Reproductive System Flashcards
Scrotum
contains paired testes and hangs outside abdominopelvic cavity
What winkles the scrotal skin?
dartos muscles
What elevates the testes?
cremaster muscle
What is the name of the serous membrane covering the testes?
tunica vaginalis
What is the fibrous capsule of testis?
tunica albuginea
What produces testosterone?
interstitial endocrine cells
What produces sperm?
seminiferous tubules
What are the testes divided into?
250 lobules
What encloses nerve fibers, blood vessels, lymphatics and ductus deferens?
spermatic cord
What are the major part of the penis?
root, shaft, glans penis and prepuse
What does the internal penis contain?
spongy urethra and 3 cylindrical of erectile tissue
What are the erectile tissue in the penis?
corpus spongiosum and corpus cavernosa(paired)
What is the order of the male duct system?
epididymsis-> ducyus deferens -> ejaculatory duct -> urethra
Site where sperm gain ability to swim
epididymis
stores sperm prior to ejaculation
epididymis
Epididymis
immature sperm conveyed from seminiferous tubules
Where does the epididymis empty into?
ductus deferens
Ductus deferens joins duct of what to form the ejaculatory duct?
seminal vesicle
Cutting and ligating ductus deferens
vasectomy
What are the 3 regions of the urethra?
- prostatic urethra
- membranous urethra
- spongy urethra
Which of the accessory glands are paired?
seminal vesicles, bulbo-urethral glands and prostate
What contains 70% of semen volume?
seminal vesicle
What are the 2 components of semen?
fructose and prostaglandins
Contains up to 1/3 of semen volume
prostate
Pea-sized glands inferior to prostate
bublo-urethral glands
Bulbo-urethral glands
lubricates glans penis and neutralizes traces of urine
What are the functions of semen
- provides transport medium for sperm
- provides fuel for ATP synthesis
- contains chemicals that enhance sperm motility
pH of sperm
7.2-8.0
Why is the pH of the sperm so basic?
this is because the vagina is acidic
How many total chromosomes in a diploid cell?
2n=46
How many chromosomes in a haploid cell?
n=23
Nuclear division process that occurs only in gonads?
meiosis
Prophase I
crossing over for genetic variation
Metaphase I
tetrads line up at metaphase plate
Anaphase I
homologous chromosomes separate
Product of meiosis I
2 diploid daughter cells
Product of meiosis II
4 genetically distinct haploid daughter cells
What is the function of meiosis?
introduce genetic variability
Sperm formation in seminiferous tubules
spermatogenesis
What are the major steps in the spermatogenesis?
- Mitosis of spermatogonia
- Meiosis
- Spermiogenesis
Stem cells at outermost tubule
spermatogonia
Starting at puberty, each mitotic division become what?
type A and type B daughter cells
Which cell type remains at basal lamina?
type A
Which cell type moves toward lumen and becomes primary spermatocyte?
type B
What occurs during meiosis I to the primary spermatocyte?
it becomes 2 secondary spermatocytes
Are the cells haploid or diploid at primary spermatocyte?
diploid
Are the cells haploid or diploid at secondary spermatocytes?
haploid
During meiosis II what happens to the secondary spermatocyte?
2 spermatids
Are the cells haploid or diploid at the 2 spermatids?
haploid
Spermatid elongates loses excess cytoplasm and forms a tail
spermeogensis
what is another name for sperm?
spermaozoon
What are 3 major regions of a sperm?
- head
- midpiece
- tail
Part of the sperm that has hydrolytic enzymes?
acrosome
What does the midpiece of the sperm contain?
mitochondria
Surround spermatogenic cells
sustentocytes
Sustentocytes
divide seminiferous tubule into basal compartment and adluminal compartment
Blood-testis barrier
tight junctions between sustentocytes
2 functions of the blood-testis barrier
- prevents antigens of developing sperm from activating immune system
- sperm absent during immune system development and so not recognizedas “self”
What lies outside blood-testis barrier in basal compartment?
spermatogonia
What is the purpose of tight junctions opening following mitosis?
type B daughter cells pass into adluminal compartment
What are other functions of sustentocytes?
- provide nutrients to dividing cells
- secrete testicular fluid for sperm transport
- move cells toward lumen
- produce chmical signals that help regulate spermatogenesis
Hypothalamic-pituitary-gonadal axis
hormonal interactions between hypothalamus, anterior pituitary and gonads
What does the hypothalamus releases?
GnRH (gonadotropin-releasing hormone)
GnRH
FSH and LH
What is stimulated by sustentocytes to release androgen-binding protein?
FSH
What is the function of FSH stimulation in males?
keeps concentration of testosterone high near spermatogenic cells
What stimulates interstitial endocrine cells to release testosterone?
LH
What is the final trigger for spermatogenesis?
LH