What Makes A Normal Sperm

Question 1

what 3 components are human sperm made up of

Answer 1

• head
• midpiece
• tail

Question 2

describe the head of the sperm with detail

Answer 2

• contains nucleus (genetic material)
• contains centrioles (inherited to zygote post-fertilisation)
• contains acrosome (contains enzymes to penetrate cumulus cells and zona pellucida)

Question 3

describe the midpiece of the sperm with detail

Answer 3

contains sperm-specific mitochondria - produce energy for movement via oxidative phosphorylation

Question 4

describe tail aka flagellum of sperm with detail

Answer 4

• contains axoneme - core structure
• axoneme functions as motors for motility through its 9+2 structure
• tail can generate energy thru glycolysis (breakdown glucose for energy)

Question 5

what sperm characteristics are measured during a standard semen analysis

Answer 5

• sperm numbers (count / concentration)
• sperm motility (progressive, non-progressive, immotile)
• sperm morphology (head, mid-piece, tail)

Question 6

what is the most widely used assessment of male fertility

Answer 6

semen analysis

Question 7

what does sperm numbers reflect

Answer 7

• numbers of sperm produced by testes
• storage ability of sperm in post-testicular duct system (transport sperm from the testes to the outside of the body)
• efficacy of smooth muscle contractions in epididymis to actively transport sperm into ejaculate

Question 8

count vs conc of sperm numbers

Answer 8

• count: total amount of sperm present in the ejaculate
• concentration: total numbers of sperm in 1ml of the ejaculate

Question 9

3 key factors that influence sperm numbers

Answer 9

• size of testicles
• endocrine status
• medications, supplements, non-prescribe medications

Question 10

describe relevance of sperm motility to fertility

Answer 10

• the amount of sperm moving forward is directly related to pregnancy rates

Question 11

explain sperm motility assessment

Answer 11

proportion of sperm that have
- progressive motility (straight forward movement)
in total against
- non-progressive motility (tails moving but going nowhere or in circles)
- immotile (no tail movement)

Question 12

if a sperm is immotile does it necessarily mean they are dead

Answer 12

no

Question 13

what is how sperm look (sperm morphology) a predictor of

Answer 13

• fertilisation potential

Question 14

what component/s of sperm is morphology evaluated on

Answer 14

• every component: head, mid-piece, tail

Question 15

how many components have to have correct morphological appearance to be classified as normal sperm

Answer 15

• all components (head, mid-piece, tail)

Question 16

what are 2 common things associated w poor sperm morphology

Answer 16

• defective spermatogenesis
• some epididymal pathologies

Question 17

what are 3 things that poor sperm morphology are associated with an increase in

Answer 17

increased:
- sperm DNA fragmentation (presence of breaks or damage to DNA strands within sperm)
- chromosomal alterations
- aneuploidy (incorrect DNA copy number)

Question 18

what is another category of interest that can be considered for sperm morphology & when is it an anomaly

Answer 18

• excess residual cytoplasm
• anomaly if more than 1/3 of normal sperm head size

Question 19

describe ideal typical normal appearance of sperm head

Answer 19

• smooth
• oval in shape
• well-defined acrosomal region - 40-70% of head area
• not too large
• length-to-width ratio so not too round or elongated
• acrosome should contain no large vacuoles, only two or less 2 small vacuoles in head
• max 2 small vacuoles should not occupy more than 1/5th of sperm head
• post acrosomal region should not contain vacuoles

Question 20

describe ideal typical normal appearance of sperm tail / flagellum

Answer 20

• uniform diameter along its length
• be thinner than midpiece
• about 10x head length
• may be looped back on itself as long as there no sharp angulation - indicate broken flagellum
• not bent
• no terminal droplet (residual cytoplasm)

Question 21

describe ideal typical normal appearance of sperm mid-piece

Answer 21

• slender, regular
• about same length as sperm head
• should come out in centre of sperm head - alignment
• not too thick or too thin
• not sharply bent
• no asymmetrical insertion into head
• no angled insertion into head
• not non-inserted (can see top of mid-piece)

Question 22

are the parameters (sperm count, sperm motility, sperm morphology) a direct measure of male fertility potential

Answer 22

no

Question 23

what % of all infertility diagnoses are idiopathic (unknown cause)

Answer 23

15%

Question 24

can men with infertility return a normal semen analysis

Answer 24

yes