unit 13 Flashcards
gross anatomy of male reproductive system
gross anatomy of the testis
what is the tunica vaginalis made of
loose CT (parietal layer) and single layer of mesothelium (visceral layer)
contains blood vessels
what is the tunica albuginea made of
dense (fibroelastic) CT
some elastic tissue
aka capsule
what is the septa in the testis
part of the tunica albuginea that invaginates and separates seminiferous tubules
what is the mediastinal testis
thickened portion of the capsule
gateway for neurovascular and lymphatic structures
organization of ducts in testis
seminiferous tubules > straight tubules > rete testis > efferent ductules (mediastinal testis) > ductus epididymis
what occurs in seminiferous tubules
spermatogenesis
what do the septa form
lobules
myoid cells
3-5 layers of flattened smooth muscle-like cells of mesodermal origin
what are the components of the lobule
interstitial stroma, seminiferous tubules, and tunica propria
what is contained within the interstitial stroma
interlobular CT, leydig cells!!
what are leydig cells
endocrine cells that secrete testosterone
contain lipid droplets
what is testosterone needed for
sexual development, maturation and maintenance of spermatogenesis
leydig cell appearance
large, polygonal, pale eosinophilic cytoplasm
round nuclei
characteristics of steroid secreting cells
extensive SER
no secretory granules!
contain Reinke’s crystals
mitochondria with tubulovesicular cristae
hormonal relationships
what is tunica propria
peritubular CT
contains myoid cells and fibroblasts
what do myoid cells do
create contractile CT external to basal lamina of the seminiferous epithelium
create peristaltic waves that move spermatozoa & testicular fluid out of seminiferous tubules
do myoid cells have a female counterpart
NO
seminiferous tubules contain
Sertoli cells and spermatogenic cells
what is the outer wall of seminiferous tubule made of
CT and myoid cells
lumen of seminiferous tubules
stratified epithelium called seminiferous epithelium
what are sertoli cells
large support cells with nucleus perpendicular to the basement membrane
seminiferous epithelium characteristics
avascular
contains basal lamina and tight junctions
polarized
has mitotic and non mitotic regions
Sertoli cell appearance
columnar cells with extensive apical and lateral processes that extend from basement membrane to lumen
form tight junctions with adjacent Sertoli cells!!
sertoli cell nucleus
jagged euchromatic nucleus with prominent nucleolus
what forms the blood-testis barrier
compartmentalization by sertoli cells
mitosis occurs in basal compartment
meiosis occurs in adluminal compartment
consequences of the blood-testis barrier
excludes plasma proteins and blood borne antibodies from seminiferous tubules
do Sertoli cells replicate
NO
functions of the sertoli cells
what is spermatogenesis
process by which spermatogonia develop into sperm
phases of spermatogenesis
what are spermatogonia
small cells within seminiferous tubules located near basement membrane
type A dark and pale, type B
spermatocytes
derivatives of spermatogonia B cells that undergo meiosis
type A dark cells
reserve stem cells, round basophilic nucleus, produce Ad or Ap
type A pale cells
round, euchromatic nucleus
committed to differentiation to type B
type B
spherical nucleus with peripheral heterochromatin and central nucleolus
what happens to type B cells
spermatogonia divide, producing primary spermatocytes
then move to adluminal side
spermatocyte phase
spermatogonia location
in contact with the basement membrane
4 phases of spermatid
golgi
cap
acrosome
maturation
spermatid Golgi phase
spermatid cap phase
nuclear material condenses, envelope looses pores and thickens
acrosomal vesicle forms cap over anterior half of nucleus
spermatid acrosome phase
spermatid maturation phase
early spermatid
small spherical nucleus
intermediate spermatid
diamond shaped nucleus
later spermatid
sharply pointed nucleus, still embedded in epithelium
spermatozoan
nucleus sharply pointed
released from epithelium
mature sperm appearance
head is flattened and pointed
acrosomal cap secretes enzymes essential for zona pellucida penetration
