Pudendal nerve and arteries (anatomy)


today's word is pudendal how many

purposes does one man need hum yeah it

we're still in a heat wave here in Wales

hence the shorts I was even examining

some students today and I put shirt on

uh some trousers as soon as I finish

these are so Hollenback too short

we don't do air conditioning in the UK

because it's never hot pudendal right

what my own about well over in exam

season we always seem to be either

examining or teaching and students again

got some terminology a little bit wrong

and it's to do with the word pudendal

we've got three pudendal arteries on

each side we only really talk about to

really talk about one anyway and we've

got a pudendal nerve they're all called

pudendal but there are other names for

the arteries students get confused too

the whole aim of this session is to

clear up the names of the pudendal

arteries and the pudendal nerve all



so do you know all about the pudendal

arteries and the pudendal nerve do you

know all their different names if you do

and you're confident and when you're in

the exam you're gonna remember the thing

right for some reason some of you are

mixing this up so this is to nail that

home right I will do the arteries first

and we'll do the nerve we'll do their

clinical stuff right all that joy again

aha there's bear we have the aorta the

aortic fits into left and right common

iliac arteries and the common iliac

arteries split into internal and

external iliac arteries it's called the

internal iliac artery because it goes

internally into the pelvis and supplies

blood to all the structures in here and

also send some branches off posteriorly

to the gluteal region and stuff hey

throwback to last week and then the

external iliac artery stays external

because it goes to the lower limb right

now the internal iliac artery goes into

the pelvis and becomes the anterior

division of the internal iliac artery

and that's the one that goes through the

pelvis and gives off a whole bunch of

different arteries different branches to

all the viscera in the pelvis it's

different if it's a male pelvis to a

female pelvis because we've got

different structures in there and it's

quite variable between people as well

but that internal iliac artery

it's anterior division eventually ends

as the internal pudendal artery that

would have pudendal me well Pretender

refers to the external genitalia that

sort of area I'm told that it comes from

the Latin word pudendal meaning shameful

and I'm sure it wasn't the grease the

names of the acts I don't think the

Greeks gave too much

they definitely cared about that too

much so I'm sure it was named by a later

anatomist you know where external

genitalia were considered shameful what

a funny way to think about you Anatomy

anyway so the internal pudendal artery

then is going to supply blood to your

shameful bits to the external genitalia

there's a bit more to it than that so we

have a little bit of a problem the blood

vessels going into the pelvis but the

blood has got to get to the perineum out

here so how is it going to get air the

pelvis and get under here one thing we

have to worry about is we've got the

pelvic floor in there levator Ani done a

video on that and we want to put as few

holes in the levator Ani in the pelvic

floor as possible because the more holes

we put in it the weaker it gets we've

got to put some holes in it but let's

not put another one in so how is the

internal pudendal artery gonna get out

well we've got a handy hole here this is

the greater sciatic foramen guess what

goes through there you see there the

sciatic nerve

so the sciatic nerve goes out through

the greater sciatic foramen and so do a

bunch of other things so sensibly the

internal pudendal artery goes out

through the greater sciatic foramen but

then to get under here there's another

hole there's a greater sciatic foramen

there's another hole here if you've got

a Great Society forum and then you must

have a lesser sciatic foramen and that's

the lesser sciatic foramen so the the

internal potential artery loops around

this ligament actor the greater sciatic

foramen through the lesser sciatic

foramen in doing that it then gets

inferior to the pelvic force now it's 8

of the pelvis and it's in the perineum

and the the canal recover runs through a

canal there which gets called all Cox

canal all the pudendal canal

that's actually made by a bit of fashion

is that anyway

that's where that's where all courts

canal is if you wonder these ligaments

have got some very sensible names done a

video on that as well but that's how the

internal pudendal artery gets as the

internal pretend real pudendal artery

then is it's now under here so this is

the perineum and we've got deep Arab in

your pouch superficial peroneal page

we've got the ischial fossa done all

this is well in other videos but that's

how the internal put it so that the

internal pudendal artery get into the

perineum and now it's supplying blood to

the structures in this region which is

going to include the erectile tissues of

the external genitalia which need quite

a bit of blood particularly in the male

so it's it's a fair-sized artery okay so

that's the internal

pudendal artery now if there is an

internal pudendal artery there must be

an external pudendal artery right so the

external iliac artery passes deep to the

inguinal ligament and then we change its

name it runs into the thigh it becomes

femoral so it's the femoral artery now

there are some branches down here so on

this model this is handy because we can

see the fashio we've got the fasciae

latae covering the lower limb and from

around this region here somewhere just

below the inguinal ligament the femoral

artery gives off superficial and deep

external pudendal arteries now if you if

you look in most anatomy textbooks if

you look really hard you might find some

mention of the external pudendal artery

unlikely you'll get a mention of both

the superficial present superficial

external pudendal artery is superficial

to the fascia the deep external pudendal

artery is deep to the fashio

that's all it is ignore superficial and

deep for the minute because oh this is

about terminology this is about the word


the external pretend the Lottery's then

they run from where they brought from

the femoral laughing they're running

towards the external genitalia we don't

seem to have any external genitalia to

use your imagination that's next time

we'll genitalia there and they stay you

