Lecture 18: Male Reproductive Organs Flashcards
What are testes?
paired oval glands found in the Scrotum
Where are testes forced?
formed in abdomen in fetus and in humans, the testes move to the scrotum from the pelvis during the last month of pregnancy or shortly after birth - low temp so sperm can survive
What is Cryptorchidism?
When testes don’t descend
Cryotirchid individuals are Infertile and are at risk of Testicular cancer
What is the progression of sperm?
- Sperm are produced in the seminiferous tubules then move –>
- into the Rete Testis, (an area where all seminiferous tubules join -single duct and collecting system –> after tube)–>
- into the epididymis single tube –>
- Vas deferens –>
- which then joins to the ejaculatory duct
What ability to sperm acquire when they’re in the epididymis?
Sperm acquire the ability to be Motile and Fertilise while in the Epididymis
- when first in epididymis, sperm ARENT capable of swimming, more can they fertilise an egg (cannot use IVF)
- aquiring these abilities takes 10-14 days (motility + fertilisation)
What second activity occurs in the epididymis?
Epididymiss also reabsorbs liquid from around sperm, make it More Concentrated
-dont swim, Pushed in fluid, Want in a smaller voume
What is the reason for sperm to move into the Vas deferens?
Sperm move from the epidiyis –> vas deferens, where sperm may be stored for several months –> ejaculation - leak out
What is the shape and size of the Vas deferens?
Vas Deferens =about a 45cm long convoluted tube
Runs form the epididymis, to p and around the bladder, then back down to join the ejaculatory duct (behind bladder)– lower pelvis
What is the shape and size of the urethra?
Urethra is about 20cm long
rune from the bladder, through the prostate –> to the end of the penis
What is the shape and size of the ampulla?
Widening of the Vas Deferens, near the ejaculating duct
is the Large site of Sperm Storage
What are the two main male accessaory glands?
Seminal Vesicle
Prostate
What are seminal vesicles?
accessory glands
are the secretory lgnads (NOT storage areas) that secrete a mucoid (sticky) substance
What are the four things the mucoid (sticky) substance secreted by seminal vesicles contain?
Alkaline
Fructose
Prostaglandins
Clotting Proteins
What is a feature of the Alkaline in the Mucoid (sticky) fluid that is secreted by the seminal vesicles?
Alkaline
High pH to neutralise acidity of the female reproductive tract (pH 4.5)
-need to buffer environment sperm are in?
What does the Alkaline feature of the Mucoid (sticky) fluid that is secreted by the seminal vesicles add?
buffer environment sperm will be in
What is the pH of the female reproductive tract?
pH = 4.5
Acidic
What does the Fructose in the Mucoid (sticky) fluid that is secreted by the seminal vesicles add?
energy source for sperm
What does the Prostaglandins in the Mucoid (sticky) fluid that is secreted by the seminal vesicles add?
lipid hormones
which may include smooth muscle contractions in the female reproductive tract to help sperm move up
What does the Clotting Proteins in the Mucoid (sticky) fluid that is secreted by the seminal vesicles add?
similar to blood clotting proteins
when semen ejaculates, component of semen mix together and clot –> forms a Coagulant, sticks sperm to vagina, won’t be flushed out by mass flow.
With prostate fluid, forms coagulant which retains sperm in the female tract
Where do the contents of the seminal vesicle empty into?
The contents of seminal vesicles empty into ejaculatory duct directly after sperm are ejected by Vas Deferens (last fluid secretion), Washed sperm down it , joins urthra at prostate
What is the Prostate?
A doughnut shaped organ about the size of a golfball
What is the relationship between the urethra and the prostate?
The urethra passes through the prostate, which secretes prostatic fluid into the urethra Ahead of sperm during ejaculation
- urethra passed through a hole in the prostate
- so you have 1. prostatic fluid 2. sperm 3. seminal vesicle fluid
What is the order of fluid in ejaculate?
