DAPAT ALAM NYO NA KASI YAN PART 2

Adipose Tissue

A specialized type of connective tissue in which fat-storing cells, known as adipocytes, are the predominant component.

Adipocytes

 Large, mesenchymally derived cells specialized for the cytoplasmic storage of lipids as neutral fats or, less commonly, for the production of heat.

Triglycerides

Long-chain fatty acyl esters of glycerol that serve as the primary form of neutral fat stored within adipocytes.

 Hypertrophy

An increase in the volume of individual cells; in the context of adipose tissue, this is one way the tissue grows in response to increased lipid storage.

Hyperplasia

An increase in the total number of cells within a tissue.

White Adipose Tissue

The more common type of adipose tissue specialized for long-term energy storage; it typically represents 15%-20% of body weight in men and slightly more in women.

Unilocular

A term describing the structure of white adipocytes, where the cell contains one large, single lipid droplet that pushes the nucleus and remaining cytoplasm against the cell membrane.

Subcutaneous Fat

Deposits of white adipose tissue located directly under the skin

Visceral Fat

Fat deposits located within the abdomen; increased levels of this fat are associated with higher risks of diabetes and cardiovascular disease.

 Leptin

A "satiety factor" or hormone produced by white adipocytes that helps regulate the body’s energy metabolism and appetite.

Brown Adipose Tissue

- A specialized type of adipose tissue characterized by its darker color (due to abundant mitochondria and capillaries) whose principal function is heat production (thermogenesis).

Multilocular

A term describing the structure of brown adipocytes, which contain many small, separate lipid droplets rather than a single large one.

Thermogenesis

The process of heat production, which is the primary function of brown adipose tissue, particularly in newborns.

 UCP1 (Uncoupling Protein 1)

A mitochondrial protein (also known as thermogenin) essential for the heat-generating function of brown adipose tissue.

Norepinephrine

A neurotransmitter released by sympathetic nerve endings that stimulates brown adipocytes to begin the mitochondrial production of heat

Connective Tissue

A tissue that provides a matrix to support and physically connect other tissues and cells to form the organs of the body.

Extracellular Matrix (ECM)

The major constituent of connective tissue, consisting of different combinations of protein fibers and ground substance.

Interstitial Fluid

The water within the ground substance that serves as a medium for the diffusion of nutrients and waste products between cells and the blood supply.

Mesenchyme

An embryonic tissue developing mainly from the mesoderm that contains undifferentiated, spindle-shaped cells; it is the origin of all adult connective tissues.

Stroma

The connective tissue that forms the supportive framework of most organs, supporting the specific functional cells (parenchyma).

Fibroblasts

The most common and key cells in connective tissue proper that synthesize and secrete most components of the ECM, including collagen, elastin, and ground substance.

Fibrocytes

Quiescent or inactive fibroblasts that are smaller and spindle-shaped with fewer processes and darker nuclei.

Myofibroblasts

Fibroblasts involved in wound healing that possess contractile functions and characteristics of both fibroblasts and smooth muscle cells.

Adipocytes (Fat Cells)

Large, mesenchymally derived cells specialized for the cytoplasmic storage of lipids as neutral fats or for heat production.

Macrophages

Long-lived, phagocytic cells derived from blood monocytes that function in ECM turnover, debris removal, and antigen presentation.

Mononuclear Phagocyte System

A group of related macrophage-like cells found in various organs, such as Kupffer cells in the liver and osteoclasts in bone.

Mast Cells

Oval or irregular cells filled with basophilic secretory granules that contain mediators like histamine and help coordinate the inflammatory response.

Metachromasia

The ability of some cell components (like mast cell granules) to change the color of certain basic dyes from blue to purple or red.

Plasma Cells

Large, ovoid, lymphocyte-derived cells with basophilic cytoplasm that are specialized for producing antibodies.

Leukocytes (White Blood Cells)

A population of wandering cells in connective tissue that migrate from the blood to perform various defensive functions for a short period.

