Male Reproductive System Flashcards
What are the two main functions of the testes?
Produce Male games (spermatozoa) Produce Androgens (sex hormones)
What are three excurrent ducts that help sperm mature and deliver them to the urethra?
Ductuli efferentes
Ductus Epididymidis
Ductus (vas) deferens
What are the three male accessory sex glands?
Seminal vesicle
Prostate
Bulbourethral Glands
What three things compose the capsule of the testes? What composes each
Tunica albuginea - dense CT outer covering
Tunica vasculosa - inner layer of loose CT with large amount of blood vessels
Mediastinum testis - thickening of tunica albuginea projecting inward posteriorly - blood, lymph vessels , and rete testes
Projections of the capsule of the testis divide it into how many lobules?
250
What is contained inside each lobule of the testis? How many?
Seminiferous tubules
1-4 each, highly coiled
Short straight segments of the seminiferous tubules are called what? What do they continue into?
Straight tubule
Rete teste
What is the testicular interstitium?
Space between the seminiferous tubules
What is contained in the testicular interstitium?
Highly vascularized loose CT
Leydig cells - endocrine interstitial cells
What do Leydig cells produce?
Steroid-producing endocrine cells
Testosterone
What are three distinct features of Leydig cells since they are steroid-producing cells?
Well-developed SER
Mitochondria with tubular cristae
Lipid Droplets
Electron microscopy of Leydig cells reveals the presence of what? What are these accumulations of?
Crystals of Reinke
Accumulations of proteins
What three structures does Testosterone of the Leydig cells pass through to get to various parts of the body?
Lymph
Blood vessels
Seminiferous Tubules
When do Leydig cells differentiate and start producing testosterone?
Early during fetal life
Leydig cells received feedback from what to produce testosterone? What hormone in particular?
Anterior pituitary
LH
How long is each seminiferous tubule?
30-80cm
What two structures comprise the seminiferous tubule?
Seminiferous epithelium
Tunica (lamina) propria - fibroblasts and collagen
What two cell types are contained in the seminiferous epithelium?
Sertoli cells
Spermatogenic cells
What are the support cells of the seminiferous tubules that constitute its true epithelium?
Sertoli cells
Where do Sertoli cells lie int he epithelium? What do they interact with?
Extend from base to apex
Interact with spermatogenic cells
What are three distinct features of Sertoli cells on stain?
Very large
Irregular, light-staining euchromatic nucleus
Well-expressed nucleolus
What is the most interesting morphological feature of Sertoli cells? What does it form these with?
Form cellular junctions - tight and adherens
Other Sertoli cells and spermatogenic cells
What are the 6 main functions of Sertoli cells
Nourish germ cells Germ cell movement Structural support Blood-testis barrier Secretion of ABP and inhibin Phagocytize residual bodies
What is a secretory product of Sertoli cells that nourishes germ cells?
Fructose
Where compartment do germ cells start in? What compartment do they move into as they differentiate?
Basal compartment to
Adluminal compartment
What type of junctions do Sertoli cells form with other Sertoli cells?
Tight junctions
What part of the seminiferous tubule is immunologically priveleged? What does this mean?
Adluminal compartment, medial to tight junctions of sertolic cells with other sertoli cells
Immune response is limited or suppressed
What binds testosterone in the seminiferous tubule to concentrate it there to allow spermatogenesis to happen?
Androgen-binding protein
What hormone stimulates the secretion of ABPs by Sertoli cells? Where is it from?
FSH
From gonadotropin cells of anterior pituitary
What is produced by Sertoli cells to inhibit release of FSH at the anterior pituitary?
Inhibin
What two things control activity of Sertoli cells?
FSH
Testosterone
What does the most immature layer of spermatogenic cells contact? Most mature?
Least mature - tunica propria/basement membrane
Most mature - Lumen of seminiferous tubules
What are the 4 phases of spermatogenic cells? Which compartment is each found in?
Spermatogonial - basal
Spermatocyte - adluminal
Spermatid - adluminal
Mature sperm - adluminal
What process of differentiation are spermatogonial cells under going in the basal layer?
Mitosis
What is the shape of the nucleus of Spermatogonial cells?
Round or oval shaped
Based on the nucleus, what are the three types of spermatogonia cells?
Type A dark - Ad - ovoid nulceus, basophilic chromatin
Type A light - Ap - ovoid nucleus, light staining
Type B - spherical chromatin condense into large clumps
What type of spermatogonia undergo mitosis?
Type Ap
After undergoing mitosis, why do Ap spermatogonia remain connected by a thin cytoplasmic bridge?
Essential for synchronous development of each clone from original group of Ap cells
What do Ap cells differentiate into?
Type B spermatogonia
What are the most mature spermatogonia?
Type B spermatogonia
Mitotic divisions of Type B spermatigonia form what?
Primary spermatocytes
What do spermatocytes undergo?
Meiosis
What phase are primary spermatocytes arrested in? For how long?
Prophase I
Up to 22 days
What comes after primary spermatocytes? Slow or quick? What results?
Secondary spermatocytes
Quick
Spermatotids
What are the four phases that make up the spermatid phase?
Golgi Phase
Cap Phase
Acrosome Phase
Maturation Phase
During the golgi phase, what begins to accumulate, becoming bound to the nuclear envelope?
