ILA6 - Jaundice Flashcards
What is the liver an embryological derivative of?
Foregut which develops in the ventral mesentry
Which parts of the abdomen does the liver lie in?
The two hypochondria and the epigastric regions
What are the two coverings of the liver and in what directions do they lie?
Diaphragm (superior, anterior and posterior, areas not covered by peritoneum = bare area) and visceral peritoneum (inferior)
What is Glisson’s capsule?
Fibrous covering of the liver and en-sheaths the portal triad. It is innervated by the lower intercostal nerves, distension results in sharp pain.
What are the associated ligaments of the liver?
a) Falciform ligament. Umbilicus (ant abdo wall) to liver, contains ligamentus teres (remnant of umbilical vein)
b) Ligamentum teres. Passes into a fissure on the visceral surface and join the L branch of the portal vein in the porta hepatis.
c) Ligamentum venosum. Fibrous band that is the remains of the ductus venosus (bypass of liver in the fetus), is attached to the L branch of the portal vein and ascends in a fissure on the visceral surface to be attached above to the IVC.
What do folds of peritoneum connect the liver to?
- Stomach (hepatogastric ligament)
- The duodenum (hepatoduodenal ligament) (both contained within the lesser omentum)
- The diaphragm (right and left triangular ligaments and anterior and posterior coronary ligaments) (on R lobe)
What are the lobes of the liver?
left, right, caudate and quadrate
What separates the left and right lobes of the liver?
Falciform ligament
What borders the caudate lobe?
On the left by the fissure for the ligamentum venosum and on the right by the groove for the inferior vena cava. superior.
What borders the quadrate lobe?
On the left by the fissure for ligamentum teres and on the right by the fossa for the gallbladder. inferior.
What is contained within the porta hepatis?
R and L hepatic ducts.
R and L branches of hepatic artery
Portal vein
Sympathetic and parasympathetic nerve fibres.
What is the arterial blood supply of the liver?
Hepatic artery (L&R)
What is the venous blood supply to the liver?
- The portal vein divides into R and L terminal branches that enter the porta hepatis behind the arteries.
- The hepatic veins (3 or more) emerge from the posterior surface of the liver and drain into the IVC.
What is contained in the portal triad?
Hepatic artery (25% of blood supply to liver), portal vein (75% blood supply) and bile duct. ALso contains nerves and lymphatics.
What are the two methods of classifying groups of cells in the liver?
Lobules (hexagon) and acinus (functional unit and diamond shape)
How does the blood reach the hepatic vein?
- Arterial and venous blood is conducted to the centre of each liver lobule by the liver sinusoids.
- The central veins drain into the R and L hepatic veins which open directly into the IVC
Which cells in the acini do which jobs?
Ones closer to arteries (portal triad) perform activities requiring oxygen, further away cells perform drug metabolism
What is the lymphatic drainage of the liver?
Lymph nodes in the porta hepatis then to the coeliac nodes
What is the nerve supply to the liver?
- Sympathetic and parasympathetic nerves form the coeliac plexus.
- The anterior vagal trunk gives rise to a large hepatic branch which passes directly to the liver
What are the parts of the gall bladder?
- A rounded end (fundus of gallbladder), which may project from the inferior border of the liver, comes into contact with the anterior abdominal wall at level of 9th costal cartilage
- A major part in the fossa (body of gallbladder), which may be against the transverse colon and the superior part of the duodenum
- A narrow part (neck of gallbladder) with mucosal folds forming the spiral fold
What is the order of veins in the liver?
Central vein, collecting vein, hepatic vein and the IVC
What is the function of the gall bladder?
a) The gallbladder receives, concentrates, and stores bile from the liver.
b) Bile is delivered to the duodenum as the result of contraction and partial emptying of the gallbladder.
c) This mechanism is initiated by entrance of fatty foods into the duodenum: the fat causes release of cholecystokinin from the mucous membrane of the duodenum – the hormone then enters the blood, causing the gallbladder to contract. At the same time, the smooth muscle around the distal end of the bile duct and ampulla is relaxed, thus allowing the passage of concentrated bile into the duodenum.
