W9- Lecture 45-Reproduction and Development Flashcards
when does testicular decent take place ?
Occurs during gestational development in humans.1st trimester
how and where are the Testis (& epididymis) anchored (pre decent)?
anchored anteriorly by the Diaphragmatic (cranial) ligament,
posteriorly by the Gubernaculum testis.
describe the decent of the testes
+ describe the impact of positional defects / why
Body grows,
gubernaculum shrinks,
diphragmatic ligament degenerates
descent through inguinal canal. (Gubernaculum degenerates.)
Positional defects ~2%. Cryptorchidism: links to testicular cancer.
due to temperature too hot for optimum
what 4 sections is the penis made of ?
root, shaft, neck & head
name two important spongy tissues found in the shaft of the penis
Corpus cavernosum & Corpus spongiosum (around urethra), which are erectile tissues.
where does the base of the the penis attach?
via what
Base, (root) attached below pubic symphysis.
Crura of corpora attached via ligament to bone.
name the structures in the head of the penis
prepuce(foreskin)
, glans penis(head)
& external meatus(external urethral orifice)
describe tumescence aka an erection
NO (nitric oxide secondary messenger )
arterial dilation
increased blood flow into Corpora cavernosa;
turgor (pressure.) reduces venous blood flow by constriction.
why is the Corpus spongiosum important?
allows sperm to exit during an erection
name two glands
location
and their role in the penus
Bulbourethral (Cowper’s) glands: at base of penis secreting alkaline mucus to lubricate and neutralise urinary acids.
Preputial glands: waxy secretion (smegma) between prepuce & glans.
what is the normal volume for the testes ?
what is this an indicator of ?
12 – 30ml vol. (mean 18ml).
indicator of sperm production
what is the Tunica albuginea ?
thick wall that encloses the testicular cavity
describe how the testicular cavity is divided
divided by septa, each containing coiled seminiferous tubules
what is the Pampiniform Plexus
+ the function
venous network - anastomosing veins wrap around the testicular artery
heat exchange mechanism
Seminiferous tubules (location of meiosis ) empty into a chamber what vessels do these go through ?
rete testis
efferent ducts
epididymis.
how is the Epididymis bound to the testes ?
via the Tunica vaginalis
what structures are found in the epididimis
+ overall function
caput, (receives spermatozoa)
corpus, (gain motility)
cauda(sperm reservoir)
- overall involved in sperm maturation
how does sperm leave the epididymis?
where does it go
what else empties into the end structure ?
via Ductus deferens
to the urethra
Prostate gland & seminal vesicles also empty into urethra.
what hormone is the prostate dependant on ?
how can this be applied to treatment
Prostate gland is androgen dependent
hormonal-based therapy for prostate cancer.
what cells are found
1 extra tubular
2 tubular
3 intra tubular
1 interstitial cells. Leydig cells(testosterone producing), macrophages
2: peritubular cells, fibroblasts, smooth muscle cells (peristalsis of tubule).
3spermatogonia (but outside blood-testis barrier), Sertoli cells (somatic), spermatocytes, spermatids, spermatozoa
where do sertoli cells attach?
where do you find spermatogonia
attached to base of tubule
spermatogonia lie beneath Tight junctions
between S. cells and blood-testis barrier
where does Post-spermatogonial stages of spermatogonia take place ?
through maturation where do they travel ?
within S. cells
towards lumen of tubule
describe the development of spermatogenic cells
+ diploid or haploid
spermatogonium (2n)
primary then secondary spermatocytes(2n)
early the late spermatids (n)
sperm cell/ spermatozoon (n)
where do immature spermatozoa in the testes move to ?
where does the Peristaltic action move the sperm into ?
Immature s’zoa shed into lumen
rete testis.
