Unit 1 Exam Flashcards
8 Segments of the Liver
Know basic
The three hepatic veins are the longitudinal boundaries.
The transverse plane is defined by the right and left portal pedicles.
The caudate lobe (segment I) is situated posteriorly. Segment I includes the caudate lobe.
Couinauds’s system provides the anatomic basis for hepatic surgical resections. By using this system, the radiologist may be able to precisely isolate the location of a lesion for the surgical team. The description of the liver segments is based on the portal and hepatic venous segments.
8 Segments of the liver
The caudate lobe (segment I) is situated posteriorly.
Segments II and III include the left superior and inferior lateral segments.
Segments IVa and IVb include the medial segment of the left lobe. Segments V and VI are caudal to the transverse plane.
Segmebts VII and VIII are cephalad to the transverse plane.
Abdominal Aorta location
Begins approximately 25cm above Transpyloric line or at aortic hiatus in diaphragm
Left of midline
As it descends assumes a more midline path
Abdominal Muscles
Rectus Abdominus
External Obliqu
Internal Oblique
Transverse
Psoas Major
Quadratus Lumborum
Iliacus
Ant. Abdominal Wall Muscles read
Arrangement of these muscles provide support for abd. Viscera and prevents tearing of the muscles themselves
The muscles work posturally by contracting and may flex the spine (rectus abdominis, obliques working both sides at once) or twist the spine (individual obliques or opposite internal/external obliques working together).
Anteriolateral wall muscles know
The muscles of the anterior and lateral abdominal walls include the external oblique, internal oblique, transversus, rectus abdominis, and pyramidal is(*)
Aortic Bifurcation where does it occur
Occurs approximately L4 Right and Left Common iliac arteries
Further divides at L5 and sacrum, to internal and external branches
Aortic Branches read
Celiac Axis 1-2 cm long
Divides into hepatic
splenic, LGA
Hepatic Artery directed to right and enters liver thru the Porta Hepatis
Splenic Artery directed to the left, behind stomach and anterior border to part of pancreas, enters spleen thru the hilum
LGA, smallest often arises off splenic artery, directed to left to supply cardiac region of stomach, anastomose with RGA and branch of Hepatic Artery
Biliary Tree
Biliary Ducts originate in hepatocystes
- *function Regulates flow**
- *Transports to intestine**
Liver secretes 1-2 liters of bile per day
Right and left hepatic ducts exit the liver… (in region of porta hepatis)
Combine to form common hepatic Duct… (approx 4mm in diameter, then descends within edge of lesser omentum
Cystic duct joins CHD….
Common bile duct… (max. diameter of 6mm)
Body of the pancreas
Posterior surface rests on anterior surface of the SMA, SA, Lt Adrenal, Lt kidney and its vessels
Seperated from Stomach by the omental bursa
Branches and Bifurcations
From superior to inferior
Celiac axis
SMA
Renal arteries
R and L gonadal
Lumbar arteries*
IMA
Bifurcation
Median Sacral Artery
Branches of Aorta
Superior Mesenteric Artery
Arises just inferior to CA
L1
Branches and anatomizes with small intestine, supplies cecum, ascending colon and transverse
LRV between SMA and Aorta
CAUDATE LOBE OF LIVER read
Situated upon the posterior surface of right
lies opposite T11-12
Bounded anteriorly and caudad by the porta
bounded posterior by IVC
Bounded on left by Lt Sagittal Fossa
Common bile duct
First part lies in rt free edge of lesser Om.
Second part is located posterior to 1st part
of duodenum
Third part lies in a groove on posterior
surface of pancreas head
End then pierces 2nd part of duodenum
Joins pancreatic duct thru ammpula of
Vater, sphincter of Oddi
Drainage of Blood Adominally
Anterior Abdominal Wall Main Venous Drainage Branches of superficial epigastric and lateral thoracic veins
Posterior Abdominal Wall oLumbar Veins oAzygos veins
Gall bladder Normal Anatomy
Lies of undersurface of right lobe of Liver
Lies anterior to Right Kidney
Extends from MLF to anterior free margin of the liver
Lateral to MPV
Medial to liver dome
Superior to Hepatic Flexure of Colon
External Oblique Muscles
The opposite of the internal obliques, they course downward and inward, largest and strongest abdominal muscles. They are on the surface and begin at ribs 5 to 12 and connect to the linea semilunaris.
start superior and course medial
External Olbique
Outermost layer of lateral muscles
Orignate at ribs and extend downward/medially
Terminates in a broad aponeurosis
Aponeurosis inserts on
Linea alba
Iliac crest
Pubic tubercle
Four Fossae
Where is it exactly?