- Prostatic Fluid
- Sperm
- Seminal Vesicle Fluid
Which fluid does the prostate secrete?
Prostatic fluid
What is the pH of prostatic fluid?
pH = 6.5 (slightly acidic)
Acts as a buffer and neutralised by alkaline seminal vesicle fluid to some extent in semen
What does the Buffering capability/feature of Prostatic fluid that is secreted by the prostate prostate add?
Seminal vesicle fluid(alkaline) and prostatic fluid (acidic)
raises pH of vagina where the sperm needs to swim
What are the 4x main features of Prostatic fluid?
Slightly Acidic (pH 6.5)
Citrate
Milky colour
Prostate Specific Antigen (PSA)
What does the Citrate feature of Prostatic fluid that is secreted by the prostate prostate add?
Citrate for ATP
acts as an energy source as can feed into the Kreb Cycle
What does the Milky colour feature of Prostatic fluid that is secreted by the prostate prostate add?
Milky colour of prostatic fluid as it has Calcium and Phosphate
-NOT very soluble
What does the PSA Prostate Specific Antigen feature of Prostatic fluid that is secreted by the prostate prostate add?
PSA is an enzyme which breaks down Coagulum and other Proteases, Releasing Sperm so that they Can Swim
Without PSA sperm will be Trapped, so it releases sperm so they can swim
What happens if there is No Prostate Specific Antigen (SPA) in Prostatic Fluid (which is secreted by the prostate)?
Sperm are trapped
by coagulum and other proteases
What causes Sperm to be trapped?
semenCoagulum and other Proteases
Lack of Prostate Specific Antigen
What is Ejaculated Fluid?
Semen
What is Semen/Ejaculate composed of?
Sperm (10%)
Seminal Vesicle Fluid (60%)
Prostatic Fluid (30%)
Other Secretions (small amount)
What proportion of semen/ejaculated is take up by sperm?
10%
What proportion of semen/ejaculated is take up by Seminal Vesicle Fluid?
60%
What proportion of semen/ejaculated is take up by Prostatic Fluid?
30%
What proportion of semen/ejaculated is take up by Other Secretions?
small amount
What is the pH of Semen?
pH 7.5
What is the pH of Ejaculate?
pH 7.5
What is the need reason for the pH of semen/ejaculated being 7.5?
Buffers against vagina’s acidic pH
Psotatic and seminal fluids neutralising each other
What is the volume of semen between species?
Semen varies greatly in volume between species
volume of 2-5 ml, vs bear is 500mls
What is the Content of semen between species?
Semen varies greatly in contact between species
normal human’s ejaculate is 20 million sperm/ml
What is the average amount of sperm per mL for an average human male?
20 million sperm mL-1
How many main structures compose the Penis?
Penis has 3x main structures
What are the 3x main structures of the penis?
- Corpora cavernosa (2x)
- Corpus spongiosum
- Penile Urethra
What is the Function of the Corpora Cavernosa (2x) as one of the three main structures in the penis?
Corpora Cavernosa (2x) is the main erectile tissue
What is the function of the Corpus Spongiosum as one of the three main structures in the penis?
Corpus Spongiosum surrounds the penile urethra and prevent occlusion during ejection
What is the function os the Penile Urethra as one of the three main structures in the penis?
Penile Urethra conducts the semen (and urine)
When does erection occur?
Erection occurs following sexual stimulation
What happens during ejection?
No bones in penis - hyhydraclic forces
Release of NO (endothelial cells of BV) and Prostaglandin E1 (all cells but RBS) cases smooth muscle of the corpus cavernous to RELAX (easy for flow of blood)
Penis enlarges and expands outwards and inwards
The engorgement of the corpora Reduces Venous outflow, adding to the engorgement - surrounding veins closed down
Do penises have bones?
no
What structure DONT penises have?
bones
instead have hydraclic
What happens to the Corpus Cavernosa (main erectile tissue) during an erection?
Relaxes
What opens and closes in the penis?
