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ANATOMY AND PHYSIOLOGY OBJECTIVE. Without reference, identify at least four out of six principles about anatomy and physiology as they relate to laboratory systems. BLOOD. Function of blood One of the body's connective tissues
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ANATOMY AND PHYSIOLOGY OBJECTIVE Without reference, identify at least four out of six principles about anatomy and physiology as they relate to laboratory systems
BLOOD • Function of blood • One of the body's connective tissues • Transports oxygen from the lungs to the cells and carbon dioxide waste from the cells to the cells. • Protect the body from disease • Carries nutrients from the digestive system to the cells • Transports waste from the cells to the kidneys
BLOOD • Composition • Blood contains red blood cells, white blood • cells, and fragments of cells called platelets suspended in a water-based, pale, somewhat yellow fluid known as plasma. • The average human has 5 liters of blood • Accounts for 8 percent of the total body weight • Blood is alkaline with a pH between 7.35 and 7.45 • Acidosis • alkalosis
PLASMA • Definition: liquid portion of whole blood with the cells removed. • fluid portion of the blood • blood has not clotted • Components of plasma: • 92 percent water • 7 percent protien
PLASMA • 1 percent ions • Sodium (Na+) • Potassium (K) • Calcium (Ca) • Magnesium (Mg) • Chloride (Cl-) • Bicarbonate (HCO3-)
SERUM • Definition: plasma minus it‘s clotting factors such as fibrinogen • Liquid portion of clotted blood • Blood is allowed to clot and the clear serum is removed (no fibrinogen or other clotting factors) • Most commonly used body fluid for chemical analysis
RED BLOOD CELLS • Characteristics • also known as erythrocytes • Have little internal organization and no nucleus or organelles • organelles are small structures within cells which perform dedicated functions • basically a small organ within a cell • Each blood cell is a flexible, biconcave disk (thinner at the center than at the edge)
RED BLOOD CELLS • Primary purpose of RBC's in the body is to transport oxygen • Number of RBC's in the body • average adult male has approximately 5.4 million RBC's per cubic millimeter (microliter) • average adult female has approximately 4.8 million per cubic millimeter of blood • RBC Production • RBC's are produced in the red bone marrow of bones. • The process of RBC formation is called erythropoiesis
HEMOGLOBIN • Contained in the ecytoplasm of red blood cells • Hemoglobin is a protein chemical which has a red pigment that gives it's color to erythrocytes • Hemoglobin contains the element iron, making it an excellent vehicle for transporting oxygen and carbon dioxide • As blood passes through the lungs, oxygen molecules attach to the hemoglobin • as the blood passes through the body‘s tissue’s, the hemoglobin releases the oxygen to the cells • the empty hemoglobin molecules then bond with the tissue's carbon dioxide or other waste gases
DESTRUCTION OF RED BLOOD CELLS • Red Blood Cells circulate in the bloodstream for approximately 120 days. • Older cells and damaged cells are then engulfed by phagocytes in the spleen, liver, and bone marrow, and the red blood cells are broken down
DESTRUCTION OF RED BLOOD CELLS • The hemoglobin is broken down to release it's amino acids, which can be reused for synthesizing new protein • The iron portion of the hemoglobin is brought to the bone marrow for new hemoglobin formation, and any excess iron is stored in the liver
WHITE BLOOD CELLS(Leukocytes) • Primary Function: to defend the body‘s tissue against infection and substance foreign to the body • A normal adult has approximately 7000 white blood cells per cubic millimeter of Blood • Types of WBC's (5 different types in two major groups) • Granulocytes which have granules in their cytoplasm and include the following:
WHITE BLOOD CELLS(Leukocytes) • Neutrophils • comprise about 60 percent of the white blood cell count in the body • the neutrophil's primary function is phagocytosis (devours foreign substances) • Basophils • least numerous blood cells • help initiate inflammation process at the site of an injury • Eosinophils: function during an allergic reaction
WHITE BLOOD CELLS(Leukocytes) • Agranulocytes have no granules in their cytoplasm and include the following: • Lymphocytes • account for about 30 percent of all white blood • serve as an important part of the body’s immune system • Monocyes • largest of all white blood cells • function primarily as phagocytic (engulfing) cells
WHITE BLOOD CELLS(Leukocytes) • Purpose for examination of WBCs • White blood cell population of the body can provide valuable insight into disease • An elevated white blood cell count may indicate a microbial infection • Also, noting whether particular WBC’s are high in number can be valuable. • This data is obtained by a differential white blood cell count
