Microvilli are tiny finger-like protrusions extending from the cell membrane and cytoplasm toward the free surface. Commonly found in renal tubular epithelium and small intestinal epithelium, with large cell surface area

Pseudostratified ciliated columnar epithelium is mainly distributed in the respiratory mucosa

Basal layer: a layer of cuboidal or short columnar cells (strong ability to divide)

Middle layer: several layers of polygonal cells

Surface layer: several layers of spindle or flat cells

Function: Release heparin, histamine, triethrin, and eosinophil chemoattractant

differentiate into osteoblasts

Produce bone and secrete cytokines

It has certain osteolytic and osteogenic functions and is involved in regulating calcium and phosphorus balance.

Osteolytic, phagocytic and digestive abilities

organic ingredients

Inorganic components

bone plate

bone mineral density

Cancellous bone (distributed within the bone)

Dense, thick fibers, painful penetration, fibrous

Loose, nutrient-rich blood vessels, nerves and osteoprogenitor cells

Biconcave disc shape, thin in the center and thick around the periphery, with dumbbell-like tubes on the sides, without nuclei and organelles

Transport oxygen and carbon dioxide

neutrophils

eosinophils

basophils

Lymphocytes

monocytes

No nucleus

Hemostasis and coagulation