Aug27 A1,2-Histo_Male_Reproductive_System Flashcards
duct system of testes
seminiferous tubules, rete testis, efferent ducts, epididymis, vas deferens
accessory glands of reprod system in males
- seminal vesicles
- prostate
- bulbourethral gland
functions of androgens (testo)
- initiate and maintain sperm prod
- *dev of male fetus
- dev of accessory organs and secondary sex charact
- secretions of the accessory glands
* testo made by Leydig cells*
tunica albuginia def in testes
tough layer of CT rich in collagen fibers right under the tunica vaginalis (vaginalis is most exterior). separates testis in parts
seminiferous tubules def
tubules with 2 ends, one ends in rete testis lumen.
ductuli efferentes vs epididymis
ductuli = many ducts. EDD = one duct + very coiled
epididymis vs vas
vas less coiled and larger
what surrounds the STs
stroma (interstitium) with interstitial (Leydig) cells + blood vessels and lymphatics + fibrocytes (CT cells) + macrophages
Leydig cells fct
make testo
Leydig cells charact
- polygonal or small ovoid
- small round central very blue nuclei
- highly acidophilic cytoplasm
EM profile of a steroid secreting cell (like Leydig)
- lot of mts in cyto
- many small profile membranes (the SER)
- bit of RER
what surrounds the STs (outermost layer)
limiting membrane formed of myoid (peritubular) cells
myoid cell fct
persistaltic mvmt allows movement of the immotile sperm to the rete testis
spermatogonia def
youngest generation of spermatogenic cells (bottom) in ST
other cell type near spermatogonia in bottom
early spermatocytes
cell after early spermatocytes found in middle layer of ST
primary spermatocytes (most abundant = Pachytene, 2ndary is transient)
upper layer of ST
- early round spermatids
- late elongated spermatids
diff vs early and late spermatid
late emptied pieces of cytoplasm (residual bodies) which are later phagocytosed by Sertoli cells
Sertoli cells charact
- somatic cells in seminiferous epith, extend base to top.
- have lateral extensions joining adjacent cells. tight junctions seal and form a base.
- small recesses acommodate all the cells in luminal compt (primary (pachytene), early, late)
spermatogonia + early spermatocytes + Sertoli cells thing in common
rest on BM. outside of BM have the myoid cells
two compt of seminiferous epith
luminal = above tight junctions of Sertoli cells
basal compt = below
chromatid of Sertoli cells charact
light colour
how Sertoli cells eat residual bodies
- internalize to form phagosomes
- fuse with lysosomes with hydrolytic enzymes
- nutrients passed to new spermatocytes
Sertoli cells fcts (7)
- supportive (structural)
- nurse cell (biochemical support)
- blood testis barrier (tight junctions)
- secrete luminal fluids in the ST (proteases + transport proteins)
- secrete hormones and factors
- endocytic and phagocytic function
- lift the early spermatocytes from basal to luminal compt
transport proteins sertoli cells secrete
- ABP (androgen binding prot)
- transferrin
- apolipoprotein J
hormones and factors S cells secrete
- Inhibin (suppresses FSH)
- AMH (anti-Muellerian hormone): promotes regression of Muellerian ducts
S cells in H and E
- light chromatid
- prominent nucleolu
rete testis def
anastomosed channels with simple cuboidal epith with NO myoid cells surrounding. surrounded CT cells, enclosed by tunica albuginia
ductuli efferentes def
- connect rete testis to epididymis
- ARE PART OF EDD
ductuli efferentes histo
- lined by simple columnar epith
- festooned appearance
- ciliated (columnar) and non ciliated (columnar) cells
DE ciliated cells fct
cilia to push sperm
DE non ciliated cells fct
highly endocytic cells, absorb fluid and material
EDD histo
- single supercoiled tubule
- pseudostratified columnar epith (basal and columnar cells)
- stereocilia (long microvilli not moving) on columnar cells
- myoid cells surround EDD
- SM surrounds also
- constant LUMEN diameter
- increasing thickness
- head, body and tail
EDD function
sperm maturation (head = immotile. tail = competent)
