lecture 35 Flashcards
what are the three regions of the epididymis?
head body tail
where would you find a spermatogonia?
adjacent to the basement membrane within the seminiferous tubules
why are the scrotum external to the body?
they are housed away from the body to maintain temp at ~34 degrees
what lines the scrotum?
dartos muscle
what does the cremaster muscle do?
contracts for heat conservation
what happens when the dartos muscle contracts?
wrinkles or unwrinkles the ball sack to reduce or increase the surface area for heat transfer
what runs between abdomen and testes?
the spermatic cord
spermatic cord contains?
ductus deferens
blood vessels - testicular arteries and veins
nerves
lymphatics
functions of the penis?
urination
copulation
3 main regions of the penis?
root
body
glans (covered by foreskin)
how many erectile tissues does the penis have?
three
what are the erectile tissues of the penis?
two corpora cavernosa
one corpus spongiosum
what are the corpora cavernosa?
main erectile tissue on the dorsal aspect
what is the corpus spongiosum?
contains urethra and forms bulb and glans on the ventral aspect
how are spermatozoa carried to female reproductive tract?
seminal fluid + spermatozoa
= semen
seminal fluid is mostly produced by which accessory glands?
seminal vesicles
prostate gland
bulbourethral glands
seminal vesicles are two glands located where?
posterior to bladder and lateral to ampulla
seminal vesicles produce what?
a viscous secretion that makes up 60% of semen and has an alkaline pH protection seem against acidic environment in urethra and vagina
where is the prostate gland located?
inferior to bladder wrapping around prostatic urethra
what kind of secretion does the prostate gland secrete?
30% semen
slightly acidic, milky fluid with prostate-specific antigen
what does prostate gland secretion activate?
sperm activation, viability and motility
where are the bulbourethral glands located?
two glands located in the urogenital diaphragm
where does the bulbourethral glands open into?
the spongy/penile urethra
how much does the bulbourethral contribute to semen volume?
5% of semen volume
what do bulbourethral secretions do?
lubricate and neutralise acidity in urethra prior to ejaculation
components of semen?
60% from seminal vesicles
30% from prostate
5% from bulbourethral glands
5% spermatozoa
what is a vasectomy?
a surgical method of sterilisation in males
What happens in a vasectomy?
the ductus deferens are tied or cauterised
does a vasectomy affect seminal fluid?
no it does not affect production or volume of seminal fluid but there won’t be any spermatozoa
name of formation of the gametes?
spermatogenesis
oogenesis
gamete formation is under what control?
hormonal control
gametogenesis occurs via?
mitosis and meiosis
meiosis produces gametes that are?
haploid, 23 chromosomes
meiosis begins with?
diploid chromosomes
what is spermatogenesis?
the process by which spermatogonia are transformed to mature spermatozoa
when does spermatogenesis begin?
continuously from puberty onwards
where does spermatogenesis occur?
seminiferous tubules
how do spermatogonia divide?
by mitosis into two daughter cells
what happens to type A spermatogonium?
stays at the basement membrane of the seminiferous tubule when mitosis occurs
what happens to type B spermatogonia?
differentiates into a primary spermatocyte which undergoes Meiosis I to form 2 secondary spermatocytes (haploid)
what happens to the 2 secondary spermatocytes?
they undergo meiosis II to form spermatids
what do spermatids differentiate into?
spermatozoa with a head, body and tail via spermiogenesis
during spermiogenesis,a spermatid will form?
a spermatozoon
what are the reproductive hormones?
GnRH
LH
FSH
what is GnRH?
gonadotropin releasing hormone produced by the hypothalamus
what is LH?
luteinizing hormone (a gonadotropin) produced by the anterior pituitary
What is FSH?
follicle stimulation hormone (a gonadotropin) produced by anterior pituitary
hormones in males?
inhibin
testorone
where is inhibin from?
nurse (steroli) cells
where is testosterone produced?
interstitial endocrine (leydig) cells
testosterone is a type of?
androgen which is a group of steroid hormones
what is testosterone responsible for?
male characteristics like:
maturation of sex organs
spermatogenesis
etc.
what stimulates production of testosterone?
LH hormone
which hormones control spermatogenesis?
FSH and testosterone
production of FSH stimulates what?
inhibin
What is the negative feedback loop for male reproductive hormones?
Inhibin suppresses FSH and testosterone suppresses LH and GnRH
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