neck contains centrioles
middle piece contains mitochondria
what is spermiation
release of sperm from sertoli cells
where does acquisition of motility occur
epididymus
does spermatogenesis rate vary
yes, varies between seminiferous tubules
straight tubules
short, narrow ducts lined by Sertoli cells
simple cuboidal epithelium
do straight tubules have spermatogenic cells
NO
rete testis
irregular, anastomosing network of tubules
wide lumen which becomes wider
simple cuboidal/low columnar epithelium
apical cilium and short microvilli
intratesticular ducts
efferent ductules
found in head of epididymis, connect rete testis to ductus epididymis
lined by PSCE, ciliated and nonciliated
lumen has saw tooth appearance
epididymis
single, highly coiled tube
PSCE, covered by long, nonmotile microvilli (stereocilia)
what happens in the epididymis epithelium
reabsorbs and digests residual bodies eliminated during spermatogenesis
vas deferens
straight tube with thick muscular wall that empties into prostatic urethra
lumen lined with PSCE with stereocilia
ejaculatory duct
collects fluids from glands
prostatic urethra
lined by urothelium
membranous urethra
transition from urothelium to PSCE
spongy urethra
transitions from PSCE to stratified squamous epithelium
main functions of epididymis
sperm maturation (forward motility & ability to fertilize secondary oocyte)
sperm storage until ejaculation (tail)
what is the duct of the epididymis surrounded by
CT with blood vessels and covered by a capsule and tunica vaginalis
what is the epithelium of the epididymis surrounded by
thin circular layer of smooth muscle cells
second layer present in body and tail
epididymis principal cells
contain long microvilli, aid in maturation of sperm
where is stereocilia found
in epididymis, vas defrens, and inner ear
what is stereocilia
extremely long processes that extend from apical surface, facilitate absorption
epithelium of vas deferens
PSCE with stereocilia
mucosa of vas deferens
characterized by folds extending into the lumen
muscularis layer of vas deferens
three layers of smooth muscle
inner longitudinal
middle circular
outer longitudinal
spermatic cord includes
pampiniform plexus of veins
testicular artery
nerves
cremaster muscle
small arteries to vas deferens
seminal vesicles info
secretions make up 70% of semen volume
fluid is rich in fructose, prostaglandins, absorb acid that provides sperm with energy
what are seminal vesicles
coiled tubular glands that lie between bladder and rectum
histology of seminal vesicles
PSCE lines lumen
fibroelastic CT lamina propria
mucosa is thrown into 1º, 2º, and 3º folds that increase secretory SA
inner circular, outer longitudinal SM
outermost layer is adventitia
prostate gland info
secretions are clear, rich in proteolytic enzymes and acid phosphatases
reduces acidity of vagina!, dilutes semen, provides medium for sperm
prostate gland size/location
size of a walnut, inferior to bladder
surrounds prostatic urethra
central zone of prostate gland
surrounds ejaculatory ducts, resistant to carcinoma/inflammation
25% of glandular tissue
peripheral zone of prostate gland
posterior and lateral aspects, palpable during rectal exam, most susceptible to cancer and inflammation, 70% of glandular tissue
transitional zone of prostate gland
surrounds prostatic urethra, contains mucosal glands
site of benign prostatic hyperplasia
5%
periurethral zone of prostate gland
mucosal and submucosal glands
what does the prostate gland consist of
30-50 compound tubuloalveolar glands arranged in three sets
what are the three gland sets of the prostate gland
inner mucosal
submucosal
peripheral glands
histology of glandular portion of prostate
simple cuboidal
simple low columnar
PSC
prostatic concretions
calcified prostatic secretions, typically display concentric rings, increase with age
what are bulbourethral glands
small, paired pea-sized glands, superior to perineal membrane
bulbourethral gland secretions
mucous-like, contain abundant galactose and sialic acid, emptied into penile urethra
lubrication function and emission of semen
bulbourethral gland, histologically
