Loose connective tissue, dense connective tissue, reticular tissue, adipose tissue

The largest and most important cells, often attached to collagen fibers Function: Synthesize and secrete collagen and elastin to form elastic fibers, reticular fibers, and collagen fibers Synthesis of secreted proteoglycans, which constitute the matrix Synthesis of bioactive substances involved in various processes LM: Large, protruding, large nucleus, light coloration, obvious nucleoli, weak basophilic cytoplasm EM: Abundant RER (rough endoplasmic reticulum) and well-developed GOL (Golgi apparatus) Functionally quiescent fibroblasts: LM, cells are small, long spindle-shaped, with small and elongated nuclei, light coloration, less cytoplasm, and eosinophilic

Mononuclear cells from the blood, with chemotaxis and directional movement capabilities, chemokines: bacterial products, inflammatory denatured proteins Phagocytosis: 1. Specific phagocytosis, recognition factor 2. Non-specific phagocytosis, no recognition factor required Secretion, lysosomes, complement, various cytokines antigen presentation LM: Pseudopodia, irregular shape, abundant cytoplasm, eosinophilic, small nucleus, dark staining, may contain foreign particles and vacuoles EM: There are microfolds or villi and globular protrusions on the surface, and the cytoplasm contains a large number of lysosomes, phagosomes, and residual bodies.

Spleen, lymph nodes, digestive tract, respiratory tract and other mucosal connective tissue or lymphoid tissue and chronic inflammation sites LM: Oval, round nucleus, located on one side, heterochromatin is thick and wheel-shaped, the cytoplasm is basophilic, and there is a light staining area next to the nucleus EM: Rich RER and GC Function: Synthesize and secrete immunoglobulins (antibodies) to participate in immune response

Hematopoietic progenitor cells in the blood, often distributed along small blood vessels and small lymph nodes, such as connective tissue in the skin, digestive tract, and respiratory tract EM: The body is large, oval, the nucleus is small and round, located in the center of the cell, and the cytoplasm is filled with thick basophilic secretory granules. Synthesizes and secretes a variety of active mediators, which are related to allergic reactions

LM: The body is large, round or polygonal, the nucleus is oblate and tilted to one side, and the cytoplasm contains a large lipid droplet. Function: Synthesize and store fat, participate in lipid metabolism

Source: Various white blood cells in blood Types: Neutrophils, Eosinophils, Basophils, Lymphocytes

Basophils: fibroblasts, mast cells, plasma cells Eosinophils: Macrophages Among them are mast cells, plasma cells, adipocytes, and white blood cells which are blood/immune/defense

Large amount of white fiber LM: pink, varying thickness, wavy, intertwined into a network EM: Composed of collagen fibrils, 67nm periodic striations Type I collagen, collagen. Fiber, high toughness, strong tensile strength

Small amount, yellow fiber LM: Eosinophilic, highly refractive, intertwined into a network Elastin, microfibrils (fibrillin) Great flexibility

Argyrophilic fiber distribution network tissue, basement membrane LM: HE dyeing is light red, silver plating dyeing is black type III collagen

Glycosaminoglycans (chondroitin sulfate, keratan sulfate, dermatan sulfate, heparan sulfate, hyaluronic acid) and glycoproteins Molecular sieve: allows tissue fluid to pass through and limits the spread of bacteria

Organic connection medium, affecting cell attachment and movement, regulating cell growth and differentiation. The most important of connective tissues

Function: Constitutes an environment for cells to survive, creates/reflux obstacles, and causes tissue dehydration/edema.

A large number of densely packed collagen fibers arranged in parallel bundles, tenocytes

Distributed in dermis, dura mater and organ capsule Thick collagen fibers are intertwined vertically and horizontally, tightly arranged, and have fewer cells.

Distributive ligaments, mainly elastic fibers, arranged in parallel bundles