HUBS192 Lecture 35 - Male Reproductive System II Flashcards
what prevents sperm from ending up in the bladder during ejaculation?
the internal sphincter closes over the bladder during ejaculation
what are the 3 regions of the epididymis?
1) head
2) body
3) tail
where would you find a spermatogonia?
found within the semi nephronus tubules close to the basement membrane
what are the 2 accessory structures f the male reproductive system?
1) penis
2) scrotum
what are the 2 testes separated by?
separated by a fibrous septum
what are the 2 epididymides associated with?
associated with the posterior border of the testes
where do the 2 spermatic cords (with part of the ducts deferens) run through?
run through the testes and up through the enginal canal
what 3 things does the scrotum contain?
1) ductus deferens
2) epididymis
3) testes
where are the testes housed?
housed testes away from the body
why are the testes housed away from the body?
to maintain temperature at 34 degrees because the optimal temp for spermatogenesis is colder than body temp (37) therefore located outside of the abdominal cavity makes it easier to adjust temp
what is the optimal temperature for spermatogenesis?
34 degrees
what muscle is the scrotum lined with?
dartos muscle
what is the function of the dartos muscle lining the scrotum?
has the ability to wrinkle and un-wrinkle and this changes the surface area of the scrotum depending on need
what is the function of the cremaster muscle?
contracts for heat conservation
what are the 2 functions of the contraction of the cremaster muscle for heat conservation?
1) contraction draws the testes up and closer to the body to help with heat conservation
2) draws the testes closer to the body for arousal providing a protection mechanism for coitus
what does the spermatic cord consist of?
two spermatic cords that contain
- ductus deferens
- blood vessels: testicular arteries and veins
- nerves
- lymphatics
where are both spermatic cords located?
both spermatic cords are located within the scrotum
where do the spermatic cords run between?
runs between the abdomen and the testes
what do the testicular veins form?
veins form a plexus around the artery
what is the function of the vein plexus formed around the arteries?
provides an increased surface area for heat transfer between the warmer blood from the testicular arteries and the colder blood going up to the body from the testicular veins
what are the dual functions of the penis?
1) urination
2) copulation
what type of organ is the penis?
cylindrical organ
what 3 components make up the penis?
1) root (bulb)
2) body
3) glans covered by prepuce/foreskin
what is the root of the penis?
part that adheres to the body wall
what is the body of the penis?
moveable part
what 3 cylindrical erectile tissues does the penis contain?
- 2 corpora cavernosa (plural) corpus cavernosum (singular)
what is the corpora cavernosa?
the main erectile tissue
where are the 2 corpora cavernosa located?
on the dorsal aspect of the penis
what does the corpus spongiosum contain?
contains the urethra
what does the corpus spongiosum form?
forms the bulb and glans
where is the corpus spongiosum located?
on the ventral aspect of the penis
where does the corpus spongiosum start and widen ?
starts in the root and winds and extends to form the glans penis
why is there less erectile tissue in the corpus spongiosum?
because the corpus spongiosum contains the urethra therefore during ejaculation it eliminates the risk of urine exiting at the wrong time
fill in the blank:
the scrotum houses the testes outside the body to maintain temperature at ____‘C
34
what are the 2 muscles involved in temperature regulation?
1) dartos muscle
2) cremaster muscle
fill in the blank:
the spermatic cords contain the ductus deferens, and the ____, ____, and the ____ vessels and nerves that supply the testes
testicular artery, venous plexus and the lymphatic
fill in the blank:
the penis contains erectile tissues known as the corpora ___ and the corpus ____
cavernosa
spongiosum
what is spermatozoa carried to the female reproductive tract in?
spermatozoa is carried to the female reproductive tract in seminal fluid
what is semen?
seminal fluid + spermatozoa
what are the 3 accessory glands that produce semen?
1) seminal vesicles
2) prostate gland
3) bulbourethral glands
where is the seminal vesicles located?
located lateral to the ampulla
where are the bulbourethral glands found?
found in the pelvic floor/pelvic diaphragm
what are 4 functions of semen?
1) transport medium for sperm
2) nutrients provide protection against acidic conditions
3) energy source for sperm
4) activate the spermatozoa
what are the 2 glands of the seminal vesicles and where are they located?