1.IVC FOSSA (Right Sagittal fossa)
- Portal Fossa
- Left Sagittal Fossa
4.Gallbladder Fossa
Fossae of the RUQ/LIVER
Four muscles make up the anterior 5 lateral wall:
Rectus abdominis
External oblique
Internal oblique
Transverse abdominis
Gallbladder function
Storage and concentration of Bile
Gallbladder Size
Location
Size 8-9 cm 2-4cm in diameter -walls less than 3mm • Shape- Pear shaped Oblong
Location RUQ
Under surface of Liver
Greater Omentum
Attached to greater curvature of stomach and hangs down like an apron in space between sm. intestine and abd. wall Folded back on itself and attached to inferior border of the colon
Greater Sac
Primary compartment of peritoneal cavity Extends across anterior abdomen and from diaphragm to pelvis
Head of the pancreas
Broad , flattened
Right extremity
Lies in C of duodenum
Small Uncinate process projects inferiorly and medially
Rests on IVC and LRV
SMV anterior to uncinate proces
How many Quadrants are they?
Name them?
Whats in each quadrant?
There are 4 quadrants
Right Upper Quadrant ,Left upper Quadrant
Right Lower Quadrant, Right Lower Quadrant
Right upper quadrant – liver, part of ascending colon and transverse colon, part of duodenum, right kidney.
Left upper quadrant – stomach, part of duodenum, transverse and descending colon, spleen, left kidney,
Right lower quadrant – cecum and appendix, part of ascending colon, small intestines, female gonad, part of bladder
Left lower quadrant – part of descending colon, sigmoid colon, small intestines, female gonad, part of bladder
How many regions are they?
Name the regions
Whats in each quadrant?
There are 9 Regions
- Right hypochondriac region
- Epigastric region
- Left hypochondriac region
- Right Lumbar region
- Umbilical region
- Left lumbar region
- Right Illiac region
- Hypogastric region
- Left Illiac Region
If liver resection is needed for removal of tumor what do we need to know?
it is important to know the tumor(s) location in relation to the hepatic vessels
Liver resections must follow the hepatic veins to preserve venous outflow and the portal veins and hepatic arteries to provide vascular inflow. Furthermore, bile ducts must be preserved to provide biliary outflow.
Illiacus muscle read
Large triangular sheet of muscle
Located in the iliac fossa on the medial side of wings the ilium
Located in false pelvis not abdomen
Close realtinship to Psoas inferior to Psoas major
Can be referred to as iliopsoas when assoc with psoas
Extends the length of the iliac fossa. The psoas muscle passes through the iliac fossa medial to the iliacus.
The psoas and iliacus muscles merge as they extend into the true pelvis. The iliopsoas muscle takes on a more anterior location caudally to lie along the lateral pelvic side wall.
Inferior Vena Cava
Originate anterior to L5 by joining of common Iliacs veins
Receives tributaries as it ascends
Goes posterior to Liver
Enters chest thru Caval hiatus (T8)
Inferior Vena Cava Fossa read
Short depression of posterior surface between caudate lobe and bare area of the liver.
Separated from the porta by the caudate lobe
Holds the IVC
Internal Oblique
Extends opposite to External
Upward and medially
Fibers runs perpendicular to external
Extends from the iliac crest to inferior borders of the ribs
Sandwiched in the middle between the external obliques and the transversus abdominis, the internal obliques begin from the side of the hip crest and the inguinal ligament, and connect with the linea semilunaris
Intraperitoneal Organ: Liver
The surface of the liver in enclosed by peritoneum except the “Bare Area”, which is the posterior surface that comes in contact with the Diaphragm. Bare area is bordered by Coronary Ligaments (peritoneal reflections)
Kidney a Retroperitoneal space
• Kidneys
Kidneys lie in the retroperitoneum in the paravertebral gutters of the posterior abdominal wall. Some refer to the as the lying in the flanks.
Retroperitoneal organs
Kidney Anatomy read
HILUM
Slit located medially in kidney
Right at level of L1
Left at the level of L1/L2
Structures pass to and from kidney thru this
Pelvis most anteriorly and renal vein posteriorly with the artery lying between. Lymph and nerves also enter at the hilum
Kidney Lies
They lie obliquely with the upper poles more medial/posterior than the lower poles.
Kidney parts
Two main portions PARENCHYMA- Outer portion SINUS- Inner Portion
KIDNEY SIZE
Size • Length- 9-12cm
Wide 5-6cm
A/P 3.5cm
Extend the length of approximately 3 and a half vertebrae.
