Lecture 43: Male Reproductive Microanatomy Flashcards
2 compartments of testis parenchyma
seminiferous tubules
interstitial tissue
seminiferous tubules: function
where spermatogenesis takes place
interstitial tissue of testis: function
steroidogenesis
what cells secrete androgens and where do they do this
leydig cells
interstitial tissue of testis
testis: stroma
connective tissue
fills space in between seminiferous tubules
support
2 cell types in seminiferous epithelium: seminiferous tubules
sertoli cells
germ cells
4 types of germ cells in seminiferous epithelium
elongated spermatids
rounded spermatids
spermatocytes
spermatogonia
4 types of germ cells in seminiferous epithelium: rank based on least differentiated to most differentiated
least: spermatagonia –> spermatocytes –> rounded spermatids –> elongated spermatids
location of spermatogonia in seminiferous epithelium
most basal
spermiation
release of sperm into lumen
what induces differentiation of spermatogonia
growth factors
sertoli cells: 4 functions
-provide physical and nutritional support to germ cells
-mediate movement of cells and molecules across epithelium
-phagocytize degenerating germ cells
-secrete molecules into epithelium and interstitial tissue
where is the blood-testis barrier located
seminiferous epithelium
blood testis barrier is formed from
cell membrane of sertoli cells and tight junctions between adjacent sertoli cells
blood testis barrier: 4 functions
create 2 compartments in seminiferous epithelium
protect germ cells from autoimmune response
sequester and secrete proteins, ions and carbs that are required by germ cells
2 compartments created by blood testis barrier
adluminal
basal
2 germ cells contained within adluminal compartment: seminiferous epithelium
spermatocytes
spermatids
2 germ cells contained within basal compartment: seminiferous epithelium
spermatogonial stem cells
differentiating spermatogonia
tubular wall of seminiferous tubules: made of
laminin
fibronectin
collagen
what 2 cells contribute to forming the basal lamina: seminiferous tubules
sertoli
peritubular myoid
what is found within interstitial tissue of testis (5)
leydig cells
blood vessels, lymphatic vessels, nerves, macrophages
leydig cells
synthesize and secrete androgens
2 steps of spermatogenesis
1) spermatocytogenesis
2) spermiogenesis
spermatocytogenesis: process
first step of spermatogenesis
undifferentiated stem cell –> spermatogonium –> mitosis –> primary spermatocyte –> meiosis I –> secondary spermatocyte –> meiosis 2
spermiogenesis
after meiosis II
meiosis 2 –> early spermatid –> sperm
excurrent ducts of testis: function
carry sperm through fluid to epididymis
2 components of excurrent ducts
-rete testis
-efferent ducts
rete testis: definition, cell type
flattened channels
cuboidal ciliated cells
efferent ducts: 2 cell types, function
columnar ciliated cells
columnar cells with microvilli
absorb seminiferous fluid
tubuli recti of testis: function, epithelium
simple, columnar or cuboidal
no germ cells
connect convoluted region of seminiferous tubules to rete testis
3 regions of epididymis
head
body
tail
where does sperm maturation occur in epididymis
head and body
where does sperm storage take place in epididymis
tail
2 aspects of sperm maturation
forward motility
fertilization
CT type in epididymis body
fibroelastic
how many ducts is epididymis duct
1
epididymis tail: epithelium
pseudostratified columnar
epididymis tail: 2 cell types
principal
basal
function of myenteric plexus in tail of epididymis
ejaculation
contraction of smooth muscle
where does epididymis carry sperm to
ductus deferens
ductus deferens: function
convey sperm to pelvic urethra
ductus deferens: 2 muscle layers
longitudinal smooth muscle
circular smooth muscle
which accessory sex gland in males is an enlargement of ductus deferens
ampullary
ampullary glands: function
secrete fluid rich in fructose and ergothioneine (antioxidant)
ampullary glands: epithelium
simple, tall columnar
importance of ampullary gland secretion
maintain sperm viability
corpora arenacea is a result of
when ampullary gland secretion becomes calcified
function and integrity of ampullary glands are highly dependent on what
testicular androgens
what happens to ampullary glands if androgens are absent
atrophy
2 regions of vesicular glands
stroma
secretory epithelium
vesicular glands: stroma
fibroelastic capsule
extends as trabeculae to support secretory epithelium
vesicular glands: secretory epithelium
simple, tall columnar
vesicular glands: secretion (definition and function)
alkaline viscid fluid rich in fructose and coagulating proteins
source of energy for sperm –> sperm viability, semen consistency
are vesicular glands dependent on androgens
yes
prostate: stroma
fibroelastic capsule that extends as trabeculae
prostate: secretory epithelium (and cells)
pseudostratified with tall columnar cells and small reserve cells (stem cells)
prostate: secretion (definition, function)
slightly acid fluid rich in acid phosphatase, citric acid and proteins
semen liquification
prostate: concretions
condensed secretion
can be calcified
which 2 accessory gland’s secretions balance each other
vesicular glands = alkaline
prostate = acidic
bulbourethral glands: stroma
fibrous connective tissue that sends trabeculae
covered by striated muscle on outer surface and smooth muscle on inner surface
bulbourethral glands: secretory epithelium
simple, columnar
bulbourethral glands: secretion (definition, function)
clear viscid mucus like fluid
rich in sialoproteins and amino sugars
urethral cleaning and lubrication before ejaculation
cryptorchidism
absence of differentiating germ cells
undescended testis
testicular tumors: 3 types
seminoma
sertoli cell tumor
leydig cell tumor
seminoma: testicular tumor
high presence of germ cells
high nucleus: cytoplasm ratio
round big nuclei
leydig cell tumor: testicular tumor
high presence of cells with typical leydig cell phenotype
sertoli cell tumor: testicular tumor
high presence of cells with nuclei of irregular shape
high cytoplasm:nucleus ratio
when does sperm become motile
after maturation in tail of epididymis
