SM_229b: Histology of the Male Reproductive System Flashcards
(33 cards)
Describe the male reproductive system
Male reproductive system
Testis is dominated by ___
Testis is dominated by seminiferous tubules in lobules
Testis interior has ____ -> ____ -> ____
Testis interior has seminiferous tubules -> straight tubules -> rete testis in mediastinum
Testis exterior has ____ -> ____ -> ____
Testis exterior has efferent ductules -> epididymis -> ductus deferens
Intermediate mesoderm gives rise to ____ and ____
Intermediate mesoderm gives rise to testicular stroma and Leydig cells
Primary sex cords give risk to ____, ____, and ____
Primary sex cords give risk to epithelium of seminiferous tubules, straight tubules, and rete testis
- Spermatogonia from hindgut enter the primary sex cords
Mesonephric tubules and duct become the ____ and ____
Mesonephric tubules and duct become the efferent ductules and duct of epididymis (and ductus deferens)
Stratified nuclei are mostly ___
Stratified nuclei are mostly germ cells in different phases of spermatogenesis
- Supporting Sertoli cells span the thickness
- Testosterone-producing Leydig cells are between tubules
Describe Sertoli cell functions
Sertoli cell functions
- Blood-testis barrier
- Androgen binding protein
- Metabolic support
- Phagocytosis
- Anti-Mullerian hormone
- Molecules that act on Leydig cells and pituitary gland
Spermatogenesis has the ____, ____, and ____ phases
Spermatogenesis has the spermatogonial phase (mitosis), spermatocyte phase (meiosis), and spermatid phase
- Takes 74 days
- Spermiogenesis: morphological change to sperm
- Spermiation: release of sperm into lumen
Cycle of seminiferous epithelium is divided into ____
Cycle of seminiferous epithelium is divided into stages according to cellular associations
Describe spermiogenesis
Spermiogenesis
- Acrosome vesicle of enzymes enlarges to surround the nucleus
- Centriole initiates formation of axoneme microtubule doublets of the flagellum
- Sheath of mitochondria wrap axoneme by the nucleus
- Fibrous sheath wraps the axoneme for most of the rest of the tail
Describe mature spermatozoon
Mature spermatozoon
- Head: flattened
- Neck
- Middle piece (mitochondria)
- Principle piece of tail (fibrous sheath around axoneme)
- End piece of tail (no fibrous sheath)
Male infertility is often caused by an interruption of ____
Male infertility is often caused by an interruption of spermiation
- Release of sperm into lumen determines how many sperm are ultimately in the ejaculate
- 3 months (74 days in testis + 12 days in epididymis) to see if drug treatment works
Epididymis is ____ + ____
Epididymis is efferent ductules + duct of the epididymis
Rete testis is ____
Rete testis is simple cuboidal epithelium
- Straight tubules with only Sertoli cells joining rete testis
Efferent ductules and duct of epididymis are composed of ____
Efferent ductules and duct of epididymis are composed of pseudostratified columnar epithelium (most of male system)
Sperm are ____ at spermiation and ____
Sperm are non-motile at spermiation and acquire motility in the epididymis
- Principal cells have stereocilia (long microvilli)
- Basal cells are stem cells
Sperm are only capable of fertilizing an ovum after undergoing the process of ____ in the ____
Sperm are only capable of fertilizing an ovum after undergoing the process of capacitation in the female genital tract
Describe sperm passage through the epididymis
Sperm passage through the epididymis
- Takes 12 days for sperm to pass through the 5 m of epididymis
- Become motile and stored in tail until ejaculation
- Capacitation in the female genital tract makes them capable of fertilizing an ovum
- Layers in the tail of the epididymis become more like the ductus deferens
Ductus deferens is composed of ____
Ductus deferens is composed of pseudostratified columnar epithelium with stereocilia
- Muscle layers: inner and outer longitudinal, middle circular
____ and ____ are involved in heat regulation in testis (countercurrent heat exchanger with artery)
Thick ductus deferens and pampiniform plexus are involved in heat regulation in testis (countercurrent heat exchanger with artery)
Ductus deferens terminates as the ___
Ductus deferens terminates as the ejaculatory duct
Describe sequence of events in ejaculation
Events in ejaculation
- Contraction of bulbourethral glands for lubrication
- Contraction of ductus deferens to move sperm into urethra (emission) under sympathetic control
- Contraction at the same time of prostate gland (secretion liquefies semen soon after ejaculation)
- Contraction of the seminal vesicles (add fructose for sperm nourishment and bulk / viscosity to the ejaculate)
- Powerful contraction of the bulbospongiosus muscle in the penis