Usually at level of T12-L4
Kidneys
The kidneys are essentially regulatory organs which maintain the volume and composition of body fluid by filtration of the blood and selective reabsorption or secretion of filtered solutes
Kidneys
The kidneys are essentially regulatory organs which maintain the volume and composition of body fluid by filtration of the blood and selective reabsorption or secretion of filtered solutes
know the bilirary metabolism
see lecture
LEFT LOBE Read
Contains medial and lateral segments
Medial segment often referred to as the quadrate lobe
Smaller and flatter than right
situated in epigastrium and Lt Hypochondria
Upper surface convex and molded onto diaphragm
Under surface presents the gastric impression and omental tuberosity
Left Sagittal Fossa know
sepates what?
Fossa of the RQU/LIVER
Separates right /left lobes
Holds the falciform ligament
Porta joins at rightangle and divides in 2 parts
Holds the falciform ligament
Falciform liagment telescopes into ligament of terres inferiorly
Recanilization of Umb vein would occur in this fossa
Lesser Omentunm
Slings the lesser curvature of stomach to the undersurface of the liver
Gastrosplenic omentum ligament connects stomach to spleen
Lesser Sac
Extensive peritoneal pouch located behind the lesser omentum and stomach
Extends upward to diaphragm and inferior between the layers of the greater omentum
Ligamentum teres
(LT, arrows) appears as a bright echogenic focus in the left lobe of the liver on a transverse image.
List the functions of the liver
- Formation of Bile
- Activity of Reticulo-Endothelial Tissues
- Metabolism of Carbs, Lipids, Proteins for preparation and excretion.
- Storage Depot
- Blood Reservoir
- Heat Production
- Detoxification
- Lymph Production
Name the liver lobes
Left lobe, Right lobe, Caudate lobe, Quadrate lobe
LOCATION OF Kidneys
Kidneys lie in the retroperitoneum in the paravertebral gutters of the posterior abdominal wall. Some refer to the as the lying in the flanks. • Retroperitoneal organs
Location of the liver
The liver occupies most of the Rt. Hypochondrium, the epigastrium, and extends into the left hypogastrium. May extend to the Left Mamillary line.
The Liver is an Intraperitoneal Organ
Main Lobar Fissure
Main lobar fissure (MLF) extends between the long axis neck of the gallbladder (GB) and the main portal vein (PV) on the longitudinal image. B, Falciform ligament extends from the umbilicus to the diaphragm in a longitudinal plane.
Mesentary
Two layered fold of peritoneum Attaches part of intestines to posterior abd wall and includes mesentery of small intesine, transvers mesocolon and sigmoid mesocolon
Mesenteric
SMA
SV and Body of pancreas are anterior to SMA
Inferior Mesenteric Arteries
Inferior to SMA
Arises off ventral surface (L3)
Curves to left to supply distal transverse colon and descending, sigmoid and rectur
Name the land marks
Lateral Margins (costal margins)
Midline (aligns with the spine)
Xyphoid Superior landmark of abd cavity
Umbilicus Seperates Abd/Pelvis
S-Pubis Inferior landmark
Name the planes and views
Anterior, posterior,superior, inferiror, Medial, lateral, proximal, distal.
Neck and Body
Posterior surface rests on anterior surface of the SMA, SA, Lt Adrenal, Lt kidney and its vessels Seperated from Stomach by the omental bursa
Nephron
Functional unit of the kidney
Consists of glomerulus, convuoluted tubules responsible for filtration of urine
Normal Anatomy of the liver
Weight and Length Which Rib
Right lobes exceeds the left by a 6:1 ratio
Weight: 1400 to 1600g
Length: us. 15-17 cm
Lower border at costal cartilage of 8-9 rib
Each Lobule is 1 X 2 mm
OMENTUM
Two-layered peritoneum that attaches the stomach to another viscus organ
Broken into Greater Omentum Lesser Omentum
Paired Visceral Branches
Suprarenal (L1)
Renal (L2)
Gonadal (inf L2)
Four pairs of Lumbar
Post/lateral surface L1-L4
Pancreas
Lies deep in the epigastrium
Retroperitoneal
Anterior to the prevertebral vessels
Tranverse Oblique Plane
Parenchymal cortex in the Kidney
Cortex- outer extensions referred to as the columns of Bertin
This separates the medulla into individual pyramids makes up one third of functional subunit (nephron
PARENCHYMA in the kidney
Parenchyma made up of an outer and inner component
Parietal and Visceral Layer
Parietal Portion that lines the abdominal wall Does not cover the organs Visceral Covers organs
Parts of Gall bladder
NECK- Lies most posterior ,Lies towards Porta
BODY Largest portion
FUNDUS, ies lateral, caudal and anterior to neck Often extends just inferior to liver edge
Peritoneal cavity?
