Histology of the male reproductive system Flashcards
what is the role of the testes?
sperm and androgen production
what is the role of the epididymis, ductus defers, ejaculatory duct, and the urethra?
sperm transport
what is the role of the seminal vesicles, prostate gland, and the bulbourethral glands?
semen production and sperm nutrient source
what is the role of the penis?
copulatory organ with erectile tissue
what is the name of the dense connective tissue capsule surrounding the testes?
the tunica albuginea
what is the network of fibrous connective tissue that is located on the posterior side of the testes that extends from the top to the bottom of each teste?
the mediastinum testis
what is house within each lobule that the septa creates?
the seminiferous tubules
where exactly does sperm production take place in the testes?
the seminiferous tubules
what is the tunica vaginalis derived from?
the peritoneum
how can the tunica vaginalis be divided?
into an outer parietal layer that is lining the scrotum and an inner visceral layer that is covering the tunica albuginea
what are the retentions testis?
a series of tubes that relay sperm out of the efferent ductules to reach the epididymis
what are the seminiferous tubules lined with?
seminiferous epithelium
what are the 2 cell types found within the seminiferous tubules?
the Sertoli cells and the spermatogenic cells
what are the seminiferous tubules surrounded by and what is the function?
they are surrounded by connective tissue and 3-5 layers of flattened peritubular myoid cells; they create peristaltic contractions that help move the spermatozoa
what cells are found in between the seminiferous tubules?
the interstitial cells of leydig
how can the interstitial cells of leydig be described?
they are steroid-producing cells (testosterone) containing lipid droplets, mitochondria, and a well-developed sER
what are the interstitial cells of leydig accompanied by?
myoid cells and fibroblasts
what kind of epithelium makes up the seminiferous epithelium?
stratified epithelium with unusual characteristics
what kind of cells are sertoli cells?
columnar cells with extensive processes
what is the hallmark of sertoli cells?
the cyclops nucleus
what is the most immature form of spermatogenic cells?
the spermatogonia
where are spermatogonia cells found?
they rest on the basal lamina
what is the most mature form of spermatogenic cell?
spermatids
where are the spermatids found?
they are attached to the apical portion of the sertoli cells near the tubule lumen
what cell population forms the blood-testis-barrier?
sertoli cells
how is the blood-testis-barrier established?
the sertoli cells are bound by tight junctions to form the sertoli-cell-to-certoli-cell junctional complex
what does the blood-testis-barrier prevent?
the attack of the haploid sperm- it significantly decreases permeability
what is found below the blood-testis-barrier?
the basal compartment
what is the basal compartment?
an open space below the junctional barrier that is adjacent to the basement membrane but also adjacent to the circulation to the testis
what is found above the blood-testis-barrier?
the luminal compartment
what is the luminal compartment?
the compartment that is exposed to the lumen of the seminiferous tubules
once cells pass from the basal compartment to the luminal compartment, what are they protected from?
any immunological response that could occur in the circulation
what happens when type a spermatogonia undergo mitosis?
it will generate a copy of itself or a type B spermatogonia
what happens to type B spermatogonia?
it will enter into meiosis and change–> it will divide to form a primary spermatocyte
where do the spermatocytes undergo two meiotic divisions?
inside the blood-testes barrier (beyond the point of being exposed to the circulating blood)
what happens when the primary spermatocyte divides?
it will form a secondary spermatocyte
what happens when the secondary spermatocyte divides?
it forms the spermatids
what are the haploid germ cells that are located in the seminiferous compartments (specifically the luminal compartment)?
secondary spermatocytes, spermatids, and sperm
what cells are restricted to the basal compartment?
spermatogonia and early primary spermatocytes
what cell types pass through the junctional complex and move from the basal to the luminal compartment by breaking up the junctions?
the primary spermatocytes
what cell types are restricted to the luminal compartment?
mature spermatocytes and spermatids
what cells undergo spermatogenesis and differentiate into mature sperm cells?
spermatids
where are the round (early) spermatids housed?
in niches of sertoli cells
where are the elongated (late) spermatids housed?
in the apical crypts of the sertoli cells
what is spermiation?
the release of mature spermatids into the lumen
what piece of the sperm tail contains the mitochondria?
the middle piece
what is the longest piece of the sperm tail called?
the principal piece
what is the sperm transport pathway starting with the straight tubules?
straight tubules–> rete testis–>efferent ductules–>epididymis–> ductus deferens–> ejaculatory duct
where do sperm mature?
in the epididymis
what is the tissue type of the epididymis?
pseudostratified columnar epithelia with long sterocilia
what 2 cell types make up the epididymis?
the principal cells and the stem cells
what does sperm maturation consists in acquiring?
forward motility
what part of the epididymis are mature sperm stored in?
the tail
what is the ductus deferens lined with?
pseudostratified columnar epithelia with sparse stereocilia
what is the ductus deferens supported by?
a CT lamina propria with elastic fibers
what is the musculature of the ductus deferens like?
inner and outer longitudinal layers and a middle circular layer
what is the ampulla of the ductus deferens?
it is the dilated portion that leads directly into the prostate gland
what does the distal end of the ductus deferens receive?
the ducts of the seminal vesicles, which forms the ejaculatory ducts
what are the accessory glands of the male reproductive system?
seminal vesicles (2), prostate gland (1), bulbourethral glands (2), and the urethral glands
which accessory glands produce the majority of the seminal fluid?
the seminal vesicles and the prostate gland
what is the function of the accessory glands regulated by?
androgens (testosterone and DHT)
what is the composition of fluid secreted by the seminal vesicles?
it is an alkaline secretion that is rich in fructose and prostaglandins
what do the seminal vesicles look like histologically?
highly folded mucosa lined by pseudostratified columnar epithelium; no sterocilia
what are the different zones of the prostate gland?
the central zone, the peripheral zone, the transitional zone, and the periurethral zone
what does the central zone of the prostate gland surround?
the ejaculatory ducts as they pierce the prostate gland
what does the peripheral zone of the prostate gland surround?
the central zone and the posteriolateral parts of the gland; it is palpable during a digital rectal exam
where do most prostatic carcinomas arise?
in the peripheral zone
what does the transitional zone of the prostate gland surround?
the prostatic urethra (contains mucosal glands
what can occur in the transitional zone of the prostate gland?
the parenchymal cells undergo hyperplasia and form nodular masses of epithelial cells- this can cause benign prostatic hyperplasia
what does the periurethral zone contain?
mucosal and submucosal glands
in later stages of BPH, which prostate zone can undergo pathologic growth?
the periurethral zone
what do all the glands empty into?
the prostatic urethra
what is the prostatic urethra?
the end site of the prostatic ducts and ejaculatory ducts
what is the prostate gland lined with?
simple columnar or pseudostratified epithelium
what does the lumen of the prostate gland contain?
corpora amylacea
what does the prostate gland produce and for what reason?
a Zn-rich alkaline fluid, it neutralizes the acidic environment of the vagina
what are the pea-sized structures that are located in the urogenital diaphragm and resemble mucous glands?
bulbourethral glands
what are the bulbourethral glands lined with?
simple columnar epithelium that is under the control of testosterone
what do the bulbourethral glands secrete?
preseminal fluid–> lubricates the penile urethra and neutralizes traces of acidic urine
what are the corpora cavernosa of the penis each surrounded by?
a dense fibroelastic layer- the tunica albuginea
what does erection involve?
blood filling the cavernous spaces of the erectile tissues (controlled by the ANS in the vascular walls)
