Thursday, June 28, 2018

Body Systems and How They Work

The body systems operate as one to maintain man’s health and well-being. There are various systems involved to ensure that the human body stays healthy. These systems are the nervous, circulatory, excretory, muscular, digestive, skeletal, integumentary, endocrine and respiratory.  Each system supports the others to maintain homeostasis and balance inside the complex network of cells, tissues and organs of the body.\

Nervous system

The hypothalamus, in the brain, is the center of the central nervous system, where stimuli from the different parts of the body are sent. It is the hypothalamus that recognizes these stimuli, and then initiates a respond appropriate for that specific stimulus.

An example is when the body is hypoglycemic, the low concentration of glucose in the body would be the stimulus recognized by the hypothalamus. It would then initiate the pancreas to secrete more glucagon so that blood sugar concentration would increase. The nervous system is composed of the spinal cord and the brain, which is composed of neurons and neuralgia.

human anatomy charts free laminated anatomical chart nervous system delivered free for free
Image credit.

Circulatory system

This is responsible in bringing blood and essential nutrients to the different parts of the body. It is composed of the heart, the veins and the arteries that transport blood for the survival of the human body.

The blood contains cellular elements (red blood cells, white blood cells, platelets) that are crucial for maintaining life. When a person loses large volumes of blood, he can bleed to death. That is how crucial the circulatory system’s function is.

Excretory system

The body has to excrete the toxic waste products of the body to allow proper functioning of the organs. The major organs involved in excretion are the kidneys. The kidneys are also responsible in maintaining the critical 7.35 to 7.45 pH (alkalinity or acidity) of blood.

This slight alkalinity of the body makes it possible for the normal function to occur. When the body’s pH is increased or decreased from the normal, conditions result which could cause coma and eventually death. The kidneys could maintain the normal pH through the retention and excretion of bicarbonate and hydrogen ions, and through the excretion of acidic waste products of metabolism.

Muscular system

This system provides the muscular structure and support for the body. Through the muscular system, man could move and function well. He is able to flex his arms, stand straight and lift weights because of his muscles. There are several types of muscles, such as, skeletal, cardiac, voluntary and involuntary; each with its specific role in the human body.

Digestive system

It includes the mouth, the esophagus, the stomach, the small and large intestines and the rectum. Without this system the food that people eat would not be digested. It also allows the essential nutrients from foods to be absorbed by the intestinal villi in the small intestines.

Skeletal system

This provides the skeleton of the body where the muscles and organs are housed. It also protects major organs, namely, the brain, the heart, lungs, kidneys and the digestive organs. It provides support for the whole body, and also in locomotion.

Integumentary system

The integumentary system is the skin, which is the largest organ of the body.  It protects all the internal organs, including the muscles, from invading foreign substances. It also acts as a thermal regulator, preserving the human body’s temperature. Without the skin, the body would be easily invaded by infectious microorganisms and toxic substances, too.

Endocrine system

This involves the ductless glands which secrete hormones directly into the bloodstream. These hormones are responsible for important body functions like the maintenance of blood sugar concentration through insulin and glucagon; the growth and development of the body through growth hormone, thyroxine and triiodothyronine.

Respiratory system

This involves the lungs, which are responsible in respiration. Through the lungs man breathes in oxygen and exhales carbon dioxide. Body cells could obtain oxygen so they could perform their biological functions well.

These are some of the systems involved in the human body and how the body systems work. All of them are interdependent on each other and are expected to perform their functions in conjunction with the function of the other organs.

Wednesday, May 2, 2018

Element Facts Fluorine

Flourine (F) has a special place in science because it is the most reactive of all the elements, and participates in almost all inorganic and organic chemical reactions. The reactions exclude oxygen, neon, krypton and helium.

Its name has originated from the French word “fluere,” meaning to flow, because it allowed metals "to flow." This deadly element was discovered and isolated by a French chemist, Henri Moissan, in 1886, for which he received the 1906 Nobel Prize in Chemistry.

Chemical properties of Fluorine

Fluorine has an atomic number of 9, an atomic weight of 18.998403, a specific gravity of 1.108, a boiling point of -188.14°C, and a melting point of -219.62°C. When it combines with water, metals, carbon and other substances, it burns and fluoresces.  It is extremely flammable and highly corrosive. With water, it produces hydrofluoric acid, one of the highly corrosive products of fluorine.

