Git + Liver, Pancreas & Spleen

8/8/2019 Git + Liver, Pancreas & Spleen

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Git + liver,

pancreas and

spleen

Special thanks to:

Nur Afiqah

Ainaa Nadia

Najwa Aiman

Nur Atiqah

Noise noise noise.

However I forgot to tell you that we have a general organization of the

muscular layer in the GI tract. We have two layers, one circular and one

longitudinal. But we have sections, and in the stomach we have third layer

which is oblique layer.

So in esophagus we have two layers, in stomach we have three layers, insmall intestine we have two layers, the same as the esophagus.

In the large intestine now we have another exception where instead ofhaving extra layer, no, the longitudinal layer is actually abbreviated with

three bands. We call them teniae coli. This band, on either side we have

another two. So the longitudinal layer, muscular layer in the large

intestine is not complete. It is limited to three bands, we call them teniae

coli.


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So lets start and to mention the part of the large intestine, which youmay know from your biology.

That ileocecal valve, which guide the passage of substances between the

ileum and the cecum. So the first part of the large intestine, we call it

the cecum. Its a blind-ended pouch, which lies below the ileocecal valve.It terminates in another point valve, we call it the appendix.

Well talk about appendix and the Mc Burneys point, which is a differentpoint to the location of the appendix. This teniae coli, Ive mentioned that

it has three bands. They all come together to make the muscular wall ofthe appendix. Alright?

The second part is the ascending colon. It ends at the right colic flexure.

This bend in the large intestine, we call it a flexure.

Noise noise noise.Things related to the large intestine, we call it colic. Its on the right

side, so its right colic flexure or we call it hepatic flexure, because it is

posterior to the liver. Then we have a transverse colon, it terminates at

the left colic flexure or we call it splenic flexure.

We start with the descending colon and the small ending with the rectum,

which is actually in the pelvic cavity.

We have differences between the large intestine and the small intestine.

As Ive mentioned, instead of having a complete longitudinal mu scularlayer, it is only limited into three bands, we call them teniae coli. You

notice that we have fatty deposits, or fatty tags, on the large intestine,

we call them appendices epiploicae (they are not found in small intestine ).

In the small intestine, we have a smoot h surface. Here the surface is

sacculated. This sacculation or each segment here, we call it haustra. And

the movement of things in the large intestine, we call it haustration. Ok?

Larger caliber, if we compare a film small intestine and a film large

intestine, of course you can see the large intestine will h ave largerdiameter or larger caliber. Also we have except for the duodenum,which

is relatively fixed,the rest of the small intestine is mobile, unlike thelarge intestine which is fixed. Especially the ascending and the descending

colons are fixed, so limited mobility.

These are the main characteristics that differentiate the two types of

intestines, the large and small intestine.


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Now we will shift and talk about the accessory organ of the GI tract.They are not part of the tract, they are accessory to it, namely liver,

pancreas and spleen.

Lets start with the liver.

It is the largest INTERNAL organ, and I said internal because if youconsider the skin to be an organ, then skin is the largest organ in the

body. So to avoid any controversy, we say it int ernal organ. It is thelargest, located on the right side. It has metabolic function, regarding

the metabolism of carbohydrates and protein. It has access ory digestivefunction, by producing the bile salts, which got secreted and emptied into

the duodenum plus blood filtration. When the body absorbs nutrientsfrom the small intestine, the blood now is loaded with the nutrients plus

whatever else that enter the GI tract. Bacteria, or maybe foreign

objects.

Were talking about molecular (). So these go to the liver for

detoxification and filtration. We have two surfaces for the liver. Onesmooth, the other is flat, and irregular. The convex, superior anterior

surface, or the diaphragmatic surface, it is shaped this way because itwill fit under the dome of the diaphragm. The inferior aspect of the

dome, is concave. So we need a convex surface to fit under the structure.

The visceral surface, which lies in contact with other viscera, like the

stomach, esophagus for example, is flat and irregular. I think irregular isthe right term for that.

So as Ive mentioned, superior anteriorly, the liver is bounded bydiaphragm. Its not in an int imate contact with the diaphragm. There is

space, we call it the subphrenic space. And the liver is suspended to thediaphragm by a ligament we call it falciform ligament. So if youre


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dissecting the abdominal organs out, you need to cut certain ligament t obe able to take the liver out. One of them is the falciform ligament.

Superiorly, we have an area of the liver that is not covered with

peritoneum, we call it the bare area. Bare means naked.The bare area of

the liver. Why? Because you notice the falcifo rm ligament does notcontinue all the way. It splits to form the left triangular ligament, leaving

a bare area of the liver. And this is one of the areas in the liver that is

not covered with the peritoneum. We have another two areas, we will

learn about in a moment.

