Flashcards in Male reproductive system Deck (45):
What comprises the testes?
1. Tunica albuginea2. Tunica vasculosa3. Lobuli testis4. Vascular supply
What is the mediastinum testis?
1. Found in the tunica albuginea2. It is the thickened portion of the tunica albuginea, where epididymis attaches3. Where blood vessels, nerves, lymphatic vessels and genital ducts enter or leave testes4. Give rise to incomplete CT septa (lobuli testis)
What are the features of the tunica vasculosa?
1. Forms loose CT layer deep to tunica albuginea2. Rich vascular supply and is capsule around testes
What does each lobuli testis contain?
1. 1-4 coiled seminiferous tubules2. Leydig cells3. Loose CT stroma - filler tissue
What comprises the seminiferous tubules?
1. Tunica (lamina) propria2. Basal lamina3. Seminiferous epithelium 4. Sertoli cells
What makes the seminiferous epithelium unique?
Contains two types of cells:1. Spermatogenic cells2. Sertoli cells
What are features of Sertoli cells?
1. Tall, columnar, non-replicating after puberty2. Clear ovoid or triangular nucleus and prominent nucleolus3. Tight junctions bind cells to form basal epithelial compartment and luminal compartment 4. Phagocytose spermatid cytoplasmic remnants5. Release androgen binding protein, hormones and nutrients (testosterone binds to ABP in seminiferous tubules to promote spermatogenesis)
What creates the blood-testes barrier?
What does the BTB separate in the adult?
Isolates haploid (antigenic) secondary spermatocytes, spermatids, and sperm from immune system
What are the compartments of the seminiferous epithelium?
1. Luminal compartment2. Basal epithelial compartment
What is found in the luminal compartment of the seminiferous epithelium?
1. Spermatozoa2. Spermatids3. Secondary spermatocytes4. Primary spermatocytes
What are the features of the basal epithelial compartment of the serminiferous epithelium?
1. Basal to zonulae occludentes which are formed by Sertoli cells2. Tight junctions form BTB segregating luminal compartment from CT3. Contains spermatogonia and early primary spermatocytes
Where are the Sertoli cells found?
1. Span the basal epithelial compartment and luminal compartment of seminiferous epithelium 2. Form zonula occludentes junctions that subdivide the seminiferous epithelium into these compartments
What is found in the spermatogenic cells?
1. Spermatids2. Secondary spermatocytes3. Primary spermatocytes4. Spermatogonia5. Umbilical vesicle
When does spermatogenesis begin?
In response to pituitary gonadotropin release shortly before puberty
What are the three phases of spermatogenesis?
1. Spermatogonial 2. Meiosis3. Spermiogenesis
Where does the spermatogonial phase occur?
What is the function of the spermatogonial phase?
Process by which spermatogonia differentiate into primary spermatocytes
What is the genetic makeup of spermatogonia?
46 single chromatid chromosomes (2n - 2d)
Where does the spermatocyte (meiosis) phase occur?
What is the function of the spermatocyte (meiosis) phase?
Process by which primary spermatocytes differentiate into spermatids
What are primary spermatocytes?
1. In luminal compartment2. Largest cells of the seminiferous epithelium3. Enter meiosis I to form secondary spermatocytes that have 23 double chromatid chromosomes (1n - 2d)
What are the features of secondary spermatocytes?
1. Rarely observed because they enter meiosis II immediately to form spermatids that have 23 single chromatid chromosomes (1n - 1d)
Where does the spermatid phase occur?
What is the function of the spermatid phase?
Process by which spermatids are transformed into spermatozoa (sperm)
What are spermatids?
1. Very small cells with round dense nuclei2. Occur in groups next to lumen
What are Leydig cells?
1. Embedded in loose CT derived from tunica vasculosa and are wedged between seminiferous tubules2. Endocrine cells with abundant sER 3. Stimulated by FSH, LH to synthesize testosterone 4. Active during prenatal development, inactive at 5 months of fetal life, reactivate at puberty
What is the order of spermatozoa transit?
1. Seminiferous epithelium of seminiferous tubules2. Tubuli recti3. Rete testis4. Efferent ductules5. Duct of epididymis6. Ductus deferences7. Ejaculatory duct 8. Urethra
What are features of the tubuli recti?
1. Lined by Sertoli cells2. Lined by simple cuboidal epithelium at distal end
What are features of the rete testis?
1. Labyrinthine spaces, mazes2. Lined by simple cuboidal epithelium or low columnar
What are the intratesticular genital ducts?
1. Tubuli recti2. Rete testis
What are the extratesticular genital ducts?
1. Epididymis2. Ductus deferens3. Ejaculatory duct
What makes up the epididymis?
1. Efferent ductules2. Duct of epididymis
What occurs in the epididymis?
Where sperm acquire motility, likely due to change in intracellular levels of cAMP, Ca2+ and pH
What is the function of the efferent ductules of the epididymis?
Apical cell membrane invaginations resorb fluid released by Sertoli cells
What type of epithelium makes up the duct of the epididymis?
What cells are located in the pseudostratified columnar epithelium of the duct of the epididymis?
1. Principal cells2. Basal cells (stem cells)
What are features of the principal cells located in the pseudostratified columnar epithelium of the duct of the epididymis?
1. Pinocytotic vesicles and stereocilia (non-motile microvilli) on luminal surface2. Resorb luminal fluid, clean up cytoplasmic fragments3. Release glycerophosphocholine, a glycoprotein that inhibits sperm capacitation
What type of epithelium makes up the ductus deferens?
Pseudostratified columnar with stereocilia
What type of epithelium makes up the ejaculatory duct?
Simple columnar epithelium
Is smooth muscle found in the ejaculatory duct?
What is the function of the seminal vesicle?
1. Secrete viscous fructose-rich seminal fluid with amino acids, ascorbic acid, prostaglandins, and proteins2. Controlled by testosterone
What type of epithelium makes up the prostate gland, and what is its function?
1. Simple to pseudostratified columnar 2. Synthesize proteins
Where are the bulbourethral glands located?
Proximal end of membranous urethra