Male Reproductive Histo Flashcards
Functions of the testes
- Sperm production
- Endocrine glands (testosterone synthesis, storage and secretion)
Mediastinum testis
Thickened posterior portion of the Tunica albuginea possessing a rete testes
Rete testis
Series of spaces that serve as a conduit for passage of sperm
seminiferous tubules is the site of ______.
spermatozoa production
(picture: TA= tunica albuginea, TV=tunica vaginalis, BV = blood vessel, L=lumen of ST)
In the seminiferous tubules, the youngest cells form the ___ layer and the more mature germ cells lie in the _____.
- basal (outermost)
- aduminal compartment (closer to center)
seminferous tubules
(stratified epithelieum w/spermatogenic and sertoli cells)
The 3 phases of spermatogenesis
- Spermatocytogenesis (mitosis)
- Meiosis
- Spermiogenesis (differentiation)
Spermatocytogenesis ends when the ____ is generated. Spermiogenesis begins with ____.
- primary spermatid
- spermatis
Type A spermatogonia
- Mitotic stem cells of the sperm lineage
- Flat, oval nucleus
- give rise to type A & B spermatogonia
Type B Spermatogonia
- undergo mitosis
- give rise to primary spermatocytes
- round, pale nucleus
Primary spermatocytes are formed by _____.
mitosis of type B spermatogonia
(largest nucleus of any cells in the sperm lineage)
When do secondary spermatocytes enter the 2nd meiotic division?
Almost immediately
(Very few are observed in histologic examination)
Spermatids are formed by which event?
2nd meiotic divison
Define spermiogenesis
differentiation process that mature spermatozoa
Is cell division involved in spermiogenesis?
No
As long as the spermatids remain attached to Sertoli cells, they are considered _____.
spermatids
Major changes that occur in spermiogenesis:
- Acrosome formation
- Condensation of nuclear material
- Flagellum formation
- Shedding of excess cytoplasm
Acrosome function
- facilitates fertilization
- enzymes (proteolytic, hyaluronidase) separate corono radiata and penetrate zona pellucida
Flagella motion is generation in the _____ of sperm.
middle piece
(also stores mitochondria)
function of seminiferous tubules
spermatozoa production
3 stages of spermatogenesis:
- spermatocytogenesis (mitosis)
- meiosis
- spermiogenesis
Sertoli cells functions
- support of developing sperm cells
- fluid secretion (propels spermatozoa)
- phagocytosis of excess cytoplasm
- androgen binding protein (ABP)
- blood-tesis barrer
Histologic characteristic of sertoli cells
- basal distinct nucleus
- pale, oval or triangular
FSH from the anterior pituitary induces synthesis of ____ by the Sertoli cells
ABP
blood testis barrier
tight junctions (zona occludens) joining adjacent Sertoli cells near their base
2 concentric compartments formed by the blood-testis barrier tight junctions
- basal compartment: between tight junctions & epithelial basal lamina
- adluminal compartment
Function of the blood-testis barrier
protects sperm cells from the immune system
Leydig cells are located within the _____ of the testes
interstitium (outside of seminiferous tubule)
Leydig cells secrete ____ .
testosterone
(stimulated by LH from gonadotrophs)
Efferent ducts
exit the testis and lie on the testis surface
Effect ducts consist of _____ & _____ epithelium
- simple w/ciliated columnar cells in patches
- cuboidal w/nonciliated patches to reabsorb fluid
(lined w/psudostratified columnar epithelium- in micrograph)
Rete Testis in Mediastinum
Efferent ductules surrounded by smooth muscle cells
(spermatozoa are the *)
______ epithelium lines the epididymis
Pseudostratified
(often appears as simple columnar)
epididymis consists of 2 cell types:
principal
basal
Signature histological feature of principal cells of the epididymis
stereocilia on the apical surfaces (long branched microvili)
How are spermatozoa propelled through the epididymis?
circularly-arranged smooth muscle surrounds CNT → peristaltic contraction
epididymis
Describe the lumen of the vas deferens (ductus deferens).
small & irregular
The vas deferens is lined with ______ epithelium.
pseudostratified columnar (with stereocilia)
(similar to the epididymis except the principal cells are shorter)
How are spermatozoa propelled through the vas deferens?
3 layers of thick smooth muscle (heavily innervated)
vas deferens
Lumen of the seminal vesicals are lined by _____ epithelium.
pseudostratified columnar
(cells vary in height in proportion to blood testosterone levels)
seminal vesicles
(arrows = folding (left) & basal cells (right), SM = smooth m.)
List the glands that make up the prostate gland.
- Mucosal
- Submucosal
- Main prostatic
The glands within the prostate gland are lined w/_____ epithelium.
pseudostratified columnar
Prostatic concretions (corpora amylacea)
- CaPO4 based accumulations
- precipitated secretory components
- increase with age
secretions from the prostate gland
serous fluid with nutriets for spermatozoa (lipids, citric acid) and enzymes (fibrinolysin: liquifies semen)
Zones of the prostate gland
- transitional
- periurethral
- central
- peripheral
(concretions may become calcified)
Bulbourethral glands (Cowper’s glands)
- paired glands at the end of the penis
- secrete viscous mucous-like lubricant (precedes ejaculate)
Urethral glands (glands of Littre) location & secretion:
location: along the urethra
secretion: lubricates urethral epithelium (protects from urine)
Epithelium of the penis
stratified columnar to stratified squamous nonkeritinized
3 columns of erectile tissue of the penis:
- 2 corpora cavernosa (dorsal)
- 1 corpus spongiousum (ventral)
epithelium of the penile urethra
stratified columnar to stratified squamous, nonkeritinized epithelium
corpus spongiosum & urethra
subendothelial cushions formed by the smooth muscles of the corpus sponsiosum
