① Spermatogenic cell 5-8 layers c 4 types of cells
① Spermatogenic cell: ---5-8 layers ---4 types of cells
a spermatogonium outerest layer, one layer structure round, ellipsoid ce‖ /12um round N, deep stained
a. spermatogonium ---outerest layer, one layer ---structure: /round, ellipsoid cell /12um /round N, deep stained
classification ● type A dark type A(Ad): ovoid, deep-stained N, stem cell Pale type A(Ap): ovoid, pale-stained N differentiate into type B e type B: round N, chromatin granules are distributed under nucleus membrane division and differentiate into primary spermatocyte
---classification: type A: -dark type A(Ad): ovoid, deep-stained N, stem cell -Pale type A(Ap): ovoid, pale-stained N, differentiate into type B type B: round N, chromatin granules are distributed under nucleus membrane, division and differentiate into primary spermatocyte
b primary spermatocytes ---diploid (2n)cell duplicate dNA tetraploid cell(4n) division structure e round cell, become largest, 18 um, left the basal layer N: large, round, on different stage of division (the prophase of meiotic division up to 22 days) through first meiosis divides into two secondary spermatocyte(2n, 23X or 23Y)
b. primary spermatocytes ---diploid(2n)cell →duplicate DNA → tetraploid cell(4n) →division ---structure: round cell, become largest, 18 um, left the basal layer N: large, round, on different stage of division(the prophase of meiotic division up to 22 days) ---through first meiosis divides into two secondary spermatocyte(2n, 23X or 23Y)
C secondary spermatocyte nearer the lumen structure e round cell, 12um o N: round deep-stained hard to see-short lived(divide quickly) through secondary meiosis divides into two spermatid (1n, 23X or 23Y)
c. secondary spermatocyte: ---nearer the lumen ---structure: round cell, 12um N: round deep-stained hard to see- short lived(divide quickly) ---through secondary meiosis divides into two spermatid(1n, 23X or 23Y)