Penile urethra CLOSES
but the Corpus spongiosum also expands (blood) allowing urethra to remain open though penis is engorged
What happens to blood flow in a penis during an erection?
Blood fills the cavernous spaces of the corpora cavernous (as this erectile tissue is relaxed)
- erect penis has 8x BV of a flaccid penis?
What is the BV ratio between an erect and flaccid penis?
Erect: Flaccid
8x more BV : 1
What is another name for Viagra?
sildenafil citrate for impotency (ED) –> decrease NO
What does Viagra do?
Relaxation of the smooth muscle in the Corpora Cavernosa requires Guanosine Monophosphate (cGMP)
-2nd messenger reduces intracelular calcium
-increase cGMP, increase Relaxation
The enzyme Phosphodiesterase breaks down GMP
Viagra inhibits phosphodiesterase (types isotoon) leading to increased intercellular GMP, relaxation of the arteries and blood structures supplying the corpora cavern and erection
What is Benign prostatic hyperplasia?
excess growth of the prostate
Is Benign prostatic hyperplasia life threatening?
no the excess growth of the prostate is not life threatening as the Banign is NOT a tumour
What occurs in Benign prostatic hyperplasia?
occludes and decreases diameter of urthra - prostate grows and as it reaches capsule, pressure goes inwards (shutting down prostatic urethra)
What does Benign prostatic hyperplasia result in?
Causes difficulty voiding bladder
causes weakening of bladder
can cause urinary infections, bladder and kidney problems (pyelonephritis)
What is another name for kidney problems?
pyelonephritis
What is the incidence of men requiring treatment in the USA for Benign prostatic hyperplasia?
aged 85 = 90% (most common)
What is the most common age bracket for benign prostatic hyperplasia?
above 85 (90%)
What is the treatment for Benign prostatic hyperplasia?
Testosterone –> xx 5 alpha reductase xx –> dihydrotestosterone (2x potent) - reduces overgrowth
selective 5a-reductase inhibitions -finasteride - dutasteride
removing androgenis stimulus -taking away potency
-stops prostate enlarging or shrinking it
surgery
others
What is the rate of prostate cancer?
2nd most common cause of cancer deaths in men (after lung(1st))
–> 29% cancer cases in men in prostate cancer
What is the percentage of men who have cancer having prostate cancer?
29%
What intervention can occur for prostate cancer?
Detection of prostate cancer is increasingly dramatically
-due to PSA screenign (inacurate –>false +ve) look for protein in blood, if Elevated (early detection) –> at risk of prostate cancer. however deaths increasingly less dramatically due to
What is some information for autopsy cancer?
30% of mean above >50yrs have prostate cancer at autopsy
9.5% have been diagnoses with prostate cancer. 66% didn’t know about the cancer
What are the 5 treatments for prostate cancer?
- Watchful waiting
- Androgen depeletion (5 areductase inhibitos (finasteride). Castration - physical of chemical to stop growth of testis. Inhibitors of androgen synthesis)
- Inhibition of testosterone action - block androgen receptor
- Surgery - prostatectomy: due to operation:
- 1% die, 20-80% erectile dysfunction, 4-21% urinary incontinence - others
What percent of people die from Prostatectomy?
As a result of the operation:
1% = death
20-80% = erectile dysfunction
4-21% = urinary incontinence
Where do the testes begin?
in the abdominal cavity
What is the descent of the testes?
abdominal cavity –> scrotum
What happens if testes remain in the abdominal cavity?
infertile
condition called cryptorchidism
How many tubules are there in each testes?