Serous membrane Lines the abdominal cavity Covers the peritoneal organs Formed by a single layer of cells MESOTHELIUM
Divided into two layers Parietal Visceral
Potential space between the parietal and visceral layers..
Cavity that contains small amount of lubrication Serous fluid lubricates with serous fluid and helps organs move on one another without friction
Peritoneal Relations
Only covered with Peritoneum on it’s anterior surface
Extends from duodenum to splenic hilum
Divided into 3 parts
Porta Fossa
Short deep fissure extending transversely across under surface of left lobe
Separates quadrate lobe in front (anteriorly) from caudate behind
Transmits PV( portal vein), HA (hepatic artey), BD(Bile ducts) , nerves, Lymphatic
Portal Venous System
Blood from digestive system travels to liver thru Portal system of veins, prior to entering IVC to return to heart
Blood from SMV joined by splenic vein enter liver as MPV
IMV, usually empties into SV prior to Portal Confluence
Portal Venous System
?
Posterior Abdominal Wall Muscles
Psoas major muscle
Lateral to lumbar region of Vertebra
Fibers begin on Transverse processes, borders and lumbar intervertebral discs
Pass along the pelvic brim
Enter the thigh to insert at lesser trichinae of femur
Posterior View of Liver
Posterior view of the diaphragmatic surface of the liver. The caudate lobe is located on the posterosuperior surface of the right lobe, opposite the tenth and eleventh thoracic vertebrae
Potal Vein
Portal Vein Confluence Main Portal Vein Right Portal Vein Left Portal Vein Posterior to BD and HA Anterior to caudate lobe Surrounded by Connective tissue
Pre Vertebral Vessels
Arteries arising from aorta
Veins draining into IVC
Portal Venous System Combo Bring blood to Liver
PSOAS MAJOR MUSCLE
The psoas muscle extends from the mediastinum to the thigh
Major are more posterior than minor
Major are more superior than minor
Origins at the transverse processes and vertebral bodies of T12-L5 and insertions at the lesser trochanter of the femur.
Quadrate lobe read
Obsolete term for medial aspect of left lobe
situated on the under surface of left lobe
Boudned anteriorly by the anterior margin of liver/ posteriorly by ports; right by GB fosse, and on left by Lt sagittal fossa.
Oblong in shape
Quadratus Lumborum Muscle
This muscle originates from the iliolumbar ligament, the adjacent iliac crest, and the superior borders of the transverse process of L3 and L4 and inserts into the marg
Appears lateral and posterior to psoas muscle on transverse section
Rectus Abdominis
On contraction, its lateral margin forms a palpable curved surface, termed the linea semilunaris,
Starting from the linea alba and working out, we first come to the rectus abdominis. [Shown in the image above with black vertical arrows. This is the left side of the body.] Starting from the pubic bone, these muscles connect with the fifth, sixth and seventh ribs and xiphoid process.
Rectus Abdominis
This extends from the ninth costal cartilage to the pubic tubercle. The anterior surface of the rectus muscle is crossed by three tendinous intersections,
These are firmly attached to the anterior wall of the rectus sheath.
Rectus Abdominis
Lie lateral to the linea alba
Extends the length of the abdominal wall
Xyphoid to SP
Enclosed by a sheath
Sheath formed by aponeuroses
Rectus Abdominis
The rectus abdominis muscle rises from the front of the symphysis pubis and the pubic crest.
Rectus Abdominis/ Pyramidal
The pyramidalis muscle arises by its base from the anterior surface of the pubis and inserts into the linea alba. It lies anterior to the lower part of the rectus abdominis muscle.
More pelvic than abdominal
Rectus Abdominis
They are divided into compartments by strips of tendon that creates what body builders inaccurately call a “six pack”, as there are 8 or possible 10 segments, or 4 to 5 pairs. These pairs can, if trained to do so, contract individually.
Relational anatomy
Anteriorly •
Right kidney
liver
second portion of the duodenus
ascending colon
small intestinal loops
Left kidney
stomach
pancreas and its vessels
spleen
splenic flexure
jejunal loops
Relational anatomy
•Superiorly •Adrenal gland more medial on right
Renal Medulla
Broken into pyramids by the Columns of Bertin, the apices of the pyramids are called papillae and jut into the calyces.