Physical characteristics

Fluorine is the lightest among the halogens, which include chlorine, iodine and bromine, to name some. It has a characteristic pungent odor, and is pale yellow in color. Previously, it could not be isolated from any of its compounds, but Moissan did this through “electrolysis of dry potassium hydrogen fluoride and anhydrous hydrofluoric acid.”


Fluorine is a halogen and is widely distributed in combination with other substances, such as in fluorspar (CaF) and cryolite (Na2AF6). It could be isolated using electrolysis with a “solution of potassium hydrogen fluoride in anhydrous hydrogen fluoride.”


Although it is a dangerous element by itself, fluorine, in combination with other substances, has its own usefulness in the field of science. Fluorine, in the forms of sodium fluoride and sodium monofluorophosphate, is added to toothpaste and drinking water to help in the prevention of tooth decay. Calcium fluoride crystals are used in the construction of infrared lenses and other bulbs. In the form of uranium hexafluoride, fluorine also plays a major role in processing nuclear fuel.

It is used too in the manufacture of high-temperature plastics, such as Teflon.  It has been originally used as a refrigerant in air-conditioning units in the form of chlorofluorocarbons, but these products were banned because of their dangerous depletion of the ozone layer, which protects the Earth from the deadly rays of the sun.

Fluorine, just like any substance here on Earth, has its own advantages and disadvantages. It is up to man to use it to his own advantage and progress. After all, science is there to develop the world into something progressive but safe for the human race.

Tuesday, May 1, 2018

An Explanation of Diffusion

Diffusion is defined by Hyperphysics as the process by which molecules intermingle with each other randomly as a result of their kinetic energy.

In layman’s terms, it is the movement of particles in solution from a higher concentration to a lower concentration. There are two common types of diffusion: the facilitated and the passive. Facilitated diffusion

This process requires the presence of energy for its occurrence. A good example is the application of heat to increase the movement of the particles in solution so they can move faster.

An example also is when molecules move through cells in the body with the use of transport proteins. This is how essential nutrients are usually transported to different cells and tissues in the body. Passive or simple diffusion

This process does not need applied energy to occur. An example is when water and its particles, from higher areas, diffuse into low lying areas until equilibrium is reached. The water seeks its own level. This is a simple but clear example of diffusion.

The spread of a teaspoon of coffee in water demonstrates also passive or simple diffusion. The granules diffuse into the areas where it is less concentrated, thereby allowing the coffee granules to spread and make the solution homogeneous.

Stirring the coffee and using warm water would make it facilitated diffusion, wherein the coffee spreads until equilibrium is achieved. Diffusion in the human body

There is also a process called net diffusion in cells, in which particles or substances in solution pass through pores or tissue walls from a higher concentration gradient to a lower concentration gradient.

As mentioned in facilitated diffusion, the human body uses this method to bring food and vital substances to cells and tissues.

Respiration is one good example of diffusion, as well. Carbon dioxide comes out when we exhale, instead of oxygen, because the concentration of carbon dioxide outside of the body is lower.

On the other hand, oxygen enters the lungs because it diffuses into the area where it is less concentrated.

Diffusion in plants Diffusion also occurs in plants in the same manner that it occurs in animals. This movement is from a higher concentration gradient to a lower one, too.

This is how essential nutrients for plants, such as carbon dioxide, are transported from the stomata to the cells. Diffusion, specifically termed transpiration, is the manner by which oxygen is excreted by plants.

Hence, diffusion is a vital process that occurs in vivo (inside the body) and in vitro (outside the body) that is significant for the existence of man.

Sunday, October 8, 2017

How Excess Salt Negatively Affects the Kidneys

Salt, scientifically called sodium chloride, lends taste to food, and helps in maintaining the water electrolyte balance in the body.

Taken in excess, however, salt has detrimental effects on the kidneys. The kidneys are the major excretory organs of the body, and are responsible in eliminating excess, unwanted substances.

