Which tissue types are avascular?

Which tissue types are avascular?

• A. Nervous tissue and skeletal muscle
• B. Cartilage and most epithelia
• C. Blood vessels and adipose tissue
• D. Dense connective tissue

Answer: (B)

Tissues that lack blood vessels rely on diffusion for nutrients and waste removal, which means they don’t have a direct blood supply and often heal slowly. Cartilage fits this pattern: its matrix contains no blood vessels, so nutrients diffuse from the surrounding tissue, such as the perichondrium, to keep the cells nourished. Most epithelia are also avascular. They receive their nutrients from underlying connective tissue through diffusion across the basement membrane, which supports their role as protective barriers without needing their own blood vessels. Nervous tissue and skeletal muscle require a rich blood supply to meet high metabolic demands, so they are vascularized. Blood vessels themselves are, of course, vascular, and many connective tissues (including dense connective tissue) are well supplied with blood vessels, though there are exceptions in some tightly wrapped structures like tendons and ligaments.

Tissues that lack blood vessels rely on diffusion for nutrients and waste removal, which means they don’t have a direct blood supply and often heal slowly.

Cartilage fits this pattern: its matrix contains no blood vessels, so nutrients diffuse from the surrounding tissue, such as the perichondrium, to keep the cells nourished.

Most epithelia are also avascular. They receive their nutrients from underlying connective tissue through diffusion across the basement membrane, which supports their role as protective barriers without needing their own blood vessels.

Nervous tissue and skeletal muscle require a rich blood supply to meet high metabolic demands, so they are vascularized. Blood vessels themselves are, of course, vascular, and many connective tissues (including dense connective tissue) are well supplied with blood vessels, though there are exceptions in some tightly wrapped structures like tendons and ligaments.