Pyramids radiate from sinus to outer portion of kidney
Striated area contain Loops of Henle and collecting tubules
Function as the proximal collecting system
Renal pyramids
The base of each pyramid starts at the corticomedullary border The apex ends in the renal papilla which merges to form the renal pelvis and then on to form the Uterer
Renal Sinus
Inner portion of kidney tissue Arises from the apices of the pyramids as cup-shaped minor calyces Each kidney has 7-14 MINOR CALYCES Each kidney has 2-3 MAHOR CALCYES
Sinus- Contains, major and minor calyces, vessels, nerves, lymphatic’s, proximal pelvis, and is surrounded by fat
Variation of interfaces cause this portion to look highly echogenic
All tissues that transport sound well, small structures beyond resolution when not dilated
RENAL VEINS
Renal Veins
they drain directly into the IVC
Left renal vein has a longer course than the right and must pass anterior to the aorta to reach the IVC. Left also receives the Inferior phrenis, adrenal and gonadal veins of that side.
Retroperitoneal Spaces
Anterior Pararenal space Vs Gerota’s fascia and post peritoneum Asc and Descending colon also in this area
Posterior Pararenal Space vs. post renal fascia and PAW muscles only fat and vessels in this
Retroperiotneal area
Perirenal Space directly around the kidney enclosed by renal fascia Kidneys, adrenals, lymph nodes, vessels and perirenal fat iin this area
Right renal artery
has a longer course and is more inferior than the left.
RRA passes posterior to the IVC
Each renal artery divides into trhee branches
one posterior, anterior/upper
anterior lower which passes anterior to renal pelvis
They then further branch and subdivide into segmental, interlobar, arcuate and interlobular arteries.
SACS
Greater and Lesser Sac Division of peritoneal cavity
See Pictures of the pancreas
cross sectional
Splenic vein and Artery in the pancreas
Splenic Artery runs anterior to the body and tail of the pancreas
Originates superiorly as a branch of the celiac axis (aorta)
Splenic Vein runs posterior to the body and tail of the pancreas
Originates superiorly at splenic hilum
Superior Cross section
Read abt it in the lecture
Surrounding anatomy in the kidney
Posteriorly
Upper third of kidney diaphragm and 12th rib and the costodiaphragmatic recess of the pleura
Lower third of the kidney medial to lateralpsoas, quadratus lumborum and transverses abdominis muscles
Tail of the pancreas
Left extremity of pancreas
Close proximity to splenic hilum
Most superior and posterior portion of pancreas
Tail of the Pancreas
Left extremity of pancreas
Close proximity to splenic hilum
Most superior and posterior portion of pancreas
The hapatic veins
How Many are they?
The hepatic veins are divided into three components: right, middle, and left. They all drain into the inferior vena cava at the level of the diaphragm.
The head of the pacreas lies where
on the duodenum
Transversus
The deepest muscles of the abdominal muscles, the transversus abdominis go horizontally from front to back.
Transversus Abdominis
Innermost of the three flat muscles
Fibers pass in a horizontal direction
Vascular Anatomy for Liver
whats Oxygenated and Deoxigenated
Receives nutrients from HA and PV from both
PV is 80% saturated and supplies 50-60% of oxygen requirements for hepatocytes
PV and HA both have echodense walls Collegen connective sheaths cause reflections.
Portal Vein walls are thicker only in that region in the liver
HV walls less echodense (thiner)
PV run in horizontal plane (oblique) intralobar path
HV vary in calliper with location and breathing
HV run more longitudinally between segments
Portal Vein Bring oxygenated to the liver
Hepatic arteries does not bring oxygenated so its deoxygenated blood in the liver ONLY IN THE LIVER Thought out, they normally are oxygenated but not in the liver.
RETROPERITONEUM
Space posterior to Peritoneal cavity
Contains the following:
Kidneys
*Uterus Ureters
*Duodenum
Adrenals
Prostate
Pancreas
*COLON
Great Vessels Bladder
Vessels
Main Artery Supply Abdominal Wall mainly supplied by Internal thoracic arteries Parietal branches of Abdominal Aorta
Main Artery Supply Posterior Abdominal Wall Lumbar arteries Direct tributaries of Aorta
What surrounds the liver?
Rt. Kidney lies inferior and posterior
Great vessels lie Posteriorly
Portal Triad enters medially
Pancreas lies inferior and posterior
Left lobe of liver can serve as a window to image the pancreas
Whats is the Couinaud’s hepatic segments?
divide the liver into 8 segments.
Each segment is independent because it has its own vascular inflow, vascular outflow, and biliary outflow…all of which are necessary to the proper functioning of the liver
Where is the Fossa in the liver
Short linear depression
located on posterior surface between caudate lobe and bare area of liver
Separates Quadrate lobe in front from caudate lobe behind
Separated from portal by caudate
