List of abbreviations
of micros-
specialist terms
explained in
English +

Every attempt was made to provide correct information and labelling, however any liability for eventual errors or incompleteness is rejected!

dieser Seite

Dr. med.
H. Jastrow

of use
Overview testis (Testis):
Pages with explanations are linked to the text below the images if available! (Labelling is in German)
Tubulus semi-
niferus overview (rat)
Tubulus seminiferus filled
with sperms (rat)
germinatve epithelium of a
Tubulus seminiferus contortus (rat)
basal part,
Sertoli cell (rat)
Sertoli cells +
spermatogons (rat)
spermatid, acrosome
formation 1 (monkey)
spermatid, acrosome
formation 2 (monkey)
development of acrosomal
cap (rat)
later stage of acro-
some formation (rat)
Leydig cells
Leydig cells 2 (rat)
2 Reinke crystals
Reinke crystal of a
Leydig cell (monkey)

The testis (Terminologia histologica: Testis, Orchis) contains hundrets of long ducts, the seminiferous tubules (convoluted seminiferous tubules; Terminologia histologica: Tubuli seminiferi contorti) in which the maturation and formation of the male germ cells called spermatozoa takes place. Sertoli cells (nurse cells, sustentocytes, supporting cells; Terminologia histologica: Sustentocyti, Epitheliocyti sustentantes) are oriented at right angle to the basis of the basement membrane and reach upwards to contact the lumen of the ducts. Different stages of the maturing germ cells are located in between these nursing cells that also form by their tight junctions the blood-testis barrier  (Terminologia histologica: Claustrum haematotesticulare; englisch blood testis barrier) at the level of the spermatogons to the level of spermatocytes I.
Testosterone producing Leydig's cells (interstitial endocrine cells; Terminologia histologica: Endocrinocyti interstitiales; englisch ) are located in the loose connective tissue in between the tubuli seminiferi. The contain lipid droplets and in some cases may show crystals of proteins called Reinke crystalloid (Terminologia histologica: Crystalloidea). Their cytoplasm contains plenty of tubular-type mitochondria as well as an abundance of smooth endoplasmic reticulum.
The spermatogenic cells (Terminologia histologica: Cellulae spermatogenicae) are located at the base of the seminiferous tubes and during undergoing meiosis give raise to primary spermatocytes (Terminologia histologica: Spermatocyti primarii) then secondary spermatocytes (Terminologia histologica: Spermatocyti secundarii)  which then loose great amounts of their cytoplasm before they become spermatids (Terminologia histologica: Spermatidia) and finally sperm cells. Sperm cells (sperms; male gametes; Terminologia histologica: Spermatozoa, Spermia, Gameti masculini) are the germ cells of males. They only contain a haploid set of chromosomes in the very electron-dense nucleus contained in their head next to a specialised lysosome called acrosome which is crucial for fertilisation. The body is poor in organelles only plenty of crista-type mitochondria with an electron-dense matrix are forming a sheath around the cilium which is the motile part of the flagella that extends to the tail of the sperm.

--> Epididymis, deferent duct, prostata, epithelium, crystals, blood-testis barrier, synaptonemal complexes
--> Electron microscopic atlas Overview
--> Homepage of the workshop

Four images were kindly provided by Prof. H. Wartenberg; other images, page & copyright H. Jastrow.