Collagen

The most abundant protein in the human body, forming strong extracellular fibers, sheets, and networks that resist shearing and tearing forces.

Reticular Fibers

Delicate networks of type III collagen that provide a supportive framework for parenchymal cells and microvasculature in organs like the liver and lymph nodes.

Argyrophilic

A term used to describe structures (like reticular fibers) that characteristically stain black after impregnation with silver salts.

Elastic Fibers

Thinner fibers composed of the proteins elastin and fibrillin that allow tissues to be stretched and return to their original shape.

 Ground Substance

A highly hydrated, transparent mixture of macromolecules that fills the space between cells and fibers, acting as a lubricant and a barrier to invaders.

Glycosaminoglycans (GAGs)

Long polymers of repeating disaccharide units that are anionic and hydrophilic, providing cushioning and space-filling functions.

Hyaluronan (Hyaluronic Acid)

The largest and most ubiquitous GAG, which forms a viscous network that binds water and is synthesized directly into the ECM.

Proteoglycans

Macromolecules consisting of a core protein with various sulfated GAGs covalently attached.

Aggrecan

A massive proteoglycan found abundantly in cartilage that joins with hyaluronan to form huge, water-binding complexes.

Multiadhesive Glycoproteins

 Large proteins with branched oligosaccharide chains (like laminin and fibronectin) that possess multiple binding sites for integrins to allow cell adhesion to the ECM.

Integrins

Integral membrane proteins that act as matrix receptors, linking the ECM to the cell’s cytoskeleton.

Loose (Areolar) Connective Tissue

Common tissue with roughly equal parts of cells, fibers, and ground substance; it is flexible but not very resistant to stress.

Dense Irregular Connective Tissue

Tissue filled with randomly interwoven bundles of type I collagen, providing structural strength and resistance to tearing from all directions.

Dense Regular Connective Tissue

Tissue consisting of parallel bundles of type I collagen and fibroblasts, specialized for great resistance to repeated stress in one direction (e.g., tendons and ligaments).

Reticular Tissue

A specialized tissue characterized by abundant type III collagen fibers forming a delicate network that supports various immune cells.

Mucoid Tissue

A gelatinous embryonic connective tissue (Wharton’s jelly) found in the fetal umbilical cord, composed chiefly of hyaluronan

Type I

The most abundant and widely distributed type, representing 90% of the body's collagen. It forms thick, eosinophilic bundles known as collagen fibers found in the skin, tendons, bone, and dentin. Its primary function is providing resistance to tension.

Type II

Primarily found in cartilage and the vitreous body of the eye. It exists as fibrils but does not form large fibers or bundles. It is specialized for resistance to pressure.

Type III

This type forms delicate, silver-staining networks called reticular fibers. These fibers provide structural maintenance in expansible organs like the skin, muscle, and blood vessels, and form the supportive stroma for lymphoid and hemopoietic organs.

Types V and XI

These participate in the functions of Type I and Type II collagen, respectively.

Type IV

 A major structural component of all epithelial basal laminae and external laminae. It self-assembles into a mesh-like network resembling a window screen to provide support and filtration.

Type X

Found in hypertrophic cartilage involved in bone formation; it serves to increase the density of the matrix.

 Linking or Anchoring Collagens

These are short collagens that link fibrillar collagens to one another or to other components of the extracellular matrix (ECM).

Type VII

This type forms anchoring fibrils that bind the basal lamina to the underlying reticular lamina in basement membranes.

Type IX

Associated with Type II collagen in cartilage, where it binds various proteoglycans.

Types XII and XIV

These interact with Type I collagen fibrils to strengthen fiber formation in tissues such as the placenta, skin, and tendons.

Type I

bundles appear white in a fresh state, but in routine light microscopy, they are acidophilic (staining pink with eosin). Under a polarizing microscope, they exhibit birefringence due to their highly regular orientation.

Type III (Reticular fibers)

are not easily visible with H&E stains but are argyrophilic, meaning they stain black after impregnation with silver salts.