What is the blood supply to the gall bladder?
The arterial supply to the gallbladder is the cystic artery from the right hepatic artery (a branch of the hepatic artery proper)
The cystic veins drain directly into the portal vein
What is the order for the duct system of the bile?
a) Bile canaliculi
b) Interlobular ducts (larger and larger)
c) R and L hepatic ducts (at porta hepatis
d) Common hepatic duct – descends within the free margin of lesser omentum.
e) Cystic duct joins common hepatic duct from the R side to form the bile duct:
- First part of its course: lies in R free margin of lesser omentum
- Second part of its course: lies behind first part of duodenum
- Third part of its course: lies in a groove on posterior surface of head of the pancreas. Here it comes into contact with the main pancreatic duct.
f) Ends by piercing the medial wall of the second part of the duodenum about halfway down its length. Joined by main pancreatic duct – together they open into the ampulla of Vater which opens into the duodenum by means of the duodenal papilla. Terminal parts of both ducts and the ampulla are surrounded by circular muscle known as the sphincter of Oddi.
What are some of the functions of the liver?
Stores iron and glycogen (100g), activates thyroxine, makew cholesterol, bile production. Excretion of bilirubin, cholesterol, hormones, and drugs. Metabolism of fats, proteins, and carbohydrates. Storage of vitamin A.
What are the key parts of the histology of the liver?
Kupfer cells, sinusoids, hepatocytes (2 surfaces-sinusoidal membrane, caniculi membrane), space of disse, fibroblasts (cirrhosis), stellate (ito) cells.
Describe hepatocytes.
- They are the parenchymal cells of the liver (75% of mass)
- Breakdown and store fats, CHO and PROTEIN (gymlad ;))
- Produce bile
- Detoxification
- Multiply rapidly
- Cuboidal
Describe Kupffer cells.
- Star shaped
- Macrophages (engulf shiz)
Stellate (Ito) cells
- Store vitamin A
- Contribute in liver regeneration, fibrosis and tumour formation
Liver sinusoidal endothelial cells.
- Line sinuses
- Regulate passage of substances from blood vesels to liver
- Extended processes & pores (fenestrations)
- Control which molecules pass through the Space of Disse
- Fenestrations
- Noncontinuous basement membrane
Describe the space of Disse.
It is the space between the sinusoid and the hepatocytes, filled with plasma. Microvilli from the hepatocytes extend into this space allowing proteins to be absorbed.
Where are RBC produced and what is the process called?
In the top portion of long bones in bone marrow (In children, occurs in all bones). Erythropoiesis.
What colour is haemoglobin?
Yellow
What is the average lifespan of a RBC?
120 days
How is a red blood cell detected to undergo haemolysis?
As the RBC ages, changes occur in the plasma membrane which make it more susceptible to selective recognition by macrophages.
What is Hb degraded to?
Haeme and globin
What is globin converted to?
Amino acids
What is haeme converted to?
Fe and biliverdin
What enzyme breaks down haeme?
Haeme oxygenase
What colour is biliverdin?
Green
What is biliverdin converted to? and which enzyme?
Unconjugated bilirubin. Biliverdin reductase.
Is unconjugated bilirubin water soluable? What colour is it?
No. Orange/yellow
What happens to unconjugated bilirubin?
Combined with albumin and transported in the blood to the liver
What happens to unconj bilirubin in the liver?
It is conjugated with glucoronic acid with the enzyme glucoronyltransferase this forms conjugated bilirubin.
Is conjugated bilirubin water soluable?
Yes
What happens to conj bilirubin?
Secreted into the common bile duct then goes through the GI tract to the colon.
What happens at the colon to conjugated bacteria?
Colonic bacteria deconjugate and metabolise it to form urobilinogen
What happens to Urobilinogen?
It is oxidised to urobilin (water sol) and stercobilin
What happens to stercobilin?
It becomes poopy, gives it its brown colour
What happens to urobilin?
It is transported to the liver (enterohepatic urobilinogen cycle) or the kidneys where it becomes piss. It can also be poopy
What are the two horizontal lines used to divide the abdomen
Subcostal plane (superior) and intertubercular plane (inferior, connects tubercles of iliac crest)
Where is MbBurney’s point?
