Podocytes

single layer squamous epithelium

renal cystic cavity

afferent arteriole

capillary half

efferent arteriole

vascular basement membrane

Mesangial cells (specialized smooth muscle cells)

matrix

(Actually, 1 to 2L of urine is urinated every day, which is 1% of the original urine)

LM

EM:

The structure is similar to that of the curvature, with only microvilli, infoldings of the plasma membrane, and reduced lateral processes.

Reabsorption: glucose, amino acids, proteins and most water, ions, urea

Secretion: hydrogen ions, ammonia, creatinine, hippuric acid, etc.

Transport and elimination: phenol red, penicillin and other drugs

The lumen is small and the wall is single-layered and flat.

Concentrated urine (thin wall, conducive to water and ion permeability)

The cells are small, the nucleus is round and central, the boundaries are clear, and the single layer is cubic.

LM: no brush border, clear longitudinal striations on the base, and lighter cytoplasmic staining

EM: Microvilli are short and small, with few lateral processes, well-developed inner folds of the plasma membrane, and sodium-potassium ATPase.

The structure is similar to that of the pars recta, except that the infoldings of the plasma membrane are not as developed as the pars recti.

Important parts of ion exchange: Under the influence of aldosterone and antidiuretic hormone, it regulates acid-base balance, absorbs H2O and Na, and excretes K, H, NH3, etc.

LM: The cells are columnar, tightly arranged, the nucleus is oval near the cell top, and the cytoplasm is light in color.

Ion receptor (sodium ion)