Male Reproductive Physiology Flashcards
What commonalities are found between sexes?
formation of gametes (sex cells) and hypothalamic/pituitary control of reproduction
What is the main difference between meiosis and mitosis? Which process is involved in gametogenesis?
both processes involve one process DNA replication, however in meiosis, cells undergo cell division twice.
Meiosis is involved in gametogenesis: the formation of gametes
T/F. Sex Cells are haploid and Sexually reproducing organisms are diploid.
True.
haploid means having one set of chromosomes
diploid means having 2 sets of chromosome
What hormones are involved in the control of reproduction
GnRH (gonadotroplin releasing hormone)
LH: luteinizing hormone
FSH: follicle stimulating hormone
Where is GnRH released from?
hypothalamus
What is the relationship between the three hormones involved in reproduction control?
GnRH puslivity controls the release of whether LH or FSH is secreted from the anterior pituitary
If there is a low frequency of GnRH, is it more likely that LH or FSH will be secreted?
FSH
IF there is a high frequency of GnRH, is it more likely that LH or FSH will be secreted?
LH
T/F. pusle frequency/amplitude does not change during development.
False. it does change during development
Describe the initial process of creating sperm
the process, spermatogenesis begins during fetal development
- spermatozoa (mature sperm) precursor spermatogonia will undergo mitosis
- one of the cells that have been duplicated will be taken further to undergo meiosis. The other will continue to divide
- the one that undergoes meiosis 1 will produce secondary spermatocytes (2)
- Each spermatocyte will then undergo meiosis 2 and produce 2 spermatids each, for a total of 4 spermatids
- Spermatids mature into spermatozoa
- Spermiogenesis will occur where the spermatids will lose their cytoplasm and gain a tail
Where is sperm stored? Why is this compartment a degree or two colder compared to the rest of the body?
Sperm is stored in the testes which are generally colder to stimulate healthy sperm development
In a male after birth, where does sperm production start
in the seminiferous tubule
In males, where does sperm mature in the testes
epididymis
What makes sperm cells unique?
They have half the amount of genetic material than the rest of the cells in the body and they have proteins on their cell surface
What is the significance of this differentiation of sperm and how may it be dangerous for their survival
they will look different that the rest of the cells and the immune system will see them as foreign and try to destroy them.
what mechanism is put in place to prevent this immune attack on sperm?
Sertoli cells, which nurse and support sperm set up tight junctions between early and developing sperm to produce a blood-testes barrier so that no sperm make it into the blood
Acrosome
contains hyaluronidase and across which breakdown the coat that covers the oocyte
What is semen? is it different from sperm?
Sperm is in semen, but it only makes up 1% of semen content
The majority of semen is made up of water, enzymes, prostaglandins, and buffers to neutralize acids in urethra and female reproductive system
Why do males need prostaglandins in their semen
prostaglandins produce smooth muscle contraction, which help push and move the semen out of the male body
Where are the buffers that make up semen produced?
in the bulbourethral gland
What is the basic journey of sperm out of the male body
- sperm moves up Vas deferens, past the Seminal vesicles, Prostate and Bulbourethral gland through Urethra and Outside body
How do the contents in semen help sperm?
- assist with expulsion from testes
- keep sperm at a healthy pH
- move through female reproductive tract
What cells nurture the developing spermatozoa
Sertoli cells
What does FSH do in male reproduction?
stimulates Sertoli cells:
- supporting sperm development
secrete inhibin
- secretes androgen-binding protein
inhibin
hormone that negatively regulates FSH
What role does LH play in male reproduction
stimulates Leydig cells which secrete testosterone
What is the difference between pre-pubescent and pubescent male testes
pre-pubescent testes volume is largely made up of Sertoli cells where as adult testes volume is made of germ cells and actual sperm
Hypogonadism
decreased functional activity of testes
decreased production of androgens and inhibin and impaired sperm production
primary hypogonadism
defect is in the gonad (testes)
this lowers testosterone, which suppresses the negative feedback loop of reproduction control hormones- increasing GnRH, LH, and FSH
secondary hypogonadism
hypothalamic/ anterior pituitary damage that causes a decrease in GnRH, LH, FSH, and testosterone
What has been shown to help treat male baldness
inhibitors of 5 alpha reductase because it decreases dihydro-testosterone (DHT)
What does testerosterone do
Sex-Specific: promote spermatogenesis
Reproductive: increase sex drive and negative feedback on GnRH, LH, and FSH
Secondary sex: baldness, muscle growth, odour
Nonreproductive: protein synthesis, aggression, erythropoiesis- making of new blood