1) posterior to the bladder
2) lateral to the ampulla
what do the seminal vesicles produce?
viscous secretion that makes up 60% of semen
what is the relationship between alkaline pH and acidity in the urethra and vagina?
alkaline pH protects sperm against acidic environment in the urethra and vagina
where is the prostate gland located?
inferior to bladder
what does the prostate gland wrap around?
wraps around the prostatic urethra
what does the prostate gland produce?
secretion that makes up 30% of semen
what is the pH and appearance of the secretion from the prostate gland?
slightly acidic milky fluid
what does the prostate gland secretion contain?
contains PSA (prostate-specific antigen)
what 3 things does prostate gland secretion contribute to?
1) sperm activation
2) sperm viability
3) sperm motility
what are the bulbourethral glands and where are they located?
two glands located in the urogenital diaphragm
where do the bulbourethral glands open into?
open into the spongy/penile urethra
how much to the bulbourethral glands contribute to semen volume?
contributes 5% of semen volume
what are the function of bulbourethral glands?
secretions lubricate and neutralise acidity in the urethra prior to ejalculation
when are the secretions of bulbourethral glands released?
released prior to ejaculation to protect against residual acidity
what are the components of semen and what are the percentages of each?
- 60% from seminal vesicles
- 30% from prostate
- 5% from bulbourethral glands
what is a vasectomy?
surgical method of sterilisation in males where the ductus deferens in cut, tied or cauterised
what is gametogenesis in males?
spermatogenesis
what is gametogenesis in females?
oogenesis
what is gametogenesis controlled by?
under hormonal control
where does gametogenesis occur?
occurs via mitosis and meiosis
what do cells need to be for gametogenesis to occur?
cells need to haploid (23 chromosomes)
what happens in meiosis I?
2 haploid cell produced from 1 original diploid cell
what happens in meiosis II?
each cell produced from meiosis divides to produce 2 haploid cells with 23 chromosome cells
what is spermatogenesis?
formation of the male gamete (spermatozoa) through the process by which spermatogonia and transformed to mature spermatozoa (sperm)
when does spermatogenesis begin?
occurs continuously from puberty onwards
where does spermatogenesis occur?
occurs in the seminiferous tubules
what happens in spermatogenesis 1?
- spermatogonia divide by mitosis into 2 diploid daughter cells (46 chromosomes)
- 1 spermatogonium (type A) stays at the basement membrane of the seminiferous tubule
what happens in spermatogenesis 2?
- the second spermatogonia (type B) differentiates into a primary spermatocyte (diploid), which undergoes meiosis I
- forms 2 haploid secondary spermatocytes (23 chromosomes)
what happens in spermatogenesis 3?
- undergo meiosis II to form haploid spermatids (23 chromosomes)
- spermatids differentiate into spermatozoa with a head, body and tail via spermatogenesis
- spermatozoa released into the lumen
what is spermatozoon?
singular of spermatozoa
what are the 3 reproductive hormones?
1) gonadotropin (GnRH)
2) luteinizing hormone (LH)
3) follicle stimulating hormone (FSH)
what does gonadotropin act on?
hormone that acts on the gonads
what is GnRH?
gonadotropin releasing hormone
where is GnRH produced?
produced by the hypothalamus
where is LH (luteinising hormone) produced?
produced by the anterior pituitary
where is FSH (follicle stimulating hormone) produced?
produced by the anterior pituitary
what are the 2 hormones in males?
1) inhibin
2) testosterone
what is inhibin important for?
important for negative feedback within the seminiferous tubules
what is testosterone a type of?
type of androgen
what is testosterone responsible for?
responsible for male characteristics
- maturation of sex organs
- spermatogenesis
- secondary sex characteristics
- libido
what are the 2 secondary sex characteristics?
- growth of hair
- deepening of the voice
what does LH stimulate the production of?
LH stimulates the production testosterone from interstitial endocrine cells
what 2 hormones control spermatogenesis?
1) FSH (follicle-stimulating hormone)
2) testosterone
what does FSH stimulate the production of?
FSH stimulates inhibin production in nurse cells
what does inhibin suppress?
suppresses FSH
what does testosterone suppress?
suppresses LH and GnRH
fill in the blank:
spermatogenesis is the maturation of ____ into spermatozoa (head, mid-piece, tail)
spermatid (round)
