Cells are distributed singly, small, oblate, and immature

Cells are distributed in groups (homologous cell groups), large, round or oval, mature The cytoplasm is weakly basophilic and contains a large number of rough endoplasmic reticulum, a well-developed Golgi complex, a small number of mitochondria, some glycogen granules and lipid droplets.

Lots of collagen fibers

A small amount of amorphous matrix (gel-like)

Mainly hydroxyapatite crystals (secreted by fibroblasts)

form

Function

form

Function

form

Function

form

Function

outer ring bone plate

inner ring bone plate

Blood vessels and nerves from the periosteum cross the inner and outer ring bone plates and are called perforating canals (Folkmann's canals)

primary support structure of long bones

The part that remains after the ring bone plate or bone unit has been absorbed

Outer layer: thicker, composed of dense connective tissue, containing collagen fibers

Inner layer: Thin, loose tissue, few fibers, containing osteoprogenitor cells, bone covering cells, blood vessels, nerves, etc.

Very thin, lining the surface of the medullary cavity, the inner surface of the perforating canal and central canal, and the surface of trabecular bone, composed of a single layer of osteoprogenitor cells and a small amount of connective tissue

Factors that can damage the red blood cell membrane, such as lipid solvents, snake venom, and hemolytic bacteria, can cause hemolysis.

neutrophils

eosinophils

basophils

Ratio: 3%-8%

Morphology

Function

Ratio: 20%-30%

Classification

Function

composition

structure

Hematopoiesis-inducing microenvironment

Irregular shape, different lumen sizes, sinus wall lined with porous endothelium, and incomplete basement membrane The sinusoids are filled with hematopoietic tissue

The cell body is large, flat and multi-projected; the cytoplasm is weakly basophilic; the nucleus is oval with obvious nucleoli; When inactive, they are called fiber cells. Their cell bodies are small and their cytoplasm is weakly eosinophilic.

Abundant rough endoplasmic reticulum, free ribosomes and developed Golgi complex

Round or irregular shape; cytoplasm is rich, eosinophilic, and red; nucleus is small and deeply stained

Microfolds and protrusions; numerous lysosomes, phagosomes, phagocytic vesicles; microfilaments and microtubules

Round or oval; the cytoplasm is basophilic, with a lightly stained area on the near-nuclear side; the nucleus is small and deviated, The nuclear chromatin is radial (also called wheel-shaped or spoke-shaped), and the nucleoli are obvious

Abundant parallel-arranged rough endoplasmic reticulum, free ribosomes, perinuclear centrosomes and well-developed Golgi complex

Round or oval; cytoplasm is filled with thick, metachromatic basophilic granules

There are microvilli and granular ridges on the cell surface; the cytoplasmic granules are of different sizes, round or oval, and are wrapped by unit membranes on the surface.

Histamine & Leukotrienes

eotaxin

heparin

Mast cells synthesize and release leukotrienes in the cytoplasm; Mast cell granule contents: histamine, heparin, eotaxin

Often distributed singly or in groups, the cells are larger and spherical or oval; The cytoplasm is filled with lipid droplets (dissolved during HE staining) and the nucleus is squeezed to the periphery, making the cells vacuolated.

Can differentiate into fibroblasts, adipocytes, endothelial cells and smooth muscle cells of new blood vessel walls, etc.

Differentiates into a variety of connective tissue cells, endothelial cells, smooth muscle cells, etc. during the embryonic period

Under the light microscope, it is thick and without branches; under the electron microscope, it is collagen fibrils. There are periodic horizontal stripes (the period is about 64nm)

Type I and Type III collagen

High toughness and strong tensile strength

Under a light microscope, they are thin and branched; under an electron microscope, they are microfibrils.

elastin

Highly elastic, dyed purple or tan by aldehyde red or lichen red

It is thinner under light microscope, difficult to color with HE staining, and black with silver plating staining; There are 64nm periodic horizontal stripes under the electron microscope

Type III collagen

Argyrophilic, PAS staining positive

Mostly distributed at the junction of connective tissue and epithelial tissue (basement membrane mesh), At the junction with nervous tissue, reticular tissue, around muscle cells, fat cells, and hematopoietic organs, etc.

Main components of matrix

include

Hyaluronic acid (which forms the backbone of the proteoglycan complex) forms proteoglycans with the help of proteins and glycosaminoglycans, and a large number of proteoglycan aggregates form molecular sieves

include

Participate in the composition of molecular sieves and affect cell differentiation and migration

Formed from a large number of proteoglycan polymers with many micropores

It has a barrier effect, which can limit the diffusion of macromolecules such as bacteria, while allowing water smaller than its pore size and water-soluble nutrients, hormones, Gas molecules, ions, metabolites, etc. pass through to facilitate material exchange between blood and cells.

Clinical: Hemolytic streptococci and cancer cells can produce hyaluronidase, which destroys the barrier function of molecular sieves and accelerates their spread.

Shoulder blade area, armpit, neck, etc.

Rarely, distributed in an island shape around the kidneys