Overview
This lecture covers the structure, types, and functions of connective tissue, highlighting Marfan Syndrome as an example of how connective tissue disorders can impact health.
Flo Hyman and Marfan Syndrome
- Flo Hyman was an Olympic volleyball player who died due to Marfan Syndrome, a connective tissue disorder.
- Marfan Syndrome is caused by a genetic defect resulting in weakened connective tissue, particularly affecting the heart and aorta.
- Physical traits of Marfan Syndrome include tall stature, long limbs, and flexible joints.
- Marfan Syndrome can cause serious issues in joints, eyes, lungs, and especially the heart.
Introduction to Connective Tissue
- Connective tissue is the most abundant and diverse tissue type in the body.
- It supports, binds, protects, insulates, and transports substances throughout the body.
- Four main classes of connective tissue: proper, cartilage, bone, and blood.
Common Features of Connective Tissues
- All connective tissues develop from mesenchyme, an embryonic tissue.
- They have varying degrees of vascularity (blood supply).
- Mainly composed of nonliving extracellular matrix, rather than densely packed cells.
Extracellular Matrix Components
- The matrix consists of ground substance (watery, rubbery material) and fibers.
- Ground substance is rich in proteoglycans and glycosaminoglycans (GAGs) that trap water.
- Three types of fibers: collagen (strongest), elastic (stretchy), and reticular (delicate, sponge-like).
Connective Tissue Cells
- Immature cells are called "-blasts" (e.g., osteoblasts, chondroblasts) and create the matrix.
- Mature cells are called "-cytes" (e.g., osteocytes, chondrocytes) and maintain the matrix.
- Some immune cells (macrophages, white blood cells) reside in connective tissue, providing defense.
Effects and Importance of Connective Tissue Disorders
- Marfan Syndrome mainly weakens elastic fibers, especially in blood vessels like the aorta.
- Weak connective tissue can lead to life-threatening ruptures and system-wide problems.
Key Terms & Definitions
- Connective Tissue â tissue that supports, binds, protects, and insulates body parts.
- Extracellular Matrix â nonliving material between cells, consisting of ground substance and fibers.
- Collagen Fibers â strong, flexible protein fibers in connective tissue.
- Elastic Fibers â fibers made of elastin, allowing tissues to stretch and recoil.
- Reticular Fibers â thin collagen fibers that form supportive networks.
- Mesenchyme â embryonic tissue from which all connective tissue derives.
- Proteoglycan â protein with attached GAGs, drawing water into ground substance.
- Blast Cells â immature, matrix-forming cells (e.g., osteoblast).
- Cyte Cells â mature, matrix-maintaining cells (e.g., chondrocyte).
- Marfan Syndrome â genetic connective tissue disorder affecting elasticity and strength.
Action Items / Next Steps
- Review the functions and structures of the four classes of connective tissue.
- Prepare for next weekâs lesson on connective tissue subtypes.