This is just a sagittal view, to show you the location of the liver under the

dome of the diaphragm. You notice that , there is a space here, subphrenic

space, and Ive mentioned in the two lectures ago, the liver is also

connected through the lesser omentum or the hepatic duodenum ligamentto the duodenum. It is also connected, as Ive just said to the

anterior abdominal wall and the diaphragm by the falciform ligament.

One thing maybe I forget to tell you about. In the introduction weintroduce the idea of bursa right?

Bursa is a sac, a serous sac that is made to reduce friction. You remember

that when we talk about bursa in the knee joint? The lesser sac of the

peritoneum sometimes we call it the omental bursa, because it reduces

friction due to the mobility of the stomach. So if you hear the omentalbursa in the exam, I mean the lesser sac. Dont tell me you ve never heardabout it.

This is a superior view of the liver, it explains what I meant by the splits

of the falciform ligament. This is the falciform ligament, you notice it


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splits leaving a bare area here. The same thing happen with the coronaryligament, it splits leaving a bare area, uncover ed with peritoneum.

So together the bare area of the liver, located on the superior surface, it

is one of the areas that is not covered by peritoneum, we still have

another two.This is the visceral surface of the liver, and this is not the anatomic

position. Because if the liver is in anatomic position I cant see all ofthese. This should be the infero-posterior surface. So part of the

surface, I should not be able to see in anatomic position. It is justpositioned this way, so that we can study different structures. You see

its flat, irregular due to having impressi on for organs. Whenever organslies in close proximity one to another, it leaves an impression.

You remember the impression in the lung? For the inferior vena cava for

example, and the aortic arch. Here we have impressions. Gastricimpressions is not clear here, and usually we can see an impression for the

esophagus. In the right side we have impression for the kidn ey and the

right colic flexure. These are the targets for the practical exam 2. And

the fossa, it is covered with peritoneum, except in two places, the porta

hepatis (hilum of the liver), which is where the portal triad enters or

leaves the liver. Remember that when we say portal triad, were talking

about hepatic vein, hepatic artery and the hepatic duct.(in the slides,it iswritten hepatic artery,portal vein,and bile duct.Anyway i think its the

same.)

Remember, portal triad talk about hepatic vein, hepatic artery and

hepatic duct. These are portal triad. So, at the portal hepatis the v isceral

surface is not covered with peritoneum also if we removed the gall


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bladder, this is the gall bladder, if we removed it, the surface of the liver

underneath, it is not covered with peritoneum. So, these are three places

in the liver where diaphragm is covered with peritoneum, two in the

visceral surface and one area in the diaphragmatic surface. I just told you

about portal hepatis which is the hilum of the liver and its components.

Let's talk about lobes of the liver. What do I mean by lobes? It's part of

the border near the liver that separated by fissures or by ligaments. So,

I have an anatomical boundary that subdivide the liver into lobes. So, we

have four. Right and left lobe, plus the caudate and quadrate lobes. Now

this is anatomical subdivisions. What about the physiological? Only have

two, right and left. Quadrate and caudate, even though they are closer to

the right, actually they belong to the left lobe. So, the arterial supply and

the ducts that collect the bile actually is the same, for the left lobe,

quadrate and caudate. Did you get the idea how physiology is different

from anatomy sometimes? We have a main division or main line heart

dividing the liver into right and left which is the falciform ligament. Ok?

So, even if I don't know the anatomy and I have the liver, I will see they

have two parts, right and left. If we look at the visceral surface, we will

see another landmarks and boundaries that define extra lobe. You see

here we have an extension of falciform ligament, and here the gall

bladder, isolating parts of the right lobe and it has quadrangular in shape

we call it quadrate lobe of the liver. The same thing on th e top, the

ligamentum venosum that I will define it to you in the moment, the hilum

of the liver and the inferior vena cava they also isolate part of the rightlobe which we call it caudate lobe. So, this is anatomy. We look at the

shape, we saw that we can actually subdivides the liver into different

areas depending on having landmarks t hat we find in those subdivisions.

Now, physiology they stated what the liver do.


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For example, the duct that collects bile, we don't have separate duct for

the quadrate, caudate and the left. They all drain into the same duct.

Same with the arterial supply. This is why we say by physiologically we

have left and right. What about the caudate and quadrate? They belong

to the left by physiology. I just told you about the quadrate lobe, the

caudate lobe and their boundaries, one thing to tell you is about

ligamentum venosum. I told you that the ligamentum of teres is actually

the reminants of the umbilical vein that carries the blood from the

placenta to the foetus and where it gonna pours? in the hepatic vein. Does

the liver in the foetus matured enough to accommodate all the blood that

comes? No.

