Male Reproductive Physiology Flashcards
Why is the scrotum out-with the abdominal/pelvic cavity?
To allow for it to be 1-2 degrees colder to facilitate sperm production
What is the fibrous capsule that surrounds the testes?
Tunica albuginea
What are the three cell types within the seminiferous tubules?
- Germ cells
- Sertoli/sustentacular cells
- Interstitial/Leydig cells
What is the function of Germ cells in the seminiferous tubules?
Produce sperm
What is the function of the sustentacular cells in the seminiferous tubules?
Support sperm production, produce inhibin
What is the function of the interstitial cells
Produce testosterone
What are the two main functions of the testes?
- Sperm production
- Testosterone production
How long is the average sperm cycle?
64 days (about 3 months)
What are the male reproductive hormones?
- GnRH (from hypothalamus)
- Gonadotrophin’s (LH + FSH from AP)
- Testosterone (from testicles)
Where does FSH act and what is the effect?
Testes and sustentacular cells facilitate spermatogenesis
Where does LH act and what is its effect?
Testes and encourages interstitial cells to produce testosterone
What is the positive feedback effect of the interstitial cells producing testosterone?
On the sustentacular cells facilitating spermatogenesis
Where does testosterone show negative feedback?
on AP and hypothalamus
Where does inhibin show negative feedback?
on AP
What is spermatogenesis?
Production of sperm from primordial germ cells
What are the two distinct phases of development during spermatogenesis?
- Spermatocytogenesis
- Spermieiogenesis
When does spermatogenesis begin and end?
Starts and puberty and continues life long (doesn’t end)
How does mitotic devision work during spermatogenesis?
- One mitotic devision (46 chromosomes)
- First meiotic division (two cells with haploid chromosome number (23))
- Second meiotic division (spermatid - two cells with haploid chromosomes)
- Spermatogenesis (maturation of spermatids into functional sperm cells)
What factors affect spermatogenesis?
- Medical
- Lifestyle
- Combination
How can the medical factors that affect spermatogenesis be categorised?
- Pretesticular (problem with hormonal control)
- Testicular (problem at site of production)
How can lifestyle factors which affect sperm production be categorised?
- From mother (irreversible bc happens in utero)
- From male (reversible bc most are environmental causes)
What steps can be taken to reduce impact of factors affecting fertility?
- Improve lifestyle
- Optimise underlying medical condition
- Stop medications or switch to alternative pregnancy compatible medications
- Reduce STI risk and treat promptly if diagnosed
- Fertility preservation (sperm freezing prior to surgery/radiotherapy/chemotherapy)
