Post Abd Wall Complete)

8/8/2019 Post Abd Wall Complete)

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Posterior abdominal wall &

kidney

Special thanks to:

Nur Asyikin

Nur Liyana

Farah Hanisah

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Weve talked about abdominal musculature and. Just 1 note,the pictures I presented to you during the last lecture, they

do not have small intestine in them because we cant see much

of the structure of the small intestine there, but that does

not mean that the arteries and venous drainage do not come

and go to the small intestine.

Todays lecture is about posterior abdominal wall and the

kidney. When we talk about the viscera lining abdomen, I toldyou, we have intraperitoneal structures that are covered with

visceral peritoneum and we have retro peritoneal organs that

are not covered with peritoneum. They are covered partially by

a layer of visceral peritoneum. The kidneys (not sure) are retro

peritoneal structures. Are they covered with visceral

peritoneum? No.

Actually they are sometimes attached anteriorly with parietalperitoneum so, the peritoneum folds around abdominal viscera,


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have a visceral layer and a parietal layer that goes around the

wall.

The kidneys are situated between the parietal peritoneum and

posterior abdominal wall. So, they are consideredretroperitoneal. We have important structures within the

posterior abdominal wall, you call it the thoracolumbar fascia.

If you remember, we talk about antero-lateral abdominal wall,

we mentioned that several muscles are actually, they take

origin from thoracolumbar fascia.

So, thoracolumbar fascia starts in the posterior abdominal

wall, it has 3 layers ; anterior, middle and posterior. In thispicture, we can see the posterior layer, this is the middle, and

this is the anterior. They merge together to give origin to the

muscles of the antero-lateral wall. Am I talking fast? (YES)

And the layers of thoracolumbar fascia, they house the

muscles of posterior abdominal wall within them. If you notice,

between the posterior and the middle layers, we have erector

spinae muscle.

Erector spinae muscle is actually a group of muscles that run

along the vertebral column, they are situated between the


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spinous process and tranverse processes of different

vertebrae.

Between the anterior layer of thoracolumbar fascia and

middle layer, the quaratus lumborum muscle is situated. Andanteriorly, this thoracolumbar fascia becomes continuous with

the deep muscle fascia lining antero-lateral abdominal wall and

transversalis fascia.

Now, well talk about muscles that make the posterior

abdominal wall, mainly, 3 muscles. They are psoas major, this

muscle (Dr speaks in Arabic, x fhm)

It is removed here, so that, we can see the quadratus

lumborum which is square in shape and the iliacus which lies or

takes origin from the iliac fossa or the hip bone. Well go over

them one by one.

Lets start with psoas major muscle. It takes origin from the

thoracic vertebrae no 12 and goes down until lumbar vertebrae

no 5. Which part of the thoracic vertebrae? Its the tranverseprocess.


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It then goes inferolaterally and pass through the femoral ring

which is the opening of inguinal ligament to be inserted into the

femur. The femur is the bone of the thigh, if you read the

table in your introduction about bones and processes of thebones, you will notice that the femur has special process called

trochanter. Its a pouch within the head of the femur that

serves as attachment for different muscles and psoas major is

one of them. We have major trochanter, .trochanter and

lesser trochanter.

The innervation of this muscle (psoas major) comes from the

lumbar plexus. Its when spinal nerves merge together to give

origin to different nerves and large mixing and matching of

different nerve fibres to have neat organization within

hemolytic nerve (x sure about this) and the action, it flexes

the thigh against the trunk or if you fix your thigh, it will flex

the trunk. So, it decreases the angle between the thigh and

the trunk regardless of which part is moved (the thigh or the

trunk)

If you notice, this small muscle here, this is what we call psoas

minor muscle. Its not found in all of us, its found only 40% .

its located anterior to psoas major, and another note about

psoas major, its the only muscle where nervous plexus actually

pass through that muscle. Usually, muscles, they just receive

their nerve supplies. If a nerve is fated to supply a muscle, it

will be a stand muscle and send fibrous to different muscle

sense (Im not sure about this sentence, please refer to thebook or other sources). Here, we have a special case where a

nervous plexus actually pass through a muscle, which is the

lumbar plexus which passes through the psoas major muscle.