WHITE BLOOD CELLS(Leukocytes) • a general reduction of white blood cells is called leucopenia • an above average population of white blood cells is called leukocytosis • leukocytosis may also indicate cancer of white blood cells called leukemia
PLATELETS • Characteristics • also called thrombocytes, platelets are blood elements produced in the bone marrow • technically, platelets are not cells because they consist of fragments of cytoplasm enclosed by membranes
PLATELETS • Platelet production • platelets form from large cells called megakaryocytes in the red bone marrow • bits of megakaryocyte cytoplasm pinch off within membranes and are released into circulation • approximately 300,000 platelets exist per cubic millimeter of blood
PLATELETS • Platelet function • work along with fibrinogen, calcium, and vitamin K to form clots • a clot begins to form when blood is exposed to air • a dried external clot is a scab • an internal clot is a bruise
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • Homeostasis of the body environment depends on a balance of fluids, electrolytes, acids and bases • In the normal body, the levels of fluids and electrolytes remain constant • the input of water and electrolytes is balanced by selective elimination through the excretory system • if serious depletion occurs immediate replacement is critical
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • Electrolyes • the products of substances that dissociate into electrically charged components when they dissolve in water • for example, the compound sodium chloride dissociates into sodium ions and chloride ions, which are electrolytes carrying electrical charges
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • Acid • a chemical compound that liberates hydrogen ions into a solution • examples of acids in the body are hydrochloric acid and lactic acid • Base • a chemical compound that takes up hydrogen ions from a solution, leaving the solution with an excess of hydroxyl (-OH) ions • a base in the body is ammonia
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • Body fluids • the fluid content of the body refers to the amount of water in the body • the amount of water can vary, depending upon the weight, sex, age, and fat content of the individual
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • for instance, woman have a relatively lower water content than men because a woman's body contains a higher percentage of , and fat tissue contains very little cellular water • water makes up about 60% of the body weight for an adult male and about 50% of a female's body weight
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • Fluid compartments: The body's total water content can be divided into two fluid compartments • Intracellular fluid compartment • refers to the water in all body cells • almost two-thirds of the body's water exists in this compartment
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • Fluid compartments • consists of the body area outside the cells • extracellular fluid provides a relatively constant environment for the cells
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • Extracellular fluid compartment continued • approximately one-third of the body water exists in this compartment • extracellular fluid contains large amounts of sodium, chloride, and bicarbonate ions and small amounts of potassium, magnesium, calcium, phosphate, sulfate, and organic ions
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • water enters the body through the digestive tract and as a result of chemical reactions that produce water as end products • water leaves the body by several exits • the kidneys excrete urine • the lungs give of water in expired air • the skin gives off sweat • the intestines eliminate water in feces • in general terms, the amount of water exiting the body equals the amount entering the body
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • Electrolyte balance • the quantities of various electrolytes taken into the body must equal the quantities lost by the body • in the extracellular fluid, two types of ions can be found • Cations: which are positively charged (sodium Na+) • Anions: which are negatively charged (chloride Cl-) • Sodium Ions • sodium ions account for about 90% of the cations in extracellular fluid
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • when the input of sodium ions exceeds the output, water is also retained in the body, and the volume of plasma and extracellular fluid Increases • may cause edema: an abnormal accumulation of fluid in extracellular body tissues • may also cause weight gain • when the output exceeds the input a decrease occurs in the volume of plasma and extracellular fluid, and the blood pressure lowers