Proacrosomal granules
During golgi phase, what migrates to the posterior pole? Forming what?
Centrioles
Axoneme - central core of flagellum
What do the dynein arms use as an energy source?
ATP
What happens during the cap phase?
Acrosomal vesicle spreads out, forming acrosomal cap
What is the orientation of the spermatid during the acrosome phase?
Head stuck in sertoli cell
Developing flagellum pointing out/towards lumen
What 6 changes happen in order during the acrosome phase?
Cell and nucleus elongate and nucleus flattens
Nucleus and cap migrate anteriorly
Manchette forms - from cytoplasmic microtules cylindrical
Neck region - connects nucleus to flagellum, centrioles form outer layer giving strength to flagellum
Mitochondria migrate posteriorly, forming middle piece of tail
Manchette disappears
What happens to the spermatid during maturation phase?
Excessive cytoplasm removed as residual bodies
What consumes residual bodies?
Sertoli cells
During what stage are cytoplasmic bridges between spermatids broken?
Maturation phase
What are the three parts of a mature sperm? What does each contain/do?
Head - contains acrosome and nucleus
Neck - connects head to tail
Tail - middle piece (mitochondria), principal piece, end piece (not covered with dense outer fibers)
What temperature must testes be maintained for spermatogenesis to occur? How is this achieved?
35 degrees C
Achieved through pampinaform plexus around spermatic artery
Outside body wall
What is cryptorchidism? What results?
Testes do not descend into scrotal sac
Inhibits spermatogenesis, leading to infertility if bilateral
What carries sperm from seminiferous tubule to straight tubules?
Fluid from sertoli cells
What are straight tubules lined with proximally? Distally?
Proximally - sertoli cells
Distally - cuboidal epithelium
What forms the rete testis?
Anastomosing system of ducts lined with simple cuboidal empithelium
What three things represent the excurrent genital ducts and play an important role in the maturation of sperm?
Ductuli efferentes
Ductus epididymidis
Ductus vas deferens
What surface of the testis does the epididymis sit on?
Superior/posterior surface
What are the three parts of the epididymis? What do each contain?
Head - efferent ductules and beginning of ductus epididymidis
Body and tail - ductus epididymidis
What are highly coiled structures that connect the rete testis to the ductus epididymidis? What composes their epithelium that makes them unique?
Ductuli efferentes
Ciliated and non ciliated cells
What happens to the spermatozoa as it passes though the ductus epididymidis?
Becomes more motile
What lines the ductus epididymidis?
Pseudostratified columnar with stereocilia
What are stereocilia?
Modified microvilli found int he ductus epididymidis, designed to increase surface area of absorption and secrete maturation substances into lumen
How does smooth muscle in the epididymidis change as you go from head to tail? Height of epithelium?
Increases - becomes three-layered distally
Height of epithelium decreases
What are the three layers of the wall of the ductus (vas) deferens?
Mucosa
Muscularis
Adventitia
What differentiates the mucosa of the ductus deferens from the epididymis?
Ductus deferens has deep longitudinal folds (make lumen look like star)
Describe the muscularis of the ductus deferens
Very thick
What is contained with the adventitia of the ductus deferens?
Many nerves and blood vessels
What does the ductus deferens form before entering the prostatic urethra? What is different from the rest of the ductus deferens? What joins it?
Ampula - muscular coat thinner
Ejaculatory ducts empty into it from seminal vesicle
What are the three male accessory sex glands?
Seminal vesicles
Prostate
Bulbourethral glands
What controls the secretory levels of the seminal vesicles?
Testosterone
What are the 4 layers of the seminal vesicles?
Mucosa
Lamina Propria
Muscularis
Fibrous coat
What serves as the energy source for sperm? Where is it secreted from?
Seminal vesicle mucosa
What is the fibrous coat of the seminal vesicles analogous to?
Adventitia
What is the largest male accessory sex gland?
Prostate
What surrounds the prostate? Does it send projections into the prostate?
Fibrocollagenous Capsule
Yes
What line the tubuloalveolar glands of the prostate?
Low columnar/cuboidal pseudostatified epithelium
What are the two main zones of the prostate? What are the main prostatic glands contained?
Transitional zone - anterior and middle lobes - BPH
Peripheral sone - posterior and lateral lobes - cancer -main glands here
What can be found in the lumina of the prostate gland, particularly as men age?
Corpora amylacea
What is located within the prostate gland?
Prostatic urethra
What is the purpose of prostatic secretions? (Acid phosphatase, citric acid, fibrinolysin, and others)
Liquefy semen
What hormone controls secretions of the prostate?
Testosterone
Where do bulbourethral glands open into? What do they secrete? What is it used for?
Bulb of spongy urethra
Mucus-secreting
Lubrication
What three main structures compose the penis?
Two corpora cavernosa
One smaller corpus spongiosum
What do the corpora cavernosa contain during erection?
Blood in vascular spaces
What runs in the middle of the corpus spongiosum?
Spongy urethra
What is the epithelium of the spongy urethral? Distally? What does it contain numerous of?
Pseudostratified columnar
Distally - non-keratinized stratified squamous.
Glands of Littre - mucus screting glands
What do deep arteries form in erectile tissue?
Helicine arteries (helical at rest, straight during erection