The 2nd muscle of the posterior abdominal wall is the iliacus. As

the name implies, it originates from the flow of the iliac fossa.

Iliac fossa is the depression within the hip bone. Which part of

the hip bone? The iliac


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This wing shape, part of the hip bone, we call it the ilium. Here,

we have a depression, we call it iliac fossa and it gives origin to

the iliacus muscle. Where does that muscle go?

It descends down to join the psoas major into 1 bundle, we call

them iliopsoas muscle and it is inserted in the lesser

trochanter of femur. It has the same action as psoas major

and also supplied by lumbar plexus. Are we cool so far?

(Coooool)

The 3rd muscle is the quadratus lumborum. (refer to the

diaqram above). As the name implies, square shape (quadratus),

it extends from the 12th rib, actually, this is the insertion. The

origin is from the iliac crest and iliolumbar ligament and the

transverse processes of lower lumbar vertebrae.

So, this is the origin of the muscle and its inserted in the 12th

rib. What is the action??Do you remember when we talked

about the thorax,we said the action of the muscle. Inspiration

and expiration depend on whether we fix the 1st rib or the 12th

rib.So, in inspiration,this muscle will fix the 12th rib. So that,

we will increase the diameter of the thoracic cage. For

expiration, it will depress the 12th rib. So,it has a function that

is related to respiration.

When we talked about the anterior abdominal wall, we


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mentioned the nerves. In the posterior abdominal wall, we have

certain nerves that supply the skin over that region to form

and send muscular branches to supply muscles. The first nerve

is the subcostal nerve which actually we can compare it to theintercostal nerves.We can call it intercostal bcoz there is no

rib behind it..We also have lumbar nerves from L1 to L5..From

L1 to L4,we call them lumbar plexus. As Ive just said, it passes

through the psoas major muscle..From branches L4 to sacral

4,we call them a network of a pelvis. Another instructor will

teach you about the pelvis will talk about it, we call them

lumbosacral plexus and just a note, if you notice the branches

from L4 and L5, we call a large bundle, we call it lumbosacraltrunk. So,lumbar sacrum trunk is just L4 to L5 and branches

to the lumbar sacral plexus.. And this is a good picture for

practical exam.

I forgot to mention, L1 actually give origin 2 nerves..which

are iliohypogastric & ilioinguinal nerves..Ilioinguinal is actually

the nerve responsible for you feeling your bands around your

head..If injury occurs, during surgery for example to the

ilioinguinal nerves, the person will be constantly checking his

back because he can feel them around his waist.

Now, we will talk specifically about the branches of lumbarplexus.We just mentioned the iliohypogastric and ilioinguinal


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nerves..The genitofemoral nerve, as the name implies, it has

genital branch and femoral branch. The genital branch called

the genitalia its a mixed sensory and motor. The femoral

branch will supply the skin over the thigh but not all of it, partof it and mainly sensory plus we have femoral nerve and

obturator nerve. You should know the origin, the fibers that

make each of these nerves..

Now,we will talk about the blood supply to the posterior

abdominal wall and we will go back to the abdominal aorta.In

the previous lectures,we talked about visceral branches or

abdominal aorta thats to say the branches that go to the

visceral by splenic artery, ciliac truck and inferior mesenteric.

These go to supply the organ.. Now, we will talk about the

arteries that supply the muscle and structure in the wall. We

have first,we call the aorta passes through the aortic

hiatus..When it is still in the thorax,we have the subcostal

artery(so it is a branch of thoracic aorta).After the aorta

passes through the aortic hiatus, so in the abdominal aorta.we

have 5 lumbar branches.The first pair will supply thediaphragm.We call them anterior splenic artery.It goes up to

supply the bottom of diaphragm.Now, the remaining 4 pairs,we

just name them first,second,third and forth lumbar

branches..ok??? The veins will correspond to the

arteries..So,we have subcostal vein that will drain into azygous

system and lumbar veins which correspond to lumbar

artery.These will drain into inferior vena cava.


