Connective Tissue Lecture Review

Vocabulary flashcards covering the key terms and definitions related to connective tissue, its components, types, and functions, based on the provided lecture notes.

Tissue

A group of similar cells and cell products working together to perform a specific role in an organ.

Organ

A structure with discrete boundaries that is composed of two or more tissue types.

Histology (microscopic anatomy)

The study of tissues and how they are arranged into organs.

Primary Tissue Classes

The four main types of tissues: Epithelial, Connective, Nervous, and Muscular.

Matrix (extracellular material)

The non-cellular material composed of fibrous proteins and ground substance found between cells in tissues.

Ground substance

A clear gel, also known as tissue fluid, extracellular fluid (ECF), interstitial fluid, or tissue gel, found in the matrix.

Connective tissue

A diverse, abundant type of tissue in which cells occupy less space than the matrix, primarily supporting, connecting, and protecting organs.

Vascularity

The extent to which tissue is supplied with blood vessels; highly variable in connective tissues.

Fibroblasts

Cells in fibrous connective tissue that produce the fibers and ground substance of the matrix.

Macrophages

Phagocytic cells in connective tissue that engulf foreign material and activate the immune system, arising from monocytes.

Leukocytes (white blood cells)

Immune cells, such as neutrophils and lymphocytes, that defend against bacteria, toxins, and foreign agents.

Plasma cells

Cells that synthesize antibodies, developing from lymphocytes.

Mast cells

Cells found alongside blood vessels that secrete heparin (to inhibit clotting) and histamine (to dilate blood vessels).

Adipocytes

Cells that store triglycerides (fat molecules), found in adipose tissue.

Collagenous fibers

Tough, flexible, and stretch-resistant fibers made of collagen, the most abundant protein in the body, found in tendons, ligaments, and skin.

Reticular fibers

Thin collagen fibers coated with glycoprotein that form the framework (stroma) of organs like the spleen and lymph nodes.

Elastic fibers

Fibers made of the protein elastin that are thinner than collagenous fibers, branch, rejoin, and allow for stretch and recoil.

Glycosaminoglycans (GAGs)

Long polysaccharides (e.g., chondroitin sulfate, heparin, hyaluronic acid) that regulate water and electrolyte balance in tissues.

Chondroitin sulfate

The most abundant GAG, responsible for the stiffness of cartilage.

Proteoglycans

Gigantic molecules composed of a core protein and GAGs that form gravy-like colloids, holding tissues together.

Adhesive glycoproteins

Protein-carbohydrate complexes that bind components of a tissue together.

Loose connective tissue

A type of fibrous connective tissue with much gel-like ground substance between cells, including areolar and reticular tissues.

Areolar tissue

A type of loose connective tissue with loosely organized fibers, abundant blood vessels, and empty space, found underlying epithelia and surrounding nerves.

Reticular tissue

A type of loose connective tissue forming a mesh of reticular fibers and fibroblasts, creating supportive stroma for lymphatic organs.

Dense connective tissue

A type of fibrous connective tissue where fibers fill spaces between cells, categorized as regular or irregular based on fiber orientation.

Dense regular connective tissue

Densely packed, parallel collagen fibers found in structures like tendons and ligaments, providing strong, unidirectional resistance to stress.

Dense irregular connective tissue

Densely packed, randomly arranged collagen fibers that withstand unpredictable stresses, found in the deeper layer of skin and around organs.

Adipose tissue (fat)

A connective tissue dominated by adipocytes, serving as the body's primary energy reservoir, providing insulation and cushioning.

White fat

The main type of adipose tissue in adults, providing thermal insulation, cushioning organs, and contributing to body contours.

Brown fat

A type of adipose tissue found in fetuses, infants, and children, specialized for heat generation.

Cartilage

A stiff connective tissue with a flexible matrix, providing shape (e.g., ear, nose, larynx) and support, and lacking direct blood vessels.

Chondroblasts

Cartilage cells that produce the matrix and eventually become trapped within it.

Chondrocytes

Mature cartilage cells that are trapped in lacunae (cavities) within the cartilage matrix.

Lacunae

Small cavities or spaces within the matrix of cartilage and bone where cells (chondrocytes or osteocytes) reside.

Perichondrium

A sheath of dense irregular connective tissue that surrounds elastic and most hyaline cartilage, containing chondroblasts for cartilage growth.

Hyaline cartilage

Cartilage with a clear, glassy appearance due to fine collagen fibers; eases joint movement, holds airways open, and forms fetal skeleton.

Elastic cartilage

Cartilage containing abundant elastic fibers that provide flexible, elastic support, found in the external ear and epiglottis.

Fibrocartilage

Cartilage containing large, coarse bundles of collagen fibers, providing resistance to compression and shock absorption, found in intervertebral discs.

Bone (osseous) tissue

A calcified connective tissue that forms the skeleton.

Spongy bone

A porous form of osseous tissue characterized by delicate struts of bone (trabeculae), found in the heads of long bones and middle of flat bones.

Compact bone

A denser, calcified osseous tissue with no visible spaces, where cells and matrix surround vertically oriented blood vessels.

Osteon (Haversian or osteonic canal system)

The structural unit of compact bone, consisting of a central canal and its surrounding concentric lamellae.

Lamellae

Onion-like layers of bone matrix deposited concentrically around each central canal in compact bone.

Osteocytes

Mature bone cells residing within lacunae in the bone matrix.

Canaliculi

Delicate canals radiating from lacunae to neighboring lacunae in bone, allowing osteocytes to contact each other.

Periosteum

A tough fibrous connective tissue covering the entire bone surface.

Blood

A fluid connective tissue that transports cells and dissolved matter throughout the body.

Plasma

The ground substance of blood, in which formed elements are suspended.

Formed elements

The cellular components and cell fragments in blood, including erythrocytes, leukocytes, and platelets.

Erythrocytes (red blood cells)

Blood cells responsible for transporting oxygen and carbon dioxide.

Leukocytes (white blood cells)

Blood cells that defend the body against infection and disease.

Platelets

Cell fragments in blood involved in the clotting process.