Male Reproductive Physiology Flashcards
where is sperm mainly made?
Main structure where sperm Is produced is the testicles in the scrotum
why are the testes outside your body
Testicular temp has to be lower that the body’s that’s why it is outside of the abdominal cavity so it is 1 or 2 degrees lower
Posterior to the testes is a gland called the _________ and this is the storage site of sperm where they mature for _ months
epididymis
3
Epididymis is connected to the ___ ________ and this passes through the ________ region and the secretions of the ______ vesicles and the _______ gland are added and converges to one tube to the _______ and travels outside the body
vas deferens
inguinal
seminal
prostate
urethra
what is the process/route of sperm?
Sperm made in testes > stored in epididymis > then travels to vas deferens > coils around the bladder > seminal vesicles and prostate make the fluid which is semen > carried along the urethra and travels out of penis
what is required ofr male fertility?
For male fertility the structure, function and pathway of sperm needs to be intact
1
epididymis
2
prostate
3
penis
4
urethra
5
testes
6
scrotum
what is the testes divided into?
lobules
what divides the testes into lobules?
Fibrous capsule surrounding called the tunica albuginea and this is what divides it into different lobules
where is sperm made in the testes?
Sperm production in the seminiferous tubules
All seminiferous tubules merge and move where?
to the head of the epididymis
Epididymis has 3 parts – what are they?
head, body and tail
A
head of epididymis
B
seminiferous tubules
C
tunica albuginea
D
vas deferens
E
body of epididymis
F
tail of epididymis
what surrounds the seminiferous tubules?
basememnt membrane
There are three types of cells within the seminiferous tubules
what are they?
Germ cells (purple)
Sertoli/substentacular cellsproducing cell, produce inhibin
Interstitial (Leydig) cells
what is the function of Germ cells (purple)?
produce sperm, different stages and as they are produced they are driven towards the lumen of the testes
what is the function of Sertoli/substentacular cells?
support sperm producing cell, produce inhibin
what is the function of Interstitial (Leydig) cells?
produce testosterone, in-between seminiferous tubules
what is the function of the testes?
Sperm production – millions of viable sperm per day, average time form production to ejaculation is 64 days
Testosterone production – male secondary sexual characters, controls spermatogenesis
What is the Endocrine Control of Testicular Function – Reproductive hormone?
- GnRH – gonadotrophin releasing hormone, produced from hypothalamus
- Gonadotrophins – FSH and LH, released from anterior pituitary
- Testosterone – released form testicles
Need enough hormones for the process of sperm production to happen and need to interact correctly
- FSH = sperm
- LH = testosterone
If you take testosterone supplements then your own axis will be ___________
suppressed
Inhibin produced by fertilized cells and creates negative feedback on ______ ______
anterior pituitary
Sperm production form the _______ germ cells
primordial
Average cycle of spermatogenesis is __ days in which the germ cells pass through different developmental stages
64
Two distinct phases during the development in spermatogenesis, what are they?
Spermatocytogenesis – clonal expansion and maturation through mitotic and meiotic process
Spermiogenesis – differentiation into mature sperm cells
Process starts at puberty and continues lifelong
what is mitosis, meiosis and a spermatid?
Mitosis – one germ cell splits into 2, duplication
Meiosis – the daughter cells only have half the number of chromosomes
Spermatid not capable of fertilization – in spermiogenesis they turn into mature sperm cells through differentiation
what is the process of Chromosomal division during spermatogenesis?
- One mitotic division – spermatogonium to primary spermatocyte-duplication, diploid chromosomes number (46)
- First meiotic division – primary spermatocyte to secondary spermatocyte, two cells with haploid chromosome number (23)
- Second meiotic division – secondary spermtocyte to spermatid, two cells with haploid chromosome number (23)
(spermatogenesis – maturation of spermatids into functional sperm cells)
What are factors affecting spermatogenesis?
- Medical
- Lifestyle
- Combination
medical factors affecting spermatogenesis can be put into what two categories?
- Pretesticular – problem with the hormonal control
- Testicular – problem at the site of production
what are pretesticular medicla factors affecting spermatogenesis?
Functional – excessive weight loss, gain
Intracranial tumours, cysts, bleed
prolactinoma
Medications – opiates, external testosterone, steroids (body building)
Genetic – Kallmanns syndrome
what are testicular medical factors affecting spermatogenesis?
Surgery – orchidectomy, orchidopexy
STI
Mumps orchitis
Testicular trauma or torsion
Radiotherapy or chemotherapy
Genetic – Klinefelters (46XXY), Y-chromosome microdeletion
what environmental/lifestyle factors can affect spermatogenesis?
- Smoking – heavily impacts sperm production and functional capacity of the sperm
- Obesity – both mum and dad
- Occupational or environmental chemical exposure
what are some steps to reduce the impact of factors affecting fertility?
- Improve lifestyle – normal BMI, stop smoking, alcohol in recommended limits, healthy diet, exercise, adjustments to occupational exposure
- 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 or cancer treatment
