MALE REPRODUCTIVE SYSTEM FUNCTIONS Flashcards
function of testes
dual function- produce both sperm and androgens, primarily testosterone
androgen definition
any natural or synthetic hormone that regulates the development and maintenance of male characteristics by binding to androgen receptors
three main androgens in males
testosterone, dihydrotestosterone and androstenedione
process of making sperm name
spermatogenesis
primordial cells in males
spermatogonium A
how is spermatogonium A produced?
by mitosis in the developing testes during childhood
spermatogenesis definition
the process by which haploid spermatozoa develop from germ cells in the seminiferous tubules of the testis
first stage of the process
- spermatogonial stem cells divide by mitosis into type A cells and type B cells
difference between type A and B
type A replenish stem cells
type B differentiate into primary spermatocytes
spermatogenesis + locations
- spermatogonia B differentiate to produce spermatocytes- basal compartment
- first meiotic division forms secondary spermatocytes- adluminal compartment
- 2nd meiotic division forms round haploid spermatids
what happens to the spermatids?
transformed into spermatozoa (sperm) by spermiogenesis
where does spermatogenesis take place?
seminiferous tubules of the male testes
begins at the bottom part of the seminiferous tubule and progressively, as the cells get deeper into the tubes, moving along untilt he mature spermatozoa reach the lumen
where does the sperm mature?
epididymus
what happens during spermiogenesis?
DNA is packed more tightly
DNA packaged using protamines
chromatin forms an annulus, squished into the nuclear head of the sperm
mature sperm structure
haploid component of DNA protected by a cap
receptors for zona pellucida and oocyte
tail protein
acromosomal protein
oocyte receptor protein exposed after acrosomal reaction
what is formed between the developing sperm + why?
cytoplasmic bridges between spermatids
ensure transfer of mRNA and proteins
Sertoli cell functions
support functions, blood-testis barrier
explain blood testis barrier
form tight and occluding junctions that partitions the interstitial blood compartment of the testis from the adluminal compartment of the seminiferous tubules
control the environment sperm develop in, preventing the body from being able to detect the spermatozoa which it would label as foreign
support function explained
secrete nutrients, absorb waste and phagocytose defunct sperm
how do the sperm pass through the tight junctions?
spermatocytes pass from basal to luminal side
bind tightly to sertoli cells, passing through
Leydig cell functions
produce testosterone, DHEA
explain sperm maturation
spermatozoa’s cytoplasmic droplet is lost
adds a glycoprotein coat to prevent premature acrosome reaction
concentrates spermatozoa, can maintain in storage
allows development of unidirectional motility
why is sperm production constant?
different seminiferous tubules at different stages of spermatogenesis
what is testes function controlled by?
LH and FSH