Due to this function, it is the primary organ affected when these excess substances are not excreted. Excess salt exerts the same extra workload on the kidneys.

Because of homeostasis, the body could sense if there is too much salt or electrolytes in the body. When salt is in excess, the body responds by retaining water so that the excess salt would become diluted. The extra amount of water would also increase the volume of blood, which would add more workload on the heart and the kidneys.

Hypertension’s effect on kidneys

The excess salt could cause then hypertension, congestive heart failure and other unhealthy conditions.  Sodium may cause also the constriction of the blood vessels that could cause hypertension.

When a person has constant hypertension, vascular stress is exerted on the kidney cells, which would then be destroyed, and excretory function of the kidneys is compromised. If the kidneys are dysfunctional, they would not be able to discard toxic products of metabolism. These products of metabolism could amass in the body causing toxic poisoning. Formation of urine crystals in the kidneys

When the kidneys become dysfunctional because of excess salt, urinary sediments may be retained to form stones and calculi. These renal stones could amass in the kidneys and block urinary ducts or passages.

The most common causes of kidney stone formation are uric acid and calcium oxalate crystals. Inability of the kidneys to eliminate these stones could result to kidney stones, which may have to be surgically removed. The formation of stones in the kidneys is called nephrolithiasis.

Increased salt causes decreased blood supply to the kidneys

This effect results from the hormonal function of the kidneys, in which it would prompt the secretion of hormones to help regulate the electrolyte. This is stimulated by the hypothalamus in order to retain more water in an attempt to increase blood going to the kidneys.

This does not happen, though. Instead, water accumulates in the heart and other organs causing congestive heart failure.

Dysfunctional kidneys could affect the whole body’s ability to function well because of the accumulation of waste products, which the kidneys could not excrete. To ensure good health, people avoid taking in excess salt.

Saturday, August 19, 2017

All about FPIA Fluorescence Polarization Immunoassay

• Fluorescein-labeled drug competes with unlabeled drug for antibody
•Sample excited with plane polarized light (490 nm)
•Fluorescein emits plane polarized light (520 nm)
•Small, free drug-fluorescein, rotates faster leading to less emission
•Larger, antibody-drug-fluorescein, rotates slower and emits plane polarized light (520 nm)

Principle: Drug in sample competes for antibody with fluorescein bound drug

•More drug in the sample; less fluorescein labeled drug bound to antibody; lower
emission of plane polarized light.

•Higher drug concentration results in lower light emission values.

•Available for a variety of drugs


Rapid turnaround times, sensitivity, ease of operation


Background interference in serum sample (requires blank measurement).

Saturday, June 24, 2017


1.    Discuss the principle of the test.

LDH in the serum catalyzes the oxidation reduction of lactate to pyruvate, which  is measured spectrophotometrically.

2.    Give the reasons why serum for LD determination cannot be refrigerated.

Because LD isoenzymes are thermolabile and are unstable at refrigerated temperatures. They would not be able to react accurately.

3.    Why should there be timed intervals in the addition of 0.1N HCL?

So that the acid could react properly with the LDH in the sample.

4.    In the experiment, why should the incubation period be done exactly in 5 minutes?

Because incomplete reaction would occur if it is less than 5 minutes and more products would be formed when prolonged more than 5 minutes. This is at specified temperature and conditions.

5.    Name sources of errors in this determination.

Hemolyzed serum increases result 100-150 X
Turbid, lipemic and icteric serum needs serum blanking for accuracy
Refrigerated blood samples lowers values
Prolonged or shortened incubation time at specified conditions could increase or decrease values respectively
Altered temperatures could either increase nor decrease values

Friday, June 23, 2017

Alkaline Phospatase (ALP) Review Questions and Answers

1.    Discuss the principle of the test.

ALP catalyzes the hydrolysis of Paranitrophenylphosphate, which is colorless, to paranitrophenol, which is colored yellow, at 405 nanometers.

2.     Name differences between ALP and ACP

CATEGORY                  ALP                                                    ACP
pH                            Basic or alkaline                                      acidic
Best specimen     Heparinized plasma (Calbreath)                  Serum citrated plasma (Calbreath)
Tissue source    Same as ACP except for prostate,                  more on bone
Clin. significance    Prostate, platelets, bone, liver, spleen, kidneys, erythrocytes
Diagnostic significance    Hepatobiliary and bone disorders    Prostatic carcinoma

3.    What is the reason for diluting serum if the absorbance is higher than 0.25

For more precise and accurate measurement of the concentration of the unknown.

