Body fluid- Intracellular, Extracellular and Specilized fluids.pptx

useful to students

1. Body fluids

2. Body fluids may be defined as liquids of changeable but steady state composition. Body fluid is the term most often used in medical and health contexts. Modern medical, public health and personal hygiene practices treat body fluids as potentially unclean. Most body fluids are neutral in charge. Body fluids are aqueous solutions with differing concentrations of materials called solutes. An appropriate balance of water and solute concentrations must be maintained to ensure cellular functions. Total amount of the fluid in the body is approximately 70% of the body weight. 

3. Composition of body fluids Organic substances Glucose Amino acids Fatty acids Hormones Enzymes Inorganic substances Sodium Potassium Calcium Magnesium Chloride Phophate Sulphate

4. Major types of body fluids Body fluids may be majorly classified into three types (compartments). They are: Intracellular fluids Extracellular fluids Transcellular fluids Intracellular fluids providing the cellular medium in which metabolic reactions can take place and extracellular fluids which serve to nourish the cells and to remove waste products .

5. Intracellular fluid (or cytoplasm ) is the fluid found inside cells. 55% of the total body water. It is separated into compartments by membranes that encircle the various organelles of the cell. For example, the mitochondrial matrix separates the mitochondrion into compartments. The cytosol is a complex mixture of substances dissolved in water. Although water forms the large majority of the cytosol , it mainly functions as a fluid medium for intracellular signaling (signal transduction ) within the cell, and plays a role in determining cell size and shape. Intracellular fluids

6. The cytosol or intracellular fluid consists mostly of water, dissolved ions, small molecules and large water-soluble molecules (such as proteins). Most of the cytosol is water, which makes up about 70% of the total volume of a typical cell. The pH of the intracellular fluid is 7.4. The cell membrane separates cytosol from extracellular fluid, but can pass through the membrane via specialized channels and pumps during passive and active transport. The cytosol also contains much higher amounts of charged macromolecules, such as proteins and nucleic acids than the outside of the cell. Intracellular Fluid Composition

7. The concentrations of the other ions in cytosol or intracellular fluid are quite different from those in extracellular fluid. In contrast to extracellular fluid, cytosol has a high concentration of potassium ions and a low concentration of sodium ions. The reason for these specific sodium and potassium ion concentrations are Na+/K ATPase pumps that facilitate the active transport of these ions. These pumps transport ions against their concentration gradients to maintain the cytosol fluid composition of the ions.

8. Extracellular Fluid Extracellular fluid (ECF) usually denotes all the body fluid that is outside of the cells. 45% of the total body water. The extracellular fluid can be divided into two major sub compartments: interstitial fluid and blood plasma. Blood plasma is the straw-colored/pale-yellow liquid component of blood that normally holds the blood cells in whole blood in suspension. It makes up about 55% of total blood volume. Interstitial fluid (or tissue fluid) is a solution that bathes and surrounds the cells of multicellular animals. The interstitial fluid is found in the interstitial spaces, also known as the tissue spaces.

9. Extracellular fluid is mainly contains cations and anions. Cations include: sodium (Na + ), potassium (K + ) and calcium (Ca 2+ ). Anions include: chloride and hydrogen carbonate. These ions are important for water transport throughout the body. Plasma is mostly water (93% by volume) and contains dissolved proteins (the major proteins are fibrinogens, globulins, and albumins), glucose, clotting factors, mineral ions (Na + , Ca ++ , Mg ++ , Cl - etc.), hormones and carbon dioxide (plasma being the main medium for excretory product transportation). Extracellular Fluid Composition

10. These dissolved substances are involved in many varied physiological processes, such as gas exchange, immune system function and drug distribution throughout the body.

11. Transcellular Fluid Transcellular fluid is the portion of total body water contained within the epithelial-lined spaces. It is the smallest component of extracellular fluid, which also includes interstitial fluid and plasma. It is often not calculated as a fraction of the extracellular fluid, but it is about 2.5% of the total body water. Examples of this fluid are cerebrospinal fluid, ocular fluid, joint fluid and the pleaural cavity that contains fluid that is only found in their respective epithelium-lined spaces. The function of transcellular fluid is mainly lubrication of these cavities, and sometimes electrolyte transport.

