Male Reproductive System Flashcards
Male reproductive system components and function of components
. Testes: sperm/hero one production
. Genital duct system: intratesticular ducts and excretory ducts
. Accessory glands: seminal vesicles, prostate gland, and bulbourethral glands
. Penis: copulatory organ
Genital duct system components and functions
. Intratesticular ducts: straight tubules/tubuli recti, rete testis, efferent ductules (carry sperm from seminiferous tubules to epididymis
. Excretory ducts: epididymis, vas deferens, ejaculatory duct, urethra (transport sperm from scrotum to penis)
Testis structure
. Post. Surface assoc. w/ epididymis
. Suspended in scrotal sac by spermatic cord
. Surrounded by tunica albuginea made of dense CT that thickens on post. Site to form mediastinum testes (rete testis there)
. Divided into 250-300 lobules by septa from mediastinum testes
. Each lobule 1-4 seminiferous tubules
. Leydig cells btw seminiferous tubules make testosterone
Spermatic cord contents
. Vas deferens . Testicular a. . Pampiniform plexus . Lymph vessels . Nerves
Role of testosterone
. Promotes development of secondary male sex characteristics
. Luteinizing hormone (LH) stimulates testosterone production
Embryological development of testes
. In post. Wall abdominal cavity
. Descends into scrotum
. During migration each testes caries layer of peritoneum that forms tunica vaginalis
. Outer, parietal layer covers scrotum, visceral layer covers tunica albuginea
Seminiferous tubules
. Sperm production
. Tubule is loop linked by short straight tubule to rete testis
. Had CT tubular wall w/ contractile myoid cells and seminiferous epithelium
. Basement membrane separates wall from epithelium
Seminiferous epithelium cells
. Spermatogenic cells: spermatogonial stem cells (SSC), spermatogonia, spermatocytes, and spermatids
. Sertoli cells: columnar, support, protect, and nourish spermatogenic cells
. Don’t divide after puberty
. Linked by tight junctions to form blood-testes barrier
. Basal compartment( spermatogonia there)
. Adluminal compartment (spermatocytes and spermatids there)
Sertoli cells functions
. Phagocytose cellular debris
. Facilitate release of spermatids in lumen (spermiation) and secrete fluid that carries sperm out
. Produces androgen-binding protein: concentrates testosterone (stimulated by FSH)
. Inhibin to suppress FSH production
. Antimullerian hormone (AMH): in fetal testis, prevents embryonic Müllerian ducts that are female parts
Spermatogenesis
. 1st part sperm production
. Starts in puberty
. SSC proliferates and 1 daughter cell remains SSC and other becomes progenitor cell (spermatogonium)
. Spermatogonia mitotically divide to become type A/B spermatogonia
. During this cytokinesis is incomplete and all spermatogonia are joined by cytoplasmic bridges
. Final division of type B cells produce 2 primary spermatocytes that replicate DNA (46C) and undergo 1st meiotic division to make secondary spermatocytes (23C)
. Secondary cells meiotically divide to make spermatid haploid
What occurs during 1st meiotic division of spermatocytes?
. Homologous chromosomes separate
Hormonal regulation of spermatogenesis
. FSH activates Sertoli cells
. LH controls testosterone production
. FSH and LH required regulators of spermatogenesis
Spermiogenesis
. Final phase sperm production
. No cell division occurs, temp. Sensitive
. Acrosome forms (hydrolytic enzymes)
. Condensation and elongation of nucleus
. Form flagellum (9+2 axoneme) from centriole that acts as basal body
. Shed excess cytoplasm as residual body
. Lose intercellular cytoplasmic bridges
. Moronically mature but not mobile cells released from Sertoli cells
. Tail movements powered by ATP in mitochondrial sheath in tail’s proximal region
Cryptorchidism
.failure of 1 or both testes to not descend from abdomen
. Causes infertility if not correct by age 2-3
Testicular cancer
. Most involves germ cell tumors (95%)
. Only appear after puberty