the liver

• what is the formula that creates carbonic acid from carbon dioxide and water?

  H 2 O + C O 2 > H 2 C O 3
• What is the formula that shows how carbonic acid dissasociates?

  H 2 C O 3 > H (+ ) + H C O 3 ( - )
• where does carbonic acid disassociate and under the influence of which enzyme?

  Carbonic acid disassociates in the blood under the influence of carbonic anhydrase- it can also occur in the plasma of the blood.
• the hydrogen ions from disassociated carbonic acid affect the pH of the cytoplasm in red blood cells. The hydrogen ions interact with bonds within haemoglobin and that changes the 3D shape- reducing the affinity of haemoglobin for oxygen and impacting oxygen transport. The hydrogen ions can then combine with haemoglobin, forming haemoglobinonic acid. The carbon dioxide that isnt converted into ions can combine directly with haemoglobin making carbiaminohaemoglobin. This will reduce oxygen transport further.
• In the blood plams, excess hydrogen ions can reduce the pH of the plasma. Maintaining the pH of the blood plasma is essential because changes would alter the structure of many proteins in the blood that help to transport a wide range of substances around the body- proteins in the blood act as buffers to resist the changes in pH.
• If a pH change in the blood plasma is small, then the extra hydrogen ions are detected by the respiratory centre of the medulla oblongata of the brain. This causes an increase in the breathing rate to help remove the excess carbon dioxide
• However, if the pH of the blood plasma drops below 7.35 it can result in headaches, drowsiness, restlessness, tremors and confusion. There also may be a rapid heart rate and change in blood pressure. This is respiratory acidosis; it can be caused by diseases or conditions that affect the lungs themselves such as emphysema, chronic bronchitis, asthma or severe pneumonia. Blockage of the airways due to swelling, a foreign object, or vomit, can also induce acute respiratory acidosis.
• why does deamination occur?

  The body cannot store excess amino acids. However, amino acids contain almost as much energy as carbohydrates so it would be wasteful to excrete excess amino acids. Instead, the excess amino acids are transported to the liver and the potentially toxic amino group is removed., The amino Group will initially form the very toxic and soluble compound called ammonia- then ammonia is converted to urea which is transported into the kidneys to be excreted. The remaining keto acid, is used directly in respiration
• What is the formula for deamination?

  Amino acid + Oxygen + Keto acid + ammonia
• WHat is the formula that shows the formation of urea from ammonia and carbon dioxide?

  2 Ammonia + 1 Carbon Dioxide > 1 Urea + 1 water
• which artery and which vein supplies the liver with blood?

  The hepatic artery and the hepatic portal vein
• Describe the purpose of the hepatic artery for the liver?

  Oxygenated blood from the heart travels from the aorta via the hepatic artery to the liver. This supplies the oxygen that is essential for aerobic respiration. The liver cells are very active, because they carry out many metabolic processes. Many of these processes require energy in the form of ATP so it is important that the liver has a good supply of oxygen to aerobically respire.
• describe the purpose of the hepatic portal vein?

  Deoxygenated blood from the digestive system enters the liver via the hepatic portal vein. The concentrations of various substances will be uncontrolled as they have just entered the body from the products of digestion in the intestines. The blood may also contain toxic compounds that have been absorbed from the intestine. It is important that such substances do not continue to circulate around their body before the concentrations have been adjusted.
• describe the purpose of the bile duct?

  Bile is a secretion from the liver which has functions in both digestion and excretion. The bile duct carries bile from the liver to the gall bladder where it is stored until required to aid the digestion of fats in the small intestine; bile also contains some excretory products such as bile pigments like bilirubin which will leave the body with the faeces.
• the cells, blood vessels and chambers inside the liver are arranged to ensure the greatest possible contact between the blood and the liver cells. The liver is divided into lobes which are further divided into lobules, which are cylindrical
• As the hepatic artery and portal vein enter the liver, they split into smaller and smaller vessels. These vessels run between and paralell to the lobules- these are called inter-lobular vessels. At intervals, branches from the hepatic artery and the portal vein enter the lobules. The blood from the two vessels is mixed, passing the sinusoid which is lined with liver cells. As the blood flows along the sinusoid it is in close contact with the liver cells. These cells are able to remove substances from the blood and return other substances to the blood
• What is the primary function of Kupffer cells, and where are they found?

  Breakdown and recycle old red blood cells. They tend to be found in the sinusoids
• Where is bile made, and where is it released?

  Bile is made in theliver cells and is released into the bile canaliculi. The bile canaliculi join together to form the bile duct, transporting the bile to the gall bladder
• When the blood reaches the end of the sinusoid,the concentrations of many of its components have been modified and regulated. At the centre of each liver lobule is a branch of the hepatic vein known as the intra lobular vessel. The sinusoid empty into this vessel. The branches of the hepatic vein from different lobules will join together to form the hepatic vein which drains blood from the liver.
• What else are liver cells known as?

  Hepatocytes
• Hepatocytes appear to be relatively unspecified. They have a simple cuboidal shape with many microvili on their surface. HowHowevercer, their many metabolic functions include protein synthesis, transformation and storage of carbohydrates, synthesis of cholesterol and bile salts, detoxification and many other processes. This means that their cytoplasm must be very dense and is specialized in the number of certain organelles that it contains.
• what are the metabolic functions of the liver?

  Control the blood glucose, amino acid, and lipid levels.

  Synthesis of bile, plasma proteins, and cholesterol

  Synthesis of red blood cells in the fetus

  Storage of vitamins A, D, and B12, iron and glycogen

  Detoxification of alcohol and drugs

  Breakdown of hormones

  Destruction of Red Blood Cells
• How does the liver store glycogen?

  The liver stores sugar in the form of glycogen. It is able to store approx 100 - 200 grams of glycogen, which makes up about 8% of the fresh weight of the liver. The glycogen forms granules in the cytoplasm of individual hepatocytes. The glycogen can be broken down to release glucose into the blood as required.