So, the body of the foetus will develop a mechanism, so that the blood will

bypass the liver and go to the inferior vena cava. So, not all the blood

that comes from the placenta will go through the liver. Some of it will

bypass the liver and this is done by the ligamentum venosum of course

the blood vessels, now the reminants, we call as ligamentum venosum.

(A student asking a question to the doctor)

Doctor : Yup, does the liver able to take all these nutrients and do the

metabolic functions it is supposed to do ? No.

Same idea in the lungs for example, for the foetus. The blood is pumped.

The oxygenated blood is pumped to the lungs for oxygenation, right? Not

all the blood of the foetus will go to the lungs. We have a bypassmechanism because the lung is not matured enough to do oxygenation for

all the blood, we call it ductus arteriosus. It is a blood vessel that ..in

the foetus, connects the pulmonary trunk to the ascending aorta or arch

of aorta, I can't remember exactly. It is another bypass mechanism. So,

the whole point I told u about lungs is about bypass mechanism, it is


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something you have seen before. Anyway, these boundaries are the reason

why we said we have quadrate, caudate lobe, right and left.

Let's talk about the ligaments of the liver and I'm g onna repeat thisagain, I told you, were not talking about fibrous dense as the rest of the

ligaments in the body. Were talking about duplication of peritoneal layers.

We have the falciform ligament which attaches the liver to the anterior

abdominal wall and the diaphragm inferiorly. This falciform ligament

encloses or houses the ligamentum teres, superiorly this falciform

ligament will split to coronary and left triangular ligament. And this spli t

is the reason why we have a bare area of the liver.

This falciform ligament is split and goes superiorly to left triangular

ligament and coronary ligament. This is a superior view. If you notice in

the right side we have the coronary ligament. The coronary ligament meet

together to form the right triangular ligament. And this right triangular

ligament will connect the liver to what structure? The diaphragm, again.

And in the left side we have left triangular ligament which also connect

the liver to the diaphragm. So, we have several connections of the liver

and this is what suspend the liver in its place in the right hypochondriac

region.


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Inferior ligament, we talk about t he ligamentum teres or we call it the

round ligament of the liver, reminant of the umbilical vein, ligamentum

venosum which I already defined it to you. And this picture here actually

explains the location of these vessels.

This is the vein from umbilicus that empties the blood in the left side of

hepatic portal vein. The blood should go to the liver for filtration. But, we

have a bypass mechanism that takes most of the blood and preventing it

from entering into the liver and empty it immediately into the inferior

vena cava. The reminants of this structure becomes ligament s of the

liver, ligamentum venosum and ligament of teres.

(A student asking a question to the doctor)

Doctor : What vein are you talking about? Umbilical vein?

(The student said something)


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Doctor : Now, forget the left lung. This is the venous system that we

discuss. ok? We will talk about it later. We see how the blood is collected

from the GI tract and it will go to hepatic portal vein. Hepatic portal vein

will have right and left side, going to the liver. After filtration, the blood

will be collected and go to the inferior vena cava to be returned to the

heart. In the foetus, one tributary of the left hepatic portal vein is called

the umbilical vein. It takes blood from the placenta to the liver of the

foetus. Are you clear so far? Now, because the liver is not mature enough

in the foetus, not all the blood will go to the liver. We need to take some

blood directly without filtration to the inferior vena cava. How do we do

that? We have a vein connecting the left side of the hepatic portal vein

before it enters the liver to the inferior vena cava immediately. And this

will disappear when the foetus is delivered and they become ligaments in

our body. They are not needed anymore and were not surrounded by

placenta anymore and we have mature enough .

This is just a review for you, now lets talk about blood supply to the

liver. Blood comes to the liver for two reasons. first li ke all other organs

in the body it needs to be oxygenated. so this is done through the hepatic

artery, which is a branch of the celiac trunk of abdominal aorta. so it

brings oxygenated blood and this marks 30% of the blood that enters theliver. 70% of the blood that enter the liver is actually for filtration. it

comes through hepatic portal vein. The blood comes through the hepatic

portal vein which collect the blood from the GI tract and this blood is

loaded with nutrients and sometimes maybe toxins or bacteria or

pathogens that needs to be filtrated. Hepatic veins are now veins that will

collect the blood again from the liver and empty it into the inferior vena

cava. They open immediately into the inferior vena cava.

Another major vessel in the liver is the bile duct. It carries bile salts

from the liver to the GI tract and we have a duct system for that. The

product is produced in the liver and it is stored and concentrated in the

gall bladder, which is a pear shape structure that lies underneath the

liver.