12. Transcellular Fluid Composition Due to the varying locations of transcellular fluid, the composition changes dramatically. Some of the electrolytes present in the transcellular fluid are sodium ions, chloride ions and bicarbonate ions. Cerebrospinal fluid is similar in composition to blood plasma, but lacks most proteins, such as albumins, because they are too large to pass through the blood–brain barrier. Ocular fluid in the eyes contrasts with cerebrospinal fluid by containing high concentrations of proteins, including antibodies.

13. Specialized Fluids of the Body Blood Lymph Milk Cerebrospinal fluid Amniotic fluid Aqueous humor Sweat Tears

14. Blood The only fluid tissue in the body Classified as a connective tissue Living cells = formed elements (RBC, WBC, Platelets) Non-living matrix = plasma Color range: Oxygen-rich blood is scarlet red Oxygen-poor blood is dull red pH must remain between 7.35 – 7.45 Blood temperature is slightly higher than body temperature

15. Functions of Blood Blood has many different functions, including : Supply of oxygen to tissues Supply of nutrients such as glucose, amino acids, and fatty acids (dissolved in the blood or bound to plasma proteins (e.g., blood lipids)) Removal of waste such as carbon dioxide, urea, and lactic acid Immunological functions, including circulation of white blood cells, and detection of foreign material by antibodies Coagulation, the response to a broken blood vessel, the conversion of blood from a liquid to a semisolid gel to stop bleeding Messenger functions, including the transport of hormones and the signaling of tissue damage Regulation of core body temperature Hydraulic functions

16. Lymph Clear and colorless fluid 96% water and 4% solids Solids – Proteins 2-6% of solids albumin, globulin, fibrinogen, prothrombin , clotting factors, antibodies, enzymes Lipids 5-15% Chylomicrons Lipoproteins Carbohydrates Glucose mainly Non-Protein Nitrogen(NPN) Compounds Urea and creatinine Electrolytes Sodium, calcium, potassium, chloride, bicarbonates

17. Functions of Lymph Return protein from tissue spaces into blood Redistribution of fluid Removal of bacteria, toxins and other foreign bodies from tissues Maintain structural and functional integrity of tissue Route for intestinal fat absorption Transport lymphocytes

18. Milk Secreted by mammary glands Complete natural food 83-87% water and 13-17% solids Solids Carbohydrates Lactose Lipids Triacylglyerols Palmitic acid, myristic acid, stearic acid, lauric acid, butyric acid,oleic acid Proteins Caesin (80%), Lactalbumin Enzymes (proteases, xanthine oxidase , lysozyme ), immunoglobulins Minerals Ca, Mg, P, Na, K, Cl Vitamins Fat and water soluble vitamins except Vit - C

19. Functions of Milk Milk sugar provides galactose, a structural unit for growing infant. In intestine, it gets metabolized to lactic acid which eliminates harmful bacteria. Source of protein, mineral and vitamins

20. Cerebrospinal fluid (CSF) Clear, colorless liquid formed within the cavities of brain and around spinal cord 500ml CSF is formed everyday At any given time, there is 120-150ml CSF in the system CSF is completely replaced about three times a day. Hydrolic shock absorber Regulation of intracranial pressure Influences the hunger sensation and eating behaviours Functions of CSF

21. Amniotic Fluid Liquid produced by membranes and fetus Volume of fluid increases with gestational age Clear with some desquamated fetal cell and a little lipid. Functions of AF Physical protection to the fetus Medium for exchange of various chemicals, food materials.