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Now.we will talk about the kidney..(you have to refer drs

slides)..itis just the surface antomy ,if you draw a line and at

the level of L1,this line will pass through the pylorus of

stomach,so that we will call this line transpyloric line. Two

kidney are not at the same level..the right one lies below bcozthe right lobe of the liver is large.The 2 kidneys stay between

vertebrae level of T12 to L3.The outer margin for lateral

border is convex,the medial margin is concave and the renal

substance or renal parenchyma (we call it the tissue) has a

space inside it (we call it renal sinus) and this renal sinus, the

renal pelvis and the blood vessels enter and mimic the drain

system for urine.

The renal substance is actually in the outer. Here,at the

hilum,there is a space and we call it as renal sinus which houses

the ureter and renal pelvis plus major& minor calyces..So,at the

hilum of kidney,we have an entering artery and exiting vein plus

ureter that carry urine to the urinary bladder. what is the

arrangement???From anterior to posterior,we have vein,artery

and ureter.. And usually the artery, we have branches. So, its

not uncommon to have vein,artery, ureter and another branchof artery.


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(pointing at the picture)

This cross-section we call it longitudinal cross section of the

kidney. Now,we talk about different layers of the kidney. The

first layer, which just a thin layer here surrounds the

parenchyma of kidney is a tough fibrous layer we called it the

renal capsule (for protection). After the capsule, we have a

layer of fat we called it perirenal or perinephric (fromneutron) fat. After this layer of fat, we have renal fascia.

Superficial to this fascia is the pararenal fat. The

retroperitoneal spaces are filled with fat. The pararenal fat

are just external to renal fascia and continue with posterior

fat layer


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pyramid and its medulla. So its not the colour that allow you to

know the structure.

Question: Doctor, which is darker in colour? Medulla or

cortex? (comparison in the picture)

Answer: Medulla is lighter in colour. Im talking about cadaver.

If you grab the kidney, and cut it. Youll see that the lighter

area corresponds to the medulla.

(A student asked a question but I cant hear it.Here goes the

answer.)

Doctor: The medulla? The blood will go around it. Ill talk aboutthe blood supply to become the apparent blood vessel, will take

blood from the glomerulus and then it will pass out. mostly

what we see in renal pyramid which is medulla is the duct that

bring the urine. Dot dot dot*cant hear. Glomerulus are located

in the cortex. But the ascending and descending loop of henle,

were talking about cortical and medullary nephron, it will be

totally in the cortex or will be deep down into the medulla.

Youll learn this more in histology. So, you have outer layer in

cortex and inner layer which is medulla and we have

projections. The two layer project into each other. The cortex

for example send the projections between the medullary

pyramids. we called them renal columns. Same way, the

pyramids will send the projections to the cortex, we called

them medullary rays. How Im gonna be able to distinguish

between renal column and renal pyramid? The shape. This onething and second, the renal pyramid, its apex will open to minor

calyx because urine will be emptied here.


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So, lets talk about the relations of each kidney. Lets start

with the right kidney. What is located anterior to it? We have

the right colic flexure, we have the second part of duodenum

and here, it is removed but you should know that its there, the

right lobe of liver. What do we have in top? We have

suprarenal gland plus again you should know that the liver is ontop or superior to the kidney. What lies posterior? We just

mentioned, the muscles of the posterior abdominal wall: psoas

major and quadratus lumborum plus the diaphragm because it

makes append over the visceral. So sometimes it lies both, on

posterior and anterior.


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renal pelvis, the urine will descend to the ureter and

(Dr is interrupted by a student asking question but I dont

understand it)

Answer: ...this is minor. This is considered major because it

goes (empty) to the renal pelvis.

Now we talk about the arterial blood supply of the

kidney. I am not sure about the number. Maybe 20% to 25% of

the cardiac output, it will go to the kidney. Blood does not go to

the kidney just to supply nutrients and oxygen. Most of it

(blood) goes there for filtration.

For example ammonium products, urea, etc. These toxic

substances that needed to be filtered found in the blood. Sothe blood go there (to the kidney) for filtration [mainly] and of

course to supply the kidney like any other organs.

We start by renal artery that will split into segmental

arteries. By arteries that exist at the hilum of the kidney.