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So,

on c c nd

ogetherto

orm commonhepatic duct.

he

ile

illgotothegall

ladder

to e

toredthereanduntilthemomentisright, ill eexcretedto

cystic duct, thatmerge ithin cystic ductand commonhepatic duct e

callitthe ileduct.

hestory doesnotstophere, the ileductsometimes ill

ointhe

pancreatic ductattheampullaof ater. s esaid, the common ileduct

illmergeinpancreatic ducttoempty intheduodenum, hichisthe

secondpart.theampullathatisformedy thetwoducts, the

ileduct

andthepancreatic duct we callittheampullaof ater. nditsgoingto

empty throughduodenalpapilla, themajorduodenum.

heleftandrighthepatic ducts, commonhepatic ducttogetherwiththe

cystic ductwillform common ileductwhichpasses ehindthefirstpart

oftheduodenum.ndthen, the

ileductwillmergewiththepancreatic

ductatthe mpullaof Vater. hisswellingherewe calltheampulla.

Nowwewillshifttothepancreas. Pancreasisanotheraccessory organof

the! "

tract."tselongatedinshape, triangularin crosssection.

"thas

othendocrineandexocrinefunction. # ndocrinemeansithassecretions

thatareemptiedimmediately inthe loodwhichwe callthemthe " sletof

$angerhansandithasanexocrinefunctionswhicharesecretionandare

Ampulla of Vater


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emptied in another system which is here, the GI tract or the duodenum.

Mainly, the secretion for the exocrine parts are hydrolytic enzymes which

aids the digestion in the GI tract.

The endocrine mainly were talking about insulin and the glucagon which

are responsible for carbohydrate metabolism. The pancreas is a

retroperitoneal organ except in the tail area. The tail area will be house

where the mesentry of the spleen. (Im gonna sho w you a picture in a

montme). So we have four parts of the pancreas, the head, neck, body and

the tail. The head actually is housed within the duodenum. The duodenum

is c-shape, it looks like letter C. so if we have stru cture fitting there it

will be disc-shape .so that is the head of pancreas. The neck, always in

anatomy the neck is a constriction in the organ we talk about. So its a

constriction between the head and the body.

The duodenum is c-shaped. So the structure which is the head of

pancreas will be disc-shape. Then we have a constriction which is the

neck, the body and ending with the tail. One special thing about the tail,

its intraperitoneal. Unlike the rest of the pancreas, where it is covered

by the peritoneum because it lies in intimate contact with the splenichilum.


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How is the pancreas supply the blood ? Its through splenic artery plus

the superior and inferior pancreaticoduodenal arteries . we will describe

the blood vessels for the abdomen in detail and the venous sy stem in the

next two lectures. And we will see the splenic artery is a branch of the

celiac trunk, the superior pancreaticoduodenal artery is the branch of

the superior mesenteric artery , the inferior pancreaticoduodenal artery

is a branch of the inferior mesenteric artery (a nd the venous region

drainage drain expile the corresponding vein). % eins that have the same

name, which will empty in the portal system, not the systemic circulation.

Now we will finish the lecture by talking about the spleen which is

intraperitoneal structure, it is the largest single mass of lymphoid tissue

in our body. Lymphoid tissues are everywhere in our body in manylocations but this is the largest mass of lymphoid tissue located in the

left hypochondriac region. Its attached to the stomach by th e

gastrosplenic ligament. gastro means stomach. splenic, and attached to

the left kidney by the lenorenal ligament sometimes we will call it

splenorenal the name used in the text book is lenorenal ligament.

And these ligaments, if you notice that lenorenal ligament is an extension

of the peritoneal covering of the spleen. it covers the blood vessel that

are reverting or going inside the spleen plus the tail of the pancreas. So

the lenorenal ligament has structure within it, a splenic artery, splenic

vein and the tail of the pancreas.

What about the gastrosplenic ligament? The superior view we can see

that the blood vessel which is the short gastric artery and left gastric

gastro-epiploic artery. They are housed within the gastrosplenic ligament.

As we said in the first lecture, peritoneal structure, whether they are

ligament, mesentry etc, they are important for carrying the blood vessel

to different abdominal organs. Blood supply to the spleen by the splenic

artery which is the largest branch of the celia c trunk. It has tortius(?)

back way until it reaches the spleen. It splits into six branches.


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Thispictureisinaccurate(?)ithas(inthree)(?)itshould & esix & ranches.

'ndthe

&looddrainageisthroughthesplenic

(eintotheinferior

mesenteric ( ein.

*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. ' ) 0 N..

1 Y JJ

Git + Liver, Pancreas & Spleen

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