Male Reproductive System Flashcards
What is hemizygous?
- one copy of x-chromosome
- what males are
- b/c male only have one x-chromosome copy they are more likely to express a disease-causing allele in the unpaired part of the x-chromosome compared to females
What is the Y chromosome?
- contains little genetic information
- contains the SRY chromosome
What is SRY?
- sex-determining region Y
- codes for a transcription factor that initiates testis differentiation and formation of male gonads
What are testes?
- produces and store sperm
- main source of testosterone
- contain 2 functional components – seminiferous tubules and interstital cells of leydig
Where is sperm produced?
seminiferous tubules
What cells nourish sperm?
sertoli cells (located in seminiferous tubules)
What do the cells of leydig secrete?
- testosterone
- androgens
What is the function of the scrotum?
maintains a temperature 2-4 degrees celsius lower than body temperature
What is the epididymis?
- where sperm flagella gain motility
- where sperm are stored until ejaculation
What is seminal fluid?
- mixed with sperm
- produced through combined effort by seminal vesicles, prostrate gland, and bulbourethral gland
What is the function of seminal vesicles?
contribute fructose to nourish sperm and mildly alkaline properties
What is the function of the prostrate gland?
gives sperm mildly alkaline properties so that is can survive the relative acidity of the female reproductive tract
What is the function of the bulbourethral gland?
produces fluid that cleans out urine reminants and lubricates urethra during sexual arousal
What is semen made of?
sperm and seminal fluid
What is the pathway of sperm through the reproductive system?
SEVE(N) UP
- Seminiferous tubules
- Epididymis
- Vas deferens
- Ejaculatory duct
- Urethra
- Penis
What is spermatogenesis?
- the formation of haploid sperm through meiosis
- occurs in the seminiferous tubules
- results in 4 functional sperm/spermatogonium
Spermatogonia
- diploid sperm cells
- form present before replication (S stage)
Primary Spermatocyte
- product after replication (S stage)
- one diploid sperm cell
Secondary Spermatocyte
- product after first meiotic division
- two haploid daughter cells
Spermatids
- product after second meiotic division
- 4 haploid daughter cells
Spermatozoa
mature spermatids
Timeline of male sexual development
- Fetal period (9 wks after fertilization - birth): presence of Y chromosome leads to androgen production resulting in male sexual differentiation
- Infancy and Childhood: low androgen production
- Puberty: increase in testosterone production by testes, sperm production starts
- Adulthood: high testosterone levels that decline in old age
What is the role of FSH?
stimulates sertoli cells which leads to sperm maturation
What is the role of LH?
causes interstitial cells to produce testosterone
