Male Reproductive Histology Flashcards
What are the innermost layers of the scrotal wall?
Mesothelium, Tunica albuginea, and tunica vasculosa
System in the testis
Tunica albuginia
Tough fibrous capsule
Excretory Ducts
Rete testis
Carries sperm out of the testis by connecting a series of efferent ducts that form part of the head of the epididymis.
Seminiferous Tubules
System in the testis
Tunica vasculosa
Sends septa into the testis to divide it into 250-300 lobules.
System in the testis
Seminiferous tubules
Are a loop through each lobule
System in the testis
Tubuli recti
Connect each ST at each end (straight tubules) to a network of channels called the rete testis
System in the testis
Rete testis
Go to efferent ducts, then the head of the epididymis and from there to the tail of it and the ejaculatory duct.
Excretory Ducts
Epididymis
Head and tail form a single coiled tube where sperm mature and are temporarily stored. Continuous with vans deferens which conveys sperm away from scrotum along spermatic cord during ejaculation.
Spermatogenesis
What is it?
The process of proliferation and maturation which transforms diploid spermatagonia into haploid spermatozoa
Spermatogenesis
Type A dark spermatagonia
Form a pool of self renewing stem cells but can also form Type A pale spermatagonia. These divide mitotically to form Type B spermatagonia.
Spermatogenesis
Type B spermatagonia
Further divide mitotically to form primary spermatocytes
Spermatogenesis
Primary spermatocytes
Pass through meiosis I to form secondary spermatocytes
Spermatogenesis
Secondary spermatocytes
Rapidly undergo meiosis II to produce spermatids
Spermatogenesis
Spermatids
Undergo a maturation process called spermiogenesis to produce spermatozoa - there is no division in this step, it is a cellular change
Clonal Syncytium
What is it?
An intercellular bridge which only breaks when the spermatozoa are released. This is because the cells do not undergo full cytokinesis
Sertoli Cells
What do they do?
Are support within the seminiferous tubules. Very important both in supporting the newly developing spermatozoa and in controlling how the process proceeds. They extend all the way from the basal lamina to the lumen of the tubule. Their cytoplasm ramifies and surrounds all of the developing cells.
Function of Sertoli Cells
Secrete
Factors regulating spermatogenesis, spermiogenesis and Leydig cells. Also secrete tubular fluid.
Function of Sertoli Cells
Phagocytose
Discarded spermatid cytoplasm
Function of Sertoli Cells
Via tight junctions
Divide the tubule epithelium into two compartments
Blood-Testis Barrier
Spermiation
What is it?
Release of the spermatozoa by the Sertoli cells into the lumen. Immotile and incapable of fertilization until swept through rete testis and epididymis by fluid flow and peristalsis, after which it will become capable.
Intertubular Tissue
What is it?
Found between seminiferous tubules. Loose connective tissue, blood vessels, nerves and lymphatics. Also clusters of Leydig cells which produce testosterone.
Efferent Ducts
What are they?
About 12 ducts which carry the sperm from the rete testis to the head of the epididymis. Lined by ciliated pseudostratified columnar epithelium and most fluid from the testis is absorbed here.
