Skip to main content

Renin Angiotensin Mechanism.

Liver.

 

Liver:

  • Largest gland in the body.

  • Located on the right side below the lungs in the upper abdominal cavity.

  • Superficially it is covered by a peritoneum which separates it into lobes.

  • Has two main lobes – right and left lobe.

  • Right lobe is further divided into caudate, and quadrate lobe.

  • The hepatic blood vessels enter the liver at the porta hepatis.

  • The gallbladder rests in a recess on the inferior surface of the right lobe.

  • The structural and functional unit of the liver is “Lobule”.

  • Each liver lobule is hexagonal in shape.

  • Composed of hepatocyte (liver cell) plates radiating outward from a central vein,

  • Portal triads are found at each of the six corners of each liver lobule.

  • Liver sinusoids – enlarged, leaky capillaries located between hepatic plates

  • Kupffer cells – hepatic macrophages found in liver sinusoids.

  • Functions of Hepatocytes:

    1. Production of bile

    2. Processing bloodborne nutrients

    3. Storage of fat-soluble vitamins

    4. Detoxification.

  • Secreted bile flows between hepatocytes toward the bile ducts in the portal triad and is stored in Gallbladder.

  • Composition of Bile:

  • A yellow-green, alkaline solution containing bile salts, bile pigments, cholesterol, neutral fats, phospholipids, and electrolytes.

  • Bile salts are cholesterol derivatives that:

  • Emulsify fat

  • Facilitate fat and cholesterol absorption

  • Help solubilize cholesterol

  • Enterohepatic circulation recycles bile salts

  • The chief bile pigment is bilirubin, a waste product of heme.

Functions of the Liver:

  1. Metabolism:

    1. Carbohydrate Metabolism: 

      1. Stores Glycogen.

      2. Gluconeogenesis.

      3. Glycogenolysis.

    2. Fat Metabolism:

      1. Oxidation of fatty acids. (Liver utilizes energy through fat metabolism).

      2. Synthesis of Lipoproteins.

      3. Synthesis of phospholipids and cholesterol.

      4. Converts large amounts of carbohydrates and proteins into fats.

    3. Protein Metabolism:

      1. Parenchymal cells of the liver synthesize plasma proteins.

      2. Deamination of amino acids.

      3. Urea cycle to remove ammonia from the body.

2) Secretion of bile.

3) Storage of many vitamins like fat soluble vitamins and cyanocobalamin.

4) Breakdown of RBCs and defense against microbes by Kuffer cells.

5) Production of heat.

6) Detoxification of drugs and bacterial toxins.

Commonly Asked Questions.

  1. Explain the structure and functions of the liver.
Labels:

Popular posts from this blog

Rate of Drying Curve.

  Definition Drying is defined as the removal of liquid from a product usually with application of heat. Rate of Drying Curve. Drying process can be divided into three periods Initial Adjustment Period. Constant drying rate period. First falling drying rate period. Second falling rate period. Initial Adjustment Period (A-B): Also called the “ Heating up” period . In this period the substance gets heat and increases in temperature. Drying has not yet started. Constant drying rate period (B-C): During this period the temperature of the solid and the rate of drying remain constant. The moisture evaporating from the surface is replaced by water diffusing from the interior of the solid at a rate equal t o the rate of evaporation.  The moisture content at the end of constant rate (point C) is referred to as the critical moisture content (CMC).  At CMC, dry spots start appearing and drying rate starts falling . First falling drying rate period (C-D): This period is also called the period of
Read more

Heat Exchangers and Heat Interchangers.

  In pharmaceutical industries many types of equipments are used for transfer of heat, they can be classified as follows, Heat Exchangers. Heat Interchangers. Heat Exchangers: These devices are used for transferring heat from a fluid (Hot Gas or Steam) to another fluid (Liquid) through a metal wall. Heat Interchangers: These devices are used for transferring heat from a One liquid to another liquid or one gas to another gas through a metal wall. HEAT EXCHANGERS; The equipment used for heat transferring are known as heat exchangers. Some of the processes that involves heat transfer in pharmaceutical industries are: Preparation of starch paste (in steam jacketed kettle). Crystallization. Evaporation. Distillation.  Classification of heat exchangers On the basis of transfer of heat, heat exchangers are classified as: Direct transfer type:  The hot and cold fluids are separated by a metal wall through which the heat is transferred from hot fluid to cold fluid. E.g. shell and tube heater, 
Read more

Flash Distillation.

  Principle: When a hot mixture is allowed to enter from a high-pressure zone into a low pressure zone, the entire liquid mixture is suddenly vaporized. This process is known as flash vaporization .  During this process, the chamber is cooled.  The less volatile fraction is condensed and the more volatile component remains in the vapor phase .  This process requires time, hence liquid and vapor are kept in intimate contact until equilibrium is achieved. Flash distillation is also called equilibrium distillation because separation of two liquids takes place when liquid and vapor phases are at equilibrium. Equipment used for Flash Distillation: Construction: It consists of a pump, which is connected to a feed reservoir.  Pumps help in pumping the feed into the heating chamber.  The heating chamber is heat supplied by steam.  The other end of the pipe is directly introduced into the vapor-liquid separator through a reducing valve.  The vapor outlet is provided at the top of the separato
Read more