what are the four functional components of the male reproductive system
testes, ductular system, exocrine glands, penis
what is the function of the testes
produce male gametes, secrete testosterone
what is the function of the ductular system
collect, store, conduct spermatozoa from testes
what is the function of the exocrine glands
produce seminal fluid
what is the function of the penis
the organ involved in copulation
the testes have two major functions, what are these generalised into
reproductive and hormonal
what are the testes surrounded by
by a thick capsule of connective tissue - tunica albuginea
there is a thick capsule of connective tissue surrounding the testes, what is this connective tissue called
the tunica albuginea
the testes have fibrous septae dividing them into lobules, what does each lobule consist of
lobules consist of seminiferous tubules, leydig cells, vessels and nerves
what is the function of the rete testis
The rete testis a network of delicate tubules located in the hilum of the testicle that carries sperm from the seminiferous tubules to the epididymis
roughly how many seminiferous are there and what is the aggregate length of them
800-1600 tubules with an aggregate length of around 600 metres
seminiferous tubules are lined by what type of epithelium
stratified complex germinative epithelium
what two cell types are present in the seminiferous tubules
sertoli cells and spermatogenic (germ cells)
what do the germ cells reproduce several times to form
to form spermatazoa
what is the process of germ cells producing spermatazoa called
spermatogenesis
what is a characteristic feature of the sertoli cells
they have a characteristic dark nucleolus that is elongated
why are sertoli cells sometimes referred to as nurse cells
because they preserve the correct environment for spermatogenesis
where is there a permanent population of sertoli cells
permanent population in outer portion of tubule
how does the nucleus of a sertoli cell stain
the nucleus stains pale, the nucelolus is prominent
what is a major role of sertoli cells
a major role is to define two separate and physiologically different compartments in the seminiferous tubule
how is the basal comparment near the periphery sealed off from the luminal compartment
the basal compartment is sealed off from the luminal compartment by processes of adjacent sertoli cells that reach out and make contact; where the processes are in contact they form occluding junctions
what cell type is present below the sertoli cell junction (basal compartment)
diploid spermatagonia
sertoli cells secrete factors which regulate the process of
spermatogenesis
sertoli cells secrete factors which regulate the function of which cell type
leydig cells
sertoli cells secrete inhibin which regulates the production of which hormone
fsh
serotli cells are involved in the phagocytosis of what
phagocytosis of discarded spermatid cytoplasm during development
who discovered sertoli cells and in which year
enrico sertoli in 1865
what is spermatogenesis
the production of male gametes
what is spermatogonia
primitive germ cells
spermatogonia are present only in ____ numbers in the male gonads before sexual maturity
small
what happens to the spermatogonia in males after puberty
after puberty, spermatagonia multiply continuously by mitosis to provide a supply of cells which then undergo meisosis to form male gametes
how long does the process of spermiogensis take place
about 70 days
where do both spermatogenesis and spermiogenesis (final stage) occur
in the testes
where does the final maturation of spermatozoa occur
in the epididymis
where re spermatagonia located
spermatogonia are basally located - at the periphery of the tubule
what are primary spermatocytes
primary spermatocytes are the initial product of spermatogonial maturation
what do the primary spermatocytes become after the first meiotic division
secondary spermatocytes
how do secondary spermatocytes become spermatids
undergo meiosis
where are the spermatids located
closer to the lumen of the tube, resting in the branches of the sertoli cell tree
where are the spermatids cast off to
into the lumen
what is spermiogenesis
process by which spermatids are transformed into motile mature spermatozoa
the golgi apparatus elaborates a large vesicle called the
acrosomal vesicle
what does the acrosomal vesicle accumulate inside
carbohydrates and hydrolytic enzymes
where does the acrosomal vesicle end up
the acrosomal vesicle becomes applied to one pole of the progressively elongating nucleus
what does the acrosomal vesicle end up forming
forms an acrosomal head cap
where do both centrioles migrate to
to the end of the cell opposite to the acrosomal head cap
how do the centrioles align themselves
centriole aligned parallel to the long axis of the nucleus
what do the centrioles elongate to form
a flagellum -
what is the basic structure of a flagellum similar to
cilium
as the flagellum elongates, how many coarse fibrils form and what do they contain
nine coarse fibrils (contain contractile proteins)
the cytoplasm migrates to surround the first part of the flagellum for what reason
to concentrate mitochondria in the flagellar region
as the flagellum elongates, what happens to the excess cytoplasm
the excess cytoplasm is phagocytosed by the sertoli cell prior to release of the spermatid into the lumen
what hormone do the leydig cells produce
testosterone
what do leydig cells contain in humans and wild bush rate
leydig cells contain crystals of reinke
what are crystals of reinke
Reinke crystals are rod-like cytoplasmic inclusions which can be found in Leydig cells of the testes
what hormone is the trigger for the interstitial/leydig cells to start making testosterone at the onset of puberty
the pituitary hormone icsh
what does icsh stand for
interstitial cell stimulating hormone
what is a sign of testes cancer caused by the leydig cells
the presence of crystals of reinke
the rete testis have low cuboidal epithelium with cilia, why is the cilia present
to move the spermatids along
seminferous tubules discharge their spermatazoa into what channels
into the rete testis
where do the efferent ducts lead to
into a long, extremely coiled single duct called the ductus epididymis
how many ducts does the rete testis open into
seven or eight efferent ducts
what type of epithelium do the efferent ducts have
pseudostratified columnar epithelium
what do many of the epithelium cells lining the efferent ducts contain
cilia
what type of cilia are present on the efferent ducts
true cilia - capable of movement. the cilia help propel the spermatozoa
what is the epididymis
the epididymis is an absorptive and secretory organ
why do sperm have to spend some time in the epididymis
to be capacitated before capable of fertilising an oocyte
what does the lining epithelium of the epididymis produce
lining epithelium produces glycoprotein material that coats the sperm
what can be seen clearly in the epithelium of the epididymis and why is this
due to the secretory nature of the epithelium, large and easily seen golgi apparatus in lining cells
what type of epithelium line the epididymis
epididymis is lined by a columnar epithelium adorned at its surface with large microvilli
the epididymis resembles the cilia found in other parts of the body, the similar appearance led to them being called
stereocilia
why are the stereocilia present in the epididymis not actually cilia
cilia have internal microtubuels and are capable of movement, stereocilia do not
what are stereocilia filled with
cytoplasm, structures for absorption not movement of fluids
once the spermatozoa are physically and phsyiologically mature, where do they move out of the epididymis into
the ductus deferens
where does the ductus deferens lead to
the urethra
what is the seminal vesicle
two highly tortuous tubes
what is the length of the seminal vesicles
15m
what type of epithelium is present in the seminal vesicle
pseudostratified columnar epithelium
what is the function of the seminal vesicle
to produce a nutrient rich fluid for survival and motility of spermatozoa
what is the epithelium lining the seminal vesicles dependent upon
testosterone
what fluid does the prostrate gland produce and when is it released
it produces prostatic fluid and stores it for expulsion during ejaculation
what is the prostate gland surrounded by
fibro-elastic capsule rich in smooth muscle
what are corpora amylacea
they are derived from degenerate cells or thickened secretions and occur more frequently with advancing age
LOL describe the penis
3 cylindric masses of erectile tissue surrounded by skin plus urethra
two of the cylinders forming the erectile tissue are dorsal what is it caled
corpora cavernosa
there is one ventral cylinder, which surrounds the urethra, what is this called
corpus spongiosum