what is blood testes barrier
it is a barrier that seperates the tissue fluid and blood vessels outside the seminiferous tubule from spermatogenic cell inside the tubule
describes function of blood testis barrier
-selection of nutrients, hormones, fluids for spermatogenesis
-protection from injurious agents like antigen drug toxin or virus
-creation of special environment for spermatogenesis
-prevent autoimmune reaction
describe LM of sertoli cells
large
acidophilic triangular
ovoid light nucleus and large nucleolus
describe EM of sertoli cells
abundant of sER, golgi apparatus and euchromatic cells
lateral cells process
tight junction
it is the main cell type till puberty
sertoli cells
what are the functions of sertoli cells
-supporting, protection and nutrition of sperm
-phagocytosis of excess sperm
-component of blood testis barrier
-release of spermatozoa (spermiation)
-secrete testicular fluid
-production of ABP
-secrete inhibin and activin hormone
describe 2 stages of spermatogenesis?
-spermatocytogenesis
-spermiogenesis
enumerate 4 types of spermatogenic cells?
- spermatogonia
- primary spermatocytes
- secondary spermatocytes
spermatids
-it is primitive less differentiated cells
-diploid chromosomes 46 S
-differentiated at puberty due to effect of FSH
spermatogonia
enumerate 3 types of spermatogonia
-type A dark cells
-type A pale cells
type B cells
what is the largest cell in spermatocytogenesis?
primary spermatocytes
it is diploid cells
divide by meiosis
primary spermatocytes
it is small cells
haploid in number
divide by second meiotic division
form 4 spermatids
secondary spermatocytes
describe spermatids?
have haploid in number
it is the smallest spermatogenic cells
define spermiogenesis
it is the process of differentiation from spermatids into mature sperms
what are the steps of spermiogenesis
golgi phase
acrosomal phase
maturation phase
enumerate golgi phase
acrosomal granules contains rER snd Golgi
centriole migrate to opposite pole
what happen during acrosomal phase
nucleus condensed elongated flattened
formation of:
-acrosomal cap
-flagella
-middle piece of flagellum
what happen during maturation phase
acrosomal cap covers two-third of nucleus anteriorly
cytoplasm forms a thin layer
sperm will be released from sertoli cells (spermiation)
enumerate the structure of mature spermatozoon and its content
head:
-condensed nucleus
-acrosomal cap
sperm tail:
-neck
-middle piece (mitochondria 9 coarse fibers axoneme of flagella)
-principle piece ( fibrous sheath axoneme)
-end piece (axoneme only)
enumerate 3 factors affecting spermatogenesis
- temperature (must be lower than body temperature below 35)
- hormone:
FSH stimulate sertoli produce ABP increase conc of testosterone
LH increase leydig to secrete testosterone
testosterone increase spermatogenesis - vitamin A and E (essential for spermatogenesis)