know they they're not deep within the

pelvis they're already outside the

pelvis they're just running across here

they're gonna run like you know

superficial to the inguinal ligament

superficial to the wrangling ermine in

the female pelvis and [ __ ] thing and

they're gonna supply blood to very

superficial structures to the the labia

majors in the female to the skin of the

scrotum to the inferior abdominal skin

that sort of thing right so the external

pudendal arteries are branches of the

femoral arteries they're outside the

pelvis and the external pudendal artery

may well even and asteroids with the

internal pudendal artery because they're

in that same region right and that sort

of thing happens so far so good so we've

got internal pudendal artery is external

put in the arteries are nice and clear

right well we also have a PUD endl nerve

and it's that's it it's just the

pudendal nerve there's a left one

there's a right one but it's just the

pudendal nerve there's no internal

pudendal nerve there's no external

pudendal nerve it's just pudendal nerve

just like um you know if you're if

you're thinking about the blood supply

to the perineum don't tell me it's

supplied with blood by the pudendal

artery because it isn't it's supplied

with blood by the internal pudendal

artery you get in my frustration now so

the pudendal nerve is very important

because the pudendal nerve is the nerve

that supplies it carries sensory and it

carries sensory innervation from the

perineum it's taking the same route as

the internal pudendal artery which is

why students mark the names up for these

things I think so in here we've got the

lumbosacral plexus the pudendal nerve is

formed from spinal roots at levels s2 s3

ns4 it is largely sensory and partly

motor and again yet actually so if the

sciatic nerve goes out through the

greater sciatic foramen the pudendal

nerve also goes out through the greater

sciatic foramen and we can see that here

there's the sciatic nerve here's the

piriformis muscle there is the pudendal

nerve next to the internal parental

artery next to the internal pudendal

vein terminology is very important in

anatomy that's kind of like why we name

everything is so that you can describe

things accurately to other people so

again the pendel knife goes out through

the greater sciatic foramen back in

through the lesser sciatic foramen and

then it's into the the perineal region

and it's going to carry sensory

innervation from this whole perineal

region around here the major sensory

nerve from the external genitalia which

is why it's so important it's also

involved in motor innervation to the

external urethral sphincter and the

external anal sphincter so it's

important for a fecal continence and

urinary continence which we've also

talked about somewhere else as well it

also innovates the muscles involved in

erection of these erectile tissues

televideo on that as well so you can

imagine that if this nerve is damaged

there will also be problems with

erectile function right and this is

levator Ani here this is the inferior

surface it also innovates bits of

levator a non although they have their

own muscles in there as well so it's

also involved in pelvic floor function

so the pudendal nerve is very very

important and it does get damaged we'll

talk about that in a moment but to do

these jobs the pudendal nerve splits

into three to get to those points it

becomes the dorsal nerve of the penis or

the clitoris it becomes the inferior

rectal nerve and the peroneal nerve so

surgeons working in these areas are very

clear on where the pudendal nerve runs

and the internal pudendal artery in the

external pudendal artery and some

clinical tidbits then because of that

that tight route that the pudendal nerve

it means that it is some more

susceptible to being compressed and we

call it entrapment of the pudendal nerve

particularly as it runs through the

pudendal canal there and if it gives if

it gets squashed if we get entrapment

here then the patient will likely have

problems with changes in sensation you

know maybe numbness maybe tingling maybe

burning sensations maybe pain and maybe

changes in function to the to the efika

continence in and urinary continence as

those fingers are also affected the

pudendal nerve is prone to damage during

childbirth because during childbirth

when the baby is pushed through the

birth canal the soft tissues of the

perineum get gets stretched and

distended and affected so the pudendal

nerve is somewhat vulnerable to injury

there and also talking of surgeons I

think in in in gynecological operations

there's something like a 1% or 1/2

percent incidence of nerve injury

as a as a as a risk factor in that

surgery not just from the pudendal nerve

but from all of the nerves in this

region the pudendal nerve is one of

those they need to be honest most of

those the majority of those those

injuries kind of fix themselves go away

with with therapy and that's all thing

very few of them are long lasting but it

is really really important to be careful

of the pudendal nerve and be aware of it

runs because of its important functions

all right cyclists actually cyclists

tend to compress their pudendal nerve

when I'm doing a lot of cycling taking

in the winter right when the cyclists it

we're sitting on the saddle here and

we're the saddle is pretty much

compressing where the pudendal nerve is

going to run under here and when you

compress your pudendal nerve or branches

of it as a cyclist well it goes a bit

numb everything goes numb you think

always gone so cold it's gone numb but

it's not cold you've actually compress

the nerve and you've lost all sensation

feeling from your external genitalia and

there been various saddle modifications

to this light little holes in the middle

to young squash things and and that's

all thing it's a temporary thing you

know it comes on slowly usually change

it your see in position have a bit of a

wiggle and and slightly you get a

sensation back again but yeah cyclists

and the pudendal nerve it's a bit of an

issue well I think oh that's it

clear as crystal right

you know the internal pudendal artery

you know the external put into arteries

you know where they come from you know

why they're different and you know that

the pudendal nerve is just called the

pudendal nerve is left with a right one

but it's just called the pudendal nerve

which you have a an internal pudendal

artery got it nailed

next time go be super clear in the exam

right good right see you next week