4.    Why do we have to adjust the spectrophotometer to zero when we read unknown solutions?

To read out errors caused by the spectrophotometer and the reagent.

5.    What is the best sample for this determination?

Unhemolyzed, clear, non-icteric, non-lipemic serum

Questions and Answers on Clinical Enzymology (ACP)

1. Discuss the principle of the most common principle of the ACP test.

ACP catalyzes the hydrolysis of Paranitrophenylphosphate, which is colorless, at an acidic pH, to paranitrophenol, which is colored yellow, at 450 to 470 nanometers.

2. Why do you have to utilize a specific wavelength in measuring ACP?

To be able to get the maximum reading of ACP in the sample.

3. What is the ideal specimen for the ACP determination?

Citrated blood is ideal, but for the determination performed in the lab, it is serum.

4. Name sources of errors for ACP test

Hemolyzed serum falsely increases values

Turbid and icteric serum need serum blanking for accuracy

Some reagents are photosensitive, exposure to light would decrease values

Prolonged or shortened incubation time would increase and decrease values respectively

Alkaline pH would decrease values

Altered temperatures could either increase or decrease values

Sunday, June 4, 2017

Effects of Decreased Carbon Dioxide in Atmosphere

Carbon dioxide is one of the gases that could cause global warming. This is because it prevents the reflection of the sun’s heat back into space.

Normally, carbon dioxide exists ideally in the atmosphere at 0.03%. The percentage continues to increase because of combustion and emissions caused by man. Carbon dioxide is essential to plants because they need carbon dioxide to survive.

If carbon dioxide levels in the atmosphere were reduced to half, these living things would be the first to be affected.

Effects of Decreased Carbon Dioxide


Environmental change

A drastic decrease of carbon dioxide in the atmosphere would cause environmental changes. Since carbon dioxide causes global warming, its reduction would cause changes in the temperature of the environment.

The climate would become colder because of the absence of the greenhouse effect, in which humidity or warmth stays in the earth’s environment. The atmosphere becomes more transparent, which would facilitate the escape of heat to space, leaving the atmosphere colder.

These environmental changes would affect every living thing existing in the ecosystem.

Plants would grow extinct


Plants undergo photosynthesis through sunlight and carbon dioxide, so without this important gas, plants would wither and grow extinct.

Even marine plants would be affected. Since plants are major sources of food, there would be scarcity of food for man and animals on land and at sea. The food chain would be disrupted; that could result to a complete reversal of the chain.

Man would then have only animals for food. This scenario would cause various problems to humans because of the major disadvantages of animal meat. Man needs a balanced diet to remain healthy and fit.

If plants grow extinct and animal meat is the only source of food for humans, it would shorten man’s life span.

Oceans would become more acidic


Decreased carbon dioxide in the atmosphere would make the ocean become more acidic. This is because bicarbonate, formed from the combination of carbon dioxide and water, is also decreased in concentrations.

Most carbon dioxide gases are dissolved in water to establish equilibrium with the atmosphere, through diffusion.

The ocean helps in eliminating the toxic carbon dioxide produced by combustion. Aside from the above-mentioned major effects caused by reduced carbon dioxide levels, there are minor effects resulting from the major occurrences.

These include: complete freezing of some continents because of cold temperatures, more glaciers formed from bodies of water, and other detrimental results caused by cold temperatures.

Any variation in the carbon dioxide that affects the ecosystem would have an effect on almost everything existing in that system.

Saturday, April 16, 2016


I. Introduction

Sodium is the most abundant cation in the extra cellular fluid (ECF), represented 90% of all extracellular cation and largely determines the osmolality of the plasma. Active transport system at the cellular membrane maintain high Na+ levels in the ECF, where as K+ is concentrated with in the cell. 
Changes in extracellular Na+ concentration result in increase or decreases in the osmolality of the ECF, which in turn, influence the distribution of body water. It is therefore related in regulation of water balance as well as blood volume in the body.

