Composed predominantly of water, glycosaminoglycans, and glycoproteins.
• Fibers: Collagenous fibers provide tensile strength, reticular fibers form supportive frameworks, and elastic fibers offer elasticity.
• Cells: Vary depending on the specific connective tissue type.

Extracellular Matrix (Ground Substance)

• Primarily composed of water.
• Contains glycosaminoglycans and glycoproteins.
• Similar in composition to blood plasma.
• Functions include nutrition and acting as a barrier to bacterial penetration.

Connective Tissue Fibers

• Collagenous fibers: Most abundant, strong, and flexible. Their fibers do not branch, but bundles can.
• Reticular fibers: Thin, branching, stained dark brown with silver stain, function in support.
• Elastic fibers: Yellow in large numbers, elastic and stretchable, stained brick red by orcein and dark violet by V.V.G stain.

Connective Tissue Cells

• Function, structure (light microscopy (LM) and electron microscopy (EM)), and origin vary widely.

Undifferentiated Mesenchymal Cell

• Spindle-shaped, many processes.
• Oval nucleus, basophilic cytoplasm.
• Divide and differentiate into other connective tissue cells.

Fibroblasts

• Two types: Young and mature.
• Young fibroblasts have spindle shapes with processes, oval central paler nuclei, basophilic cytoplasm; function in synthesis of connective tissue.
• Mature fibroblasts (fibrocytes) have smaller spindle shapes with processes, oval central darker nuclei, acidophilic cytoplasm.

Macrophages

• Psuedopodea with a kidney-shaped, eccentric nuclei.
• Large number of secondary lysosomes.
• Function in phagocytosis.

Mast Cells

• Largest of free cells.
• Contain basophilic granules stained red with toluidine blue (metachromatic staining).
• Central rounded nucleus.
• Function in secretion of histamine.

Plasma Cells

• Large, ovoid cells.
• Basophilic cytoplasm (rER), spherical eccentric nuclei.
• Cartwheel appearance of the nucleus.
• Function in antibody formation.

Adipocytes

• Large, spherical or polyhedral cells containing single or several lipid droplets.
• Flattened peripheral nuclei.
• Function in lipid storage.

Types of Connective Tissue Proper

• Loose areolar connective tissue: Contains all fiber types and abundant ground substance; found in lamina propria and papillary dermis of the skin.
• Dense regular connective tissue: Collagenous fibers are arranged parallel; found in tendons and ligaments.
• Dense irregular connective tissue: Collagenous fibers run in all directions; found in the deep dermis of skin and capsules of lymph nodes.
• Reticular connective tissue: Composed of reticular fibers; found in liver, lymphoid tissue, and bone marrow.
• Elastic connective tissue: Contains elastic fibers, which run parallel or in a wavy pattern; found in large arteries and vocal cords.
• Adipose connective tissue: Contains adipocytes (fat cells); found in subcutaneous tissue and surrounding vital organs.

Test your knowledge on the main components and functions of connective tissue. This quiz covers topics such as intercellular substances, types of fibers, and the specific roles of different connective tissue cells. Challenge yourself and see how well you understand the intricacies of connective tissue!