Body Fluids PDF

Body Fluids Body Fluids  Total amount of fluid in the human body is approximately 70% of body weight  Body fluid has been divided into two compartments – – Intracellular fluid (ICF)  Inside the cells  55% of total body water – Extracellular fluid...

Body Fluids Body Fluids  Total amount of fluid in the human body is approximately 70% of body weight  Body fluid has been divided into two compartments – – Intracellular fluid (ICF)  Inside the cells  55% of total body water – Extracellular fluid  Outside the cells  45% of total body water Body Fluid Compartments Extracellular fluid includes  Interstitial fluid  Present between the cells  Approximately 80% of ECF  Plasma  Present in blood  Approximately 20% of ECF  Also includes  Lymph  synovial fluid  vitreous body,  aqueous humor  endolymph,  cerebrospinal fluid  perilymph,  pleural, pericardial and peritoneal fluids Body Fluid Compartments Barriers separate ICF, interstitial fluid and plasma  Plasma membrane Separates ICF from surrounding interstitial fluid  Blood vessel wall Separate interstitial fluid from plasma Composition of body fluids  Organic substances  Inorganic substances  Glucose  Sodium  Amino acids  Potassium  Fatty acids  Calcium  Hormones  Magnesium  Enzymes  Chloride  Phophate  Sulphate Difference  ECF  ICF  Most abundant cation - Na+,  Most abundant cation - K+ – muscle contraction – Resting membrane – Impulse transmission potential – fluid and electrolyte balance – Action potentials – Maintains intracellular volume  Most abundant anion - Cl- – Regulation of pH – Regulates osmotic pressure – Forms HCl in gastric acid  Anion are proteins and phosphates (HPO42-) Na+ /K+ pumps play major role in keeping K+ high inside cells and Na+ high outside cell Sodium Na+ – Most abundant ion in ECF – 90% of extracellular cations – Plays pivotal role in fluid and electrolyte balance as it accounts for half of the osmolarity of ECF Chloride Cl- – Most prevalent anion in ECF – Moves easily between ECF and ICF because most plasma membranes contain Cl- leakage channels and transporters – Can help balance levels of anions in different fluids Bicarbonate HCO3- – Second most prevalent extracellular anion – Concentration increases in blood passing through systemic capillaries picking up carbon dioxide CO2+H2O H2CO3 H++HCO3- – Chloride shift helps maintain correct balance of anions in ECF and ICF Potassium K+ – Most abundant cation in ICF – Establish resting membrane potential in neurons and muscle fibers – Maintains normal ICF fluid volume – Helps regulate pH of body fluids when exchanged for H+ Magnesium – Mg2+ in ICF (45%) or ECF (1%) – Second most common intracellular cation – Cofactor for certain enzymes and sodium-potassium pump – Essential for synaptic transmission, normal neuromuscular activity and myocardial function Specialized Fluids of the Body  Lymph  Milk  Cerebrospinal fluid  Amniotic fluid  Aqueous humor  Sweat  Tears  Synovial fluid  Urine  Pericardial fluid  Peritoneal fluid 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 – NPN  Urea and creatinine – Electrolytes  Sodium, calcium, potassium, chloride, bicarbonates 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 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 Functions of Milk  Milk sugar provides galactose, a structural unit for growing infant.  Inintestine, it gets metabolized to lactic acid which eliminates harmful bacteria.  Source of protein, mineral and vitamins Cerebrospinal fluid (CSF)  Clear, colorless liquid formed within the cavities of brain and around spinal cord  At any given time, there is 120-150ml CSF in the system  CSF is completely replaced about three times a day. Functions of CSF  Hydraulic shock absorber  Regulation of intracranial pressure  Influences the hunger sensation and eating behaviors Amniotic Fluid  Liquid produced by membranes and fetus  Volume of fluid increases with gestational age  Clear with some fetal cell and a little lipid Functions of AF  Physical protection to the fetus  Medium for exchange of various chemical Aqueous Humor  Fluid that fills the anterior 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) Sweat  Secretion of sweat gland  Regulates body temperature by cooling and evaporation  Sweat glands controlled by ANS, Adrenal cortical steroid - which affect the quantity of electrolyte present 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 sweating Sweat  Electrolyte in sweat varies – Na+ 12.6-127 meq/l – K+ 5-32 meq/l – Cl- 8.5-85 meq/l Tears  Produced by lachrymal glands  Isotonic but becomes hypertonic due to evaporation as fluid passes over the cornea  When the tear flow is copious, fluid is isotonic  Under stimulus with a slow rate of tear flow, the fluid is about 25m osm hypertonic Copious – Rapid tear flow induction Tears  pH – 7 to 7.6 due to loss of CO2  Protein content is 0.6 to 0.18g/dl with an albumin/globulin (A/G) ratio of 1:5 or 2:1  Small amount of mucin is also present  Lysozyme – lyses the cells of a number of micro-organisms by breaking down the polysaccharides of their outer layer 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 Synovial fluid  pH 7.40- 8.16  Clear and colorless  Hyaluronan, lubricin, proteinase, collagenases, and prostaglandins  WBC: less than 200 cells/µL  Synovitis Function of Synovial fluid  Lubricatethe joint and provide a cushion for the ends of the bones  Act as a nutrient source (diffusion) Urine  pH 6.0–7.5  Water (95%)  Urea (2%)  Creatinine (0.1%)  Uric acid (0.03%),  Chloride, sodium, potassium, sulphate, ammonium, phosphate and other ions and molecules in lesser amounts Function of Urine  Eliminate liquid waste called urea  Keep chemicals, such as potassium and sodium, and water in balance Pericardial fluid  pH 7.35 to 7.55  Cells: nucleated cells, mesothelial cells, leucocytes, lymphocytes  Protein, albumin, LDH  20 to 60 mL  Clear, straw-colored fluid  Pericardial effusions Function of Pericardial fluid  Reduce friction between the pericardial membranes of the heart during its beats  Heart fixed in place within the chest cavity  Preventsthe heart from stretching too much and overfilling with blood Peritoneal fluid  pH range 7.46 - 8.10  Peritoneal cavity, a space between the wall of the abdomen and the organs inside  Clear to pale yellow  Ascites/peritonitis  A few desquamated mesothelial cells, Mast cells and macrophages  Less than 50 mL  3.0 g/mL of protein Function of Peritoneal fluid  Support the organs of the abdomen  Acts as a conduit for the passage of nerves, blood vessels, and lymphatics  Lubricates your organs inside of your peritoneal cavity