Normally, serum Na+ concentration varies between 136 and 145 mmol/L in healthy individuals. The normal daily intake of Na+ is 100-250 mmol. Ordinarily, the amount of Na+ loss is balance by the daily intake.

Determination of Na+ level is of vital key in the proper diagnosis and treatment of diseases associated with it. 

A decrease in serum sodium level, termed as “hyponatremia” is usually seen in hypoadrenalism, potassium deficiency, diuretic use, ketonuria, salt-losing nephropathy, prolonged vomiting, diarrhea, renal failure, hepatic cirrhosis, congestion heart failure (CHF) and diabetic ketoacidosis. 

Whereas, an increase in serum sodium level, termed as “hypernatremia” is seen in profuse sweating, severe burns, dehydration, malnutririon, edema, ascitis in chronic failure, uncontrolled diabetes, and nephritic syndrome.

II. Procedure/ Flowchart of the experiment
Pipet out 0.1ml serum and place in a test tube
Add 3ml base reagent followed by 3 drops of color reagent
Mix thoroughly for 30sec. and let it stand for 30min. at room temperature
Read at 550nm against a water blank
Interpret results obtained


Place 0.1 ml of unhemolyzed serum into 16X100 mm test tubes.

Label tube as test serum standard.

Add 2.5 ml of Sodium Base Reagent into the tubes.

Place 3 gtt of Sodium Color Reagent.

Mix well and read at 550 nm against a water blank.

III. Results and Discussion

Concentration of the unknown: 531.62 mmol/L
Normal range for serum specimen: 134-148 mmol/L
Interpretation: “Above normal range”

The interpretation of the result obtained was above normal range because it exceeds the maximum Na+ level that a normal adult could have.

IV. Intrinsic and Extrinsic factors

The probable sources of errors are:
-          contaminated tubes or cuvets
-          contaminated serum
-          ineffective reagent
-          under/ over centrifugation
-          prolonged standing of specimen
-          misreading of result by spectrophotometer

Tuesday, August 11, 2015

Chemical Structure of Seawater

Seawater differs in chemical structure from plain water because of additional components that are present.  Just by tasting, you would know that seawater is briny and contains salts that are not found in your ordinary drinking water. What is the chemical structure of seawater that makes it different?

1. Seawater has salts

Seawater has an average salt content of approximately 35 grams for every    liter of seawater or 3.5% salt content.  The salt includes calcium (Ca++), potassium (K+), chloride (Cl-), sodium (Na+), sulfate (SO4++), and magnesium (Mg++).

Sodium and chloride constitute majority of the seawater salts.
This chemical structure allows salinity of seawater. The salinity of seawater is constant and measuring one major salt allows representation of the other concentrations.

2. Seawater is denser than fresh water

The density of pure water is 1.00 grams per milliliter at specified temperatures. Seawater is denser, which is 1.025 grams per milliliter. The salt content of seawater makes it denser.

3. Seawater has a pH of 7.5 to 8.4

Pure water has a neutral pH at 7, but seawater
is more alkaline with pH range of 7.5 to 8.4. This is due to the presence of additional chemical components not found in fresh water.

4. Seawater has traces of other chemicals

Aside from the salts mentioned, seawater also has smaller amounts of strontium (Sr), bicarbonate (HCO3), bromide (Br), borate (BO3), and fluoride (F). There are still various chemicals present in sea water depending on its location and depth.

The aforementioned chemical structure of seawater enables measurement of distances based on sound which travels through the seawater’s components. These chemical components make seawater different from fresh water, pure water or river water.

The chemical components and salinity of water also prevents it from becoming potable or drinkable. The salt content of seawater could aggravate an existing condition of hypertension and cardiovascular conditions because the increased concentration of salt in the blood will influence the amount of water inside the cell.

The increase of sodium will promote osmosis, which will eventually drain the cells of water. The dehydration of the cells can cause heart conditions like arrhythmia.

It is great to know the seawater’s chemical structure so that you will know why seawater is not advisable to drink and to hydrate the body with. Knowing this basic fact would also allow you to keep abreast of simple scientific information that are essential for your health and well-being.