Then, they start filling more branches; we call them lobar

arteries. Each lobar arteries supply one renal pyramid. We call

it because, through the renal pyramid, ascending branches


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around renal pyramid, so they pass through the renal cortex.

So this is renal artery, segmental renal arteries, the lobar

branch; it will supply one pyramid and send branches; we call

them interlobar. And this interlobar will archaround the baseof the pyramid. We call it arcuate artery. This arcuate artery

will send the branches to the cortex. We call them interlobular

branches. This now will become continuous with what? With the

upper blood vessels that takes the blood to the glomerulus for

filtration.

Yes, glomerulus is the main structure of the nephron. Now the

blood will enter that region. Within the nephron, urine will be

formed and will drain from each renal pyramid, into the minor

calyx and so on until it reaches the urinary bladder.

Q : Dr, is the arteries around the pyramid the interlobar

artery?

A: No. Interlobar artery is within the renal column or at

the side of the renal pyramid. When they arch on top of

the renal pyramid, we call them arcuate arteries.

Q: How about around the cortex? Does arcuate arteries

form the branches?

A: Those are interlobular (forming branches)

Q: They are around the cortex?

A: They are within the cortex. Because the glomerulus is

located in the cortex.


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Now when kidney fails due to trauma or disease or congenital

anomaly, we need to replace the function of the kidney. So if

we have a right medical case, a renal transplant will be done.

Just to say we take a kidney from a donor and replace it in the

diseased person.

Where do we place that kidney? We need to protect thatkidney, so we put it in the iliac fossa. Right iliac fossa. How do

we connect the renal artery and vein? We connect them to the

iliac artery and iliac vein. You are unfortunate to not see a

cadaver. Ill try to find one, make sure you see it before the

end of the course. (3an jad????YEAYYY!!)Youll see how many

fats are there. Within, around the abdominal visceral etc.

So, the patient will receive immunosuppressive drug forthe rest of his life. Why? Because he has foreign object in his

body, and the immune system will destroy that object if it is

left unleashed. So we need to strain the immune system by

immunosuppressive drugs.

If we cant find the donor, the kidney for that patients

alternative solution is hemodialysis. In hemodialysis, the blood

will pass through a machine. The machine will havecompartments separated by semi permeable membrane. So


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basically, the toxic materials that we need to remove from the

blood, we will have them in lower concentration on the other

side of the membrane. So this toxic material will leave the

blood, and go to the machine. Thats the basis of hemodialysis.Or there are types of hemodialysis that can be done at home

actually. And that we call peritoneal dialysis. Instead of having

a blood to go to the machine, we will put the fluid that we use

to create different concentrations of gradients inside the

abdomen, and the peritoneal membrane will replace the

membrane that we use in the machine. So hemodialysis; and we

have something that we call peritoneal dialysis, in which the

peritoneum is used as the semi / distinctive permeable

membrane.

Final thing to talk about is the ureter; which is the

muscular tube that conducts the urine from the renal pelvis to

the urinary bladder. Around 25 cm, it has 3 areas for

constriction. So when we have stones, etc, the phalangeal (not

sure) calcifications within the kidney, usually they will be stuck

in these locations.

Just on exiting the renal pelvis (pelvis joins the ureter) we

have a constriction over the brim of the hip bone, there is a

constriction, and when the ureter pierces and goes inside the

urinary bladder we will have the third constriction; and it

induces the posterior aspects of the urinary bladder.

And it would go obliquely to increase the distance within themuscles in the bladder. Why? Because when the bladder will

contract during urination, we dont want urine to flow back. So

when the ureter passes obliquely in the wall, it will be

compressed by the muscular coat of the bladder. So it will act

as a valve (It is not a valve, just act like it).


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*No comment will be entertained*

SEKALUNG PENGHARGAAN BUAT SEMUA YG TERLIBAT

DLM PEMBUATAN LECTURE NOTE NI. MOGA ALLAH

MEMBALAS JASA KALIAN DENGAN GANJARAN YG

LEBIH BESAR DI AKHIRAT KELAK

INSYAALLAH, ALLAH YUSAHHIL UMURUNA

AMIN..

BY JJ

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