80
highly convoluted to create large SA
What are areas of sperm collection?
off sertoli cells –> Seminfierous testes –> rete testis –> epididymis –> vans deferens –> up urethra
Are sperm fully functional when they fall off sertoli cels?
no
they have the potential to be (morphologically)
but aren’t actually
need to go through one more phase of maturation (in epididymis) -gain ability to be motile - gain ability to fertilise an egg
+ concentrated 100x (sucks liquid from around sperm, so can deliver max # sperm in smallest ejaculated -conserve energy and highest change of fertile)
How long does it take for a sperm to travel from head of epididyimis –> tail of epididymis
10-14 days
What abilities do the sperm gain as they pass through the epididymis?
ability to swim (motile)
ability to be able to fertilise an egg
What would you find if you were byopsying an epididymis?
end of vas deferens sperm are swimming
When do sperm swim?
NOT in the testicles
What is the primary site of sperm storage in humans?
Vas deferen
how long is the vas deferens?
45 cm allows huge amount of sperm to be stored Ampulla = widening= huge area for sperm storage Single tubule Doesn't take the direct route
Do seminal vesicles store sperm?
NO
they are secretory glands
produce part of the fluid of semen
What is the last connecting duct in the reproductive tract?
urethra
Where does the urethra begin?
at the bladder
for conducting urine
Is the rete testis inside or outside the testes?
inside
How do and how long is movement in the vas deferens?
via muscular contractions
slow movement –> towards ampulla
What is close to the ejaculatory duct?
Ampulla - the main site of sperm storage
allows sperm to join ejaculate
Where does sperm get their energy from?
mostly outside the sperm itself
fructose from seminal vesicle secreation
What are lipid signalling molecules in seminal vesicles?
Prostaglandins
causes smooth muscle contractions of the female reproductive tract
AFTER semen is deposited
-helps with sperm migration
Where do clotting proteins from?
seminal vesicle fluid
sticks fluid into female reproductive tracts
What is the size of a prostate?
golf ball
What shape is the prostate?
American Doughnut shaped
hole in middle = for urethra
Are the contents of the semen mixed in the reproductive tract?
NO
they’re only mixed upon order of squirting out during ejaculation
(order pushed though ejaculatory duct) (pf –>sperm–> svf)
what happens if the seminal contents were mixed in the reproductive tract?
problems with coagullan
Which secretions have a high pH?
Clear Alkaline seminal vesicle fluid
What colour is prostatic fluid?
gives semen its characteristic colour
Calcium and phosphate
How long does it take PSA to break down coagullum?
10 min
What is the largest component of ejaculate?
Seminal Vescile fluid = 60%
What is the third laargest component (out of four) of ejaculate?
Semen = 10%
What composes 30% of ejaculate?
Prostatic fluid
-first to enter
Why is the seminal Vesicle Fluid the last to be ejaculated?
makes up the greatest proportion (60%) of ejaculate
to push semen just ahead of it, through the female reproductive tract
Where does semen mix?
first in the reproductive tract
What things buffer each other in the reproductive tract?
Seminal vesicle fluid = high pH = alkaline
Prostatic fluid = acidic= low pH
What is the ejaculate volume of a boar male?
500mL
What doesn’t the human penis contain?
Penis DOESNT contain any SOLID structures
What are the two structures mainly responsible for erection?
corpora cavernosa x2
What passes through the centres of the penis and centre of the corpus spongiosum?
urethra
What does the corpus cavernosa do during an erection?
EXPAND out towards fascure and inwards (expands in all directions)
Where does the ejaculate have to pass through?
penile urethra
What replaces the function of the absence of solid structures in the penis?
Hydraulic forces
What does ejaculated run into initially and why?
a collapsed corpora cavernosa
due to hydraulic forces going in all directions (inwards and outwards)
saved by corpus spongeosum (blown up by blood flow- like a tyre)
What happens during ejaculation?
corpus cavernosa fills with blood
vaso relaxants causing penis to become erect
What does the filling of blood results in during ejaculation?
8x more blood than in a flaccid
Stretches, to cause the walls o`f the balloon to become more pliable (relaxation)
NO and prostaglandin
What instigates the relaxation during erection?
NO
Prsotaglandins
allows more blood to flow into the cavities of the corpora cavernosa and corpus spongiosum
Where is the corpus spongiosum located?
completes surrounds the penile urethra (which is directly in the middle)
Where are corpora cavernous located?