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • Regulation of sodium levels • reflects how well the kidney is working and is affected by blood pressure • when the blood pressure drops, the blood flow to the kidney is reduced, and the filtration rate diminishes, resulting in less sodium filtered • as the concentration of salt and water increases, the blood pressure elevates and the sodium excretion increases
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • Potassium • Potassium is the primary intracellular cation • It functions in regulating the electrical activity of the muscle and nerve tissue • In the extracellular fluid, potassium influences the balance of acid and base • Excessive potassium can cause fibrillations of the heart • Deficits of potassium can cause arrhythmia of the heart
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • Other ions • Other ions balanced in the body are calcium, magnesium, sulfate, chloride phosphate, and bicarbonate • Calcium ions have roles in blood clot formation, muscle contraction, hormonal activity, nerve conduction, and as structural components of teeth and bones • The most common extracellular anion is chloride, which is almost always linked to sodium
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • Acid/Base balance • The balance of acids and bases in the body is associated with the regulation of the hydrogen ion concentration in the body fluids • This concentration, expressed as ph, influences the activity of cell enzymes as well as maintenance of cell structural and cell membrane permeability
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • A strong acid produces the maximum number of hydrogen ions possible and forms ions more completely than weak acids • hydrochloric acid is a strong acid • carbonic acid is a weak acid • There are many sources of hydrogen ions in the metabolism of the body • during the respiration of glucose, carbon dioxide reacts with water to form carbonic acid which dissociates to release bicarbonate ions and hydrogen ions • the breakdown of fatty acids and amino acids also results in acid compounds
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • The regulation of the concentration of hydrogen ions in the body occurs primarily by acid base buffer systems • Acid/Base buffer system • A buffer is a solution that prevents substantial changes in the pH when either an acid or a base enters the system • Usually a buffer system contains a carbonic acid and a salt of that acid. • an example is the carbonic acid and sodium bicarbonate system
FLUID, ELECTROLYTE, AND ACID/BASE BALANCE • A solution containing both carbonic acid and sodium bicarbonate • Should a strong acid such as hydrochloric acid enter the system, it will react with the bicarbonate ions of the sodium bicarbonate producing carbonic acid and sodium chloride • Carbonic acid is a weaker acid than hydrochloric acid, and therefore the increase in hydrogen ions in the solution will be minimal • If a strong base such as sodium hydroxide enters the solution it will react with the carbonic acid to produce sodium bicarbonate a weaker base than sodium hydroxide, and there will be a minimum base shift
URINARY SYSTEM • Primary function: regulates the composition and concentration of the extracellular fluids surrounding the body cells • extracellular fluids • known as interstitial fluids • include plasma and fluids surrounding tissue
URINARY SYSTEM • The urinary system accomplishes its functions by forming urine from blood plasma in the kidneys and associated ducts and organs
KIDNEYS • Location • The kidneys are attached to the posterior abdominal wall of the body outside the peritoneum
KIDNEYS • They lie lateral to the vertebral column and are held in place by adipose and connective tissue • Adipose tissue is fatty tissue that surrounds internal organs • Adipose tissue serves as a cushion and as a nutrient reserve • In an adult each kidney weighs about 4 oz and is about the size of a fist
KIDNEYS • Microscopic structure • More than a million microscopic units called nephrons make up the interior of each kidney • The purpose of these nephrons is the production of urine • A nephron looks like a tiny funnel with a very long stem
KIDNEYS • Kidney function • Regulates the volume of blood plasma and thereby contributes to blood pressure • Controls the concentration of waste products in the blood • Regulates the concentration of the plasma‘s electrolytes • Contributes to the acid/base level of the plasma
FORMATION OF URINE • The kidneys 2 million or more nephrons form urine by a series of 3 processes • Filtration of water and other dissolved substances out of the blood • Reabsorption of water and other dissolved substances needed by the body back into the blood • Secretion of waste molecules and excess ions into the urine
URINARY SYSTEM • Once urine has formed it drains out of each kidney and down the ureter into the urinary bladder • To leave the body, urine passes from the bladder down the urethra and out its external opening