Connective Tissue - Part 1 (Chap. 5 and 6)

60 vocabulary flashcards covering the key connective tissue concepts from the lecture notes.

Connective Tissue

A tissue that forms a continuum with epithelium and other tissues; provides structure, diffusion medium, defense, fat storage, and tissue repair.

Extracellular Matrix (ECM)

The combined fibers, ground substance, and fluid outside cells in connective tissue.

Ground Substance

Gel-like material in the ECM that surrounds cells and fibers.

Fibers

Protein filaments in the ECM (collagen, reticular, and elastic) embedded in ground substance.

Collagen Fibers

Thick, unbranched fibers that confer tensile strength; main structural collagen type.

Reticular Fibers

Fine collagen type III fibers forming supportive networks around structures.

Elastic Fibers

Fibers made of elastin that stretch and recoil; supported by microfibrils.

Tropocollagen

Triple-helical collagen molecule that polymerizes into fibrils.

Collagen Fibril

Aggregate of tropocollagen molecules forming the basic unit of collagen fibers.

Collagen Type I

Most abundant collagen; resists tension; found in tendons and bone.

Collagen Type II

Collagen in cartilage; forms fibrils that resist compression.

Collagen Type III

Collagen forming reticular fibers; provides scaffold in organs.

Collagen Type IV

Collagen in basal lamina; forms a network in the basement membrane.

Basal Lamina

Basement membrane component underlying epithelium.

Hyaluronic Acid

A large, non-sulfated GAG in ground substance that retains water.

Proteoglycans

Core protein with sulfated GAGs; binds water to form a gel.

Glycosaminoglycans (GAGs)

Long, unbranched polysaccharides that are sulfated and bind water in ECM.

Glycoproteins

Proteins with carbohydrate groups that mediate adhesion between ECM and cells.

Interstitial Fluid

Fluid in the ECM between cells and vessels; enables diffusion of nutrients.

Water

Hydrating component of ground substance that supports diffusion.

Fibroblasts

Primary ECM-secreting cells of connective tissue; spindle-shaped with basophilic cytoplasm.

Adipose Cells

Fat-storing cells that synthesize and store triglycerides; little division.

Mast Cells

Tissue-resident cells that mediate inflammation and immediate hypersensitivity; store mediators.

Histamine

Mast cell mediator causing vasodilation and increased permeability.

Heparin

Mast cell mediator with anticoagulant effects.

Prostaglandin D2

Mast cell lipid mediator involved in inflammation.

Leukotrienes

Mast cell lipid mediators contributing to inflammation.

Reticular Cells

Fixed cells that secrete reticular fibers forming supportive networks.

Mesenchymal Cells

Multipotent progenitor cells that differentiate into connective tissue cells.

Pericytes

Multipotent cells surrounding blood vessels; a source for new cells.

Fixed Macrophages

Resident tissue macrophages that phagocytose debris and present antigens.

Monocytes

Blood precursors that migrate into tissue to become macrophages.

Wandering Macrophages

Macrophages that migrate through blood/lymph to perform phagocytosis.

Lymphocytes

White blood cells involved in adaptive and innate immunity.

T-Lymphocytes

Lymphocytes mediating cell‑mediated immunity.

B-Lymphocytes

Lymphocytes that produce antibodies in humoral immunity.

Plasma Cells

Differentiated B cells that secrete antibodies; clock-face nucleus.

Natural Killer Cells

Innate immune cells that kill infected or transformed cells without prior sensitization.

Neutrophils

Granulocytes that phagocytose and kill bacteria.

Eosinophils

Granulocytes targeting parasites and modulating allergic responses.

Basophils

Circulating granulocytes similar to tissue mast cells; release mediators.

Macrophages

Phagocytic cells derived from monocytes; ingest pathogens and debris.

Loose Connective Tissue

A loose arrangement of fibers and ground substance; common in body regions.

Areolar Tissue

Synonym for loose connective tissue; supports epithelia and other structures.

Procollagen

Precursor molecule that is processed to form tropocollagen.

Triple Helix

Collagen molecule structure consisting of three polypeptide chains.

Clock-face Nucleus

Nucleus appearance in plasma cells with pale staining areas and clumped chromatin.

Supravital Staining (Neutral Red)

Staining living cells to visualize certain structures without fixation.

IgE

Immunoglobulin E; antibody involved in allergic responses and mast cell activation.

Antigen Presentation

Process by which macrophages present antigens to lymphocytes to elicit an immune response.

Phagocytosis

Engulfment and digestion of particles by cells like macrophages.

Inflammation

Local tissue response to injury or infection characterized by redness, heat, swelling, and pain.

Immediate Hypersensitivity

Rapid allergic reaction mediated by IgE and mast cells.

Mast Cell Mediators

Bioactive substances released by mast cells (e.g., histamine, heparin, prostaglandins, leukotrienes).

Basophil Similarity to Mast Cells

Basophils circulate in blood and are functionally similar to tissue mast cells.

Diffusion in Ground Substance

Movement of nutrients and gases through the hydrated ECM to cells.

Structural Support

One of the main functions of connective tissue providing framework for organs.

Medium for Exchange

Function of ECM to permit diffusion of nutrients between vessels and cells.

Defense Against Microorganisms

Connective tissue participates in immune defense via resident and wandering cells.

Fat Storage

Adipose tissue stores triglycerides for energy and insulation.