22. Aqueous Humor Fluid that fills the interior chamber of eye Secreted by ciliary body, enters anterior chamber Blockade in the flow of aqueous humor causes glaucoma due to increased intraocular pressure. Posterior chamber of eye is filled with vitrous humor which contains a gel ( vitrous body of hyaluronic acid secreted by retina)

23. Sweat Secretion of sweat gland Regulates body temperature by cooling and evaporation Sweat glands controlled by autonomic nervous system (ANS), Adrenal cortical steroid - which affect the quantity of electrolyte present

24. Tears pH – 7 to 7.6 due to loss of CO 2 Small amount of mucin is also present Functions of Tears Lysozyme protects eye from infectious agents Lubricate the surface of the cornea Fill the irregularities of the corneal surface to improve optical properties Protects eyes from injury

25. Circulation of body fluids Fluid Movement Extracellular fluid is separated among the various compartments of the body by membranes. These membranes are hydrophobic and repel water; however, there a few ways that fluids can move between body compartments. There are small gaps in membranes, such as the tight junctions, that allow fluids and some of their contents to pass through membranes by way of pressure gradients.

26. THANK U

27. Formation of Interstitial Fluid Hydrostatic pressure is generated by the contractions of the heart during systole. It pushes water out of the small tight junctions in the capillaries. The water potential is created due to the ability of the small solutes to pass through the walls of capillaries. This buildup of solutes induces osmosis. The water passes from a high concentration (of water) outside of the vessels to a low concentration inside of the vessels, in an attempt to reach an equilibrium. The osmotic pressure drives water back into the vessels. Because the blood in the capillaries is constantly flowing, equilibrium is never reached.

28. The balance between the two forces differs at different points on the capillaries. At the arterial end of a vessel, the hydrostatic pressure is greater than the osmotic pressure, so the net movement favors water and other solutes being passed into the tissue fluid. At the venous end, the osmotic pressure is greater, so the net movement favors substances being passed back into the capillary. This difference is created by the direction of the flow of blood and the imbalance in solutes created by the net movement of water that favors the tissue fluid.

29. Removal of Interstitial Fluid The lymphatic system plays a part in the transport of tissue fluid by preventing the buildup of tissue fluid that surrounds the cells in the tissue. Tissue fluid passes into the surrounding lymph vessels and eventually rejoins the blood. Sometimes the removal of tissue fluid does not function correctly and there is a buildup, which is called edema. Edema is responsible for the swelling that occurs during inflammation, and in certain diseases where the lymphatic drainage pathways are obstructed.

30. Starling Equation Capillary permeability can be increased by the release of certain cytokines, anaphylatoxins , or other mediators (such as leukotrienes , prostaglandins, histamine, bradykinin , etc.) that are released by cells during inflammation. The Starling equation defines the forces across a semipermeable membrane to calculate the net flux. The solution to the equation is known as the net filtration or net fluid movement. If positive, fluid will tend to leave the capillary (filtration). If negative, fluid will tend to enter the capillary (absorption). This equation has a number of important physiologic implications, especially when disease processes grossly alter one or more of the variables.

31. According to Starling’s equation, the movement of fluid depends on six variables: Capillary hydrostatic pressure (Pc) Interstitial hydrostatic pressure (Pi) Capillary oncotic pressure ( π z) Interstitial oncotic pressure ( π i ) Filtration coefficient ( Kf ) Reflection coefficient ( σ) The Starling Equation is mathematically described as Flux= Kf [(Pc-Pi)- σ (π z- π i )].

32. Sweat Insensible perspiration amounts to 800-1200ml/day Volume of sweat produced/day during muscular exercise at elevated temperature may range from 10-14l, which may lead to water and electrolyte imbalance Water content of sweat varies from 99.2-99.7% pH – 4.7 to 7.5 Total non protein nitrogen (urea) varies from 0.07-1% per hour during copius sweating Electrolyte in sweat varies Na + 12.6-127 meq /l K + 5-32 meq /l Cl - 8.5-85 meq /l

33. Tears Lysozyme – lyses the cells of a number of micro-organisms by breaking down the polysaccharides of their outer layer Protein content is 0.6 to 0.18g/dl with an albumin/globulin ratio of 1:5 or 2:1