Lecture 7: Male Reproductive Histology Flashcards
(41 cards)
Identify A-D
A) Tunica Albuginea
B) Epididymis
C) Rete Testis
D) Septa
The Rete Testis are channels formed within?
The CT of the mediastinum
Identify A-E
A) Leydig Cells
B) Sertoli Cells
C) Spermatogonia
D) Primary Spermatocytes
E) Spermatids
How do we identify Leydig Cells histologically?
- Contain lipid droplets (for steroid synthesis), mitochondria w/ tubular cristae, and a well-developed sER
- Close to blood vessesl and lymphatic channels
- Present in the intertubular space
The seminiferous epithelium houses which 4 structural types of nuclei; describe the characterisitcs of each?
1) Nuclei of Spermatogonia and Sertoli Cells –> close to tubular wall
2) Spermatogonia cell (primary spermatocytes): larger nuclei and clumps of chromatin
3) Early spermatids —> round, light nuclei
4) Late spermatids –> cylindrical-shaped, condensed nuclei
What is the function of Sertoli Cells?
- Support, protect, and nourish developing spermatogenic cells
- Eliminate residual bodies via phagocytosis (discared by spermatids during spermiogenesis)
- Release of mature spermatids into lumen of tubule, spermiation
What are the characterisitcs to identify the Sertoli Cells histologically?
Oval or pyramidal nuclei (potato shaped; light staining)
Identify A and B
A) Sertoli Cells
B) Peritubular Myoid Cells
At the basolateral domain of the Seminferous Epithelium, what do Sertoli cells have that is special to the testes?
- Tight junctions creating basal and adluminal compartment
- Special to the testes: typically an apical specialization
What is the function of the tight junctions in the Adluminal compartment of the Seminiferous Epithelium?
Establish the blood-testes barrier
Identify the structure labeled by A
Leydig (interstital) cells
Where are the diploid spermatogenic cells found?
- Reside in a niche of basal compartment of Sertoli cells
- Located outside the blood-testes barrier
What process do primary spermatocytes undergo and what is the product?
Undergo 1st meiotic division (reductional division) (4C) –> two secondary spermatocytes (2C)
What process do secondary spermatocytes undergo and what are the products?
- Undergo 2nd meiotic division (equational division) (2C) –> two spermatids (1C)
- Spermatids mature w/o further division
What is the ploidy of spermatids and what do they intiate?
- Spermatids are haploid
- Initiate spermiogenesis
Where are the round (early) spermatids housed vs. the elongated (late) spermatids?
Round (early): house in niches in cytoplasm of Sertoli Cells
Elongated (late): housed in crypts, deep invaginations in Sertoli apical cytoplasm
The last step of spermiogenesis is the development of what 4 characteristics?
1) The acrosome
2) The manchette
3) The tail
4) Shaping and condensation of the nucleus
What is spermiation?
Release of mature spermatids into the seminferous tubular lumen, involving the contractile forces generated by Sertoli cells
What are the 3 subdivisions of the tail of the sperm and characteristics of each?
Middle piece: helically arranged mitochondrial sheathe, Axoneme, 9 longitudinal columns, outer dense fibers, surrounding axoneme
Principal piece: is the longest segment of the tail, consists of the central axoneme surrounded by a fibrous sheath, which provides scaffold during sliding/bending of tail during forward motility
End piece: very short, only contains the axoneme
What is the sperm maturation pathway for mature spermatids (immature sperm)?
Straight tubules —> Rete Testis —> Efferent ductules —> Epididymal duct
What is A pointing to and what structure is this?
A) Columnar Sertoli Cells, which are transitioning into Cuboidal Sertoli Cells
- This is a Straight Tubule (Tubulus rectus)
What structure is this?
Rete Testis
Each Efferent Ductule is lined with what 3 cell types?
1) Columnar cells w/ microvilli/sterocilia (Principle Cells)
2) Ciliated Cells
3) Basal cells
*Also a thin inner circular layer of smooth muscle underlies epithelium and basal lamina
Identify A and B
A) Efferent Ductule
B) Smooth muscle