other name to SM surrounding EDD
tunica muscularis
vas deferens histo
- pseudostratified epith like in EDD
- myoid cells
- SM (tunica muscularis) in longitudinal and circular orientation
vas deferens goes where
joins seminal vesicle to form ejaculatory duct
ejaculatory duct goes where
prostatic urethra
penile urethra travels in what structure
corpus spongiosum
and two corpus cavernosum around
what surrounds the corpora cavernosa in the penis
tunica albuginia (not related to testes)
artery travelling in each corpus cavernosum
deep a
vessel found in dorsal part of penis
superficial dorsal vein
tube found in ventral part of penis
urethra with surrounding corpus spongiosum
structure of corpus cavernosum (erectile tissue)
smooth muscle and endothelium
regulation of SM in corpus cavernosum
SS makes it contract (tonicity), smaller volume
PSS makes SM relax (during erection) + inhibits SS impulses to the penis
Peyronie’s disease def
bending of penis bc of orientation and character of the collagen in the tunica albuinigia
start and end cell of spermatogenesis (SG)
- non diff spermatogonial stem cell
- highly specialized motile spermatozoa
BM where in ST
between epith and myoid cells
number of layers in ST epith
4-6 layers, each is a generation of cells, grouped in 3 main phases
base cells in ST epith
- spermatogonia (3 types)
- early spermatocytes
3 types of spermatogonia
- type A dark (Ad) (dark nucleus)
- type A pale (Ap) (paler chromatin)
- type B spermatogonia (reticulate chromatin)
spermatogonia generations
Ap gives B and B gives early spermatocytes
Ad spermatogonia fct
resting arrested state. reserve to repopulate the other spermatogonia if radiation or wtv destroys cells
what happens to early spermtocytes in the base
lifted up by Sertoli cells in luminal compt
what happens to early spermatocytes in the middle compt
transform into primary spermatocytes (Pachytene type is the most common type of primary spermatocytes)
what happens to Pachytene spermatocytes (primary)
undergo two meiotic divisions.
after the SECOND one, you get early round spermatids
what happens to early round spermatids
metamorphose into late elongated spermatids (spermatozoa)
secondary spermatocyte def
come after primary spermatocytes but are very transient
Ap does what
active stem cell dividing ASYMMETRICALLY by MITOSIS.
daughter cells of Ap
- more mature B spermatogonia
- more immature type Ap spermatogonia
Ap, Ad and B spermatogonia stem cell or not
Ad yes
Ap yes
B no
B spermatogonia result of mitosis
gives TWO EARLY SPERMATOCYTES (pre-leptotene) in the basal compt
what happens to pre-leptotene (early) spermatocytes
- shifted up by S cells
- become leptotene then zygotene then pachytene
what happens to pachytene spermatocytes
become late pachytene spermatocytes (step 1 of meiosis where lot of recombination happens) + reduction at meiosis nbr of chromosomes reduced in 2
what comes after late pachytene spermatocyte
early round spermatid (result of 2nd meiotic div)
spermiogenesis def
step from round early to late mature spermatozoa
3 phases of spermiogenesis
- Golgi
- acrosomal
- maturation
how is chromatin condensed in elongated late spermatids
histones are replaced by protamine
characteristics of spermatogenesis
- duration of steps and total duration are fixed and constant and species specific
- stem cells enter spermatogenesis at a regular interval (16 days in man)
- stem cells enter spermatogenesis in groups and the cells of the group are connected by IC bridges (this is true for all daughter cells and derivatives: spermatocytes, spermatids, until end of spermatogenesis)
- 4-5 gens of cells in the seminf epith
- sensitive to toxic factors (temperature as in cryptorchidism and chemicals)
name for one group of cells at one stage of dev in spermatogenesis
one generation of germinal cells
androgens act how in spermatogenesis
- produced by Leydig cells
- allow Sertoli cells to maintain their function but DON’T act on germ cells (ANDROGEN R ONLY ON SERTOLI CELLS)
- germ cells dev bc Sertoli cells are working