2/3 way from umbilicus to to ant sup iliac spine
What are the two vertical lines used to divide the abdomen?
Mid clavicular lines
What are the three central regions of the abdomen (sup to inf)?
Epigastric, umbilical, suprapubic
What are the three lateral regions of the abdomen (sup to inf)?
Hypochondria, lumbar (loin), iliac fossa. More lateral is flank
What organs are contained in the right hypochondrium?
Liver, right kidney, gall bladder, hepatic flexure of large colon
What organs are contained in the epigastrium?
Stomach, 1st part of duodenum, descending aorta, Oesophagus (T10), Pancreas
What organs are contained int the left epigasteium?
Left kidney, spleen, splenic flexure of large colon
Which organs are contained in the left iliac fossa?
Sigmoid colon
Which organs are contained in the right iliac fossa?
Appendix, Caecum
which organs are contained in the hypogastrium?
Distended bladder (Not healthy)
Which organs are contained in the left lumbar?
Descending colon
Which organs are contained in the right lumbar?
Ascending colon
Which organs are contained in the umbilical region?
Small intestine
Name some key branches of the abdominal aorta and at what levels?
Coeliac trunk T12 Superior mesenteric L1 Renal arteries L2 (paired) Inferior mesenteric L3 Bifurcation L4
What are the three causes of jaundice?
pre-hepatic, hepatic and post hepatic (intrahepatic and extrahepatic)
Describe pre hepatic jaundice.
-Pathology is occurring prior to the liver.
-INCREASED RATE OF HEMOLYSIS
-This increase results in a rise of bilirubin production
Deposition of the unconjugated bilirubin into tissues can lead to a jaundiced appearance
-Common diseases:
Malaria
Sickle cell anaemia
Thalassaemia
PALE URINE (no bilirubin)
NORMAL STOOL
Describe hepatic jaundice.
-REDUCED ABILITY OF THE LIVER TO METABOLISE AND EXCRETE BILIRUBIN
-Can be caused by acute or chronic hepatitis, hepatotoxicity, liver cirrhosis and alcohol liver disease
-Cell necrosis reduces the liver’s ability to metabolise and excrete bilirubin leading to a build-up of unconjugated bilirubin in the blood
-Causes:
Hepatitis A, B and C (Also autoimmune hepatitis)
Alcoholic liver disease
Glandular fever
Drug misuse
Primary biliary cirrhosis
Gilbert’s syndrome
Liver cancer
DARKER URINE (increased bilirubin)
NORMAL STOOL
Describe post hepatic (obstructive) jaundice.
-OBSTRUCTION OF BILIARY SYSTEM
-Occurs when the bile duct system is damaged, inflamed or obstructed
-Caused by an interruption to the drainage of bile containing conjugated bilirubin in biliary system
-Causes:
Gallstones
Pancreatic cancer in the head of the pancreas
Gall bladder or bile duct cancer
Pancreatitis
DARK URINE(blocked CBD leads to conj bilirubin into tissues, water sol so ends up in urine)
PALE STOOL
Name some risk factors for jaundice.
a) Alcohol and drug misuse suggests X
b) Travel to countries where malaria and Hep A are widespread suggests X
c) Sexual activity with people with Hep A or Hep C suggests X “sometimes related to sexual activities etc”
d) Past medical history:
- Pancreatic problems
- Anaemia (include family history)
- Inflammatory bowel disease
- Past surgical history involving hepatobiliary tract and pancreas
Name some signs and symptoms of jaundice.
- Flu-like symptoms indicates hepatitis
- Abdominal pain
- Whether you have travelled to a country where malaria and hep A are widespread
- Colour change to urine and stools
- History of alcohol and drug misuse
- Swelling of legs ankles and feet may indicate cirrhosis
- Past medical history
- Sexual contact with people with jaundice
What is physiological jaundice?
In newborns, breakdown of foetal Hb causes jaundice. Can put baby under uV lamp to break the bilirubin.