2x
so either side of the corpus spongiosum
What is the chemical name for viagra?
sildenafil citrate
What is viagra used for?
erectile disfunction
-helps achieve erection
What does erection of the corpora cavernosa in particular require?
relaxation of the smooth muscle in the corpora cavernous
cGMP
(Guanosine Monophosophate)
What is Guanosine Monophosphate?
cGMP in corpora cavernosa
= second messenger, controls regulates/REDUCES intracellular calcium levels
What is GMP?
= cGMP
Guanosine Monophosphate in Corpora cavernose
What is the enzyme which breaks down corpus cavernosa Guanosine Monophosphate?
Phosphodiesterase
particularily type 5 isoform
What does viagra do?
Inhibits the breakdown of type 5 enzyme of Phosphodiesterase
What occurs due to the presence of viagra?
Increase in intracellular cGMP (less broken down by type 5 isoform of phosphodiesterase due to its INHIBITION)
Increased relaxation - arteries and blood structures
=Overall increased supply
What is the role of cGMP on blood vessels?
vasodilator
What is other uses of Viagra?
dilator of smooth muscle tissues in pregnancy
What is the similarity between Benign Prostatic Hyperplasia and Prostate cancer?
“prostatic”
both effect the prostate gland
What does Benign Prostatic Hyperplasia suggest?
Benign = unharmful
Prostatic = prostate
Hyperplasia =over growth
donut shaped prostate enlarging (over growth) but isn’t harmful
-since donut shaped it can only go outwards so far- if continues to enlarge, it needs to grow Inwards, which will eventually occlude urine at top of prostatic urethra
What sort of problems does Benign Prostatic Hyperplasia result in?
unable for urine to get from blassed
weakenign of bladder
ASCENDING urinary tract infection
–> pilinary frightes infection if really bad
How prevalent is Benign Prostatic Hyperplasia?
really prevalent
almost all men over 85
5th of population have BPH which requires treatment by age of 60
What is a common treatment for BHP?
trans urethral resection fo prostate (corrective surgery)
What is a chemical treatment for BPH?
finasteride
duterasteride
IHIBITS 5aR
-leaves with testosterone which is 50% less potent
causes prostate to stop growing and shrink
What produces dihydrotestosterone?
5 alpha reductase
converts from testosterone
Which androgen is more prevalent ad what effect does this have?
testosterone va 5a dihydrotestosterone
5 alpha dihydrotestosterone -more prevalent and 50% more potent = stimulates overgrowth
What does chemical treatment for BPH result in?
stoop growth of prostate (esp inwards)
and hopefully shrinkage
Is BPH life threatening?
Benign prostatic hyperplasia
Not normally life threatening
How do you detect Prostate cancer?
look for levels of PSA
this increases the detection dramatically
What is prostatic cancer complicated by?
Autopsy cancer
What happens with autopsy cancer?
50+yrs, 50% have prostatic cancer
only a 10th knew they had cancer, not bothering them enough to go see doctor (don’t have enough symptoms)
What is prostatic cancer like in many people?
In many cases prostatic cancer is a really benign disease
-men die from another case without even knowing they had the disease (don’t have enough symptoms to know)
What are the treatments for Prostate cancer?
watchful waiting
Androgen depletion
Inhibition of testosterone action
Prostatectomy surgery
What is the benefit of PSA screening?
out of 1000 men, 136 return positive, 95 false positive, therefore only 41 actually with prostate cancer
Hight FALSE Pos
What is the benefits of Prostatectomy?
Out of 100 men (%)
1 die from procedural/anaesthetic complicate
20-80 have erectile dysfunction as a result
4 - 21 have urinary incontenance as a result
Should we screen for prostate cancer?
Only really occurs in older men, and benign in most men who die earlier without knowing
vs complications of prostatectomy surgery
Once you have screened about it what do you have to do?
No not quite appropriate
