W10: Andrology

Question 1

sperm prod

Answer 1

hormonally driven by hypo & ant pit
hypo secreted GnRH - acts on ant pit to stim it to release FSH & LH
FSH & LH release into bloodstream & act on testes to encourage spermatogenesis w/in seminiferous tubules (action of FSH) & testosterone prod by neighbouring Leydig cells (action of LH) btwn the seminiferous tubules

Question 2

how many sperm can be prod/day?

Answer 2

120mil

Question 3

how long does spermatogenesis take?

Answer 3

64 days

Question 4

development of sperm

Answer 4

Diploid sperm cells divide into haploid spermatids
W/in the seminiferous tubule, germ cells are arranged in a highly ordered seq from outside to inside.
Lining the tubules, there are SCs that begin the process of sperm prod.
Even tho there are high numbers of sperm prod there are quality control checkpoints throughout the process to ensure the biological & genetic integrity of ejaculated sperm.

Question 5

infertility =

Answer 5

being unable to conceive 12m or more

Question 6

causes of infertility

Answer 6

Unexplained 25%, Ovulatory disorders 25%, Tubal Damage 20%, Male Factor Infertility 30%, Uterine or peritoneal disorders 10%.

Question 7

sperm morphology: head, neck & tail

Answer 7

head: nucleus & acrosome containing enzymes rqrd for penetration of egg for fertilisation
neck: maintains connective btwn sperm head & tail & consists of connecting piece & proximal centriole
tail: made up of axial filament & powered by midpiece which contains axoneme (defects in this assoc w/ infertility)

Question 8

sperm morphology: abnormal

Answer 8

Abnormal sperm can reduce fertility. Abnormal sperm can have misshapen heads, large or small heads or even an extra head

Tails can be bent, coiled, stumpy or not attached to the correct location

Incr testicular temp, toxic chemicals, infection & genetic traits can incr % of abnormal sperm

Question 9

what % of normal sperm is sufficient for fertility?

Answer 9

4%

Question 10

normal sperm

Answer 10

oval-shaped head, an intact midpiece & an uncoiled single tail. Correct number of chromosomes
are able to swim well & in a straight line.

Question 11

macrocephaly

Answer 11

giant head, often carry extra chromosomes may be caused by homozygous mutation of the aurora kinase C gene. Abnormality may be genetic

Question 12

tapered head sperm

Answer 12

“cigar-shaped” often contain abnormal chromatin or packaging of the DNA. Abnormal number of chromosomes (aneuploidy). high temp locations such may exacerbate this

Question 13

coiled-tail sperm

Answer 13

have been exposed to either incorrect seminal fluid conditions or the presence of bacteria. These sperm cannot swim, as their tails are damaged. Linked to heavy smoking

Question 14

appearance & consistency of sample

Answer 14

Normal semen: grey, liquifies in 30 mins & has a distinct odour.
Abnormal appearance would incl; brown or red in colour, failing to liquify after 60 mins, contains a mucus or jelly & having a strong odour.
sample is either normal or viscous. Viscous is if there is a thread of 2 cm long when a small sample of semen is pipetted & pulled away.

Question 15

vol & pH

Answer 15

pH: lower reference limit is 7.2. Lower pH can indicate a blockage of both seminal vesicles & a high pH can indicate infection.

vol: lower reference limit for semen vol is 1.5 ml (1.4–1.7ml).

Question 16

determining motility

Answer 16

Number of progressive sperm = most significant predictor of fertilisation and pregnancy.
A min of 200 sperm on 2 slides are counted & divided into the following categories;
Progressive: sperm moving is a forward direction
Non progressive: sperm twitching or moving in a small circle.
Immotile: sperm are not moving
If progressive motility <32% or the total progressive + non-progressive motility is <40% this counts as low motility.
If the count is low the sample may be repeated or the couple are referred to a fertility clinic.

Question 17

a low sperm count is classified as total sperm no.:

Answer 17

15 mil/ml

Question 18

what happens if there are probs w/ the sperm?

Answer 18

assisted reproductive technologies
intauterine insemination
IVF
intra cytoplasmic sperm injection
donor sperm