Structure & Components
What is the non-cellular network of proteins and carbohydrates in connective tissue called?
Extracellular matrix (ECM).
Which connective tissue cell produces collagen and other matrix proteins?
Fibroblasts.
Which fiber provides tensile strength to connective tissue?
Collagen.
Which connective tissue type stores energy and cushions organs?
Adipose tissue.
Give two general functions of connective tissue.
Support/structure and protection (also transportation, storage, defense).
Name the three main fiber types found in the extracellular matrix.
Collagen fibers, elastic fibers, reticular fibers.
Which cell type stores fat and provides insulation?
Adipocytes.
Which fiber gives tissue the ability to stretch and then return to shape?
Elastic fibers.
Name the connective tissue found in tendons and ligaments with high collagen content.
Dense connective tissue (dense regular connective tissue).
How does adipose tissue help protect organs?
Adipose cushions organs physically and absorbs mechanical shock; it also insulates and reduces friction.
Describe how the consistency of the extracellular matrix can vary (give one example for liquid, gel-like, and solid).
Liquid = blood (plasma); gel-like = cartilage; solid = bone.
Which immune-related cell in connective tissue helps remove debris and pathogens?
Macrophages.
What is the ground substance and name two components found within it?
Ground substance is the non-cellular material between cells and fibers; components include water, glycoproteins, and proteoglycans.
Which connective tissue is avascular and helps in joints and the ear?
Cartilage.
Name one-way connective tissue participates in the immune response.
Macrophages and mast cells participate in immune defense by engulfing pathogens and releasing signaling molecules.
What are the two main parts that define connective tissue structure (one is cells; what is the other)?
Cells and extracellular matrix (ECM).
Which cell releases histamine and is involved in allergic responses?
Mast cells.
Explain how collagen and elastic fibers work together in skin to allow both strength and flexibility.
Collagen provides tensile strength to resist pulling forces; elastic fibers allow stretch and recoil - combined they let skin resist tearing while remaining flexible.
Why is bone classified as connective tissue? Give two functions of bone.
Bone has a hardened ECM with mineral deposits (calcium/phosphate) making it rigid; functions: structural support and protection of organs, mineral storage.
Explain why cartilage heals slowly after injury.
Cartilage is avascular (lacks blood vessels) and lacks nerves, so it receives nutrients slowly by diffusion, delaying repair processes.
Explain why connective tissue is classified separately from epithelial tissue, using structure and function in your answer.
Connective tissue has cells scattered within an abundant extracellular matrix specialized for support and binding, whereas epithelial tissue is composed of closely packed cells that form continuous sheets covering surfaces — connective tissue provides support and connection; epithelial tissue provides coverage and protection.
Compare the roles of fibroblasts and macrophages in tissue repair after an injury.
Fibroblasts synthesize and maintain the ECM (collagen and proteins) to rebuild tissue structure; macrophages clear pathogens and debris and help orchestrate inflammation and healing - together they remove damage and rebuild functional matrix.
Predict how a defect in ground substance production might affect nutrient and waste exchange in connective tissue and give a possible consequence.
A defect could reduce the matrix's ability to hold water and exchange nutrients/wastes, impairing cell survival and repair - possible consequence: poor tissue maintenance or slower healing.
Blood is considered a connective tissue. Explain the reasoning based on its components and matrix.
Blood has cells (red/white platelets) suspended in a liquid extracellular matrix (plasma), fitting the connective tissue definition of cells within a matrix that originates from mesenchyme.
Identify one lifestyle factor that supports healthy connective tissue and explain its role (for example: nutrition, hydration, or exercise).
Adequate vitamin C supports collagen synthesis (nutrition); or regular weight-bearing exercise strengthens bone and connective tissue; or hydration helps maintain ground substance viscosity for nutrient exchange.