Male Reproductive Physiology P1+2

Question 1

describe key parts male reproductive organs

Question 2

normal process ejaculation

Answer 2

sperm created in testes

sperm travels through vas deferens

seminal vesicles and prostaye creae semen carried along with sperm to urethra

sperm and semen travel through urethra ejaculated out of penis

Question 3

what three types of cells are within the seminiforous tubules

Answer 3

Germ cells- produce sperm
Sertoli/sustentacular cells- support sperm producing cell, produce inhibin
Interstitial(Leydig) cells- produce testosterone

Question 4

function of testes

Answer 4

sperm and testosterone production

Question 5

sprem production

Answer 5

Millions of viable sperm per day
Average time from production to ejaculation 64 days

Question 6

testosterone production

Answer 6

Male secondary sexual characters
Controls spermatogenesis

Question 7

endocrine control of testicular function

Answer 7

Reproductive hormones

GnRH- Gonadotrophin releasing hormone, produced from hypothalamus

Gonadotrophins- FSH and LH, released from anterior pituitary

Testosterone- released from testicles

Question 8

pituitary hormone effects

Answer 8

LH and FSH stimlate spermatogenesis and testosterone secretion by the testes

Question 9

testes hormone effects

Answer 9

testosterone and inhibin inhibit the secretion of gnrh bythe hypothalamus and lh and fsh by the pituitary

Question 10

what is spermatogenesis

Answer 10

Sperm production from the primordial germ cells.

Question 11

how long is the average cycle of spermatogenesis

Answer 11

Average cycle of spermatogenesis is 64 days in which the germ cells pass through different developmental stages

Question 12

what are two distinct phases of spermatogenesis

Answer 12

Spermatocytogenesis
Spermiogenesis

Question 13

Spermatocytogenesis

Answer 13

Clonal expansion and maturation through mitotic and meiotic process

Question 14

Spermiogenesis

Answer 14

Differentiation into mature sperm cells

Question 15

when does spermatogenesis start

Answer 15

Process starts at puberty and continues lifelong

Question 16

spermatocytogenesis phases

Answer 16

A - mitosis 16 days
B
1- meiosis 1 24 days
2 - meiosis 2 some hours

[clonal expansion/maturation]

Question 17

spermiogenesis phases

Answer 17

differentiation
spermatid –> sperm

Question 18

mitotic division of spermatogenesis

Answer 18

Spermatogonium to primary spermatocyte-duplication, diploid chromosomes number(46)

Question 19

first meiotic division

Answer 19

primary spermatocyte to secondary spermatocyte, two cells with haploid chromosome number(23)

Question 20

second meiotic division

Answer 20

secondary spermatocyte to spermatid, two cells with haploid chromosome number(23)

Question 21

spermiogenesis chromosomal division

Answer 21

maturation of spermatids into functional sperm cells

Question 22

what factors affect spermatogenesis

Answer 22

lifestyle
medical
combination

= infertility

Question 23

medical factors that affect spermatogenesis

Answer 23

Pretesticular-Problem with the hormonal control

Testicular- Problem at the site of production

Question 24

pretesticular medical factors

Answer 24

Functional- excessive weight loss, gain
Intracranial tumours, cysts, bleed
Prolactinoma
Medications- opiates, external testosterone, steroids(body building)
Genetic- Kallmann’s syndrome

Question 25

testicular medical factors

Answer 25

Surgery- orchidectomy, orchidopexy
STI
Mumps orchitis
Testicular trauma or torsion
Radiotherapy or chemotherapy
Genetic- Klinefelter’s (46 XXY), Y-chromosome microdeletion

Question 26

lifestyle factors

Answer 26

sperm from factor - reversible
mother - irreversible

SMOKING

Question 27

Steps to reduce the impact of factors affecting fertility

Answer 27

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

Question 28

how would you take a history

A 30 years old man attends the fertility clinic with his 28 year old partner. The couple are trying to conceive for 18 months without any success. Initial investigations organised by the GP are reviewed. Female results are normal. Semen analysis report for the man shows very low sperm count of 2million/ml (oligospermia) and reduced sperm motility.

[normal 15 million or more]

Answer 28

Past fertility- puberty, personal or family history of genetic problems, previous fertility treatment
Androgen deficiency symptoms- Infrequent shaving, unable to grow a beard, low libido, erection/ejaculation difficulty
Medical problems current or past- systemic disease, malignancy, prolactinoma
Genitourinary history- STI, mumps orchitis, testicular trauma/ torsion, undescended testicle, recurrent UTI
Past surgery- inguinal hernia repair, orchidepexy, orchidectomy
Medications- high dose steroid, testosterone replacement,
Supplements- body building products(exogenous steroids)
Occupation
Lifestyle- sedentary, food habits, smoking, obesity, alcohol, recreational drug use

Question 29

what are pretesticular clues

Past fertility- puberty, personal or family history of genetic problems, previous fertility treatment
Androgen deficiency symptoms- Infrequent shaving, unable to grow a beard, low libido, erection/ejaculation difficulty
Medical problems current or past- systemic disease, malignancy, prolactinoma
Genitourinary history- STI, mumps orchitis, testicular trauma/ torsion, undescended testicle, recurrent UTI
Past surgery- inguinal hernia repair, orchidepexy, orchidectomy
Medications- high dose steroid, testosterone replacement,
Supplements- body building products(exogenous steroids)
Occupation
Lifestyle- sedentary, food habits, smoking, obesity, alcohol, recreational drug use

Answer 29

Systemic illness, local malignancy
Chemoradiotherapy, prolactinoma, Kallman’s(GnRH deficiency, genetic),
Steroid/testosterone/medication use
Extreme exercise, weight gain or loss(functional hypothalamic)

Question 30

what are testicular clues

Answer 30

STI
Testes trauma or torsion,
Surgery- orchidopexy, orchidectomy, inguinal hernia repair
Varicocoele
Genetic(Klinefelter, cystic fibrosis, Kartangener’s syndrome)

Question 31

what are lifestyle clues

Answer 31

Heat affecting testicles
Smoking
High BMI
Excessive alcohol
Recreational drug use
Occupation- exposure to
chemicals/ heavy metal/radiation

Question 32

what examinations/investigations should be done on this man

Answer 32

BMI
Genital examination- external genitalia, testicular size, palpation of vas deferens, inguinal hernia, varicocoele

USS testis
Hormonal profile- FSH, LH, Testosterone, Prolactin
Genetic test- Karyotype, Y-chromosome microdeletion

Question 33

diagnosis of this man

Answer 33

Oligospermia
Hormonal

Lifestyle

No cause
(Idiopathic)

Genetic